Panzer04

I don't think these are comparable. EUCs are fast enough to ride on the road, and often are ridden on the road. I think its valuable to know about traffic accidents related to EUCs, because it informs behaviour when riding on the street. Many EUC riders really do not respect traffic laws, weave between cars, ride at high speed around vehicles where they could get dragged by wind, etc. We have both sets of information here, that's good enough. The fact it emphasises that the best thing you can do to increase your Ir safety is ride very carefully on the road or avoid riding on the road at all is a benefit - it makes people wary of the most dangerous place to ride their EUC.

I can respect not wanting to ride with pads, but the fact of the matter is that the larger the wheel diameter and the heavier the wheel, the more obligatory they become to exercise good control authority. Your capabilities without pads are just less. If you run the numbers on how you accelerate and brake with an EUC, you'll find that smaller and lighter wheels generally don't need pads (as much) because a small weight offset forwards or backwards is enough to provoke a large acceleration/braking response - In other words, it's very hard to fall off a small EUC by simply leaning forwards or backwards (at the extreme, for example, you'd probably overpower an Mten4 first before falling off the front). On a big wheel, it's very easy to lean forward, and without pads or squeezing the wheel between your legs, you'd simply fall off before the wheel accelerated hard enough to "catch" you. For large and heavy wheels, though, pads are basically mandatory to get good performance. At a minimum, everyone should be using brake pads. IMO, good "acceleration" pads are also a good idea, even if you aren't doing offroad, since there are situations where having the ability to lean into something and get more torque can help control the EUC. A reasonably close foot-lock (it doesn't have to be insanely tight) is also a good idea, to reduce the chance of you being bumped off the pedals and losing control. These risks are admittedly reduced by good terrain, sensible speeds etc, but nonetheless they are reduced by using pads. Perhaps the risk in a crash is higher, but IMO this would be more than compensated by the reduced risk of a crash altogether. I definitely sympathise with fears about increased risk in a crash - I've had my foot partially twisted before it escaped a foot pad before (fortunately uninjured) during offroad trailriding. If you're a new rider, or you have a smaller wheel, then I do think the returns of pads are smaller. New riders crash a lot, so overtight pads pose a larger risk (and they have less experience safely disengaging), and they also don't know how to take advantage of the increased control afforded by pads in the first place. Smaller and/or lighter wheels also don't really need pads to get enough control like you'd need for a 40kg 20" wheel. Those going padless on large wheels will be compensating by squeezing the wheel - this is certainly viable, but I find it chafes on my legs to do that constantly. If you don't have pads you have to be doing this to avoid falling off while applying torque.

Well, there goes any interest I might have had in the Falcon (and honestly, the T4 as well). Those overpower tests were disappointing. I was looking at getting a lighter, zippier wheel but there's no point if the wheel will drop me. Begode really needs to stick a full-sized controller in these wheels. I guess that'll increase the price, but what's the point of putting 50S cells in if the controller is underwhelming? As the video quite rightly states, the motors should be fully capable of providing enough torque if the motherboards could supply the current, they'll just get hotter (and only if the user is regularly pushing the wheel that hard). I suppose these sorts of wheels really are just designed for a lower market segment, so they take the excuse to cheap out on the controller and fatten those margins a bit :'( I'm probably applying an unfair standard - I want these wheels to be enthusiast-class with the same torque as eg. my master, which is for all practical purposes impossible to overpower..

Honestly, 50s is a great compromise. Wheels don't regularly hammer the batteries at 3C/8kw or more, usually it's a brief spike up to that sort of power draw. I suspect that overall the great capacity of the 50s and correspondingly higher voltage towards the end of the discharge will probably result in better overall performance. Between P45A and 50S it's 50S no question IMO.

If the BMS is reliable replacing individual cells should still be OK, but chances are those cells will always be a little different to the rest. If the BMS is good this shouldn't really be a problem, though (not ideal, but hopefully less expensive than 140 new cells/brand new battery)

