Looking for suggestions as to how to get the proper seat height adjustment on a uni. After practicing for a little over a week, I’m hitting the 50’ mark about one out of five trys. I’m wondering if maybe I may have my saddle too low. I know on bicycles, if you put the cranks in the 6 and 12 o’clock position, your heel should barely touch the lower pedal. Being as you position the pedal under the ball of your foot as you pedal, this puts you in the ball park. Any formulas like this apply to uni’s?
Well Kenny, for Unicycles, there is a special “Formula”:
Your foot should be able to touch the pedal that is at 6 O’clock completely with the leg almost perfectally striaght, but with NO strain.
i always make sure that my seat can go under me with my feet on the ground. just in case one foot slips, i like to know i can land and not hurt my boys too badly. i ride with my seat very low however, and i think everyone has their own preference. Kevin
For what its worth:
Some thread suggested it and I’ve adopted it…
I ride NOT on the balls of my feet. Rather, the pedal is under the arch of my foot. If my shoes had heels, the back edge of the pedal would touch the front edge of the heel. This is more stable for MUni anyway.
Are there different placements for Freestyle or Trials.?
i hate to contradict but
For muni and trials you should DEFINITELY ride on the balls of your feet - it gives you a lot more control and the ability to spring over things.
Re: Proper seat height?
Same exact one. Just make sure you’re sitting straight (level) when you measure. Make sure you aren’t shifting your hips to one side or the other.
Other bike sizing techniques, such as dropping a plum line from your knee, don’t apply. Unicycles (with few exceptions) are straight up & down.
That will give you the optimum height for learning, for riding on flat & level ground, and Freestyle. For rough terrain or Trials you will want your seat either a little, or a lot lower.
The default position of your feet on the pedals should be balls lined up over pedal axles. Riding on the arches improves foot grip, but cuts down on ankle extension as a useful part of your pedal stroke. It’s also harder to ride fast that way.
And I still can’t figure out why you would need to reach the ground with your feet on a straight-up unicycle. If you’re falling, it tilts over! The only reason you’d want your seat that low is to protect against unintentional coasting. This is where you lose control, but not enough to know which way you’re going to fall. Those are scary!
If you’re riding that low, try raising it up. It’s scary at first if you’re not used to it, but you will eventually convince your body that the unicycle will always tilt in one of 360 degrees to allow your feet to touch the ground in a dismount. I promise.
Re: Re: Proper seat height?
I’m a beginner and from what I’ve gathered from the forums you’re kind of experienced, but I’ll still contradict you
I have my seat high enough that I can’t touch the ground on both sides and it has happend to me a couple of times, especially while trying hopping, that I’ve missed or slipped on the pedals, the uni stays upright long enough that I land in the seat and sit there for a short period before falling over, very much like the coasting scenario you mentioned.
Haven’t hurt my self this way yet though and I’m not planning on lowering the seat. Even though I don’t have much experince yet, the rest of the stuff you said about seat height feels right.
And thanks to everyone on this thread for clearing up the foot-position for me. Ball on pedal always felt natural for me but I read somewhere that it wasn’t ideal for uni.
Some unconventional but carefully thought out ideas. Feel free to reject or modify…
As a former bicyclist, I started unicycling with the assumption that the seat - pedal adjustment on a unicycle should be the same: sit with the the cranks at 12 and 6, and put your heel on the lower pedal. If your leg’s straight but not stretching, then the seat height’s right. Now pedal with the balls of your feet.
Now I’m not so sure, for a number of reasons.
Firstly, virtually all bicycles have 170mm cranks. Within 5 mm either way, all adult bicycles have the same length of cranks, as far as I know. It may be possible to buy special short or long ones these days, I don’t know.
So on a bicycle, you pedal in a circle of radius 170mm or diameter 340mm (which is a circle over a foot wide).
The pedalling circle has various significant points on it, including top dead centre, bottom dead centre, and a point at which you can exert maximum torque: about 2 on the clock face. Each of those points is a different distance from the seat.
Now on a uni, cranks can vary from around 3 inches to around 7 inches, so the pedalling circle can vary in diameter from around 6 inches to around 14 inches. Positioning the seat according to the bicycling rule makes bottom dead centre the “right” distance from the seat, but top dead centre and (IMPORTANTLY) the max torque (2 on the clock face) position are often further from the seat than they would be on a bicycle.
That means that (with cranks significantly shorter than 170mm) your leg is straighter at the ‘max torque’ position than it would be on a standard bicycle. Obviously, that will have some effect on the efficiency and effectiveness of the pedal stroke. (For good or ill.)
Secondly, on a bicycle, you tend to pedal at a steady cadence and vary the speed by selecting the appropriate gear. You can exert more torque on the pedals because you are not relying on ‘back pressure’ for correcting your balance, and you can pull on the handle bars to aid power and balance. On a unicycle, speed is controlled exclusively by pedalling cadence, and the emphasis is on spinning rather than pushing - there is very little ‘push’ needed on a 20 or 24 with standard cranks.
So the action is different, which implies that the ideal seat position may be different.
