40t t-rex or similar with SLX cassette

Searched forum but must be useless at searching…

can you use the range extender with the SLX cassette…?

ta

Pretty sure that’s a no I’m afraid.

ok ta…

new cassette and chain then…

You can use the one up components one with SLX if you get the hacksaw out

http://row-oneup-components.myshopify.com//pages/slx-hg-81-and-xg-1080-cassette-special-instructions

Probably better going with a new chain and cassette anyway, less chance of issues.

I’m going to give that hacksaw method a go tonight, will report back…

Just watch out for additional wear on your freehub body now that the cogs are separate.

I might be wrong but I’m pretty sure you can and that I did it on a mate’s bike a few months back. We just removed the 11T end sprocket.

You will need a hacksaw as mentioned already as it’s normally the 17t cog that you remove from the cassette which you can’t do on the SLX.

We just removed the 11T end sprocket.

So you added what you removed?

Exactly – removing the 11t is changing your ‘range extender’ into a ‘range lower-er’
You may as well get a smaller chainring instead.

Obviously if you’re already on the min chainring size, then I can see some logic to it.

We just removed the 11T end sprocket.

Hang on then…so it can just be as simple as removing the smallest sprocket and sticking a bigger one on the back.
In which case there’s no reason that couldn’t work on 9speed cassette is there?

So can anyone that understands gear inches answer a question for me – what would give the lowest/lower gear, adding a 42 tooth extender to a 32t chain ring, or keeping the current cassette (12-36) and dropping to a 30t chain ring?

cheers

you can’t do it with SLX by removing the 11T sprocket it’s a different thickness to the 17t. Ask me how I know and why I’m getting the hacksaw out. 🙄
I’m hoping I can tap the rivets back in to the two lower ratios once I’ve split the 17t off.

You don’t need gear inches. Simply work out the ratio.
32/42 = 0.762
30/36 = 0.83

30/42 = 0.71

Compare to an old triple of 22/34 = 0.64

Thanks both – given me a little more to ponder!

Just done, extremely simple and easy. Punched the rivets out, took out the 15&19T and a spacer, replaced with a 16T and snipped the rivets with pliers.

10 mins to do the whole job.

Works infe, on my second SLX cassette with an extender, just hacksaw it where it says on the oneup site and sorted, no abnormal wearr to freehub either yet

We just removed the 11T end sprocket.

don’t do that unless you’re only after lower gears, can’t remember how to do the maths but iirc an 11-36 cassette has pretty much the same range as the 13-42 cassette you created but costs a lot less.

A smaller chainring with a standard cassette will be cheaper and probably lighter.

<edit> bit of gear calculator[/url] abuse says
with 26″ wheels a 32×11-42 setup gets you a 76″-20″ gear range
32 ring with std 11-36 gets you the same range (76″-23″) as a 38 ring and your 13-42 cassette.
your cassette on a 32 ring gives you the 20″ low gear but a crap top end 65″, same as a 27* ring with an 11-36 cassette, or you could just stick with a 2×9 or 10 setup and still have a decent top end gear – if you can handle being slightly less enduro/on trend.

*yes I know you can’t get NW in that

Mate of mine has fitted one of these to his 9 speed cassette. Removed the smallest cog. Works well enough. He doesn’t care.

if it was an 11-34 and he added a 42 he would have the same range limitations with a big jump to the 42.
With an 11-32 he’d have a slightly better range (12t smallest) but a massive 10T jump to the oneup.

I’m not going to lecture anyone on what gears they should be running or bandwagon jumping but just be aware of spunking a load of cash on something that may not give you any actual benefits.