Begode Extreme Review: Off-Road Thrills & Durability Insights

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Long post warning

 

On 11/15/2023 at 8:39 AM, Vince.Fab said:

Thank you for sharing this type of information, while some of it is going right over my head, math doesn't really lie.  Anytime I've had to design something critical on a suspension component in the past i've just overbuilt.

No problem - thinking about how things fail is pretty interesting, but it's tough to pin-point or prove definitively as figuring how estimated repetitive dynamic forces might apply to static equation checks with something like this which involves a fair amount of guessing/assumptions. I got fixated on the possibility of the fastener galling being significant or a contributor to the failure, but that doesn't take away from what you, @timmytool, and others said earlier about these mounts being, structurally, a notably weak design (especially in stark comparison to robustness of the RS19 hanger that you’ve shown).

On 11/15/2023 at 8:39 AM, Vince.Fab said:

I can share a STEP file if that is better for calculations.  Also I will probably to a few static stress simulations in CAD to help with the motor mount design but honestly we only have so much space available.

That's OK, I got bored and went ahead roughly estimated the dimensions of the cross section earlier estimating h1 to be ~6mm, modeled in CAD, and got a cross sectional area of 0.28 in², a strong-axis moment of .09 in³ (for fore-aft forces) and a weak axis moment of inertia of .01 in³ (for inbd-outbd forces).

The first problem to guess at is what grade aluminum they used as well as heat treatment if relevant – let's be generous and assume they used a relatively strong grade of extruded aluminum such as 6061. Might as well run the calculations for both ideal heat treatment and non-heat-treatment just for comparison sake because it’s China and I really don’t know the composition of the aluminum. That said, aluminum tensile yield strength of 6061-T6 is 40,000 psi and 6061-0 is 8000 psi respectively.

In this case we could also simplifying applicable stress calculations by ignoring combined stress checks and figure what static force individually is required to yield the material to see if that force component alone could be reasonably generated by a normal use load scenario.

So shear force applied equally per side:
σ_alu,yield = P/2*A. For 6061-T6, P = .577*2*.28 in² * 40,000 lbs/in² = 12,925 lbs. Even at 8,000 lbs/in², P = 2,585 lbs. These are unrealistically high static forces in isolation required to yield material, so we can probably neglect this contribution to simplify things in this rough estimate.

Bending moment on the other hand, think force (vector = magnitude + direction) applied at some distance relative to the center/centroid of the bolt pattern on each side of the motor axle/hub creating a torque that stresses the slider mount all the way to the motor axle fasteners:

So σ_alu,yield = Mc/2*I, where M or F x d is a force parallel to the direction of travel applied equally against both power pads and/or the pedals at some distance d, relative to bolt pattern centroid (3-bolt mount). We know c = b1/2 (from my earlier picture), I had it at 1.65 in/2, and one way to estimate d is to measure the center of where a power-pad would react against the leg. Lacking actual measurements, let’s say 6 inches above the bolt pattern centroid.

Now we can solve for F:
(40,000 lbs/in * 2 * .09 in³)/(6 in * 0.83 in) = F = 1446 lbs. This is still a very high unrealistic force for a dynamic load scenario in which forward momentum slammed your shins against the forward power pads assuming you didn’t immediately fall out and fail to react this load. That said, 6061-T0 at 8000 lbs/in² ultimate tensile yield strength results in an F = 289 lbs which ironically is the claimed rider limit though I sincerely doubt this haphazard calculation was what they used to determine the limit.

Is reacting 289 lbs against the power-pads even possible given maximum motor torque? Given Raging Grandpa’s pull force test, the Extreme has a peak tractive force of 187 lbs taken at tire radius of ~0.75 ft (1/2 diameter of tire) = 140.25 ft-lbs maximum motor torque. Reacting 289 lbs at .5 ft (assumed power pad distance) = 144.5 ft-lbs. So, if the aluminum grade used was this weak, and the rider could withstand or generate this big impulse against their power-pads, then yeah, maybe you could yield the mount without loose fasteners being a compounding factor in this limited artificial analysis.

Conclusions and some other thoughts:

• The bending moment checks are more critical / contributes more given the dimensions of this cross section.

• For stress calculation purposes, outside of a pedal strike, most fore-aft directional force (and resultant torque) as a component of rider weight applied at the pedals is likely to be less than the maximum force that could be resisted at either of the power pads in rapid acceleration or braking including when encountering bumps in terrain.

