Due to a condition which prevents me from pushing hard on pedals, but which allows me to pedal at a high cadence, I wanted to lower my gearing.
To actieve this, I swapped my chainring from the standard 50T to a 40T. Furthermore, I did the 5 speed conversion by following guides from other posts on this subreddit (so a big thank you!).
I went for 11-13-15-17-19 from a new Shimano 105 cassette I had laying around.
For the shifter, I opted for the Sram GX as others have shown this to be a proven sollution. I set it up so that I use the 5 lowest gears of the shifter to avoid the cable being pulled out of its retaining bolt due to "overshifting".
Chain is a KMC X11EL, degreased and waxed as I prefer the cleanliness of a waxed chain.
As shift cable outer, I used the front outer from a H-type (my bike is an M-type), as I believe the extra 5cm gives a cleaner cable path.
All in all, it was a 2.5 hour job for me, an it was pretty straight-forward due to good how-to´s online. Just finished my first ride, and the changes suit me very well.
by janvda
2 Comments
Is that condition knee related?
If you are using a 40T chainring, the seat tube chain guide can probably be lowered 7mm by removal and resetting the adhered base of the guide. However, the chain guide part is available from Brompton for about $10 USD, if the removal process causes damage to the guide.