Flipping the spindle to achieve the right chainline?
Has anyone done this with success?
I recently installed new cranks (no name generic square taper road cranks) on my 80's fuji conversion and even after chainring spacers, my chainline is off by probably somewhere in the neighbourhood of almost 10mm (yikes!).
I am using the original bottom bracket and had a straight (well, straight enough) chain line with my old cranks. I'd rather not buy a new BB as I'm pretty low on cash, plus I just spent the effort to repack the bearings yesterday (probably for the first time in the bike's 30 year existence) .
i suppose modern cranks not meant to fit on these old japanese bottom brackets?
Last edited by hoyc; 04-24-11 at 11:54 PM.
Goes to 11.
TL;DR - Maybe, but why go through all the effort?
You have to worry about two things:
1) Will the short spindle arm be short enough to correct my chainline issue?
2) Will the drive side crank arm fit on a shorter taper?
On older road bikes, you're usually looking at a spindle length of 118, minimum. Most modern road doubles require a 107mm spindle, and most track cranks require 103mm. 1-2cm is a huge amount to mess with. Also, some Japanese BB spindles were symmetrical, some weren't, and you can only measure it accurately when the BB is disassembled.
The "correct" way to get a good chainline is to use an appropriately-sized BB spindle, and then dish the wheel. If you're not willing to do that, then it's going to take a hell of a lot of fiddling.
is this one that much pooptier? I know it only comes in 110, although I think I can make that work easily enough with spacers and whatnot.
Originally Posted by rustybrown
To put in perspective maybe, the UN-54 was more expensive (w/o shipping) than my new crankset.
Flipping the spindle worked well for me on some projects.
Did you do this with new cranks? or another set of older older cranks meant for wider spindles?
Originally Posted by Build your own
Now I'm thinking that the pedals may be spaced too far apart to be comfortable. I rode my bike today for about 15 minutes and felt a little spread out with this new crank set up although maybe i just need to get used to it?
Last edited by hoyc; 04-25-11 at 08:15 AM.
I used old road doubles, but they were similar to the new budget "track/single speed" cranks.I have used sugino rd,origin 8,bulletproof/rpm etc and they give the same CL as old shimano,sugino,sr(typical 110 bcd,removable rings) on the same bb, because they are all road doubles that are being sold with only one ring.If your pedals feel too wide apart it might be your crank.The bulletproof crank i use on a beater has a really wide thread.
i think going along with what striknein said, that I might be better off getting a new bottom bracket that fits my new cranks.
I suppose I was being a bit self-righteous and ignorant after an weekend of fixing up my bike and just wanting a quick fix.
Anywho, I found a site with a cheapish 110 length bb, but to my surprise when i measured my BB shell, I found it was 70mm instead of 68!
After a little google search, I found this was sort of common with japanese bikes, but the BB i'm buying doesn't appear to have a lip on the non-fixed side, so should this be alright to run?
edit: the bb i found is 68 btw
Last edited by hoyc; 04-25-11 at 07:48 PM.
If you have JIS cranks, go for the 107.