I just wanted to have a simpler bike, and I've been considering removing the granny and outer chainrings from my crankset for a while, but I just did it a few weeks ago. What has been preventing me for doing it earlier was the fear of not having enough gear range for XC, but I just realized it would be OK. I also went through this post which gives plenty of useful information.
Here's a picture showing the whole stuff:
Let's talk about gears.
My crankset is now a single 32 teeth chainring. I have an 11-32 cassette, so the math is easy, I'm ranging from 1 to almost 3 gear ratio. With a regular 22-32-44 crankset and the same cassette, it was ranging from 0.67 to 4 gear ratio. These are obviously not the same ranges but:
1. I basically never use the last two gears at the top end
2. With a bike I enjoy more, I would ride better, and probably not need the last two gears at the bottom end :)
I didn't have to shorten the chain, just have a look a how the rear derailleur is positionned at highest and lowest gears:
Based on what I've read on various posts, a good chain tension is important to prevent chain jumps (not sure what a good chain tension should be, though).I transformed my XTR crankset into a single speed one by removing the 22 teeth and 44 teeth chainrings.
Biggest issue with 1x9 setups is chain jumps.
I replaced the outer chainring with a BBG Superlight chainguide. I'm using no chainguide on the inner side so far, but I took two actions to prevent the chain from jumping on the inside:
1. I removed the spacer that was installed on the right side of the bottom bracket (this was used to replace an eventual E-type front derailleur) and moved it to the left side. This has the effect of moving the crankset a few millimeters on the left. Thus, the chainline is better aligned and the chain would jump inside less frequently (jumps on the outside are prevented by the chainguide I installed on the crankset).
2. I replaced the regular XTR 32 teeth chainring with a non-ramped, non-pinned Blackspire Mono Veloce chainring. It is said this would have a positive effect on the chain stability, I rode it a couple of times and I can tell it's true.
I considered installing an N-Gear Jump Stop but it wouldn't fit on my frame.
Here is some pictures of the chainguide I installed:
I found it kind of hard to get all those single-speed components (especially if you don't live in the US).
Here are the options available to you if you want a single-speed 32 teeth chainring (based on what I read on various posts):
- Salsa chainring
- e-thirteen Guide-Ring (G-Ring) (one of the lightest)
- Blackspire Mono Veloce chainring
- Race Face DH chainring (heavier than the other options)
- Boone titanium chainring (expensive, may take months to get one...)
- Salsa Ring Dinger Guard
- BBG (the lightest one!)
- Race Face Lightweight Bash may do the work
I rode this setup without a single-speed chainring in the first place, and also because I haven't installed any chainguide on the inside, I had to be careful when going downhill - if I stayed on the lower gears the chain would have jumped out of the chainring in shaky grounds. Having installed a single-speed chainring just dramatically improved chain stability: no chain jumps at all, even when I'm going downhill on lower gears. Actually I think that the chainguide I installed on the outer side of the crankset may not be of any use.
Some additional pictures:
