Leaperkim Lynx 2700wh: 151V, 20" tire, suspension, 89lb

[UPONIT]

3 hours ago, cegli said:

There's two big reasons pretty much every mid-range to high-end mountain bike fork is an air fork, not coil.

1.  The designer can't (easily) use a linkage to tune progressiveness, and air shocks are naturally progressive.  This progressiveness allows them to feel "bottomless", while still feeling supple at the top of the stroke.  Air shocks are also completely tune-able.  Negative-air, positive air, and tokens can be added/adjusted by the end user to perfectly tune the amount of sag, mid-support, and ramp-up at the end of the stroke to match the riders weight and riding style.

2. Weight.  Springs are heavy, air is not.

The only downside of an air fork is the extra stiction from the air seals, plus the slight additional maintenance of keeping those seals smooth running.

I really wish the forks we were using were more like high end mountain bike forks.  Air chambers with a well engineered mix of positive and negative air, plus the ability to add tokens to reduce the positive air volume.  There's no need for linkages, etc.  That's all extra weight that doesn't really give any benefit outside of allowing someone to run a preexisting coil shock.  Linkages add tons of extra weight, sliders, and pivot points, which add friction and negate the maintenance/stiction savings.

Forks are the future of good EUC design, but right now they're limited by only having an option of one very basic "fork" with 2x springs and a small amount of travel.

Thank you for this take on suspensions. I know it isn't a "fork," but I feel my V13's suspension is exactly as you describe air suspensions. With the dampers barely engaged and the separate shocks inflated to about 30 lbs. less than the recommended psi for my weight, the wheel really is cushier than any other kind of EUC suspension I've tried. Granted I've only tried a couple others, and not for very long. But they were a lot noisier and crunchier and linear than the cloud like air suspension. I'll be very curious to try the V14's and the Lynx's spring suspensions.

This might just be confirmation bias, but I feel like people who dislike the air suspension just didn't take the time to dial it in (or have enough time to learn how and then experiment). Especially all the reviewers who got the V13 with the busted dampening adjuster. It doesn't seem fair to judge something that is crippled from reaching its full potential. The same goes for trying out a wheel at a demo, where you don't have time or knowledge to take advantage of the infinitely adjustable air suspension. It goes meh, decent, good, better, then... perfect and you're on a cloud.

"Bottomless" is a great description. And knock on wood, but my air shocks don't leak and I haven't had to do any maintenance so far except check for lube on the rails.

Edited November 24, 2023 by UPONIT

[Rawnei]

2 hours ago, cegli said:

Problem is, what's the "right spring"?  It depends on the aggressiveness of the rider, weight, whether they do drops, how big of drops, etc.

I disagree, I think it's much simpler, use sag as baseline for selecting spring,then tune dampening depending on how aggressive you ride.

[cegli]

20 hours ago, Rawnei said:

I disagree, I think it's much simpler, use sag as baseline for selecting spring,then tune dampening depending on how aggressive you ride.

Being forced to use compression damping to compensate for lack of progressiveness is a crutch that typically leads to a sub-optimal suspension tune.  Here's a tech talk about it:

https://www.pinkbike.com/news/the-tuesday-tune-ep-11-adjusting-spring-rate-vs-compression-damping.html

Snap-shot for people who don't have time to watch an 11 minutes video:

On a fork with tokens, air pressure, and compression damping adjustments, you can adjust everything independently.  You aren't forced to increase compression damping, sacrificing things like small bump compliance for bottom out resistance.

 

Edited November 25, 2023 by cegli

[Rawnei]

3 hours ago, cegli said:

Being forced to use compression dampening to compensate for lack of progressiveness is a crutch that typically leads to a sub-optimal suspension tune.  Here's a tech talk about it:

https://www.pinkbike.com/news/the-tuesday-tune-ep-11-adjusting-spring-rate-vs-compression-damping.html

Snap-shot for people who don't have time to watch an 11 minutes video:

On a fork with tokens, air pressure, and compression dampening adjustments, you can adjust everything independently.  You aren't forced to increase compression dampening, sacrificing things like small bump compliance for bottom out resistance.

 

Sure, we can theorize all we want, I used to do this also, but I know how the wheels perform in reality, with enough dampening I don't bottom out on my wheels from jumping and I'm a heavy rider, I know other riders that is jumping on the Sherman S twice as high as me no problems, no bottoming out, and suspension still feels plush over small obstacles.

So reality doesn't reflect the theorycrafting in this instance.

Edited November 24, 2023 by Rawnei

[Jason McNeil]

So.... one potential complication LK identified is that the typical injectable sealants might be corrossive to the magneisum rim. The proposed solution is to apply a vulcanizing bead-sealer to the tire during installation—they'll obviously be cleaning the residue from the tire, this is to demonstrate means-and-method.  

Chooch & Haydn will be receiving the tubeless Lynx today & tomorrow, providing more validation to this change.

 

Edited November 24, 2023 by Jason McNeil

[Rawnei]

40 minutes ago, Jason McNeil said:

So.... one potential complication LK identified is that the typical injectable sealants might be corrossive to the magneisum rim. The proposed solution is to apply a vulcanizing bead-sealer to the tire during installation—they'll obviously be cleaning the residue from the tire, this is to demonstrate means-and-method.  

Chooch & Haydn will be receiving the tubeless Lynx today & tomorrow, providing more validation to this change.

 

Personally I'm not that interested in tubeless but wouldn't this solution be difficult to take the tire off when it's time?

[techyiam]

43 minutes ago, Rawnei said:

Personally I'm not that interested in tubeless but wouldn't this solution be difficult to take the tire off when it's time?

Tubeless car tires and motorcycle tires don't require tire bead sealers.

That means that if a tire bead comes off, you would have to clean up the old sealer and apply the new sealer.

On my new Abrams, the valve stem wasn't installed properly out-of-the-box. Consequently, there was a slow leak. I didn't know early on.

As the tire pressure got too low, one of the tire beads came off. Surprisingly, I could still ride the wheel with little to no air in the tire.

However, after the valve stem was properly installed, and the tire beads sealed, I haven't had any problems since. 

Moreover, in my specific case, if the tire pressure is below roughly 25 psi, tire losses air slowly. Again, a tire bead breaks when the tire pressure gets too low. 

Edited November 24, 2023 by techyiam

[Duster]

13 hours ago, novazeus said:

idk who thinks a center rib on a unicycle is clever. 

What are your experiences for how "center rib" treads ride? I'm still experimenting on the ideal tire that does well enough off-road for being a street tire and here is what I've found:

1. If you want to go street, you'll want some tread that addresses water and debris (no slicks, basically). That's where the Michelin Pilot Street 2 gets the most love.

2. If you want something better for off-road, the gaps between the knobs of a trail tire will make your top speed and max range lower (like the Kenda 262)

3. If you want a good in-between, then, you want something that has long "knobs" (if you can really call them that on a street-biased hybrid tire) off the center of the tread pattern so get traction off-road, but you also want a consistent tread in the middle for smooth conversion of energy into forward motion (addressing the knob issue in point #2). That consistent center tread will also provide longevity for the tire through a more-even wear of that part of the tread.

4. If you remove the center tread and just have a gap in the middle of the tread with close-but small knobs all over the tread pattern (like the K66), staying upright at high speed will be tough because the tire is effectively split in half. So you'll be tipping from one side to the other (again, at high speed).

5. With 4 in mind, you could still refuse to have a center rib, but also eliminate the issues the center gap and knobs by having your tread pattern make sure that any knob-like gap in the center has tread on the outer edges of the tread that meets the ground instead. This allows for the tire to have bite off-road and reduce the range/speed effects of that bite on-road (hence why I was rooting for the ChaoYang H626)

 

With all that in-mind, tires with the center rib like the 340a and the Longxin L841 seem to be one of two approaches to having an all-rounder tire. The other, more slicks-like options tested, like the ones in previous photos on this thread and the Pilot Street 2, all seem a bit too street-biased. That is, if we're taking about what tire should be shipped stock on all wheels instead of a knobby.

Hopefully, the day will come when we get the H626 in a 3.00" width and more options like that. I think it'd give many more riders the versatility they need while also showing them the kind of agility they can get with a dedicated street tire!

Edited November 24, 2023 by Duster
I forgot "battery life" and "maximum range" are different.

[stizl]

14 hours ago, cegli said:

There's two big reasons pretty much every mid-range to high-end mountain bike fork is an air fork, not coil.

1.  The designer can't (easily) use a linkage to tune progressiveness, and air shocks are naturally progressive.  This progressiveness allows them to feel "bottomless", while still feeling supple at the top of the stroke.  Air shocks are also completely tune-able.  Negative-air, positive air, and tokens can be added/adjusted by the end user to perfectly tune the amount of sag, mid-support, and ramp-up at the end of the stroke to match the riders weight and riding style.

2. Weight.  Springs are heavy, air is not.

The only downside of an air fork is the extra stiction from the air seals, plus the slight additional maintenance of keeping those seals smooth running.

I really wish the forks we were using were more like high end mountain bike forks.  Air chambers with a well engineered mix of positive and negative air, plus the ability to add tokens to reduce the positive air volume.  There's no need for linkages, etc.  That's all extra weight that doesn't really give any benefit outside of allowing someone to run a preexisting coil shock.  Linkages add tons of extra weight, sliders, and pivot points, which add friction and negate the maintenance/stiction savings.

Forks are the future of good EUC design, but right now they're limited by only having an option of one very basic "fork" with 2x springs and a small amount of travel.

I agree with avoiding the unnecessary complexities and friction of linkage design, except perhaps for wheels meant for bigger jumps. A big part of what makes the LK suspension wheels renowned is the small bump compliance, and much of that has to be credited to the low static friction of the fork-type shock with coil.  

I have had most of the major MTB suspension systems (Fox, RockShox, DVO…Float Factory, Lyrik, Monarch, Topaz) from the past few years across seven different bikes (XC, Trail, AM, Enduro, Dirt Jumper). I find the air systems to be the best for efficiency and “pop”, so for XC, fast flow trails, and jump lines.

When it comes to carrying speed with control through rocky and/or rooty trails, however, I always go for the one coil bike I have (Ripmo), even though it has the cheapest and heaviest fork I own (Marzocchi Bomber Z1 Coil) with the oldest damper (the original GRIP). 

The added bonus that I never have to worry about air pressure helps too. The higher-end MTB systems really hold air well for many months, but I have yet to see an air EUC suspension that doesn’t need regular top-ups. 

Focusing on the topic here, I think that the Lynx with a dual-rate coil spring is the ideal setup for me and my use case, which is choppy off road and mid-speed distance rides on street. 

[UPONIT]

13 hours ago, Rawnei said:

Sure, we can theorize all we want, I used to do this also, but I know how the wheels perform in reality, with enough dampening I don't bottom out on my wheels from jumping and I'm a heavy rider, I know other riders that is jumping on the Sherman S twice as high as me no problems, no bottoming out, and suspension still feels plush over small obstacles.

So reality doesn't reflect the theorycrafting in this instance.

Sorry if this is a dumb question, but how does dampening prevent bottoming out? I thought dampening meant slowing the rate of return to uncompressed. Is that just for air shocks?

--confused emoji--

Edited November 25, 2023 by UPONIT

[Planemo]

33 minutes ago, UPONIT said:

 I thought dampening meant slowing the rate of return to uncompressed.

It is indeed dampening, but the above is rebound damping.

Adding lots of compression damping can prevent bottom out. Not ideal though as has been said, plus you risk blowing the damping circuit, leaving you with no damping at all..

[UPONIT]

6 minutes ago, Planemo said:

It is indeed dampening, but the above is rebound damping.

Adding lots of compression damping can prevent bottom out. Not ideal though as has been said, plus you risk blowing the damping circuit, leaving you with no damping at all..

Thank you!

But I still don't get what compression damping is. Is it something that makes the compression rate slower? As opposed to making the rebound rate slower? And are we talking about spring shocks or air shocks? Or both?

Is there a Cliff Notes Explainer of all this somewhere that you recommend, so I don't have to keep bugging you?

I never rode mountain bikes. My RCR has aftermarket adjustable progressive motorcycle shocks in the rear and stock adjustable front fork. The shocks don't feel as cushy as I would like, but that's a different topic...

[stizl]

54 minutes ago, UPONIT said:

But I still don't get what compression damping is. Is it something that makes the compression rate slower? As opposed to making the rebound rate slower? And are we talking about spring shocks or air shocks? Or both?...

Yes, compression damping slows travel during compression, rebound damping slows travel during rebound, and both do this regardless of spring type (air or coil). 

[Planemo]

1 hour ago, UPONIT said:

Is there a Cliff Notes Explainer of all this somewhere that you recommend, so I don't have to keep bugging you?

I don't want to insult your intelligence, but this video is quite a good overview of how to set things up. It's a very basic but has helped a lot of guys that are just getting into things. Theres plenty more in-depth tutorials out there if this one sends you to sleep

 

 

[techyiam]

5 hours ago, UPONIT said:

Sorry if this is a dumb question, but how does dampening prevent bottoming out? I thought dampening meant slowing the rate of return to uncompressed. Is that just for air shocks?

In a mass-spring-damper system, the sprung mass is supported by both a spring and a damper. So when a rider lands a jump, as the tire strike the ground, the resulting impact force would drive the unsprung mass (motor/wheel/tire mainly) towards the sprung mass. Countering this impact force are a spring force and a damping force. If the spring force is not enough to prevent bottoming, the damping force can make the difference.

A spring stores energy. Once the unsprung mass stops going up vertically, the energy stored in the spring would then cause the spring to push the unsprung mass away from the sprung mass.

Whereas, a damper dissipates energy. Also, the damping force is proportional to speed of motion. The faster the motion, the higher the damping force. And the relationship is nonlinear. This implies that the harder the impact, the higher the compression damping force would be generated. Hence, compression damping can contribute significantly to bottoming prevention. In simple terms, a hydraulic damper uses a piston to push oil out of a cylinder through a metered orifice.

As to damping, there can be both compression damping and rebound damping. Damping always opposes motion. Rebound damping occurs when the unsprung mass is pushed away from the sprung mass by the compressed spring.

[Rawnei]

Again, reality shows a lot of riders jumping their LeaperKim wheels and the shock handling both the landing really well and holding up very well over time, with the Lynx dual rate spring it should only be better.

So it really doesn't make sense for the average rider who doesn't even jump at all to worry about bottoming out their LeaperKim suspension wheel IMHO.

[Duster]

1 hour ago, Rawnei said:

it really doesn't make sense for the average rider who doesn't even jump at all to worry about bottoming out their LeaperKim suspension wheel IMHO.

The only two scenarios where a casual rider should worry about bottoming out is if they're experimenting with softer suspension settings, or if it's their first time attempting a jump. Neither are really serious instances, though.

I, for example, bottomed out my Sherman S jumping on little sidewalk imperfections simply because I had my suspension relatively soft. That was on my because I liked the feeling of the suspension like a car's, soft and giving around 1.5 rebound bounces. The other scenario is one's first time doing a big jump. It took a while to occur to me that I'll need to really stiffen up my suspension when I want to hit a big jump and not bottom out.

Both scenarios are just solved by stiffening the suspension, as long as the right weight springs were chosen for the rider in the first place.

[Rawnei]

1 hour ago, Duster said:

The only two scenarios where a casual rider should worry about bottoming out is if they're experimenting with softer suspension settings, or if it's their first time attempting a jump. Neither are really serious instances, though.

I, for example, bottomed out my Sherman S jumping on little sidewalk imperfections simply because I had my suspension relatively soft. That was on my because I liked the feeling of the suspension like a car's, soft and giving around 1.5 rebound bounces. The other scenario is one's first time doing a big jump. It took a while to occur to me that I'll need to really stiffen up my suspension when I want to hit a big jump and not bottom out.

Both scenarios are just solved by stiffening the suspension, as long as the right weight springs were chosen for the rider in the first place.

Did you check your sag also?

The cool thing is that even upping the compression dampening it still feels plush!

[techyiam]

I had a chance to hop on a Lynx at Eevees, and putt very briefly around the showroom. Ditto on a Patton, and an S22 Pro, back-to-back. I rode my S22 there.

The impression that I got was a positive one for the Lynx. It is impressive to see that Leaper Kim is able to make significant improvement over the Patton.

I can see that the Lynx is a possible candidate as an upgrade to my S22 for riding around town. That is, on mostly bike routes, comprising primarily of bumpy residential streets. And sometimes, I also ride in a bike lane on the side of a main road. When traffic has quieten down, I may depart from the bike lane onto the main road. Away from park cars gives me an opportunity to shorten travel time.

With freshly cleaned and lubed stock sliders on my S22 and with a 300 lbs spring, I had gotten a taste of what could be with a properly working suspension on bumpy road under dicey conditions where the broken surface is always damped and covered with fallen leaves in near freezing temperatures. I am amazed at how much improved the ride can be, but equally important, how much more secure I felt, allowing travelling speed to increase substantially. Unfortunately, on my S22, equipped with stock sliders, this was short lived since the stiction will return only after some kilometres. Kingsong really dropped the ball with the original sliders. 

This experience has allow me to understand, how a good compliant suspension can do for a wheel beyond comfort, and how significant stiction can adversely affect suspension performance.

On the suspension front, I felt the suspension action on the Lynx is further refined over the Patton. The stiction seemed to be less and the feel of quality is higher. As a rough analogy, it is akin to comparing a stock shock to a more expensive premium shock.

