Possible remedy for shoulder-leading

I was experimenting with my Nimbus 29er this morning and switched the crank arms from the stock 125 mm Quax to the 127 mm ProWheel. No change to the pedals or any other part of the uni set-up.

The difference in the ride was noticeable. Most remarkably, I rode straight and square on a road with a crowned center. Usually on this road, I end up kind of twisted with one shoulder leading. I think I can manage tighter turns now too, but that might just be imagination.

I don’t think the difference in length (2mm) matters, but in comparing the two brands of crank arms, the ProWheel arm tapers away from the wheel of the uni by almost half an inch more than the stock QUAX arm. This spreads my feet further away from each other and I think this adds an element of stability to the ride.

I suppose this could be tested without buying new cranks by just placing the feet further to the outside of the pedals. Anyone else notice this effect?

Well, this could explain why I had lots of shoulder leaning with my 29er, but hardly any with the coker - wider hub and I ride with my feet not at the inner edge of the pedal.

Thanks for the feedback. Glad you are enjoying the Coker. Your posts helped convince me to get the 29er a few months ago. My next step will be to try shorter ProWheel cranks on the 29er and in early 2007, I’ll hop up to the Coker.

It’s been interesting to see a lot of posts concerning the shoulder leading problem. Seems most of them were related to 29-inch wheel unicycles and many of those were Nimbus 29ers. Not much about the problem on bigger wheels. Maybe it’s just an issue with the crank-arm offset.

The distance between your feet (well, technically, the distance between the pedal mounting of the two cranks) is known as Q-factor (quack factor). In bicycling circles, high Q-factor is generally viewed as undesirable, at least among those who bother to have an opinion about it. But for unicyclists, Q-factor can be either good or bad. A low-Q setup will tend to ride more smoothly and wobble less, as your feet are closer to the plane of the wheel. A high-Q setup will give you somewhat more control, as you have more leverage relative to the plane of the wheel. Angled cranks, which contribute to high-Q, also help some people bang their ankles less.

Which is better really depends on your riding style, and the purpose of the unicycle.


On my Nimbus 29er I’ve found that I could deal with road crown by leaning sideways so that the wheel made contact perpendicular to the road. This was a bit uncomfy to start with, but it eliminated the twisting problem which was initially very difficult to deal with. I don’t notice the leaning so much now, so I’m not sure if I still do it. I kinda suspect much of the difficulty in riding the 29er was due to the Big Apple 2.35 tyre…

My 36er has ProWheel 150s on it (and a wide hub) which makes my feet very wide apart. But for whatever reason, I don’t feel any road crown issues - and there was me expecting it’d be worse.

This makes a lot of sense, but I’m surprised that a high-Q would help with the shoulder-leading issue. In fact when I got the Nimbus, I was happy to notice a low-Q factor as I thought this would be better for speed. Never had a problem with knocking the ankles, but I found I need to be careful during freemounts so as not to step on the crank-arm.

Thanks for the information.

I agree with everything you said about the 29er. The strange leaning to keep the wheel sort of “perpendicular” to the road crown, right down to the Big Apple tire. I am getting used to it and riding on the road crown is not near as big a problem as it used to be.

I am glad to hear your comment regarding the 36-inch wheel. As bad as road crown issues were with the 29, that concern has contributed to my reluctance to buy a 36.

Very interesting.
Shoulder-leading is a common problem and seems to appear and disappear with infuriating unpredictabillity.
In all the discussions on the issue, I can’t recall ever seeing Q-factor mentioned as a possible cause and/or remedy.


I agree. I have no crwon issues with the 36". I did have with the 29er with both the big apple and the kenda klaw tyres.


last time it happened to me I had a sore muscle on one side of the back and I suspect it subtly affected my riding. But happened before with no apparent reason :angry:

I’ve tended to lead with my left shoulder for quite a while, and almost got used to it. Then I had to get my wheel rebuilt and when it came back I found I was leading with my right shoulder. The difference was huge - really hard work to turn left because I can’t really twist much further in the seat, it’s hard enough going straight.

I’ve tried to check everything is symmetrical, adjusted the seat height, tyre pressure, anything else I could think of…

Today I tried adjusting the seat left-right. It looked as central as it could be but as I noticed different pressure on my thighs I thought I’d give it a go, so:

Seat twisted noticeably to the right: lead with right shoulder, UPD after only a few yards

Seat twisted noticeably to the left: lead with left shoulder, last slightly longer before UPDing

Seat twisted just slightly to the left: I can ride again! Still leading with the right shoulder slightly but maybe I can fine tune it.

