Thursday, October 08, 2009

don't SLAP ME

Here's a simple technical change I made to my cross bike that someone might find useful. My Shimano 105 front shift lever broke a couple races ago and I can't shift to my big chain ring. I figured this was an opportunity to test out the single chain ring idea. Many people run this on a cross bike to reduce the risk of chain drop. Much of this is due to less chain slack which reduces the opportunity for chain slap which reduces dropping a chain. I'll give this new setup a try the rest of the season and plan to upgrade to an "official" single chainring if all goes well.

I consulted the fellow with the most impressive toolbox at the team tent last race and he suggested remove links of the chain until your hanger is about 45 degrees to the flat chain. Here's a couple before and after photos.


BEFORE (about 135 degrees when in big ring in rear and small ring in front)




AFTER (about 45 degrees in same condition - much more tension on chain)



Remember, technique of bike handling plays a BIG part in dropped chains. It's important to set a bike down gently after a bike carry and getting ready to re-mount. Also important to pick up the rear wheel alittle if you run along side your bike instead of carrying it. I rode a 2 chain-ring setup for 3 years and rode in the small chainring most of the time. However, I really only had a couple dropped chains.

Cyclocross racing has alot to do with "avoidance of bad luck". Reducing the chance of a dropped chain that can take time to repair and that just means you getting passed by others.

Ride hard and ride smart!

1 comment:

Anonymous said...

This is important and I am sure not considered when going to a single ring setup. Good call for sharing.

Another way to arrive at the desired chain length is to note the note the position of the rear Derailleur cage in the big ring/big cog position prior to removing links and the big ring.

Note: Careful not to go too short on the chain or your options for larger cogs on the rear are limited.