Singlespeed & Fixed Gear - This is what my chainline looks like

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zambaccian
04-22-08, 04:23 AM
Converted an '82 Peugeot road bike.
I have some Shimano double road cranks; put the outer ring on the inner side:
http://i279.photobucket.com/albums/kk138/rmatei/IMG_1653.jpg
To get a good chainline I had to move a big spacer around:
http://i279.photobucket.com/albums/kk138/rmatei/IMG_1655.jpg
I hear this gives you bad handling / an unstable bike. This is my first nice bike so I can't really tell how it's being affected.
http://i279.photobucket.com/albums/kk138/rmatei/IMG_1650.jpg
What can I do about this?
This is what the cranks look like in the BB:
http://i279.photobucket.com/albums/kk138/rmatei/IMG_1651.jpg
The stock cranks put the chainring further in, but I'd rather use these...
TheBrick
04-22-08, 04:35 AM
replace the b.b.
zambaccian
04-22-08, 05:15 AM
With one with a shorter spindle? Do I need to change the cups too? I don't know if mine are ISO or Swiss threaded...
TheBrick
04-22-08, 05:25 AM
Peugeot are usually iso or french. Check Sheldons website for details of both there is a b.b data base with all the shell widths but from memory French have the same shell width as iso so you'll have to remove the b.b to find out. When you remove the drive side you will find out from wheather it has left hand or right hand threads.
If it is iso buy a cheap shimano cartridge b.b (providing your crank is jis taper). If you need to move the chain line 2 mm inboard get a b.b 4mm shorter (due to symmetries).
If it is french, buy a non cartridge b.b of what ever length you want and just use the spinddle.
Or spend £$ on a phill wood french b.b
TheBrick
04-22-08, 05:27 AM
also try and keep your rear wheel central. IF you cant you may have to redish the wheel.
zambaccian
04-22-08, 05:55 AM
Thanks for that. To clarify, I know that this model isn't French threaded - it's either Swiss or ISO.
I was hoping to find a solution that doesn't involve changing the BB or redishing the wheel - is it possible to use some washers to bring the chainring closer in?
As far as i know every place you could put washers (under the chainring bolts, under the fixed cup) will only move the chainring out in that position. Unless you do something weird like reverse the bb completely, which will only work if your threads are italian or similarly right threaded on both sided.
You can always put the chainring in the inner ring position---shimano doubles are more or less perfect for a track hub with a stock bb on the inner ring---but I guess you know that. :)
More off the wall solutions: Get a paul, Goldtec, ON-one/Kogswell, ENO, Level, etc hub or convert an xt iso front disc hub to fixed for a 45 mm chainline in the rear. That should line up nicely.
As someone else said, a shorter bb is probably the most elegant and cost efficient solution. Redishing the wheel is ok but a bit kludgy in comparison.
zambaccian
04-22-08, 06:21 AM
The chainring IS in the inner ring position.
TheBrick
04-22-08, 06:47 AM
Washers on the chaining bolts can be used to tweak the chailine a mm or so but personally I would not go for any more than that.
A new b.b sould not be expensive. Over here a chap shimano b.b is £15 or a little less if you in the states I bet you could get one for $20.
Do it right and so it well and your bike will be sorted for a long time giving you hours of minimal maintenance free miles. I tried boding a bike when I first build it up fixed gear and it ended up being alot of hassel. Once I sorted it it road like a dream and rode (and still rides) on forever.
jet sanchEz
04-22-08, 06:51 AM
As said above, the wheel should be in the center of the rear-stays. I used the brake-bridge to align the wheel on my conversion and spacers on either side to make sure it is snugly in there. That should help your chainline a bit.
You want to redish the wheel. It is hard to tell but it looks like your chainring is already pretty close to the stay, I doubt you'll be able to move it in enough. Redishing isn't hard.
tradtimbo
04-22-08, 11:27 AM
Redish your wheel: tighten all the spokes that end on the left side of the hub a 1/4 turn, and loosen all the spokes on the right side a 1/4 turn. do it again if you need to until the tire is centered. the way you turn a spoke wrench is a bit tricky, so make sure you get it right. This will more the rim relative to the hub towardws the centerline of the bike.
Tighten the ride side cup of your bottom bracket before you ride the bike. It looks loose. tighten it well.
