Swabes Does Science

I always bang on about not 'cross chaining' (riding in the big cog on both front and back or indeed the small cog front and back). Why?

1) It wears out your chain quicker

2) You may be surprised to hear its usually 'not supported' by Shimano / SRAM etc

3) It usually makes a horrible noise!!!

Well, here's the thing. You never need to do it - because you will have the same gearing (or as near as dammit) elsewhere! On an 11 speed Compact you have 22 gears right? Well yes - but some of them are the same - or so close as to make no difference - looks like its more like 18 at the most. Here's the Science bit:

http://www.gear-calculator.com/?GR=DERS&KB=34,50&RZ=11,12,13,14,15,17,19,21,23,25,28&UF=2150&TF=90&SL=2.6&UN=MPH

So, riding at a cadence of 90rpm on a 700c tyre with a Compact Chainset in both big rings means you are travelling at 12.9mph. Exactly the same speed as when you are in the small ring at the front and the 5th ring at the back - i.e. right in the centre of the block, nice and quiet - happy chain :-)

#YouKnowItMakesSense #Science