Singlespeed & Fixed Gear - Best way to line up my chainwheel to the freewheel..?

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wocketpatch
04-18-11, 07:57 PM
So I've got an SS conversion that is pretty much ready to go, except that I don't have a chain on it yet. The chainwheel on my crank doesn't exactly line up with the cog on my single-speed freewheel. If it were about 1/4" (possibly slightly more) further from the hub, then it would line up. Is there any sort of little spacer out there I can thread onto the wheel before screwing on the freewheel that will position it a little farther outward? Or is using a different crank set (to reposition the chainwheel instead of the freewheel) the only option?
As a side question -- since I am using a wheel that was designed for a multi-cog freewheel, it is dished. Does this mean that the freewheel will inevitably be closer in to the center of the wheel, or would an SS-designed wheel place it in about the same place?
Thanks for any and all advice.
wocketpatch
04-18-11, 08:06 PM
btw I tried searching for previous answers to this question but I couldn't think of any keywords that didn't bring up a bajillion unrelated threads.
FastJake
04-18-11, 08:29 PM
There are several ways to accomplish what you're asking. Read: http://sheldonbrown.com/chainline.html
striknein
04-18-11, 08:35 PM
Kill two birds with one stone and have the spacing and dish adjusted on your rear wheel. $20 at a LBS should cover it. If that doesn't resolve your issue then consider a bottom bracket with a shorter spindle.
wocketpatch
04-18-11, 11:26 PM
Well I don't know that this wheel is worth much more than $20 in the first place (Weinnmann RM19) so I'd prefer not to take it into the LBS and spend money. This bike is intended as only a backup since I mainly commute by bike. It's an old cheap Gitane, not worth much, that used to be my daily rider until someone stole the wheels and seat off it. I now have another bike as my daily rider.
I managed to re-space the axle and by some luck, swapping the large spacer with the smaller one on the other side left the freewheel in just the right spot to line right up with the chain ring. I got it all set up thinking that re-dishing the wheel was probably not even necessary. Once I got everything spinning smoothly (I cleaned and repacked the bearings in the process) and all mounted up, of course I realized my error. I still have to re-dish the wheel, otherwise the center-pull brakes won't work properly since the wheel is not exactly in the middle relative to the frame anymore. Ahhh!!! OK fine.
According to the Sheldon Brown article linked above, re-dishing the wheel is "a bit of trouble" but doesn't link to any info on how to do it.. Is this something I shouldn't try without experienced help? I don't want to be messing with something I'm likely to break, and I don't exactly know how to make sure a wheel is "true"... But then again I'd prefer to do it myself, depending on how much trouble is meant by "a bit". Thoughts?
striknein
04-18-11, 11:34 PM
Before you try to dish the wheel, try putting the axle spacers back in their original positions. Get an old lockring from a bottom bracket and thread it onto the hub. Then thread the freewheel over it. You might get lucky.
You dish a wheel the same way you true a wheel. Take tension out of one side of the rim and add it to the other.
wocketpatch
04-18-11, 11:49 PM
Ah ha, that's the kind of solution I was looking for. So I take it then that these bottom bracket lock rings follow the same threading as a common hub?
striknein
04-19-11, 12:06 AM
Generally, yes. Take note that any bike shop that sees a wheel setup like that will either laugh at you or yell at you. Probably both.
rustybrown
04-19-11, 04:14 AM
Generally, yes. Take note that any bike shop that sees a wheel setup like that will either laugh at you or yell at you. Probably both.
Not at all, the laugh will be stifled until later. At least in a professional shop.
FastJake
04-19-11, 08:45 AM
Whenever I need to adjust chainline I just respace and dish the wheel. It's free and it always works. OP: all you have to do now is loosen half the spokes (left or right depending on which way you need to dish it) 1/4 turn, then tighten the other side 1/4 turn. Repeat until your wheel is centered again. Then check to make sure the wheel is still true. All you need for this is a spoke wrench, which you will find is very handy to have.
EpicSchwinn
04-19-11, 11:00 AM
On my fg instead of addressing the issue at the cog, I adjusted at the chainring. I'm not sure how kosher it is to do this but it got me a fairly straight chainline.
I'm using the bigger ring on a crankset meant for two rings to be sandwiched around it. My chainline was too far to the right on the crank end so I put the big ring on the small ring side of the crank with washers to make up for the chainring bolts being too big.