I agree - this is what I found in the first post, with big references to your calculations there. This second thing is a separate, second, very noteworthy force component. If the wheel is accelerating, then as Techiyam suggests, it will experience another force consisting of the wheels CoG pushing backwards (with F=MA), with this applying another torque force depending on where this CoG is. Then it also has to accelerate the rider, and since their only point of contact is at the pedal, the pedal is therefore being pushed back by the riders weight during acceleration. If the pedal is at axle-height, this force applies no net torques. Crucially, however, if the pedal is lower than the axle, this acceleration force applies a net torque to the wheel, which in some sense you can view as reducing the torque that the rider needs to apply in the conventional down direction you computed (for a given acceleration) After all, this backwards force, below the pedal, is attempting to rotate the frame forwards about the axle, so the wheel must also counter it. If the pedals were super high, above the axle, it would work against you because the force now rotates the wheel backwards, reducing the amount of torque it needs to supply. I think this is a super significant consideration, because it makes a big difference, in theory - on par with the effects of smaller wheels. In theory a well designed wheel, with all of it's weight placed low, could feel much easier to accelerate. I think it explains to some extent why I found a V13 and EX30 actually quite easy to push around, given their additional weight (and larger tyre, for the V13) - lower pedals and better-distributed EUC weight. So assumingg I'm correct, the overall model has two major components: - The rider's weight, applied vertically at a point along the pedal - the primary control input - The weight of the EUC + rider applying a force in the opposite direction during acceleration. The lower both of these components, the less force required on the main control input for a given acceleration, as part of the torque is supplied by the mass itself being accelerated. On further thought there's more to it - but I think there's an intuitive sense to this interpretation: consider a rod mounted with a free bearing in the middle. If you placed a weight on the bottom, then moved the bearing forwards the rod would rotate forwards at the top. If you placed a weight at the top, it would rotate backwards at the top. Apply this analogy to an EUC and you can see how these torques would help or hinder acceleration. I don't know how to make sense of this with a rider that will lean to maintain stability in this situation and how that effects things, but clearly there must be a forward force applied at wherever the point of contact happens to be, right?

At low speeds, I don't believe any EUC sans tiny things like mten mini should be power limited (ie battery limited). Not much voltage is required to drive current at zero speed, so the controller turns 100v 20A from the battery into 10V 200A at the motor. Instead they are controller limited, and upgrading the controller is what would prevent low-speed overlean. The issue is primarily at high speeds where you are power limited, as getting that same 200A at 50kph might need 150A from the battery (since the motor now needs say 80V), which is clearly not happening without a bigger, higher current battery.

The only hard limitation on power and torque is the controller, and to some extent the battery. You can put as much power as you like through a motor, so long as you don't let it overheat all is well. In 99% of usage an overheating motor is not a problem, so it might be a sacrifice worth taking for, say, 5kg of motor weight reduction. Yeah, 1kwh of 50e cells or whatever is not great. There's no reason a light euc can't go fast, mfgs just don't configure the right batteries/motor/voltage setup to permit high speeds.

I suppose it also explains why people like the EX30 so much - despite weighing more than the Master, it keeps its batteries low and wide, mitigating some of that weight, and I believe its pedals are also a bit lower. Given all this, I guess the "ideal" design is to have low, wide batteries putting as much of the weight as possible as low as possible. Suspension makes this more awkward, because you'll often be sitting 50-100mm higher than you could be to give it room to slide. That being said, lots of wheels have taller designs that could easily be wider if they wanted to - just staying within the confines of the wheel at full suspension travel, and otherwise as as low as possible.. It also occurs to me that the above implies that the wheel size downsides could be mitigated if the weight is still kept below the (steadily rising) axle with bigger wheels. I suppose you will always suffer the inherent penalty of being able to apply the same torque via your feet vs increasing requirements from the wheel.. but if the pedals are low, then you don't need as much torque anyway..

This is an excellent point, and one I hadn't considered before. I'd generally neglected to consider pedal height as a factor in acceleration/braking, honestly, despite it being widely accepted that lower pedals make wheels feel more responsive. I suppose this would be exactly why - It goes a bit further too - The same logic would apply to the EUC itself (ie. if it carries weight high-up then that would apply another countertorque during acceleration). Incoming wall of text + some quick math Thought experiment: A wheel with the pedals at ground level (ignoring the ground :P) would experience a countertorque from the riders weight directly equivalent to that produced by the wheel to go forward - which means that you could totally ignore the rider weight when computing the pedal forces required to accelerate to a certain speed - because the torque required to accelerate the rider weight would also be completely produced just by the pushback of that weight at the pedal. Of course, there's also the weight of the EUC to consider - and it seems the lower-slung (further away from the top) it can be made, the easier things will be to accelerate as well because this would also apply a countertorque, but in the direction resistant to the desires of the rider :(. Given how some wheels (*cough* master) carry their batteries rather high, along with a substantial chunk of metal holding the controller quite high, that probably adds up to quite a bit of resistance to acceleration. 15kg of weight an average of a wheel-diameter away from the axle would add (for a master), accelerating at 2m/s^2 15 * 0.25 * 2 = 7.5nm of countertorque vs the forces required to accelerate at 2m/s^2 by the wheel, for an 80kg rider (ie. me) (80 + 40) * 2 = 240N To produce 240N at the ground, the wheel needs to produce: T = 240 * 0.25 = 60Nm of torque. There's definitely some more complexities to the math, but at a surface level the long story short certainly appears to be that the lower you can carry the weight, the less force required to initiate and hold an acceleration because part of the mass will then, by being accelerated, create an additional torque on the wheel. I guess the way to look at is that weight carried halfway between the axle and the ground contributes only half as much to the "apparent" weight of the whole system in terms of torques required to produce a force... Naively my intuition is saying this: Weight at axle - 1x multiplier: Counts as itself for the purposes of the rider torque needed to accelerate Weight at (theoretical) ground level (-1r from axle) - 0x multiplier: It doesn't exist for the purposes of calculating torques for a given acceleration, although it would affect the torque required by the motor - it's just that you, as the rider, don't need to generate the torque to accelerate that weight. Weight at top of wheel (+1r from axle) - 2x multipler: It counts 2x for the rider torque needed to accelerate And as the weight gets higher the multiplier is directly proportional to the distance from the axle. So for example, on a Master: 80kg rider weight, approximately at axle level (for simplicity) = 80kg apparent Not sure how to count the motor - I'd guess it can be considered to *always* apply its weight as a countertorque - but most of it is centered close to the axle with a small radius, but guessing ~possibly 15kg (motor/tyre/rim) at +r/2 = 1.5*15 = 22.5kg apparent 15kg of wheel frame, batteries, etc. at 1r, 10kg at the axle, so 2x15 + 1x10 = 40kg Adding all of this up gives an apparent weight against acceleration of 140kg, rather than 120kg as naive math would suggest (assuming all of the above are actually correct XD) It's not a massive effect, but that's still ~15% additional torque required for a given acceleration, on par with (actually a little bigger) than the effect of choosing a 18" /12"rim wheel instead of a 20"/14" rim, compared with if the weight were lower-slung and mostly in-line with the axle. This is also in line with the torque calculation earlier which implies a roughly ~15% countertorque from 15kg above. I think the above is what I was missing when comparing other wheels (in particular the S22) vs the master - I believe the S22 slings its weight lower than the Master, on top of weighing less. It might also have been the pedals were slightly lower after accounting for suspension sag (though I'm not certain on that front) - given even a couple of centimeters adds up to 3-4Nm of assistance that adds up fast as well.

