Air pressure experiment w/ Big Apple

Unicycles and Equipment
1

OK. So I’ve been getting really frustrated with a riding problem I’ve been having with my 29er. I tend to ride it pretty crooked. I’ll be cruising along down the road, and in order to keep it straight, my body’s twisted WAY to the right with my left arm pointing ahead and my right arm pointing behind. This is really starting to p*ss me off. I don’t have this problem with my 24" Torker but it’s prevalant w/ my homebuilt 29er. The uni is straight. I put it on a super flat welding table we’ve got at work and used precision gage blocks under the forks and there is no twist at all to the frame. The wheel is nice and true and I’ve got a friend who’s ridden it and he said it feels just fine to him. Oh yeah, the seat is on as straight as I can possible get it by eyeball.

I’ve read in other posts that the Schwalb Big Apple seems to be sensitive to little things like the road crown but I’ve tried riding on both sides of the road and this doesn’t seem to help. Yesterday, I decided to mess around with tire pressure.

I weigh 180 lbs. and I tried the following pressures. I would start in my garage and use a hand pump with a built in pressure gage and then ride around a couple of blocks always going the same route and on the same side of the road just for consistency.

25 psi (lowest my gage would read); Tire was very soft and mushy. Just plain old difficult to steer. Decided I just couldn’t ride here. Soft enough that I think I’d pinch flat if I dropped off a curb.

30 psi; Couldn’t tell any difference from 25 psi.

35 psi; More controllable but still felt like I’m riding ‘crooked.’

40 psi; Slight improvement over 35 psi.

45 and 50 psi; These pressures felt the best to me. I still felt like I’m riding a bit crooked but it was the least pronounced at this pressure.

55 and 60 psi; I’d say that these pressures were the worst. I couldn’t tell a difference between the two and my crooked riding was the most pronounced.

I still beleive that I’ve got some riding technique ‘issues’ going on but I also think that this tire is fairly sensitive to pressure. Too low and it’s just mushy. Too high and I think that I end up with too much of a point contact at the road and the round tire profile wants to kind of roll off to the side a bit. I dunno, it’s just a theory :roll_eyes:

Anybody got any suggestions or comments? Something I might have overlooked? Should I maybe try a Nanoraptor or just keep riding 'til I figure out how to overcome this whole crooked thing?

It kinda sucks 'cause I’d love to ride my 29er more but I keep gravitating to my 24 because I ride it so much better.

2

I think it’s just a question of practice. One thing you might try is changing which hand is on the handle to see if that straightens you out (or overcorrects). But mostly, you’ll just get straighter as you get more comfortable on the 29er and are fighting it less.

I don’t think a Nanoraptor is likely to solve your problem. The Nanoraptor does perform better in loose dirt situations, but on the road the Big Apple is significantly better.

3

Try lightening the pressure on your pedals until you’re just barely pushing them. Be sure to concentrate on each/both sides.

Sometime leg dominance gets into a state where it gets worse and worse, and in this situation the body’s set gets way off. By doing the lightening bit, you help back the dominant side off to match the non-dominant side better.

It wouldn’t hurt to work on this on a non-inclined surface for a while.

4

I ride 2 29ers - one with 150mm cranks and kenda claw tyre and another with 125mm cranks and the Big Apple tyre. I find that there are similar problems with road crown with both of them. I am quite heavy and I ride them both with the tyre so hard I can barely get any more air in with my littlest pump. Probably about 70 psi.

Although I would hesistate to give anyone advice as most people are much better than me, I do have an observation to share with you.

I have been practicing riding with my hand on the handle - I’m not very good and with anything approaching bumpy I still have to wave the old arms for balance. BUT I have found that sometimes when I’m riding along my right shoulder and arm ‘twists’ inward and my left arm goes out behind me. I find that this is rectified by putting slightly more weight onto the left foot. My arms just sort of naturally return to being relaxed and facing forward.

I don’t know if this will help you at all.

Cathy

5

I ride a big apple on my 29" and it’s a bit low (my air pump is f’ed up). I haven’t had any notice of leaning one way or the other.

I don’t hold the handle other than mounting and I ride on all sorts of uneven surfaces (the parking lot that I tend to ride in has a very uneven grade).

I’ll see if I notice anything subtle tonight, but I haven’t noticed anything yet.

6

[QUOTE=underdog]
“OK. So I’ve been getting really frustrated with a riding problem I’ve been having with my 29er. I tend to ride it pretty crooked. I’ll be cruising along down the road, and in order to keep it straight, my body’s twisted WAY to the right with my left arm pointing ahead and my right arm pointing behind. This is really starting to p*ss me off. I don’t have this problem with my 24” Torker but it’s prevalant w/ my homebuilt 29er. The uni is straight. I put it on a super flat welding table we’ve got at work and used precision gage blocks under the forks and there is no twist at all to the frame. The wheel is nice and true and I’ve got a friend who’s ridden it and he said it feels just fine to him. Oh yeah, the seat is on as straight as I can possible get it by eyeball."

I think you might be on to something with the tire thing. I have exactly the same thing happening. onl I didnt switch to a new uni I switched to a new innertube in my tire. Where I live they are building a lot of new houses so I was getting flats all the time to i switched out my reular tube for one of those thick rubber “puncture proof” tubes filled with slime (that green stuff that seals punctures). Right after I swapped tires the weather got bad and then I got busy so I didnt ride for about a week after I changed the tire. The first time I got on I noticed I had to fight the Uni to stay in a straight line and I was riding left shoulder forward and pumping hard with my right leg. I put it down to something I had adjusted incorrectly when putting my tire back on. So over the next few weeks I started tweaking the uni before every ride, loosten the bearing clamps, tighten the bearing clamps , twist the seat more one way then the other, I even went as far as to put padding under one butt cheek to see if I was just sitting crooked. It never dawned on me that it might be the tire since i pumped it to the same psi as the old one. I think I’m going to change back to a regular tube and see if it helps…

7

It’s true that the Big Apple is prone to this behavior anyway. I don’t have any experience with them on a uni but I have them on the my road bike which I use to commute every day. I can tell when the pressure is getting soft becasue I get under steer when cornering and it twitches going over the edge of manhole covers etc as the wheel tries to grab a line I am not steering in. Obviously it isn’t a big prblem with two wheels but very noticable and it corrects as soon as I pump up the tires again. I think this tire squishes around at low pressure like a studded tire does. Also on a narrow rim there is very little lateral stability.

Andy

8

To correct this problem, I recommend tieing your dominant foot to your waistband for a day or two, and hopping around on your non-dominant foot. Build up the muscles in your non-dom leg and you’ll be in better shape.

9

That’s a good idea :roll_eyes: I’ve taken a slightly different tact to correcting a very dominant right leg. I’ve been trying to do more of my mounting left footed and trying to idle left footed. It’s really hard for me to stay focused on it though. At my meager lever of riding, a little frustration goes a long ways. I still relish the successes so when I start getting a little frustrated at not being able to mount or idle consistently I revert back to my dominant foot. :angry: and my 24"

I’m hearing real mixed reviews on the Big Apple here. I’m thinking a good experiment might be to put something like 700c X 32 road tire on it just for fun and see what happens. I’ll keep you posted.

I’m still betting that it’s just bad technique.