Have questions or want to discuss cycling? Join Now or Sign In to participate in the BikeRide community.

New: Take part in the June Giveaway for NAKTO Camel e-bike worth $739


Drive pin hole slightly large
#1
I have an american bottom bracket and a one piece crank. The drive pin and drive pin hole are not exactly the right size for each other so the crank has a little bit of play to it. Normally this isn't a big deal but this is on a fixed gear. When switching from pedaling forward to resisting motion you can feel the pedal slip just the slightest bit as the drive pin moves about 1 or 2 mm. Any ideas on how to stop this? Would a spot weld be good or should I come up with something a little less drastic?
  Reply
#2
Not sure a spot weld would work, as your cranks are likely steel and the chainring is probably aluminum. Sounds like that chainring may be meant for 3-pc cranks? I'd recommend finding a BMX style chainring that fits snug.
  Reply
#3
No other ideas? I ordered the parts together from a bike shop so I figured they would give me properly fitting parts. Hmm.
  Reply
#4
I would send a note to the bike shop explaining the problem and see if they have any suggestions.
  Reply
#5
I think this is actually not that uncommon. One piece cranks aren't typically used on fixed gears so the pin would normally only get pushed one direction.

I think you'd be able to force some metal into the gap to take out the play. Ideally you bend something over the end of the pin so when you tighten the chainring down it just fills the gap. Note that you need to be carefull not to put something too thick so that it forces the chainring out and bends it. Needs to be just the right size. Of course, check with the seller first to see if it was a defect or just a crank with low tolerances.
  Reply


Possibly Related Threads...

Forum Jump:

[-]
10 Latest Posts
Electric Bike Safety Tips
Today 03:56 AM
Hello!
Today 03:45 AM
Bike Computer /w No Minimum Circumferenc...
Today 03:40 AM
ZULIANI Oria 'helical' tubing 80s
Today 12:07 AM
Old Shimano cassette..how dismantle ?
Yesterday 11:16 PM
Rode my First Double Century in June
07-01-2022 10:50 AM
Need help identifying this frame.
06-29-2022 05:31 PM
NAKTO Giveaway June 2022
06-28-2022 03:52 AM
NAKTO GIVEAWAY
06-28-2022 12:16 AM
2022 road cycling season
06-27-2022 02:31 PM

[-]
Join BikeRide on Strava
Feel free to join if you are on Strava: www.strava.com/clubs/bikeridecom

[-]
Top 5 Posters This Month
no avatar 1. Jesper
24 posts
no avatar 2. Yevhen
8 posts
no avatar 3. ReapThaWhirlwind
8 posts
no avatar 4. Munich Transfers
7 posts
no avatar 5. aliccon
7 posts