fitting a 42t expander ring. whats needed

You just remove your 15 or 16 keep your smallest so you don't lose your top speed gear. Depends what rear mech you are running but most medium cage should work fine, I've only had one xo that didn't. You will just have to screw in the main adjustment screw a but more or use the longer one that should come with the expander sprocket.

You can get a 10 speed cassette that goes from 42 to 11 for about the same money as an expander. I had to fit a rad cage to my mega to get it to shift correctly with a 42 tooth one up expander.

No mate you don't need to get a new small cig you just keep the smallest one and remove the second smallest. You are in effect replacing one gear eg the 15 with another the 42.

Fair point above if anybody is buying a new cassette to run with a new expander cog I would just buy something like a praxis or a sunrace wide range cassette 10 or 11 to 42. The set up and shifting is better and can be had for 60£ all in so much better than a decent cassette and expander. I've had several different configurations and brands of expander and the sunrace wide range cassette I've just started running shifts much better than all of them. It's on a par with the xt 11 speed for smoothness.

running an xt cass and just read id need to fit an xlong b tension screw aswell. can you buy these on there own.

I might have a 16t sprocket for an XT cassette in the garage (makes the jump up and down the gears not so noticeable) and a b tension screw in my spares box.

You can have em for a few quid if your interested?

I just took the little plastic washer off the B screw - that gave me the range I needed.

Same as what pezo said worked a testy one small tip
Med cage works better than a long cage

Did you swap front rings out for a narrow wide paul with the 40t or use original big ring on already. I could use ring on now as a 36t at front but I notice a lot go 32 for climbing rather than top end speed

If you used the granny ring before than I wouldn't want to be left with a 36 up front if you are going 42 then 32 chainring should be fine but for the most steepest winch ups were you may be quicker walking. If you go 40 at the back I would Try a 30t. Unless of course you are a mountain goat then rock on with 36 and 40t.

Seriously though I wouldn't worry too much about top end speed, I've never heard anybody complaining that they can't pedal fast enough downhill, whereas the realisation that you are already in the highest gear when you are struggling with a gradient is not good.

i had a 36 on the mega i built with an 11-36 rear cass. was hard climbing the steepest stuff tbh. ill probs go as sugested 11-42 rear with a 30/32 front nw.


i thought you were a mountain goat paul but then realised its just a tash and beard. pmsl.

what you saying?

I'm quite intrigued by this 1x10, 11x42 cassette.