My 10 year old 9speed XT cranks have some slack in the splined interface so need replacing. I’m on a 29er so would like lower gearing than for a 650b/26er, have a perfectly functioning 24mm Hope BB and remainaing 9sp drivetrain but would like to have the option to dabble in 1×10/11 if the mood takes me in the future.

As far as I can see this means I need:
– a 24mm spindle
– 2x spider but with the ability to take a 28t ring to maintain low gear, I suspect this requires a direct mount chainring.

Hope are out (spindle and cost), Shimano are out (no 1x ability for <32t), Race Face are out (spindle).

As far as I can tell Middleburn RS8 or SRAM GXP (and even then I can’t work out which take 28t rings) are the only ones to fit the bill.

All seems very (and unnecessarily) complicated. I though it would be a simple process, but it looks like it would be easier to replace my entire bike with a flying, fire breathing, rainbow shitting Unicorn than to sub in some cranks…..

Any other suggestions for normal trail use cranks that fit my (apparently unreasonable) desires?

Much obliged,

S

EDIT – Just realised that chainline may come into play. Where does the chainline sit for 1x compared to 2x (and is 2x on a 3 ring crank the same chainline as a dedicated 2 ring crank)? Does it even matter……

On the 28t front yeah it has to be direct mount, as far as I’ve been able to ascertain. Looks like GXP is your best bet.

SRAM with the Hope GXP adapter.
Why are you going all the way down to 28t? The top end loss must be massive at that.
The direct mount should sort out chainline but if not you can swap DS/NDS spacers to suit.

Thank you. Seems strange to be limited to SRAM though, I’d assumed there would be more options out there.

Long big hills up here in Scotland and very bad knees so want to keep the easiest equivalent gearing I can currently get on my 22×34 9sp set up. In terms of ring size I currently have 32×12 as (never used off road) top gear so 28×11 wouldn’t leave me that short.

If you’re not in a hurry there’s some new cranks coming out from various manufacturers that will fit your bill nicely. Nice cranks with a 24mm spindle and 28t capability should be here by June I’d expect.

Shimano are out (no 1x ability for <32t)

I’ve got a 30t on mine

I’ve got a 30t on mine

Is that a normal 104bcd ring or is it one of those special offset mount ones?

Ben – which cranks are those that are coming in June ?

Normal 104, race face ring on one, works components on the other

Sorry to hijack!
Which shimano crank is that on rocketdog? I have an old shimano xt crank and was thinking about putting a 30t on it, but had heard various rumours…
cheers
Jim

Normal 104, race face ring on one, works components on the other

Both of these are offset by a couple of mill to clear the crank tabs.

Normal 104, race face ring on one, works components on the other

Both of these are offset by a couple of mill to clear the crank tabs.[/quote]

Ah, thought it would have to be something like that. Cheers.

So SRAM GXP is really the only option for 28t? And even then it has to be the spendy ones?

EDIT – Does the removable spider on XO and X9 10sp cranks allow for the same chainring options as the dedicated 1x cranks?

1x systems are a compromise. To be perfectly honest, if you feel the need to go all the way down to a 28 then it’s probably not for you. Just stick with a 2x

I’m running a Deore crank(2x Variety) with a Superstar 30T Ring(which has the built in stand offs for chain clearance).
Moved 1 x BB spacer from DS to NDS and chainline is fine.

If you must run a 28t Chainring than Absolute Black do them to go on the Grannyring tabs(64BCD) not sure what thats going to do for your chainline though.

A 30t Chainring plus a decent sized cassette will get you up most things but still ends up getting a bit spinny when in the smallest ring at the rear.

1x systems are a compromise. To be perfectly honest, if you feel the need to go all the way down to a 28 then it’s probably not for you. Just stick with a 2x

Why is 1x a compromise? All of the gear ratios I currently have access to on my 22/32 11-34 9sp set-up are covered by a 28t 11-42 set up bar the 2 tallest “road only” gears. My bike (Banshee Phantom) was designed with 28-32t chainrings in mind too so I can’t imagine it would negatively affect the pedalling character (which my 22t granny definately does)

On a medical note, a few years ago I tore all of the ligaments around the base of my left thumb and damaged the tendons too. I now have very little “push” power with the thumb, which makes changing front gears painful and awkward and when I’m tired next to impossible. I then have to use my palm to push the shifter. Hence, for me, 1x looks like it could be a winner.