  • However, the above statement may not account for more dynamic loading - say where the rider's center of gravity is situated further behind the wheel c/g in deep deceleration and the wheel encounters a bump where both the distributed weight of the rider remains planted on the pedals (knees not absorbing much of the bump) and friction of the pedals is enough to possibly generate significant shear force without launching the rider forward and off the pedals. It's tougher to conceptualize if this kinda of force application is realistic in exceeding the above though and this is getting long enough.

• Weight of the motor/rim/tire assembly don’t directly contribute to structural calculations against the slider mounts.

• Assumes weight of the suspended assembly (sans rider weight) mostly contributes in direct shear as the center of gravity of this assembly is probably relatively close to the axle/axis of rotation.

  • Edit: I was lazy, assumed and didn't look. Suspended assembly c/g it's not centered about the axis, especially with the suspension not compressed. So this definitely contributes as an additive to the Mc/I calculation and is not dependent upon dynamic rider interaction with power-pads and/or friction on pedals to transfer fore-aft loads. Translation, less momentum load reacted against the pads is required to achieve yield making the failure result more feasible.

• Also, this limited analysis that doesn’t account cyclical fatigue (rapid accel to decel transitions) or other (crash) load scenarios in which the mounts could fail like dropping or spinning from a crash to land impacting the upper suspended assembly too.

Earlier you said:

On 11/15/2023 at 8:39 AM, Vince.Fab said:

about 3/4 of a mile in, the wheel starts to make questionable noises then the motor starts to just buck back and forth on its own.  This time, both motor mounts sheared right off of the sliders.

Looking at those mounts again, it looks like the weaker configuration 3-screw mount started to yield (as evidence by the deformation) and subsequently tear/rupture first before enough material separated to eventually shear the stronger 4-screw mount all at once in this catastrophic failure. This makes sense as the 3-screw mount configuration is basically structurally weaker in an already strength compromised area.

I don't know what the pedal assembly looks like in terms of clearance in it's fully uncompressed position, but you definitely pay a structural penalty to gain motor wire clearance in this way. IMO it would be better to keep the top screw and figure a way to pass the wire between the screws, or some other pass-thru scheme that allowed for the most amount of material to remain and all 4 screws to be used if uncompressed suspension assembly clearance allowed.

On 11/15/2023 at 8:39 AM, Vince.Fab said:

I think 303 stainless should fit the bill

Sounds good to me. I like that you added a radius (or that’s just angle stock) to reduce the stress concentrations; however, I’d make a couple more suggestions to strengthen your new parts:

1. Go as wide as you can fit even if it doesn’t match the upper stanchion bearing housing width (unless it ends up conflicting with path of motor wire harness). I don’t see any reason to do anything fancy with curving around the fastener bolt holes as it’d be better to just keep more material throughout for reasons of strength.

2. Similarly, keep as much material underneath the fastener heads as possible. In your CAD screenshot above, it looks like you’ve bored the depth thinner than the original mount to the point where structural weakness in the cross section is now right at the/above the head of the upper fastener. I’d err on the side of more thickness, sans tube cut-out, throughout as long full travel clearances are accounted for.

One more thing to be aware of if you don’t already know, there’s some friction induced by the suspension linkage axial loads between the stanchion tube and the stanchion housing bearings. The closer you move these stanchion bearings together, the higher the friction force will be resisting travel near/at full- suspension compression possibly impacting performance. Just something to be aware of as you increase suspension travel this way, there is a trade-off.

PS: if you search Begode extreme slider on duckduckgo, interestingly this page is the first and second result, at least for me.

Edited November 18, 2023 by Vanturion
correction added

[ikeceosaor]

3 hours ago, Vanturion said:

Is reacting 289 lbs against the power-pads even possible

 Though I'm no physiologist, I'd think that the human ankle is quite able to react against 289 lb transferred from the pedal. Of course our muscles/tendons and even the sole of the shoe would absorb some of the impact so it wouldn't be an instantaneous impulse force.

On 11/12/2023 at 9:39 PM, Vanturion said:

say a glancing pedal strike (with a 90-degree force component to direction of travel) also has the maximum moment developing right at the lower bearing basically exactly where the break occurs (no surprise there)

I can imagine that Vince rides quite aggressively off-road, and may have even powered through glancing pedal strikes. As a relative beginner I have even done this, seeing a low-clearance object coming up and just smacking into it with a pedal, both successfully recovering from the impact and continuing on, and other times failing, being forced to jump off because it wasn't quite a glancing blow. This type of pedal strike would easily exceed your case of 6061-0 yield strength, no?

