Singlespeed & Fixed Gear - chainring sizes

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.




View Full Version : chainring sizes


tadhgnealon
04-15-12, 03:04 PM
i recently got a create frame and when i put a 46 tooth chainring on it catches the chainstay ( i think thats what its called). I checked the chainring to see if it was bent but i don't think it is and the bottom bracket is crooked either. Is the only way to fix this to get a smaller chainring.

thanks


Scrodzilla
04-15-12, 03:27 PM
Cool story.

You could be using a BB with the wrong length spindle for your crankset.

gigantor
04-15-12, 03:31 PM
i recently got a create frame and when i put a 46 tooth chainring on it catches the chainstay ( i think thats what its called). I checked the chainring to see if it was bent but i don't think it is and the bottom bracket is crooked either. Is the only way to fix this to get a smaller chainring.

thanks

Just curious, but how come you didn't go to a bike shop and ask them to do this for you, or ask them what BB they would recommend using with this frame?

I think it would have ended up being cheaper for you in the long run.


hamfoh
04-15-12, 03:37 PM
tell us your parts

Santaria
04-15-12, 04:01 PM
http://i.chzbgr.com/completestore/12/4/15/oUXtfwm2_kanVKOYo9c-dQ2.jpg

gigantor
04-15-12, 04:12 PM
Hahaha

Germanicus
04-18-12, 12:26 AM
I had the same problem on my SS build up but mine was an even noobier mistake. I bought a an S300 courier track crank to use on a rigid MTB frame. BAM right into the chain stays before it was half screwed in. Don't know why it didn't occur to me before I bought the crank. Still trying to sell that crank.

10 things the noob (me) learned:
1. Road and track cranks don't usually work on a mountain bikes for this reason.
2. Cranks with attached spindles need a perfect fit because you can't swap out for a shorter or longer spindle.
3. Different bikes have different chain stay curve angles and different chainrings will hit it at different places.
4. Mtn bike cranks have a wider q factor than road bikes to allow clearance of the wider chain stays
5. It is possible to mount the chainring on the inside or outside of the crank arms depending on the model to adjust chain line and chain stay clearance.
6. If your frame is made of steel and the chainring just barely touches, you can dent your chain stay with a hammer to make it fit. (or so Ive been told.)
7. If you have to swap out the crank or chain ring remember to get a smaller cog and/or shorter lever arms to compensate for the adjusted Gain ratio.
8. Better to ask dumb questions at the bike shop before buying the parts online at the discount vendor that doesn't take returns.
9. It might be better to have the guys at the bike shop do this particular job for you so they can play around with different size chainrings and cogs until they find a combo that works right.
10. Don't get too attached to any particular component until after you find out if it even fits on your bike.

Good luck.