Help diagnose play in chainset/BB

Discuss light weight issues concerning road bikes & parts.
Post Reply
iamalex
Posts: 226
Joined: Sun Oct 30, 2011 5:25 pm
Location: London, UK

by iamalex

Any advice gratefully received...

If I hold the end of the cranks arms I can push and pull them and there is sideways movement of around 2mm. The movement is even, I can pull on one arm and the other will move. It is not flex in the arms. The chainset seems to pivot slightly through the BB. It creaks and I can make it creak by doing just this by hand in the workstand.


- Focus Izalco Max Disc - 18 months old
- Chris King PF30 30mm - installed from new. 4 season UK use. maybe 15000km
- Rotor InPower 3D+ 30mm axle - 3.5 years old.

- To properly isolate this creak I went through all the usual suspects cleaning, greasing or replacing for wear; through axles, chainring bolts, chainring/spider interface, saddle rails, saddle clamp mechanism, seat clamp, pedals, pedal threads, rear freehub replaced and other bearings checked, cassette replaced, chain replaced, cleats checked, shoes checked.
- I stripped and cleaned chainset. Pulled and refit BB.
- There is no lateral play through the BB. Preload nut tightened correctly. Overtightening does not solve the problem.
- Bearings run turn smoothly in BB, no grinding.
- If I assemble the chainset arms+axle outside of the bike there doesn’t appear to be any play in the axle/arm interface.
- There is a slight bit of wear to the anodising on the chainset axle but doesn’t look structural. Doesn’t feel worn when running a finger over.

Next steps:
- Measure chainset axle for wear.
- Replace Chris King plastic bearing spindle sleeves - maybe the plastic has worn/ovalised.

Any thing else before going nuclear and replacing the BB and (hopefully not) the power meter?

by Weenie


User avatar
pdlpsher1
Posts: 2419
Joined: Thu Jul 19, 2012 6:09 pm
Location: CO

by pdlpsher1

It sounds like the spindle sleeves are worn. This could be caused by too little preload set which causes the spindle to rock in the BB.


Sent from my iPhone using Tapatalk

iamalex
Posts: 226
Joined: Sun Oct 30, 2011 5:25 pm
Location: London, UK

by iamalex

I went ahead and ordered the replacement sleeves for now. I’ve been careful with the preload so I’ll be disappointed if that was the root cause. Fingers crossed.

Post Reply
  • Similar Topics
    Replies
    Views
    Last post