Also, would you be able to do some calculations along the weak axis? I bet it'd be more complex but that cross-section laterally is concerning. I'm not sure what kind of riding or incident would cause such an impact from the side, maybe bailing from a botched jump attempt?

 

[RagingGrandpa]

4 hours ago, ikeceosaor said:

I can imagine that Vince rides quite aggressively off-road, and may have even powered through glancing pedal strikes.

Absolutely!
It's a fact of life in the woods. 
You've seen Begod's marketing videos of Extreme doing Extreme things, right?

Here's Vince. You can guess how the mud got there 

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On 11/17/2023 at 3:44 AM, ikeceosaor said:

Though I'm no physiologist, I'd think that the human ankle is quite able to react against 289 lb transferred from the pedal. Of course our muscles/tendons and even the sole of the shoe would absorb some of the impact so it wouldn't be an instantaneous impulse force.

I should probably emphasize again that I really don’t know the grade aluminum used (see this reference to get an idea of wide diversity of aluminum grades, which doesn’t cover all the heat treatment options) and have estimated a wide range of material strength to account for this very important unknown so 289 lbs or any number downstream of this fact is really of limited use. The above is more of a haphazard gut check to see what’s what and partially puzzling out the start of the process to do this kind of structural check in a way that was hopefully somewhat informative if not accurate.

To answer your first question though, maybe. In reality, the load would be halved per side and distributed over an area rather than a point load making it somewhat more believable/reasonable a rider might be able to react this force without shooting past the pad. On the other hand, realistically the impulse force would be reduced given the use of velcro and flexible power pad material resulting in some give, lengthening delta t, and subsequently reducing peak force so forward momentum would have to be greater.

So in this load scenario, it wouldn’t be so much the ankles acting as a force couple between the pads and the pedal surfaces, but the momentum of the rider weight thrown forward against the pad which can happen from an unanticipated elevation change in terrain that rapidly reduces wheel speed carrying the rider forward against the acceleration pads that acts as a kind of last ditch contingency to remain mounted on the wheel. That said, the above analysis is missing a lot, it makes more sense to calculate max motor torque shown in LC1 below.

AFAIK (and I wouldn’t really know) there’s no design handbook for EUCs that describe a standard set of worst case load scenarios engineers could use to confidently assign a maximum rider weight limit after running their structural checks. Thinking about this problem again, if I was actually responsible for the design I’d go through a series of checks using more complicated and thorough calculations with the actual measured geometry of the Begode Extreme given the actual material strength values to come to accurate conclusions about the design strength of the structural components.

Some examples and partial notes as a thought exercise:

• Load Case 1: Maximum acceleration on tarmac from or near standstill

  • In my EUC experiences, the majority of acceleration is usually mostly generated by placement of rider C/G (W) at some distance (s) out in front of the motor axis, and less by force (F) acting against the acceleration pad at some distance (d) above the motor axis. These two forces are additive up to the maximum overlean condition. So T_max = 140.25 ft-lbs = W*s+F*d.

  • Would probably use this case to assume F*d = 0 considering LC2 similarity and solve for W*s which has both x and y bending stress and shear stress components for a combined loading check (like many of these load cases below)
     

• Load Case 2: Maximum deceleration on tarmac at or below speed where maximum constant torque occurs

  • Requires dynometer motor performance chart data to find this limit

  • Assumes maximum brake/deceleration torque = maximum acceleration torque

  • Differs from LC1 only in the that it’s much easier in practice to generate a horizontal reaction force against the brake pad to resist forward momentum.

  • Can assume/calculate a larger value F while decreasing s for balancing the W*s+F*d = T_max equation.

• Load Case 3: Overtaking bump/obstacle of height h at speed where maximum constant torque occurs

  • Like in LC2, the speed at which torque begins to decrease is most likely somewhere between 10 and 25 mph for these EUC motors, by constraining max speed in relation to max torque, the theoretical height of the obstacle, h can be maximized (within reason) without exceeding overlean generating higher impulse forces for worst case loads.

  • Shear force from the suspended assembly W_suspended contributes

  • Would need to make some assumptions about dynamic positioning of rider C/G (how W gets distributed) with relation to motor axis to make sure the rapid deceleration from overcoming h doesn’t unbalance rider and how much to deload suspension in anticipation of bump.

  • Can easily calculate distance to overcome bump given tire radius, change in velocity from climbing obstacle, and delta t given average (Vi+Vf)/2.
     

