New Life for old XX1 or XO1 Cassettes

I’m a frugal bastard. Though I expect a high level of performance from my bike bits, I often have a hard time justifying the prices that come with premium hardware. I’m all about bang for the buck. Sometimes this means buying components a step or two down from top tier. Sometimes I’ll even buy used. The products I buy new will get ridden into the ground before they get replaced. Extracting as much value as possible from every purchase helps lessen my consumer guilt.

What to do when the largest ring of your expensive cassette gets worn out while the rest has life left?

So – I’ve got an XO1 cassette on my primary ride. The one-piece steel X-Dome cogset was in good shape, but the aluminum 42T big cog was worn out and skipping. Replacement price on the cassette is a hard to swallow msrp of $369USD. Throwing out the gorgeous steel monoblock because of one easily replaceable cog seems such a waste. What were you thinking SRAM? (I know, Capitalism).

The GXC Cog is available in black, red, green, orange and blue and in either 42 or 44t.

Enterprising small business to the rescue. Wolftooth is no stranger to big cassette cogs; they’ve been making range-extending cogs for a couple of years. Now they’ve also got a replacement big cog for your 11 speed XO1 or XX1 cassette.

That used to be all black so clearly Perry has gotten lots of use out of his cassette. Wolftooth tells us installation only takes 5 minutes. Instructions are here.

Thankfully, the SRAM big cog isn’t permanently affixed, and can be easily pried off. Wolftooth has a tutorial here on how to perform the transplant surgery, but it’s a simple procedure: pry off the old cog with a flat screwdriver, then tap the new one on with your trusty BFH (and perhaps a block of wood if you’re feeling kind). A few minutes of wrenching and I was back in business. The larger diameter cog required a shade more B tension screw, but apart from that it’s plug and play with your stock SRAM derailleur.

Installation was as described and shifting is as good as new.

How’s it work? Shifting up and down the cog is smooth, albeit slightly slower dropping off. The 36-44t jump is fairly big, but I appreciate the bailout gear. I’ve been on the cog for a couple months of wetcoast riding with nary a glitch. Chain retention whilst backpedalling is excellent on my setup. A bit of the anodizing has come off (as expected) but the wear appears to be largely cosmetic at this point. I don’t know how long the the steel cogs will ultimately last, but they’re still in decent shape, and I feel that the effective lifespan of the cassette could be at least doubled with the addition of this cog – at least for someone who spends a reasonable amount of time grinding out climbs in the granny. As such, this piece is a good bit of value, and the option to drop the basement gear a little is a nice bonus.

The cog is available in both the stock 42T count, and a larger 44T version which I have here. I run a 32T front ring, and I liked the idea of a bit of added range for tech climbing. Price is $89.95USD for both sizes.

Don’t throw away that cassette!