I have a 26 inch yuni frame, profile hub, and 24*3.0 gazz tire all bought from our favorite store. But, the wheel is offset to the left. There is about 1mm of clearance on the left and much more on the right.
I’ve also noticed that the width at the bottom of the forks is greater than at the top of the forks.
So, I was wondering, what is the best way to center the wheel?
I had the same problem with my 20" Yuni frame, and I’ve seen it with most other Taiwanese
frames. You can fix it without to much trouble by putting shims between the top bearing
holder and the bearing. Do this on the side of the frame that’s closer to the wheel. I used cut
up pieces of aluminum soda can for shims. I’ve done this fix and several of my unis, and its
never caused any problems.
The tubing getting wider near the bearing holders is normal. I think they do it so the weld between the bearing holder and the bottom of the frame has more surface area.
I can not and will not comment on this technical solution, but it did remind me of a fine passage from the book “Zen and the Art of Motorcycle Maintenance” by Robert Pirsig, which I offer here. (Nice job, Ben):
His handlebars had started slipping. Not badly, he said, just a little when you shoved hard on them. I warned him not to use his adjustable wrench on the tightening nuts. It was likely to damage the chrome and start small rust spots. He agreed to use my metric sockets and box-ends.
When he brought his motorcycle over I got my wrenches out but then noticed that no amount of tightening would stop the slippage, because the ends of the collars were pinched shut.
“You’re going to have to shim those out,” I said.
“It’s a thin, flat strip of metal. You just slip it around the handlebar under the collar there and it will open up the collar to where you can tighten it again. You use shims like that to make adjustments in all kinds of machines.”
“Oh,” he said. He was getting interested. “Good. Where do you buy them?”
“I’ve got some right here,” I said gleefully, holding up a can of beer in my hand.
He didn’t understand for a moment. Then he said, “What, the can?”
“Sure,” I said, “best shim stock in the world.”
I thought this was pretty clever myself. Save him a trip to God knows where to get shim stock. Save him time. Save him money.
But to my surprise he didn’t see the cleverness of this at all. In fact he got noticeably haughty about the whole thing. Pretty soon he was dodging and filling with all kinds of excuses and, before I realized what his real attitude was, we had decided not to fix the handlebars after all.
As far as I know those handlebars are still loose. And I believe now that he was actually offended at the time. I had had the nerve to propose repair of his new eighteen-hundred dollar BMW, the pride of a half-century of German mechanical finesse, with a piece of old beer can!
The problem is not the legs are different lengths (well not in my
experience) but that the Susue hub is narrower than the Taiwanese hub.
Place the stem in a vice then place the wheel in.
Note the side that is closest to the tyre.
Remove the wheel.
Hold the end of that side near the bearing holder and apply force inwards.
Hence bending the frame.
Re-apply the wheel. Repeat above until wheel is central.
You want to have the frame so that it is narrower than the bearings by about
1mm. This means that there is always load applied to the bearings.
The centre of the wheel should be in the centre of the seatpost, this is the
check that the frame legs are equal length.
If you are not sure if your wheel is built symmetrical, then turn the wheel
around and repeat, the side it is closest to should be the same each time,
if it swaps side then the wheel is not built symmetrically… get it sorted!
The frames are quite durable so can take this kind of manipulation.
> I had the same problem with my 20" Yuni frame, and I’ve seen it with
> most other Taiwanese
> frames. You can fix it without to much trouble by putting shims between
> the top bearing
> holder and the bearing. Do this on the side of the frame that’s closer
> to the wheel. I used cut
> up pieces of aluminum soda can for shims. I’ve done this fix and several
> of my unis, and its
> never caused any problems.
> The tubing getting wider near the bearing holders is normal. I think
> they do it so the weld between the bearing holder and the bottom of the
> frame has more surface area.
> Hope that helps.
> Ben Plotkin-Swing
> Ben Plotkin-Swing’s Profile: http://www.unicyclist.com/profile/378
> View this thread: http://www.unicyclist.com/thread/20638
I mean on top of the bearing. Doing this effectively lengthens that side of the frame. Roger could be right that that isn’t the real problem, but shimming it will center the wheel without having to mess with the frame. Functionally, I don’t think it will make a difference which fix you use.
I had to shim my stock Coker frame – it took about three pieces of aluminum soda can to get it right. The pieces have wedged up into the bearing holder nicely and don’t fall out when I remove the wheel.
Jonny D had the same problem (I was helping him) and not only did we not get it to work, the bolts that hold the bearing caps broke INSIDE the nut!!! it was so frustrating, well, he will probably post soon, so I will let him tell the story.
One other thing to check besides the frame is the bearings on the hub. When my wheel has gotten uncentered in the frame it’s been because a bearing has slipped on the hub. If you have a standard cotterless hub make sure both bearings are tight on the hub and that they are both pressed on the same distance on the hub. If you have a Profile hub make sure that you have the same number and size of spacers on both sides of the hub. Just a slight bit of movement in the bearings will cause the wheel to tilt to the side and possibly even rub on the frame.
I have to vote with Roger’s solution, even though i haven’t tried it yet. My 24" x 3" was off center in the Yuni frame, and i went the shim route. Didn’t notice any problem the first couple of days, hopping around the yard. The first time i took it for a ride on flat level ground, noticed that when my weight was centered over the wheel, the saddle wasn’t centered under me! Will try taking the shims out and tweaking the frame…Thanks for the tip, Roger.