• Load Case 4: Overtaking lower bump/obstacle of height h near maximum speed with respect to motor-cut out speed limit

  • Involves lower delta t on account of increased velocity → higher impulse forces

  • Same dynamic rider C/G assumptions as LC3 above.
     

• Load Case 5: Rolling drop to flat from some arbitrary height

  • Large compressive force from bottoming out as well as rider weight distributed over pedals

  • Would want to check buckling at slider mount cross section.

Crash Loads

• Crash Load Case 1: Drop from height (3 ft?) on side of body (or various other locations in different drop orientations) to simulate impact forces in unintended crash (or just straight up dropping it from a carry).

• Crash Load Case 2: Pedal strike, straight on

  • Most likely to occur on trail, assume reasonable velocity like 15 mph.

  • Negates rider weight (they go flying)

  • Have to assume some fraction for impact forces to account for after impact velocity/motion of wheel.
     

• Crash Load Case 3: Pedal strike, with inbd force component

  • Run check with same assumptions and negation above.

  • Realistically the value of this check would depend if you had a pedal mounted where strike occurred against outer forward edge was rounded or chamfered to direct a component of the impact force inward.

 

On 11/17/2023 at 3:44 AM, ikeceosaor said:

I can imagine that Vince rides quite aggressively off-road, and may have even powered through glancing pedal strikes. As a relative beginner I have even done this, seeing a low-clearance object coming up and just smacking into it with a pedal, both successfully recovering from the impact and continuing on, and other times failing, being forced to jump off because it wasn't quite a glancing blow. This type of pedal strike would easily exceed your case of 6061-0 yield strength, no?

Also, would you be able to do some calculations along the weak axis? I bet it'd be more complex but that cross-section laterally is concerning. I'm not sure what kind of riding or incident would cause such an impact from the side, maybe bailing from a botched jump attempt?

Without filling in a lot more unknowns like actual material strength and taking actual measurements of the geometry, there’s not much point going any further with hypothetical calculations tbh. There's more than likely a lot of impact energy bled off in most pedal strikes in the form of spinning the wheel and/or shunting it off in some tangential direction. Because the rider tends to go flying off too, you don't have to worry about rider weight contributing to the impact energy either.

At a high level, now I’m more convinced the math would validate Vince's experience, that a heavier rider can fail their stock slider mounts if ridden aggressively on the trails over time for what it’s worth. The heavier you are, the more you should probably dial back riding your Extreme extremely or at least proceed with caution. Also, it’d be a good idea to inspect this area around the axle pinch screws with some frequency for damage, especially as a trail rider.

Edited November 19, 2023 by Vanturion

[timmytool]

I think a easy test someone that has a spare motor mount should do is....

Remove motor, cables etc. Mount the euc to a immovable post(metal) via the motor mount screws. Bolt/clamp some >2m planks centred on the pedals, notch the 4 1m location from the euc's centre point. Add a pin across the notched planks add hooks and weighs as needed. Now we have a infinite torque motor on our extreme to test loads on the motor mount. Now its trivial to calculate how many N.m of torque the motor mounts can take.

We can also see a number of other things like system slop, pedal strike effects etc depending how how you want to treat the extreme. In all honesty this should be a part of the preproduction testing begode etc, should be doing to verify a design. Maybe even a part of batch qc testing.

 

[timmytool]

And dont forget the obligatory youtube vids of begode taking a baseball bat to this rig.

[ikeceosaor]

21 hours ago, Vanturion said:

Also, it’d be a good idea to inspect this area around the axle pinch screws with some frequency for damage, especially as a trail rider.

It seems you could only inspect it easily from one side, I mean you can't see the mount from the wheel side without removing the wheel/motor. I guess hairline cracks would be hard to spot no matter what. Still, it'd be better to check frequently than to have a catastrophic crash with zero warning.

Honestly, I do wonder how much engineering design goes into EUC development; I doubt these companies all follow the same safety margin for support structures.

I was ready to purchase a Begode Extreme and was assuming with all these years of development, structural strength outside of suspension linkages/pivots wasn't something I have to worry about.

[0000]

16 hours ago, ikeceosaor said:

It seems you could only inspect it easily from one side, I mean you can't see the mount from the wheel side without removing the wheel/motor. I guess hairline cracks would be hard to spot no matter what. Still, it'd be better to check frequently than to have a catastrophic crash with zero warning.

