1/2'' Pitch for a Simple Switch

August 17, 2010

1/2'' Pitch for a Simple Switch

So I have a Surly CrossCheck that is pretty cool. I don't ride it a ton but with the cooler months rolling in I honestly see myself crusing some friendly winter rides on the plush feel of steel. I also plan to use it as my commuter to and from school on a daily basis because I like the mechanical advantage of a bicycle. I have ermm uh HAD a problem of trying to ride it as a SS monster-cross or big, ugly cross bike for mountain bike trails AND as a cushy tired road fixed gear. The solution is to run a different size track cog and freewheel. The difference in the gear didn't give me as much change as I wanted. I want to roll with either a tame mountain bike ride OR a tame road bike group ride.The track cog is a 17t and the freewheel is a 21t. The chain needs to be two different lengths because I don't have enough dropout to accomodate a 4t difference. The fix is so simple and only includes one chain. I was wracking my brain as I drove down I-40 on my way to work one morning and it hit me. Everyone with a computer should be familiar with the DingleCog and how cool of an idea it is. Well what about the DingleRingle? (trademark is NOT pending) While I understand that Surly promotes this already I had never thought of applying the idea to the two sides of my flip flop wheel and have a super easy 39x21 for monster-cross-coast-ability and a 44x17 fixed gear for street-shred-brah-ability. I already had a pretty bland 44t chainwheel that was compatible with my Dura-Ace 9speed stuff. I had the double chainring bolts. It was time to get tricky. Fast-forward 24 hours until I had worked, slept, gathered my bits from my apartment, and returned to the shop. I slapped it all together and it works. So what does 1/2'' pitch have to do with anything? Well each chain pin is exactly 1/2'' apart, as is a tooth on a cog. So when you take 4t out of a ring, you should be able to add those 4t up front and make your chain in the NEIGHBORHOOD of the same position. Mine has a slight difference because I change the rear by 4t but the front by 5t. Now I have that super easy gear that allows me to climb all the hills at Shelby Forest and I have that hammr fixie set up for hitting 28mph when the group ride points downhill and all the guys dive bomb for free speed.