Thirdly, on bicycles, it is common to use toe clips, straps, or cleated pedals (or on modern bicycles, snap fit systems where the shoe locks onto the pedal). On unicycles, these systems are er… rare, perhaps due to evolutionary selection. So once again, the pedalling action is different. A good bicyclist pulls up slightly on the upstroke, and can push with more confidence around more of the circle. Again, for a different action, a different position might be ideal.
Fourthly, the bicyclist does not sit directly above the bottom bracket (centre of the cranks). A typical bicycle has a seat tube angle around 72 degrees (or so) whereas a unicyclist sits directly over the axle (with the exception of Unibiker! )
Fifthly, The unicyclist controls speed and balance with back pressure on the pedals. This is important when stopping, idling, reversing, or descending hills. Except for those rare bicyclists who ride fixed wheel, bicyclists only ever exert forward pressure on the pedals. Think about this: a pedalling circle of around 10 - 14 inches (say) with the centre of that circle around 26 (say) inches from the seat. That’s a huge difference of angle between pushing the front pedal down and pushing the back pedal down. Different leg action, different muscle groups.
Sixthly, bicyclists are taught to ‘ankle’ which means using the flexibility of the ankle to alter the direction of thrust as the pedal passes over top dead centre and past bottom dead centre. This ‘ankling’ adds to the length of the arc through which the bicyclist can exert pressure on the pedals. Some bicyclist believe that the use of the extra muscles provides more power, but this is a mistake, as all of that power still has to be transmitted through the upper legs eventually. So it’s not more power, it’s power delivered in a different way. Unicyclists don’t really have this option of ‘ankling’, or if they do, it is in a much reduced form.
Indeed (seventhly, if you like!) there is a strong argument for pedalling a unicycle with your insteps in some circumstances. It gives a more direct drive, and reduces the risk of hyperextension of the ankle if there is a sudden ‘kick back’ on a descent. I know some of you will disagree, but I guess that the majority of MUni riders ride on their insteps in certain circumstances. Bicyclists NEVER do this (except for old fogeys riding to the shops and the pub).
So, there are differences between what is required of a bicyclist and a unicyclist when pedalling. If the requirements are different in terms of leg extension, angle of force, direction of force and everything else I’ve described, then it would be surprising to find that the IDEAL seat height for these two very different machines would be exactly the same.
I’m learning a little more every day, and one thing I’ve learned recently is that a slight lowering of the seat from the ‘ideal bicyclist’ position can greatly increase my control when mounting, idling and reversing. I spotted this when I shortened my cranks by 25 mm, and raised my seat by 25 mm, then had to put it back down a bit! It was the same distance from bottom dead centre, but NOT the same distance from the 2 on the clock face position!
Of course, I’m a sad git who experiments with different lengths of crank more than most of you, and those of you who stick with 150s may find that the difference is so slight as to be negligible. However, in conclusion (ahem!:o ) I’d suggest setting the seat according to the ‘ideal bicyclist’ rule as set out above, then lowering it a bit. Possibly by an inch or two.
Of course, this could all be rubbish, but…
for the riding that i do, i need my seat that low. ive hurt my boys a few times with my seat a little higher, but it hasnt happened since i lowered it. it has also helped my hop to raise by as much as i lowered the seat.
i’ll try to explain how it works. when you hop, your pedals are always going to be the same distance from the ground. then, once i jump, i get to my maximum height above the ground and pull my seat up until it hits me between the legs (not too hard of course). the lower the seat is, the higher i can bring it up.
this will not apply to hopping with the seat out in front however. i dont hop with the seat out, cause i find it useless for how i ride. i have a style that is fast paced where you dont pause and hop around before you do stuff. if you watch my video you will see that on my drops, i got straight out of a ride instead of hopping around and wasting time first.
and like i said, everyone has their own preference. i was merely suggesting that this might work for other people cause it does for me. i wasnt saying that this is how it should be done. see ya, Kevin
It’s the same power delivered in a more efficient way. More efficient=less power to do the same work, or more power for equal work, or winning the race.
Ankling, as Mikefule describes above, allows your legs to make the same rotation with less range of motion on the heavier parts of the leg. Less energy expended for equal amount of pedaling. On paper this may not sound true but believe me, I can prove it in the field.
If you’re not using your ankles, you are wasting all the muscles in your lower leg, and may as well ride on your arches or heels. Though you can’t pull up like a bicyclist using clips, you still get an advantageous effect from ankling.
I agree, and sometimes ride on the insteps for long, slow uphill slogs, and for the occasional rough downhill. I’ve learned over the years that I’m less prone to hyperextension of the ankle than many other riders, so they may need to do it more.
Yes, but after all that explanation of the variance in angles and such, it boils down to a question of whether we want to run our seats lower. We can’t go much higher without too much leg extension, though some people like it that way (Sem Abrahams is famous for riding tippy-toe). We can only go lower. But as you compress your legs more and more, you lose power.
I prefer the power of as much leg extension as possible, though without extending the knee too much. This works out to the standard rule for bikes, which is based on ‘getting as much leg as possible.’