50S would be ideal, I doubt the sacrifices for the 40T are worth it - it's low enough capacity that you'll be at a significantly lower voltage than the 5Ah cells for a significant portion of the ride, which amounts to the same penalty in available headroom (mostly at speed). Even if they sag less, they'll be starting from eg. 3.65V instead of 3.8V halfway through the same ride, so you probably end up with negligible benefit, and less range overall.

It depends if the S18 motor has enough copper to avoid overheating in more intense usage (mostly offroad stuff/hill climbing). I'd hazard a guess that's a sacrifice some people wouldn't mind making though. I'm assuming the S18 uses a lighter/thinner motor than is common in the 40kg class, so it'll heat up more to generate the same amounts of torque. I think this also shows how the marginal weight of adding more battery to an EUC isn't actually that much. You can see that with the 3600wh EUCs which are only 4-5kg (the weight of 1200wh) heavier than all the 40kg 2400wh EUCs but with 50% more battery.

The motor on a big EUC is going to weigh around 10kg, which gets you to ~25kg immediately. Add structural members for suspension etc, optimistically 10kg and you're looking at around 35kg. The lightest EUC near that class currently is the S22 with 2200wh. I suspect the difference comes from motor + tyre being heavier than I expect and suspension frames being heavier than they could be (almost certainly true - lightweight frames are not exactly high priority on big wheels). Manufacturers tend to just throw more material at the problem to make sure nothing breaks. This is not like the bicycle market, where they will optimise to the nth degree to shave weight off a bike frame. I think most heavy 40kg EUCs could optimistically shave about 5kg off their current weights with good design, but there's going to be big diminishing returns as you go lower, and a lot of expensive work getting custom hub motors that weigh less, reducing and eliminating unnecessary material, etc. All this will inevitably make them a bit more fragile as well, probably.

Everything I have heard indicates traditional unicyclists pick up EUCs almost immediately. That being the case, you'll be fine with a Master. Just take it slow working up to those speeds, learn how to hard-brake and deal with wobbles, etc. I have many fewer reservations about recommending a bigger wheel (and in any case I think the only annoying part is constantly dropping a 40kg EUC and not banging up your ankles etc :P) I don't think bigger wheels are really comparable to motorcycles, oddly enough. They let you go faster, yes, but they don't have better acceleration like bigger motorcycles do. if anything, I could accelerate faster on a smaller wheel, but the top speed and limited power means you have to be much more aware of overleaning it. You are limited by the physics inherent to EUCs that mean you just can't accelerate and brake as quickly as you could on a motorcycle or in a car. Just take it as it comes, practice how to ride and before you know it you'll be flying around I will strongly encourage setting good safety settings (ie. PWM tiltback and beeps) - Later begode firmwares make these available and IMO are a huge boon to safety, since you can consistently ensure you are aware of where the limits of your wheel lie and when you're getting close to exceeding them (unlike older "fixed speed" warnings and the like)

Never ridden offroad? You should ride some MTB trails some time, it's a lot of fun