Expander cogs, do they work as well as a full cassette?

[ishaw]

I'm looking at potentially using an expander cog to increase the ratio on an 11sp cassette on a build. I've never used one before, they clearly do a job or they wouldn't exist.

Cassette in question is an SRAM 11-42, looking to go to 46.

Which cog would you recommend dropping to accommodate? Are there any issues to be aware of?

I'll be honest and say the expander cog is probably more of a vanity ring, I don't often find myself using the largest one and I've a green one which will match other green bits, so my concern is will I miss the cog that is dropped?

 

[Frankenorange]

I played around with expanders a bit and extenders for the rear mech. The latter work a treat and way better than winding the B screw all the way in. Have tried a couple of different expanders and they shifted very well.
I thought it best to delete the smallest cog and not monkey with cogs in the cassette. I have no experience of Sram cassettes, though. I use Shimano cassettes as i think there are way more tuning options, regarding individual cogs and clusters.
If the cog you are going to end up locking on to(say a 13t if you delete the 11t) is not suitable( some 2nd cogs dont have the right surface for a lockring to clamp on) then the same size will be easily available that can be used for locking up on.
I think i am right in saying that Shimano have 11t, 12t, 13t, 14t(junior cassette) and 16t ( junior again) as start cogs in 10 and 11 speeds.

 

[ishaw]

Thanks for the reply.

So having actually looked at what I have, turns out the green expander cog is a 42t. I have an xtr 11sp cassette which is 11-40, so I could slot the 42t on the back and have a nice ratio there. The decision on which cog to lose is the conundrum. As you've said, the simplest option would be to lose the 11t, but imagine it would potentially be better to lose one further up.

I've got a nice one up cage in the matching green to swap out for the original xt cage. I don't think I'll need to faff with a mech extender as I'm not creating a range the mech isn't designed to take, at least I don't think I am.

 

[clubby]

Two tooth difference not worth the bother IMO. With 1x you really use the whole cassette, especially the smaller cogs. Don’t think I’d want a missing gear down there. From what you’ve said before I don’t think low range is an issue. If it turns out to be, 11-46 XT cassettes are very good.

 

[ishaw]

I agree, the only benefit I'll be getting by adding a 42t cog is some green bling, which I'm not averse to. I have some larger expander cogs somewhere but not in green, so could increase from 42 on my SRAM cassette to 46 iirc.

 

[Mikey08]

The Garburuk expanders are the nicest I've seen. Pricey though

 

[jimo746]

I think cassette range expanders have kind of had their day, it'd be easier to swap out the cassette for a wider range one.

 

[yakboy]

I think cassette range expanders have kind of had their day, it'd be easier to swap out the cassette for a wider range one.

I agree, there is a vast choice of ratio's these days and some of the cheaper cassettes work really well

 

[novocaine]

I've got one hung in the garage along with a drop extender.
every time I change the chain and cassette (which obviously isn't every chain, honest) I think about it. still haven't done it though.