It's likely that the beginnings of a crack would start on one of the outer edges (fore-aft) depending upon the direction torque is applied with the outermost element experiencing the highest amount of tension. And we know the 3-bolt configuration is the weaker side where damage is most likely to occur first. It looks like you could just have another person stand on the wheel or remove the pedal assembly to check the area.

16 hours ago, ikeceosaor said:

Honestly, I do wonder how much engineering design goes into EUC development; I doubt these companies all follow the same safety margin for support structures.

Yeah, at the end of the day it's just more evidence that a 3rd party engineering design review wouldn't be a bad idea with new wheels.

[OldSolo]

This thread & Marty's V14 adventures are giving me pause as I prepare to buy a 'real wheel' to accompany my A2.  The lack of engineering in these wheels is shocking to me.  I do not consider myself naive, and realize that very little engineering seems to occur among Chinese manufacturer.  For other products they copy successful designs & SOMETIMES produce excellent products.  As they really are the primary innovators in EUCs (and I APPLAUD them for this!), the LACK of actual engineers is telling.  Between the structural concerns, lack of understanding suspension performance issues (such as linkage ratios), very poor firmware development (there is a lot that could be added that would improve safety - I saw something elsewhere about a spinning wheel that was out of control, it should be simple to add some factors that would instantly shut it off when it has fallen over, rather than keep spinning & potentially hurt rider or bystander), and electrical design (connectors, hall sensor "gooped" into place, etc), I am hesitant to buy anything yet.

It is obvious that they are relying on riders who are so "addicted" to riding EUCs and cannot wait for the next one!  And I write this as someone who was certainly "addicted" to MTBs & new innovations.  But I honestly do not remember seeing so many new products come out that were so poorly engineered.  I even am sort-of counting myself among the 'addicted' as these EUCs have fascinated me, and the feeling of riding is quite unique.  Having had a crash (well geared up!) due to wobbles, I know that my knee was twisted BECAUSE the wheel kept spinning even though it was on its side.  That should not happen, the controller should have no problem stopping the wheel within some number of milliseconds, not 2-3 seconds.

Being older I heal more slowly & am more risk-averse than I was in my youth.  So broken wheels & bodies need to be limited, and proper design would go a long way in accomplishing this.  Am I completely off base?  Have all of you simply accepted that this is how they do business?  I see comments about it, but the Quality Improvement process clearly is failing among these manufacturers.  That they are having Marty return a wheel TO CHINA due to a simply Hall sensor failure is nuts!  But then again testing suspension by having a fat guy launch off a platform was absurd, so I suppose this is the state of the industry.

[0000]

So with Marty’s V14, it’s a combination of astute business sense and luck that this problem with the motor showed up before production units were delivered IMO. I could be wrong, but I would think that the motors are supplied by an external manufacturer that specializes in motors regardless of the EUC company we’re talking about.

Anyway, it’s a shitty situation because whatever QA process does exist at either the motor manufacturer or at Inmotion was apparently insufficient to catch this problem. Worse, the wheel worked fine until it failed in a relatively short period of time so it’s less likely any short duration QA function tests post motor assembly would bear out this kind of failure. Remember, Marty said he has extreme resistance to turning the motor and it wasn’t clear whether this was with the wheel powered on or not so it could be the controller locking the motor up deliberately reporting the hall issue or something more mechanical in nature if the motor is hard to spin powered down. Also it’s understandably not Marty’s responsibility to do failure analysis on a pre-production demo wheel as well as why Inmotion wants it back for analysis.

That said, I wouldn’t throw away your V14 aspirations on account of Marty’s experience thus far, it’s pretty clear there was a lot of positive attention to detail (repair assitance/diagnostics thus far notwithstanding) going on with the wheel design that should make it stand out when the issues are ironed out IMO. It’s not yet another batch 1 disaster and may still prove not to be.

All of the above just gives more ammunition though to those who take the wait and see approach which will always be a wise way to mitigate some of the risk that comes with riding/owning new wheels.

Couple things:

    • affixing the 3 hall sensors with epoxy is standard practice AFAIK, I'm not sure about attaching the hall sensor board though. I've seen other PEV motors use a kind of paper between the board and windings. In any case, you need some kind of fixing strategy to prevent this component from coming loose for disintegration.
    • I’m not an expert on the programming parameters of all wheels, but it’s my understanding that they all sense tilt and have an automatic spin-kill feature often that’s customizable too.
 

