Thinking of going 1×11 on my 29er
Any advice?
Need new bottom bracket and planning whole new crankset etc
Gear ratios?
Doing relentless 24 so thinking there may be quite a bit of climbing…..

It’s great. Avoid Shimano cassettes. Use existing cranks if you want to save cash. XT mech/shifter and SRAM GX cassette seems best value setup to me (needs XD freehub)

Don’t think I have xd freehub

Buy the xd. Freehub if you can most hubs that are not shimano do it, full gx here great drivetrain. Ratio wise divide front by back for the ratio 32x 10-42 is very close to 26/38 double on 11-36

Just bought the new Shimano SLX (M7000) and very happy with it.

Went XT last year, been very happy with it since. But I’m on a 26er so ratio advice from me is worthless.

Avoid Shimano cassettes.

On the contrary, there are some very good reasons why a Shimano 11 speed cassette is a good idea. I’ve read way too many reports of the SRAM XD freehubs shearing and snapping due to over-tightening, making replacement of an already pretty expensive cassette eye-watering. For the sake of a hundred and fifty grammes and one extra gear tooth at the top end, you’ve an existing standard and cassettes that are reasonably affordable – although SRAM also do an 11 speed cassette to fit a standard freehub now.

My 29er runs 11-42 at the back and a Hope 30T chainring. I’m also using previous generation XT cranks, so the chainring is slightly offset so the chainring tabs on the crank don’t interfere with the chain.

If there’s a lot of steep stuff then the 11-46 cassette might be a better bet, plus you could compensate with a 32T chainring and still have a reasonably wide gear range.

Shimano cassette, mech and shifter with a Sram chain avoids all possible problems apart from a marginally smaller range. Bits are cheaper, cassettes aren’t heinously expensive and they just work.

For the sake of a hundred and fifty grammes and one extra gear tooth at the top end,

That one tooth is a big one,
32-10 gives me a higher gear than 34-11, it’s one of the good things about it. However fitting correctly is always reccomended, if your a ham fisted mechanic seek professional assistance 😉 the XH cassettes have been a regular sight here for a few years now and I think I’ve seen one gone bad. MMV obviously.
As for eye watering take a look at GX comparable (yes a bit more) than XT bigger range and lighter.

I run XTR / XT mix with XTR shifter & Mech with XT 32t cranks and 11-42, plenty of range for me and shifting is flawless

I’m running an XT 11-42 cassette with an On-One 45 cog (cos I’m a wuss) and a 32 tooth Superstar oval front. Works for me.

PJM1974 – Member

On the contrary, there are some very good reasons why a Shimano 11 speed cassette is a good idea. I’ve read way too many reports of the SRAM XD freehubs shearing and snapping due to over-tightening, making replacement of an already pretty expensive cassette eye-watering. For the sake of a hundred and fifty grammes and one extra gear tooth at the top end

You can mess up any part if you install it wrongly. Properly greased and torqued XD cassettes are problem free.

Weight benefits are significant, but the extra 10% range at the bottom makes a real difference. Unless you go for the XT11-46, which is an absolute boat anchor of a cassette

Plus XD doesn’t leave you with a scored freehub, and the hubs themselves are lighter.

I have an 11 speed Nukeproof Mega 29er. It has a SRAM 10-42 cassette. I swapped its 32t chainring for a 28t chainring.

With a 28t chainring its lowest gear is about equal to a 22:30 ratio on a 26er. That’s not quite as low as most 9 speed/triple granny gears which would be typically 22:32, but it’s close. Top gear is roughly equivalent to 44:14 (big ring/7th sprocket) on a 26er with a 9 speed triple, or top gear with a 34t chainring on a 26er that has a double chainset.

I find I use the complete cassette range. Another gear at the top might be nice but not nice enough that I’m willing to sacrifice my spinny granny gear. 🙂

(All calculations are done the lazy way, assuming that each wheel size is as stated, rather than actual wheel + tyre sizes.)

I think that sub 30t chainrings will require cranks with direct mount chainrings.

If you want to go oval then the smallest you can fit to a set of 104 bcd cranks is 32T unless you go for a granny tab mount ring which seem to be 26 or 28 so far too small unless you have an expensive 9T cassette (E13). If sticking with round then you can get down to 30T.

I have opted for an 11-42T sunrace and 34T oval on my 26″ hard tail and have just got an 11-46T sunrace for my 650b full susser and pondering on a 32 or 34T oval. I think I will be going with 34T which is a sod as I stocked up on 32T ovals in the superstar sale. Part of me wishes I had just got a GX 10-42T cassette as I have a spare XD freehub for my hope hubs but was worried I would want an oval ring <32T.

Currently running 42/28 double chainring and 10/36 cassette on a Planet X Dirty Harry 29er

Ordered the shimano xt kit 32t and 11/42 .
Probably will miss the 42 on the downhill road and fire road stuff we do but reckon it should be good for majority of stuff.

Hi Chrisl , been a few years since you swearing on night rides in the pentlands!

I’m running shimano 1×11. On my
Plus sized.

11/42 and 32 chainring. I’ve not struggled to climb anything, I love the feel and lost nothing on the trails. Flat
Out downhill road blasts I spin out… But who cares.

one thing I am pondering for the 11-46 cassette is whether to go GS or SGS RD. I have both sat here and went GS for 11-42 on my 26″ hard tail but on the 650b I am thinking of going SGS due to the dinner plate cassette.

Shimano say GS is only good up to 42T

http://cycle.shimano-eu.com/content/seh-bike/en/home/components1/mountain/deore-xt-8000/rd-m8000-gs.html

Scratch that. They don’t even list a longer cage mech for XT M8000. The compatibility chart suggests it’s GS for everything 1x

I thought the GS was a 35T capacity but they say 39 on that shimano page. 46-11 = 35T hence why I thought it was risky being right on the limit but the SGS looks like 47T so GS it is.

backinireland – Member
Hi Chrisl , been a few years since you swearing on night rides in the pentlands!

Graeme! Good to hear you’re still MTBing. 🙂 It’s been quite a few years since I last went on a night ride, with or without swearing but I still occasionally get into the Pentlands.

It’s all very personal but I use 30t ring and shimano 11-40 cassette on my 29er epic

As someone who was hesitant to ditch my much loved granny ring, I’m now 1×11 and have a 32t up front, but an e-thirteen 9-44 on the back. I find it gives me the range I need. Some climbs are still a struggle, but I cope and the 9t makes a noticeable difference to my mates 10/11t when spinning

Same as above. Had 22-32-4w triple with 11-32 cassette.

Now got Sram Gx1, 32 ring and 10-42 XD cassette.

Very happy. Might try 30t chainring for big hill days. No issues at top end, 25+mphon on the road is fast enough for me.

Seriously considering doing 1x on my road/commuter bike.

Also – remember to consider wheels size. Its like your “final drive” ratio.

The jump from 27.5 to 29 is roughly like a 2t increase in chainring I think.