I’ve a Race Face Evolve 1x crankset with 30T chainring and a Hope BB on my Solaris. As for chainline: just use the spacers to get the BB shell to the right position, I need one 2.5mm.

From a 3x setup, I have lost about 1.5 ratios at either end (this is with the TRex 40T). By the time I’m spinning out I’m doing something like 37kph so might as well do a bit of freewheeling 🙂

Obviously this is a more expensive solution but how much can you get a SRAM 1×11 drivetrain for? With smaller wheels and less desire for such low gearing I get away with a standard Shimano 1×10 set-up but as you’re finding with the cranks and the need for a range extender cog, it gets a lot more complicated!

I used to use SRAM cranks with a Hope BB adapter which worked fine but occasionally was squeaky as the adapter rubbed the tophats when pedalling.

EDIT – Does the removable spider on XO and X9 10sp cranks allow for the same chainring options as the dedicated 1x cranks?

Yes, it does. X0, X01 and XX1 are the same cranks.

1x systems are a compromise.

I disagree, had it been a compromise I wouldn’t have changed.

I ran an Absolute Black 28T ring in the granny position of my Shimano cranks and all seemed fine. I used a 42T One Up range expander (with Rad cage) and put a bash guard on the outside (mainly for aesthetics, but it protects the ring too I guess). Here are a few pictures of the setup (in top and bottom gear).

The shifting worked just fine for the few months that I ran this setup, but I didn’t really see the point, so went back to a 2×10 setup.

Roverpig – Thanks for the insights, what made you change back?

Roverpig – Thanks for the insights, what made you change back?

28×42 isn’t quite as low as 22×36 and I’m a wuss 🙂

Actually I was starting to get some knee pain. It may have just been coincidence, but having a 9% higher bottom gear didn’t seem to be helping. I could have gone down to a 26T at the front (I think Absolute Black do one), but I was already spinning out on road sections.

Basically my front mech has never caused me any problems, so I couldn’t really see any advantages in getting rid of it. Even if the reduction in gear range is small, it’s still a reduction.

I also tend to find that I often want to make large changes quickly (e.g. when I hit a steep ramp). It’s easy to ride into a section on my 32T chainring then quickly drop to the 22T granny, but trying to drop a couple of gears quickly on the 1×10 setup (e.g. going from the 32 to the 42 sprocket in one go) sometimes jammed. I think that’s just a problem of trying to shift up 10 teeth under load at the back, compared with dropping down 10 teeth at the front.

Hmm, definitely something worth mulling over. I’m fine with my 22×34 gear but wanted easier shifting not harder!

To be fair it is easy most of the time. Even multiple shifts lower down the block worked fine. It was just trying to jump 10 teeth into the 42 sprocket under load that caused problems and of course, that’s crap technique anyway. It’s just crap technique that I’ve come to rely on 🙂

I’ve got a 30t on mine
Is that a normal 104bcd ring or is it one of those special offset mount ones?
Ben – which cranks are those that are coming in June ?

Can’t say sorry. But they do look pretty nice. I know of 2 options coming to market in the mid priced range.

Cheers all. It looks like the new SRAM GX lineup may be one way forward too. Although I imagine there will be something in there that will FUBAR my plans.

EDIT – yep, the 2×11 set up uses a different rear mech to the 1×11 which is different to the 2×10….groan………and there isn’t a 42t 10sp cassette option.

http://canfieldbrothers.com/components/am-dh_cranks

Those canfield ones do look good.

But just noticed that the longest they do is 170mm (although it probably isn’t an issue for most people, I have long legs and a 20+ year habit of using 175mm).

And they will undoubtedly cost a lot – 325 US$ for a 1x spiderless set up.

Oh Shimano, why won’t you up your game and do what people want rather than navel gazing and letting SRAM do you over…………

http://www.cranknuts.com/cranks/

£185 so more than XT but they fit what you’re asking for.
Shorter crank arms will do you good, you’ll forget about it in 5 mins and smash your pedals less often.