h3y all,
the wheel in my new 28" yuni frame is hardly close to centered. maybe 3/8" off. the down tubes are a wee bit bent from each other, as viewed from the top or bottom o’ the frame. backwards or forwards the tire is off center the same amount so it’s not the wheel, which appears to be reasonably true. what is the best way o’ centerin’ the tire?? shimmin’ the bearin’ bracket?? thoughts??
thanks,
doc
Doc,
Considering your location, I think the Uni Physicist on his newly born tire smokin’ speedster should be able to make a house call in about Uni.5 minutes! (Sorry Harper) 
centering tire in wonky frame…
Doc,
What kind of frame do you have?
If your fork is bent, get it straightened. Or get a new one.
Ya gotta have a straight fork, man!
>>What kind of frame do you have?
it’s a marvel from taiwan, a yuni. actually, for the price i can hardly complain bout its inadequacies. it arrived bent. not sure if it was bent in transit or at uni.com. the 26" i bought i had to bend to fit the suzue hub on me 26" street wheel. when i bought an irc lover’s soul tire, the 26" frame was too small so i went with the 28". the hub fit perfectly in this frame, but the wheel is not centered which makes me drift to the left a little. {well, i don’t actually drift, but it does force the seat into me left thigh} i did bend it an’ it’s considerably closer to straight than it was, but the tire is just as uncentered {is this even a word??} as before…
doc
Re: centering tire in wonky frame…
I just put some paper underneath the bearing on one side and it brought my
wheel up enough to center it. Not the best solution but it works.
Dylan
Re: centering tire in wonky frame…
dr garbanzo wrote:
> reasonably true. What is the best way o’ centerin’ the tire?? shimmin’
> the bearin’ bracket?? thoughts??
When I ordered my 20" trials Yuni frame, I had the same problem- the
frame was not straight. I simply eye balled it and tweaked it by hand. I
figured hey, that’s what you get for $40.00. But I do think you will
want to either get it straightened or replaced.
Cheers,
Jason
Re: Re: centering tire in wonky frame…
my shim was slightly more elegant, but not much. i used some foam from the fairin’ from me fiancee’s yakima rack. i was hopin’ someone would have a better idea for shim material. straightenin’ out the frame has not seemed to help enough. it’s not perfectly straight now, but it’s bloody close. probably at least as much as it ever will/would be given build quality. if it were my hunter i’d bitch. as it stands, i only wanted a cheap frame for this ride, so i’ll futz with it some more.
thanks for all the replies…
doc
how about cutting a half circle piece of PVC pipe and stickin that under there?gotta be better than foam or paper.
merde,
undoubtedly, i need more caffeine. ‘tis so obvious, why did i not think o’ it???
thanks!
doc
Re: centering tire in wonky frame…
dr garbanzo <dr.garbanzo.bchka@timelimit.unicyclist.com> wrote:
> i was hopin’ someone would have a better idea for shim material.
Drinks can (even root beer) is the classic source of thin shims for
bike maintenance. I expect it works for unicycles too. You can fold
it for adjusting thickness of the shim, and being aluminium is
generally fairly durable (thin steel shims can rust in place and jam
permanently whatever you were trying to shim).
regards, Ian SMith
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aluminum cans seem to work well as shim material…
Taiwanese frames including the Yuni/Nimbus2 are spaced for Taiwanese hubs that have bearing spacing somewhat greater than the 79mm of a Suzue.
The frames have to be “cold set” i.e. bent inwards to accept a Suzue hub. This needs to be done carefully as each side needs to bent in by the same amount.
I’ve noticed (more so on the rounded frames) that an unbalanced bend will cause a true wheel not to be central (try reversing the wheel to check this).
In effect your frame can form something slightly more akin to a paralleogram than a rectangle.
Leo White
N.B. it’s also possible to re-space steel bike frames see
you can imagine what fun i had trying to fit a profile hub into a nimbus ii / yuni frame,
i remember the susze hub being a bit of a squeeze, butv the profile was even worse,
eventualy with two people pulling the frame appart and me pushing the bearings into the bearing holders. it worked.
its about 0.5cm out and i don’t think it realy matters.
the actual mesurements of the frame peices seem kind of variable, particularly around the crown.
still, there isn’t a better trials/muni frame for the price.
>>Taiwanese frames including the Yuni/Nimbus2 are spaced for Taiwanese hubs that have bearing spacing somewhat greater than the 79mm of a Suzue.
this was the case on me 26", somehow i managed to get a pretty even bend…
>>The frames have to be “cold set” i.e. bent inwards to accept a Suzue hub. This needs to be done carefully as each side needs to bent in by the same amount.
i think that uni.com may have tried doin’ this for me. i’ve gotten it straightened out. {whatthehell, pun intended…}
>>I’ve noticed (more so on the rounded frames) that an unbalanced bend will cause a true wheel not to be central (try reversing the wheel to check this).
this was me first thought. however, regardless o’ the direction o’ the wheel, it was still offset to the same side an’ amount. i’ve taken jagur’s advice on the pvc an’ built up a shim that works beautifully. when i lose it, i’ll try the soda can shim. that’ll work out a little easier, methinks. won’t need to spend 20 minutes sandin’ the pvc back…
thanks,
doc