Geared help...

I was out on my MTB the other day and after a particularly gruesome attempt at a jump I found had no traction and was just spinning. I stopped and everything looked normal, but it was 'freewheeling' forward as well as back.

Turned over the bike and took off the rear wheel and then the cassette was catching properly and all seemed ok again.

Riding home after a long freewhweel down from wimbledon village I again had no forward purchase - pedalling wasn't driving anything. Stopped, upended the bike and jiggled it a bit till it engaged again (not after any specific bit of jiggling) and it was OK to get me home.

Any idea what the problem is and how to mend it (if that description of the problem makes sense)? I can't imagine it is anything good...

Cheers!

Sounds like the freewheel mechanism is bust, likely that the pawls aren't engaging when you pedal. I don't know how mechanically competent you are, but stripping and repairing modern hubs is not for the faint of heart.

new block

Freehub swap

http://bicycletutor.com/freehub-body/

Thankyou

I am mechanically incompetent and that is what i feared.

bloody balls.

aha! I have a freeby bike repair course coming up...now to check if they cover this.

[B]COURSE CONTENT INCLUDES: Level 2:[/B]

• Bearings, Hub, Bottom Bracket, Headset and pedals
  
• Wheel Truing, Straightening
  
• Stem and Handle Bars
  
• Cycle Care and Protection
  
  

Excellent - this may help!

It's pretty straightforward to replace the entire freehub, assuming you have a rear hub that is replaceable (and most road hubs are, assume MTB ones are the same).

You can service freehubs, rather than just replace them. There are some good instructions here:
http://www.icebike.org/Equipment/freehub.htm

Bear in mind that they're using these hubs in very cold conditions, you probably won't need the same special low-temp lubricants.