It’s good to feel in control again, especially when the buses go past me:)

I’m still a bit new to unicycling, (learned a few months ago and have level 1), but I have also dealt with this leading thing you guys are talking about. I believe it is due to subtle differences in my body structure, anything from skeletal alignments to muscle tone. I think years of sitting at desks using the right hand to operate the computer mouse and the left arm to lean on the chair have trained my body to lean left.

I also tend mainly to veer left as I ride, and have had troubles in the past with right turns, (less so now that I’m getting more experienced it seems), and if I concentrate I can feel how the left side is moving less freely than the right. So for me it is becoming an exercise in biofeedback as I try to feel how the joints and limbs are moving and get them to move in balance.

And then some days I think I’m just crazy and thinking too much. Time will tell if any of my observations mean anything.

Hopefully some intense juggling will help counteract the effects of the right-hand-mouse/left-hand-lean posture.

I’m keeping the ProWheel Cranks on the Nimbus

Just completed a 3-mile test ride on a variety of road conditions. It’s confirmed - increasing the Q factor decreases the tendency for shoulder-leading (at least it’s true for me).

Up hills, down hills, off-camber roads, bumpy roads, turns, etc. I rode straight and square in all circumstances. The real test was at the end of the ride: a slightly downhill, off-camber 90-degree turn on pavement covered with loose gravel. I had done this before, but it’s always unnerving and not without some arm-flailing. With the wider cranks, it was smooth and uneventful.

Hope this helps others.

I strongly suspect it will.
There’s a lady playing unihoki with us who is seriously battling with this at the moment.
I’m going to suggest it to her tonight.

For the record, the basic unicycle is a UDC 36er, but upgraded with an airfoil rim and ProWheel cranks. I’m using the slick 36er tyre, not the original Coker.

I friend of mine, borrowing my Nimbus 29er recently said “Everything that’s good and bad about this uni is because of this crazy tyre”. The Big Apple has some great properties, and - it seems to me - some not so great ones. But once I got used to it, I found it a pleasure to ride. Still, the 36er is even nicer to ride :wink:

Oh boy, I could do with a definitive answer to this shoulder-leading thing - it’s got me thoroughly hacked off. I wondered whether it was related to turn direction preference. I find turning left easier, and lead with my left shoulder.

The thing is, I’ve recently been riding on a wide tarmac area, and on large areas of grass (rather than roads and paths), practicing turning, and have found the shoulder thing goes away! So I was concluding that shoulder-leading was tied to turning ability.


Could still well be.
Can you get hold of higher Q-factor cranks and be the second experimental rider?

Interesting – I’m better at left turns, too. Nevertheless, the shoulder-leading effect seemed to be independent of this for me. It was most pronounced when riding off-camber surfaces (i.e., a surface with a slight tilt to the left or right), but sometimes it happened for no apparent reason. Again, this was my experience on the standard UDC Nimbus 29er (big apple tire, 125 mm Quax cranks, KH seat, etc). If you look at these cranks, they merely extend outwards from the hub with no offset. Thus, the 29er has a substantially larger wheel diameter but with the same basic hub and Q-factor specs as a 24” or 20” uni. I suspect this introduces an inherent sensitivity to riding technique and/or surface angles. The Big Apple tire (and all the possibilities of tire pressure influences) probably increases this sensitivity to some extent. I now believe the increase in Q factor counters the inherent sensitivity. This makes sense in view of the comments about the Coker, which has a wide hub due to the immense wheel and the riders are not plagued by shoulder leading effects. Anyway, I am very happy now that with a set of cranks that give me a positive Q factor, I don’t have the shoulder-leading problem anymore. And besides, I like the Big Apple tire.


Leaning can be corrected by turning the wheel out of the direction of travel. For instance, if riding on the right side of a road which slopes toward the curb, turn the wheel a little toward the center of the road.

You might think of it as riding a little bit up hill, or maybe counteracting the turning effect caused by gravity pulling the unicycle toward the downhill side of the unicycle. Same problem with wind or any other force on the unicycle, you need to adjust the a little the direction of travel.

Anyway, the mental technique is to disregard where you think the wheel should be heading, if you are leaning to one side, you can get the same effect by turning the wheel a little and riding slightly toward the side you are leaning into. And then your direction of travel will be slightly to the opposite side of the direction you were previously leaning.