52t sprocket hitting my frame

Beagle123

10 kW
Joined
May 2, 2007
Messages
620
Location
Los Angeles
Hi:

I'm trying to install a 52t sprocket on my bike, but the teeth of the sprocket are rubbing against the frame. In this picture, you can see that if I tighten the retaining bolt, the teeth of the sprocket will contact the white bar on the frame. Is there some kind of spacer I can use? I'm trying to locate a large washer (1 3/8 inches ID) to space the whole crank about 1/8 inch to get clearance.

DSCN1555.JPG

Also, I purchased a 46t sprocket too. I doesn't have the same problem. However, that sprocket is for a single speed bike that uses a thicker chain. This sprocket is too thick to be used with a normal mountain bike chain because the skinny mountain bike chain can't seat properly on the teeth because of the thickness of the sprocket.

I'd like to find a supplier for a working sprocket for this bike. When I get a good model, I hope to sell them to others. Does anyone know a good source of 46t-52t sprockets for $20-$30? I'm trying alibaba.com, but I know the reputation.

How do you guys do this?

Thanks,
Eric
 
Beagle123 said:
Does anyone know a good source of 46t-52t sprockets for $20-$30?

I had a 52T on my Giant AC from Rennen Design Group, it only just fit with ~1mm to spare. Guess I got lucky.
http://endless-sphere.com/forums/viewtopic.php?f=6&t=17944&p=343636
file.php

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You may be able to loosen the bottom bracket on the chainring side and tighten it on the opposite and get a bit of relief. Although it depends on your BB and moving your chainline may make shifting to the lowest gear on the freewheel no longer an option.
 
You can use washers or just get a wider bottom bracket.
 
On a steel frame or cromoly I have used a hammer and made a mod. Yes wasn't the prettiest but is under the chain ring. Can't be done with aluimuin.
 
http://www.chainreactioncycles.com/Models.aspx?ModelID=29489

You can use chain line spacers to move the BB out a little too.

Kudos
 
Campy&PhilWood.jpg


I used a custom Phil Wood BB to extend my 53T beyond the frame. Just needed about 3mm more, but I had up to 10mm with the kit they suggested. End of problem. :)

~KF
 
Thanks for the input, you guys.

My major challenge is finding a design that I can build quickly and cheaply to sell to others.

I can buy these sprockets for $22.00 at a distributor. Doing things like buying a new bottom bracket will add more cost that I will have to pass on to the buyer. That makes my job of selling more difficult.

I tried loosening one side and tightening the other, but the ball-bearings are fixed on the sprocket side. The side without the sprocket is the one that is variable.

Also, I don't really have the option of not using a gear because buyers might question the engineering of the bike. It has to look like a finished product. However, I don't think that moving it over a tiny amount would impact the gears. It looks like the chain would have a "straight-shot" to the gears.

I never anticipated how difficult it would be to find the right parts. I thought this would be easy. Its amazing how hard it is to buy the exact sprocket or spokes even in a major metropolotan area like Los Angeles.

I'm looking into the other suggestions now. Thanks!


Eric
 
Hi Team:

I think I found the solution:

http://www.chainreactioncycles.com/Models.aspx?ModelID=36416

I measured the diameter of the bottom bracket, and its about 1 3/8 inches (35mm). This spacer is made by a company called "Hope." I guess they have that name because you have to hope this thing is the right size. :)

I'll let you know if it works.
 
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