But sometimes you need your seat to be lower, especially for riding on bumps or doing seat-in hops. There’s nothing like hitting a big bump with your pedal in the 6 o’clock position (especially with a suspension seat post!), and having your foot suddenly in dead air. I definitely ride with a lower seat on trails, though my version of “low” is higher than that of many of my friends.
I agree with the first part, but not the second. For level ground, start at the ‘ideal bicyclist’ height, then adjust to taste. For rough terrain, lower it at least 1/2 inch, but how much depends on rider height, crank length, roughness of terrain, and especially personal taste.
On Tue, 28 Jan 2003 15:01:23 -0600, Mikefule <Mikefule.email@example.com> wrote:
(1stly to 5thly snipped and more snips follow)
>Sixthly, bicyclists are taught to ‘ankle’
>Some bicyclist believe that the use of the
>extra muscles provides more power, but this is a mistake, as all of that
>power still has to be transmitted through the upper legs eventually. So
>it’s not more power, it’s power delivered in a different way.
I’m not a biophysicist but…
If by ‘power’ you mean ‘maximum output power’, I disagree. If you would have said ‘force’ instead of power, I would agree. But by ‘ankling’ the upper leg muscles need only muster less power. So the same power can be sustained longer when ankling, or more power can be sustained for the same duration.
>Unicyclists don’t really have this option of ‘ankling’, or if they do,
>it is in a much reduced form.
Why is that? Or ankles are as flexible as anyone’s aren’t they?
>Indeed (seventhly, if you like!) there is a strong argument for
>pedalling a unicycle with your insteps in some circumstances. It gives
>a more direct drive, and reduces the risk of hyperextension of the ankle
>if there is a sudden ‘kick back’ on a descent. I know some of you will
>disagree, but I guess that the majority of MUni riders ride on their
>insteps in certain circumstances. Bicyclists NEVER do this (except for
>old fogeys riding to the shops and the pub).
This is contrary to many recommendations I’ve read. But I must admit I do exactly the same. For MUni I ride with my heels against the pedal’s rear. It feels like it gives me more force (I almost wrote ‘power’). On a bike I never do that.
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On Tue, 28 Jan 2003 16:38:45 -0600, johnfoss <firstname.lastname@example.org> wrote:
>I prefer the power of as much leg extension as possible, though without
>extending the knee too much. This works out to the standard rule for
>bikes, which is based on ‘getting as much leg as possible.’
The following is partly from theory so I might be wrong.
A bike rule is not necessarily a unicycle rule. On a bike the requirement for max power output is dominant (assuming you are into bike /sports/) and cadence will not be overly high due to the presence of gears. Conversely, on a standard unicycle, max power output is seldom achieved because your legs rev out. Well, on the flat at least.
Now, the last possible bit of saddle height increment involves a disproportionally large additional upper leg swing. So I think that that last bit will have a profound effect on max cadence while the effect on max power output is limited, especially at high cadence.
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This is true. We definitely pedal faster, though with less power at those high speeds.
However we are still working within the limits of our max. leg extension, or something less. In fact, we may actually average lower seat heights than a bike, to keep our feet on the pedals. Where on a bike you can lift your feet up if you want, on a unicycle you need the feet and pedals to remain attached at all times (for normal riding).
For pedaling at high revs, my un-sicentific research says you want the seat as high as you can reasonably and comfortably get it, which ends up being about where the “bike rule” would put it, or a little higher. As always, the danger of a high seat is bumps in the road (not to mention knee problems or crotch rocking, which I’d expect you to notice relatively quickly). For a track-only situation, you can run a higher seat. For street or rough terrain, it has to be lowered appropriately.
Yes, we definitely apply power differently on a unicycle than on a bike, but as long as we’re using the same drive system (pedals and cranks), we will have certain basic ergonomic necessities that are the same. Namely, reaching the pedals and staying in contact with them.
I’m not aware of any situations where having a lower seat increases power. To my knowledge, lower seats have always been associated either with keeping feet on pedals, or allowing more leg compression for jumps or tricks. Anyone’s thoughts on that?
Agreed - i ride with a very low seat - even on 6 hour epics.
This is because it suits my style. ie I ride anything and head straight for the gnarly downhills at every oppoturnity, hopping and jumping as i go.
that said having the seat higher definitely seems to help most people to climb the steep stuff - it seems to be a bit more stable under power
What you need is a quick release seatpost clamp. None of these double bolt thingummyjigs.
Some interesting responses there. perhaps I was a bit over enthusiastic with my reference to 1 - 2 inches lower, but there is definitely an ‘effect’ when you ride with very short cranks. I gather from other posts over the last few months that most people use cranks between 125mm and 170mm.
89mm on my 24… a challenge to idle
110mm on my 28…surprisingly easy.
110mm on my main 20… some sacrifices of control, but faster.
150mm on the Coker… 125s took too much planning!
150 on the 26 MUni… I never got on with 170s: I’m a shortarse.
On all of these, I find that a slightly lower seat (compared to a standard bicycle) helps. Perhaps it’s only half an inch or so lower for normal use.
I used to know what proper seat height was- then I became infected with Mike’s celebration of short cranks. Now I don’t know anything. Thanks Mike.
What can I do with a 24" Hookworm and 124’s?