Bike pic just for fun, not the build in question.
I have an XTR RD-M960 long cage rear derailer and sunrace m96 friction thumbies. I want to shift a wide range cassette with this setup. I know the sunrace thumbies will pull a modern deore m5120 1x derailer through the 11-42 10speed cassette. Will the XTR derailer handle it?
I don’t mind if it’s 8,9 or 10 speed, I’m after the 11-42 range though. Cassettes are available to me in that range in all 3 speeds. Has anyone done this already, what were the results? Do I need a Road link thingy? Or will it be pure garbage no matter what I do?
I can’t afford to mess around with it to much to discover myself, so if I do it I need to get it working pretty well first try lol
Thanks!
by Grouchy-Salary3124
6 Comments
You’re still basically limited to the max cog capacity of the derailleur.
Can’t answer the question I’m afraid.
You know what year your frame is? Mines identical and I can’t figure it out. Love the build
Just run a goat link
Wolftooth road link
It’s likely not going to work without a road link, but if you have the derailleur and the cassette you might as well try it. The one of the best things about friction shifting, setting up derailleurs is super quick.
Nice question! Welcome to the fun of combining random shifting parts into one functioning system – a great hobby of mine haha
As far as I know you could be lucky with the derailleur to shift 11/42 even without a derailleur hanger extender if you adjust the B-Screw all the way in. With the long cage version you have the best chance of success. 3 factors to look at: cable pull, total capacity, biggest mechanically fitting cog.
At first you have to look at cable pull: How many gears you want to shift, depends on the shifter and its pull ratio. Keep in mind that your RD is a „rapid rise“ which means that the actuation of the RD is the other way around! A normal shifter that shifts „down“ when pulling on the cable, will downshift if coupled to a rapid rise RD! Regarding the pull ratio itself you are good to shift 8/9 or 10S – it is the same with your RD, even though the actuation is „upside down“. If your shifter pulls the deore 10S it will also pull your XTR Rapid Rise on a 10S cassette 🙂
2nd factor: total capacity:
The RD doesn’t mind if your shifting at the crank or at the cassette – what matters is its overall capacity (difference in teeth between biggest chainring in front and smallest in the rear). This value defines if the cage is able to tension the chain enough to be functional in all gear combinations. It differs between different RD types and cage lengths.
Your RD in SGS version (long cage) has a capacity of 43T, so theoretically you can shift a one by with 11T smallest cog + 43T = 54T -> 11/54T cassette. That’s more than enough! Chain will be tensioned in all gears.
3rd factor: biggest mechanically possible cog on the cassette without collision to the upper RD pulley wheel:
As your capacity is okay, I would give it try to mount the RD without hanger extender. Adjust B-Screw all the way in so that the upper pulley moves furthest away from the cogs. If it clears the 42T by about 5-8mm – you’re good to go!
Also look at this link, it’s a great resource and probably easier to understand as the novel I have just written here:
https://mattias.bike/2022/dead-simple-one-by-conversions/