Sunday, January 5, 2014
SRAM Automatix 2 Speed Hack
I loved the idea behind the design. Simplify the function and style of the bike by eliminating the shifters, brakes, and cables, while still allowing for a gear change.
After installing it on my Sports I noticed a problem right away. It shifted way too early, before you could get up to speed it would kick into high gear, robbing you of all momentum. Hill climbing was nearly impossible and it made the bike feel sluggish.
I went online to see if others had the same problem and found this article: http://mccraw.co.uk/sram-automatix-review/. Someone else had the same issue and was able to modify the timing and correct the problem. After reading the article I was interested in attempting to modify the hub but I was hesitant due to not fully comprehending the instructions and the fact that this was a brand new purchase, vs. some old junk I had laying around.
Once I got started it turned out to be pretty easy to do. The whole operation took about 30min.
I included some pictures of the disassembly and created a couple diagrams to help answer some of the questions that I had before attempting this modification.
This fix can be done with the hub still laced to the wheel. Just remove the wheel from the bike and start by removing the nuts on the non-drive/sprocket side of the hub.
So the goal is now to bend the spring to give a little more resistance against the weights so the the wheel has to be going faster to engage the higher gear. Only one weight has the spring on it. It is held together by a small clip labeled "3".
Cheers to Dave McCraw for pioneering this method and sharing it on his blog!