I have a spiffy new Muni with a 24x3 tire. It’s a beautiful piece
of machinery in every way but one: I’m having a hard time with its
“tracking.” It feels like it really wants to steer left all the
time and I have to work hard to keep it going in a straight line.
The tire’s a 24x3 Duro and is properly seated all round. Everything
seems balanced, true and square. Initially I thought I was just
feeling road-crown effect, but it persists on dirt and grass. I’ve
just re-mounted the tire going the other way 'round and it has
helped somewhat, but it still feels wrong - I think I can get used to
it now though.
My question is, is this a common experience? Is there much one
can do about it? Is it possible that there’s a problem with the
tube or tire itself that could cause this sort of thing?
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Gardner Buchanan <gbuchana@rogers.com>
Ottawa, ON FreeBSD: Where you want to go. Today.
I had the same problem with the same tire, I saw a post about the problem which suggested pumping up to a higher presure, which I did and the it made the ride somewhat better. I put a Gazz on and the problem went away.
It’s possible that the wheel is not centered in the frame. Some frames, like the Yuni, need to be squeezed together to fit certain hubs. Some hubs have wider bearing spacing than other hubs. It’s possible that one leg got squeezed in more than the other. The solution is to bend the legs so that the wheel is centered. You can do it yourself or take it to a bike shop that has experience straigtening forks (front fork on a bike).
Another possibility is that one leg is actually longer than the other. The solution is to use some soda can shims under the bearing block of the short leg.
A third possibility is that one of the bearings is not fully seated on the hub. The bearings are just press fit on the hub. If one of the bearings is didn’t get pressed on all the way the wheel will not be centered in the frame. A related problem is a bearing that is actually loose on the hub and is able to slide back and forth on the hub as you ride.
I’ve experienced the same problem three times now. When I first rode my 20", 24" muni and giraffe. Don’t worry, it should go away soon. Just get out and ride a lot.
Andrew is right, a lot of people get this, especially with bigger tyres, ride it for a week or so and if it still turns then have a look at doing stuff that might fix it.
Its particularly noticeable when switching between flat profile and rounded profile tyres, I get it going from Gazz to IRC 29er and back. If you ride Onza trials tyres which aren’t very rounded and a rounded 24x3 tyre it’s likely to be noticeable until you’ve got used to both.
When I ride, I tend to twist to the left. I think its because my right leg is stronger and I tend to favor it. I also prefer holding the handle with my right hand. I’ve found that if I force myself to hold the handle with my left hand, it straightens me out. Its hard at first, but it gets easier.
It was really bad when I moved to a 26" muni from my 24" street uni. It got better. It was really bad when I got the Coker, but it seems to be getting better.
I have a leg length inequality. The tibia/fibula of my left leg is 3/4" (about 2 cm) shorter than my right and I have found that I have a tendency to drift to my (short) left side.
After I bought my KH24 with a Gazz the problem seemed to be amplified slightly. I guess the bigger tire was maybe the culprit, I don’t really know. This summer I decided that I wanted to be able to handle my KH24 quite well to minimize my UPD’s (I have some knee trouble and I want to have err, happy knees. What I have found is that the problem took care of itself and I don’t know how I’m compensating for the discrepancy. It could be that I’m shifting my hips in the saddle, rotating my shoulders or pedaling lighter or heavier on one side. Perhaps a combination of all three? I never had to modify my MUni for this and I only put a dedicated effort in when I first noticed it. I would try to ride very straight and very long on an even surface keeping my shoulder sqaure. I didn’t do this too much but I did practice a few times. One factor that played a small roll was tire pressure. If the pressure is too high I drifted more so I keep it low and bouncy. After a few hours in the saddle it just went away. Perhaps this will happen for you too…
I agree with the low pressure group. I have noticed that at a low pressure the Gazz 3" will wander around randomly on any terrain but is more pronounced on concrete. It’s any easy test to do.
Thanks everyone for the ideas. I think I have it sorted now.
What I did first was to turn the seat the other way round and try
that for a couple of minutes. That helped enough that I went ahead
and turned the tire itself around.
I then cranked up the tire pressure, and that fixed things up
entirely. I kinda liked the springy, cushy feel I had going on,
but being able to comfortably ride in a straight line is more
important to me.
The yellow “Killer Bee” in the second row is my new - and now more
steerable - Muni:
============================================================
Gardner Buchanan <gbuchana@rogers.com>
Ottawa, ON FreeBSD: Where you want to go. Today.
What I have found is that the problem took care of itself and I don’t know how I’m compensating for the discrepancy. It could be that I’m shifting my hips in the saddle, rotating my shoulders or pedaling lighter or heavier on one side. Perhaps a combination of all three? I never had to modify my MUni for this and I only put a dedicated effort in when I first noticed it. I would try to ride very straight and very long on an even surface keeping my shoulder sqaure. I didn’t do this too much but I did practice a few times. One factor that played a small roll was tire pressure. If the pressure is too high I drifted more so I keep it low and bouncy. After a few hours in the saddle it just went away. Perhaps this will happen for you too…