9 hours ago, OldSolo said:

But then again testing suspension by having a fat guy launch off a platform was absurd, so I suppose this is the state of the industry.

To circle back to the Extreme, yeah – engineering, that is complete structural analysis calculated using realistic worst case loading doesn’t appear to something diligently adhered to in the industry. Like for this instance, I would ask Begode to see the calculations where the 290 lb rider limit comes from. If they ran the analysis, they shouldn’t have any problem showing proof IMO. It could be illuminating to see what they would say with this request because right now we just see fat guy test videos and speculate semi-intelligently on a great deal of missing information in forum posts.

Anyway yeah, these issues are what I’ve come to expect as pretty normal. It’s just higher performance and larger & more aggressive riders are bearing out unaddressed weaknesses in some of these EUC manufacturer’s product development process. For you, I’d say let the younger people take the risks, and don’t pay too much attention to brand new wheels.

Edited November 23, 2023 by Vanturion

[Panzer04]

7 hours ago, OldSolo said:

This thread & Marty's V14 adventures are giving me pause as I prepare to buy a 'real wheel' to accompany my A2.  The lack of engineering in these wheels is shocking to me.  I do not consider myself naive, and realize that very little engineering seems to occur among Chinese manufacturer.  For other products they copy successful designs & SOMETIMES produce excellent products.  As they really are the primary innovators in EUCs (and I APPLAUD them for this!), the LACK of actual engineers is telling.  Between the structural concerns, lack of understanding suspension performance issues (such as linkage ratios), very poor firmware development (there is a lot that could be added that would improve safety - I saw something elsewhere about a spinning wheel that was out of control, it should be simple to add some factors that would instantly shut it off when it has fallen over, rather than keep spinning & potentially hurt rider or bystander), and electrical design (connectors, hall sensor "gooped" into place, etc), I am hesitant to buy anything yet.

It is obvious that they are relying on riders who are so "addicted" to riding EUCs and cannot wait for the next one!  And I write this as someone who was certainly "addicted" to MTBs & new innovations.  But I honestly do not remember seeing so many new products come out that were so poorly engineered.  I even am sort-of counting myself among the 'addicted' as these EUCs have fascinated me, and the feeling of riding is quite unique.  Having had a crash (well geared up!) due to wobbles, I know that my knee was twisted BECAUSE the wheel kept spinning even though it was on its side.  That should not happen, the controller should have no problem stopping the wheel within some number of milliseconds, not 2-3 seconds.

Being older I heal more slowly & am more risk-averse than I was in my youth.  So broken wheels & bodies need to be limited, and proper design would go a long way in accomplishing this.  Am I completely off base?  Have all of you simply accepted that this is how they do business?  I see comments about it, but the Quality Improvement process clearly is failing among these manufacturers.  That they are having Marty return a wheel TO CHINA due to a simply Hall sensor failure is nuts!  But then again testing suspension by having a fat guy launch off a platform was absurd, so I suppose this is the state of the industry.

Most wheels do have angle cutoffs (as I understand - my KS16X, an older design, certainly does). Careful consideration would need to be made when implementing things like that though, since you really don't want to have the wheel "false positive" and cutoff on a rider who's actively using it. Hitting a bump, wobbling, and having the wheel immediately dump you thanks to overly-sensitive thresholds would be much worse than occasionally running for longer than it should in a crash.

[SoleCycle]

27 minutes ago, Panzer04 said:

you really don't want to have the wheel "false positive" and cutoff on a rider who's actively using it

I completely agree with you. My only EUC injuries and wheel damage have come from tilt angle cutouts while I'm in complete control of a deep turn. There absolutely needs to be an option to delay cutout by giving a couple seconds of warning and time to correct or emerge from peak carving depth. Most wheels have this warning period for max PWM. But I don't know if any wheel has a warning period for tilt angle. Which is crazy. Cutting out without ample warning should NEVER happen mid-ride.

Edited November 23, 2023 by goodsignal

[chopsywa]

17 hours ago, OldSolo said:

Being older I heal more slowly & am more risk-averse than I was in my youth.  So broken wheels & bodies need to be limited, and proper design would go a long way in accomplishing this.  Am I completely off base?  Have all of you simply accepted that this is how they do business?  I see comments about it, but the Quality Improvement process clearly is failing among these manufacturers. 

I agree with you 100%. I am the same. 25 year old mind in a 62 year old body. I have a Kingsong S22 Pro. I am not worried about it breaking physically as I will only get to about 20% of the loading (if that) of what all the daredevils do, but I do worry when I am doing 50km/h+ that it might just say "goodnight nurse" and drop me face first. 