I'm not sure if you've done this, but you can flip the spindle so the short side is where you put the crank on. the result is a left foot a bit out wide while you pedal, but the setup you want, you have to sacrifice something.
Tim
frankstoneline
04-22-08, 12:14 PM
Redish your wheel: tighten all the spokes that end on the left side of the hub a 1/4 turn, and loosen all the spokes on the right side a 1/4 turn. do it again if you need to until the tire is centered. the way you turn a spoke wrench is a bit tricky, so make sure you get it right. This will more the rim relative to the hub towardws the centerline of the bike.
Tighten the ride side cup of your bottom bracket before you ride the bike. It looks loose. tighten it well.
I'm not sure if you've done this, but you can flip the spindle so the short side is where you put the crank on. the result is a left foot a bit out wide while you pedal, but the setup you want, you have to sacrifice something.
Tim
It's a track wheel, redishing it is completely unnecessary. Spend 20 dollars on a bottom bracket, or get a new bottom bracket spindle from your LBS if it's loose ball and french. You could also use spacers to space the chainring out further on your crank spider. If you redish the wheel eventually you will just have to dish it back to center when you decide you want a proper setup and buy a fitting bottom bracket. Save yourself the headache.
tradtimbo
04-22-08, 02:13 PM
It's a track wheel, redishing it is completely unnecessary. Spend 20 dollars on a bottom bracket, or get a new bottom bracket spindle from your LBS if it's loose ball and french. You could also use spacers to space the chainring out further on your crank spider. If you redish the wheel eventually you will just have to dish it back to center when you decide you want a proper setup and buy a fitting bottom bracket. Save yourself the headache.
your right. Its not needed if the chainring side of the equation can be fixed, however, if he centers the wheel in the frame he'll have to bring the chainring over quite a bit (looks like 3mm or so) to get the chainline to be correct. Will there be enough clearance for the chainring? I've found on some bikes that this can be a problem. It depends on the frame. If it is a problem, but only slightly, cold setting the frame to 120mm may fix it.
couple other things: Chainline doesn't need to be perfect. you won't really notice if its off a mm or so.
dishing a track wheel to centerline of the bike will not effect the wheels integrity.
roadgator
04-22-08, 02:32 PM
also try and keep your rear wheel central. IF you cant you may have to redish the wheel.
No man, don't just try. YOU HAVE TO. Having the wheel in the center of the frame is WAY more important than the chain line.
It already looks like there is a pretty short spindle in there, so a shorter one may not fit, or may not help.
Its OK to have a chain line as much as 5mm off. OR you could leave the spacers as they are and have the wheel re-dished (but then it looses flip-flop capability).
Whatever you do get that wheel back in the center.
zambaccian
04-22-08, 05:56 PM
Are all bottom bracket spindles (from loose ball BBs) compatible?
It seems like I have three options, right?
- shorter BB spindle
- redish wheel
- track cranks
Which of these would you do?
peugot's are usually standard english threaded
i say just get a new BB w/ a shorter spindle
go to an LBS to see if theyll let u try a few lengths before actually buying one
operator
04-22-08, 06:09 PM
Are all bottom bracket spindles (from loose ball BBs) compatible?
It seems like I have three options, right?
- shorter BB spindle
- redish wheel
- track cranks
Which of these would you do?
Redishing the wheel is free. Provided you don't have to do it extremeely to fix the chainline. The rest require aan investment monetarily. And no, bb spindles are not all compatible with each other.
frankstoneline
04-22-08, 06:54 PM
Are all bottom bracket spindles (from loose ball BBs) compatible?
It seems like I have three options, right?
- shorter BB spindle
- redish wheel
- track cranks
Which of these would you do?
changing to track cranks will just change the length spindle you use.
I would buy a cheap cartridge bottom bracket, though that is me. You could also pull at least one of those fatty spacers out and coldset the frame. It looks like it's currently set at 130mm, track standard is generally 120mm, but if you pulled out one of those spacers you could cold set down the ~5mm and maybe fix the problem (thats what I did on my old conversion). Redishing wheels is just a bit excessive IMO for a conversion. I like going to a local bike shop if you arent sure what to do, because more often than not they can shoot you an answer then and there and help you with an explanation/parts on the spot. Most local wrenches are pretty nice guys.
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