So it goes like this:
[bolt][chainring][small washer][spider][bigger washer][other end of bolt]
It's been working fine for months so it might be worth a shot in your situation.
striknein
04-19-11, 11:07 AM
On my fg instead of addressing the issue at the cog, I adjusted at the chainring. I'm not sure how kosher it is to do this but it got me a fairly straight chainline.
I'm using the bigger ring on a crankset meant for two rings to be sandwiched around it. My chainline was too far to the right on the crank end so I put the big ring on the small ring side of the crank with washers to make up for the chainring bolts being too big.
So it goes like this:
[bolt][chainring][small washer][spider][bigger washer][other end of bolt]
It's been working fine for months so it might be worth a shot in your situation.
Also laughworthy at a LBS. Chainring bolts cost about 5 bucks, why not make the investment?
EpicSchwinn
04-19-11, 11:51 AM
Also laughworthy at a LBS. Chainring bolts cost about 5 bucks, why not make the investment?
It was just one of those quick fixes that ended up working ok in the long run. I figure next time it's apart I might replace the bolts but it's not a big enough deal to me yet.
JohnDThompson
04-19-11, 12:49 PM
Before you try to dish the wheel, try putting the axle spacers back in their original positions. Get an old lockring from a bottom bracket and thread it onto the hub. Then thread the freewheel over it. You might get lucky.
Why a lockring? Just use a spacer:
BR 1mm BB/FW SPACER, Silver, Ea
Price: $0.25
Item #BR-FWS1: Bicycle Research Freewheel & Bottom Bracket Spacers, 1mm Thickness, Aluminum, EACH (http://www.biketoolsetc.com/index.cgi?id=164034817560&d=single&c=Repair-Parts&sc=Spacers&tc=Bottom-Bracket,-Cassette-and-Freewheel&item_id=BR-FWS1)
Available in 1.0mm, 1.5mm, and 2.0mm thickness.
striknein
04-19-11, 02:32 PM
Why a lockring? Just use a spacer:
BR 1mm BB/FW SPACER, Silver, Ea
Price: $0.25
Item #BR-FWS1: Bicycle Research Freewheel & Bottom Bracket Spacers, 1mm Thickness, Aluminum, EACH (http://www.biketoolsetc.com/index.cgi?id=164034817560&d=single&c=Repair-Parts&sc=Spacers&tc=Bottom-Bracket,-Cassette-and-Freewheel&item_id=BR-FWS1)
Available in 1.0mm, 1.5mm, and 2.0mm thickness.
Because BB lockrings are easy to find in a parts bin at a LBS, and BB/FW spacers generally have to be ordered for a special purpose.
FastJake
04-19-11, 02:36 PM
It was just one of those quick fixes that ended up working ok in the long run. I figure next time it's apart I might replace the bolts but it's not a big enough deal to me yet.
Nothing wrong with that. I've been to 3 shops and none have ever had SS chainring bolts in stock. They said they could order them for $20. I'll use 10 cents worth of washers instead.
striknein
04-19-11, 02:50 PM
Nothing wrong with that. I've been to 3 shops and none have ever had SS chainring bolts in stock. They said they could order them for $20. I'll use 10 cents worth of washers instead.
That surprises me. Do those shops not sell BMX bikes?
JohnDThompson
04-20-11, 03:39 PM
Because BB lockrings are easy to find in a parts bin at a LBS, and BB/FW spacers generally have to be ordered for a special purpose.
Point taken, but at $0.25/ea it's easy to keep a few on hand for cases like this.
striknein
04-20-11, 09:22 PM
I wasn't trying to sound like a prick about it. I realize I may have seemed a little abrasive. I only made the recommendation of a BB lockring because they're easy to find and probably free to beg. OP sounded like he didn't want to spend any money on the bike.
wocketpatch
04-22-11, 04:47 PM
Re-dishing the wheel ended up working out, though it was pretty out-of-true by the time I was finished. It's quite possible there was the occasional nipple I absent-mindedly twisted the wrong way making for a bit of a mess. Anyway, the whole process took me well over an hour but I managed to tweak it back into line.. I was never really able to get it quite as straight as I wanted but it's at least not hitting the brake pads and is working fine. I do think I'll get a few of those spacers to have on hand though since they're so cheap, and my friend's bike looks to have the same problem (she's just been running it with a crooked chain for upwards of a year) which I can now heroically fix. Thanks for all the advice and links!
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