I never buy first run wheels. I have had my eye on the V14 for a while, but it will be a year before I buy one if I do. I sort of think I will stick to 14" rims as you can buy "proper" tyres for them easily and the Lynx looks pretty nice. I know Kingsong and Inmotion (and Veteran?) make better quality wheels than Begode, but I think the reality is that they make less worse quality wheels. I have stripped my S22 down and rebuilt the suspension with new rollers, suspension linkage pins, etc and it's gone from being squeaky and clunky to buttery smooth on the suspension, with a decent (Shinko 241) tyre. I've come to the conclusion that with a lot of these things, the design is good, but the execution is poor. 

Don't give up though until you just can't do it any more.

[OldSolo]

On 11/23/2023 at 3:14 PM, chopsywa said:

I agree with you 100%. I am the same. 25 year old mind in a 62 year old body. I have a Kingsong S22 Pro. I am not worried about it breaking physically as I will only get to about 20% of the loading (if that) of what all the daredevils do, but I do worry when I am doing 50km/h+ that it might just say "goodnight nurse" and drop me face first. 

I never buy first run wheels. I have had my eye on the V14 for a while, but it will be a year before I buy one if I do. I sort of think I will stick to 14" rims as you can buy "proper" tyres for them easily and the Lynx looks pretty nice. I know Kingsong and Inmotion (and Veteran?) make better quality wheels than Begode, but I think the reality is that they make less worse quality wheels. I have stripped my S22 down and rebuilt the suspension with new rollers, suspension linkage pins, etc and it's gone from being squeaky and clunky to buttery smooth on the suspension, with a decent (Shinko 241) tyre. I've come to the conclusion that with a lot of these things, the design is good, but the execution is poor. 

Don't give up though until you just can't do it any more.

 

I am so very new into this sport.  I have been riding motorcycles for over 50 yrs (and I really need to get my Husky TE449 back together after I added RaceTech suspension parts), can no longer pedal a bicycle since my last ankle surgery, and REALLY miss hitting the MTB trails.  Even as an old fart I still can get obsessed with a new sport/toy very easily.  Frankly, I need to get a LOT better on my little A2 before even thinking of buying the next wheel.  The Extreme for $2300 looked to be such a bargain for what it offered, and Vince's link development is great.  Realistically I do not think I will ever get to the point of riding an EUC on trails as I could as an Expert class mtb racer.  Don't even know WHAT trails I could actually ride an EUC on! 

In my late 40s I could still compete with anyone when I switched to racing singlespeeds.  That competitive nature has not left me - hell, I MISS the butterflies at the start, the surge of adrenaline when chasing down someone ahead, and the incredible feeling of winning a race.  These EUCs are too dangerous for me to push to the limit.  After learning about speed wobbles and crashing on a steep downhill, I have taken a couple of weeks off from my learning.  Now that was my fault BUT: these things are inherently unstable and we are trusting some NON-ENGINEERS who design & build them!

I was looking at where the electric dirt bike market is, but the Surrons don't have real suspension, and the Varg is simply beyond my needs.  I long for something in the 180-200# arena with competent suspension for trails & perhaps hare scrambles.  I have pondered racing my Husky in the old fart class at a hare scrambles race, but I already know in the heat of competition I will kill myself on that bike! 

Back to the subject: the Extreme showed so much promise, but the lack of engineering AND Begode now controlling free market pricing likely would tilt me toward a Patton instead.  But would i like a 14" rather than 12" (I really WISH people would describe these by WHEEL SIZE not some arbitrary tire height) better?  Living in a place where I have never even SEEN another EUC, I obviously cannot ride to compare the feel for myself.  The Lynx looks great ... but over $4k?!  Seems insane pricing.  Anyway, enough of my rambling.  I WILL continue to enjoy 1 & 2 wheels.  Still plan to craft a little carrier to throw the A2 on the back of my Yamaha to take it into the city in the spring.

 

And VINCE: PLEASE keep updating your development work!  Had hoped to hear more by now.

 

[techyiam]

1 hour ago, OldSolo said:

The Lynx looks great ... but over $4k?!

Just curious, aren't mtb's more expensive, especially for bikes that would interest an expert class rider?

[stizl]

18 hours ago, techyiam said:

Just curious, aren't mtb's more expensive, especially for bikes that would interest an expert class rider?