Now I know what suspension can do, I can appreciate this level suspension quality better.

Mind you, the suspension action on the Patton comes close.

Acceleration from a standstill, I thought the Patton was more responsive off the line than the Lynx. This is just me doing a test of how I would normally ride.

On the Lynx, I can feel the extra inertia during acceleration. The acceleration is good, but the Lynx has a refined quality feel to the power delivery. Not sure what Leaper Kim did to the motor and controller. In any case, they did good.

In contrast, the S22 Pro felt less peppy. My own S22 felt very similar to the S22 Pro. TBH, I couldn't tell the difference. In fact, just rolling around, the S22 Pro felt overall just like my S22, except for one very important area, the slider action. Although the suspension action isn't as good as the Patton, but it seemed to be in about the same ball park. This convinced me to get the Hou Ningning sliders.

I can say for my next wheel I am going to hold off on the 22" wheels. I now think it is likely a good 20" suspension wheel may be the sweet spot for my use case.

It is quite astounding that Leaper Kim appears to be able to pull another rabbit out of a hat. And this with me not haven't even had the opportunity to test out the 151.2 V motor system at speeds.

I can see the Lynx going to be garnering more praise as more people get the opportunity to ride it.

The type of quality that Leaper Kim appears to be pursuing is not just quality of parts alone, but rather the quality improvement one see when comparing an Audi A4 to an Audi S4.

The S22 Pro is more like a Volkswagen Jetta, from a perceived quality perspective, IMO.

Incidentally, I lift up the Lynx using the front and rear lift handles. Wow, I was surprised how light it felt. And the handles were well placed, and nicely shaped. In fact, if I was not mistaken, it felt lighter than Gabe's own Patton. That was unexpected.

I like where Leaper Kim is going. I am glad that Leaper Kim came out with the Lynx. I think it is better suited to me than the Sherman S.

Edited November 27, 2023 by techyiam

[Jason McNeil]

Another new feature that's being added onto the Lynx is telemetry/data-logging, with an onboard memory chip, sort of like a 'black-box', similar to what Inmotion has, but with LK you'll be able to download/analyze the log from the App, without having to depend on a remote server out in CN. This functionality will be added onto the LK App. 

 

Edited November 25, 2023 by Jason McNeil

[jimjam.nyc]

4 minutes ago, Jason McNeil said:

Another new feature that's being added onto the Lynx is telemetry/data-logging, with an onboard memory chip, sort of like a 'black-box', similar to what Inmotion has, but with LK you'll be able to download/analyze the log from the App, without having to depend on a remote server out in CN. This functionality will be added onto the LK App. 

 

Really cool stuff going on in this wheel. Thanks for keeping the thread up to date and informed! Do you know if LK will offer any upgrades for Patton down the line with any of the new software features? Like smart BMS for people who get newer battery packs, etc?

Just curious!

[Jason McNeil]

16 minutes ago, jimjam.nyc said:

Really cool stuff going on in this wheel. Thanks for keeping the thread up to date and informed! Do you know if LK will offer any upgrades for Patton down the line with any of the new software features? Like smart BMS for people who get newer battery packs, etc?

Almost anything is potentially doable, but it's a question of effort-cost/benefit. Sourcing 4x of the SmartBMS will cost about $100 in materials + the labour to swap those out; as a guesstimate, it would be about $250 + parts. If there's demand, we can certainly try to source some of the SmartBMSs for the Patton & SS, once LK has all their preorders shipped, probably 1-2 months out.

[JZT-Colorado]

38 minutes ago, Jason McNeil said:

Another new feature that's being added onto the Lynx is telemetry/data-logging, with an onboard memory chip, sort of like a 'black-box', similar to what Inmotion has, but with LK you'll be able to download/analyze the log from the App, without having to depend on a remote server out in CN. This functionality will be added onto the LK App. 

 

Hopefully will include an English-language option.

[Stickysock]

This is another feature Zero has with their battery+controllers. It was monumental in diagnosing premature battery wear and a sharp reduction in range during cold weather. This feature combined with viewable cell voltage really adds value during late term ownership of this wheel.

Looks like leaperkim is really trying to make legit vehicles out of these wheels.

[Duster]

4 hours ago, Rawnei said:

Did you check your sag also?

The cool thing is that even upping the compression dampening it still feels plush!

I haven't checked yet. I'm 155lbs, with a 62lb suspension kit, so I initially figured the sag would probably be too little. Been meaning to use that post-it note method to confirm/adjust it, though!