I know this question was for @OldSolo, but as a lifelong motorcyclist and avid MTB rider (but who rarely races) myself, yes! $3k-$4k range is where MTBs just start to have decent brakes, durable drivetrain, and serviceable suspension. $5k-$6k bikes may be the best bang for the buck for a serious rider, as past that you are paying for mostly incremental gains.

Of course like in any sport, there are phenoms out there that can win a race on a WalMart bike, but they are the rare exception. 

Given the above, coming from MTBs to EUCs can be dangerous to your bank account. $4k for a top-of-the-line wheel seems like a steal vs $10k for an equivalent MTB. The flip side is that wheels have horrible resale value compared to high-end MTBs. I rode a $8k Yeti MTB for two years and sold it for $6k within 24hrs of posting it. With wheels, you have to accept that you’re losing at least half the value in a year.

Still, I’d recommend getting the best wheel you can afford that fits your needs. If you have the time/desire to more frequently service your wheel and/or are tolerant of it being out of service sometimes, then save some money and go Extreme or step it up a bit and go S22.  If you just want to set-it-and-forget-it and go ride, then pony up the extra cash and go LK. You get what you pay for, either way. 

[OldSolo]

On 11/28/2023 at 6:19 PM, techyiam said:

Just curious, aren't mtb's more expensive, especially for bikes that would interest an expert class rider?

Well, it simply depends on many factors.  While I am a number of years past my serious racing days ('93-'06), I can speak to issues from that time that likely still make sense.  First: I over the years I had different sponsors, but most of the time I was riding on frames that were handmade.  My best years were racing Ellsworth (best FS bikes for XC racing IMHO).  Just a frame retailed >$2k.  Forks - new tech coming out constantly, upgrading was pricey.  Components: moving from mid-level to Shimano XTR was terribly expensive, and honestly the cost/benefit ratio really wasn't there, but I usually used it anyway.  The feel, performance, and weight differences were subtle but very real.  I had different custom-built wheels for weight savings & strength (paid out of pocket, generally with a solid discount sponsorship).  Again, SKILLED LABOR involved.

These wheels are being built in Chinese factories, unclear if they are of the "slave labor" type as has been documented with Apple & others, but still underpaid & relatively unskilled.  The CRAPPY motor winding has been commented on related to Marty's V14 & other wheels.  Compare the "quality" of Fastace to someone like Fox?  Not likely.  Circuit boards & battery packs => again, mass production type of stuff.

I did race in the singlespeed class 2003-4 on a bike I put together from an old Russian Ti frame, etc.  Won a large regional race in 2003 - one of my greatest accomplishments given I was likely the oldest guy out there (no age classes in SS), broke my neck 2 weeks later in a road event, and returned a year later to finish 2nd in another large regional event, 1/2 min behind a kid young enough for me to have been his father!  This bike was just old parts put together w/ a chain tensioner & hub spacers!

When 29ers became 'a thing' and I picked up a year old Garry Fisher (sold from a sponsored rider after his season) and saw I could ride the rocky, rooty trails in the South without rear suspension, I had a couple of custom frames made.  My second was a GORGEOUS steel singlespeed, just the tubing cost was considerable, then throw in all of the machining & welding by the SKILLED builder.  Again, I see NOTHING comparable in these wheels.

Perhaps my ultimate absurdity was a road tandem  frame I had built for my late wife & me.  It is a magnesium alloy tubing, built with exceptional components.  I invested aound $8k in the bike in 2008.  Weighed ~26-27# (from memory, but it was lighter than any I had ever seen) and was a DELIGHT for us to ride!  Did many centuries, the Georgia & Tennessee Tandem Rallies in 2009 on it, it was amazing.  Now this was a silly, expensive splurge.  But we could afford it and I wanted it.  The frame was actually being built for us in March, 2008 when we were hit & run on our old 'factory' tandem, severely fracturing my wife's left leg & tearing a chunk out of her arm (where she knocked the passenger side mirror off the offending vehicle).  I wondered if she would want to ride again, and once she was healed up some months later & I had the new bike assembled, we greatly enjoyed it.  Actually, I really need to put that bike on the market, but nostalgia has prevented me!

One final thought: by 2000 I was flying to several races/year (out of my pocket; sponsorship had contingency payments for results; while I was a top-10 national level rider, it was in the 40+ age group and so it was NOTHING like the young studs had!).  Racing expenses were far more than the cost of the bike.  It was an EXPENSIVE hobby!

Whew ... the old guy started rambling on ... comes with age!