I saw an interesting bike for sale that I may well take a pint on. Before I do that I need to get some things straight.
It’s a Shimano 2x9 set up. I’ve been using Rohloff for so long I have no clue about the potential options with 2x9.

It’s I think 22/36 at the front 11-34 at the back.

1) What’s the largest 9 speed casssette generally available - looks like 34t - am I missing something. For example I saw a Box Prime cassette that goes to 50t but looks like it needs specific derailleurs etc.

2) Will a 10or11 speed cassette go on the freeing body?

3) Is SRAM 9 speed compatible with Shimano 9 speed?

4) Is the lowest gear here 22x34 low for a large diameter tyre eg. 26 fat or 29+

I don’t really want to get into spending tons of cash but this bike would definitely need the crawliest crawling gear I can muster.
I’d be willing to swap out the STI shifter for friction thumbies if that’ll expand my horizons.
Thanks

I've fitted 9 speed 11-36 on my Fargo, originally deore, might be alivio now. Decent quality chromed sprockets all the same. For similar money you can get 11-42 from Microshift.

https://www.decathlon.co.uk/p/cassette- ... R-p-202614

Can't vouch it'll work with a 2x though. The 11-36 is ok on a three by.

i have changed both my bikes back to 9 speed. from 1 x 12
largest sprocket is a 36 tooth. 22 front 36 back feels better to me than 30 x 51 on a 12 speed set up.
12 speed stuff feels like it is gonna break all the time.

a 8/9/10 speed cassette should fit on a hg freehub body. i asked surly about this before converting back to 9 speed.

if i can femember, sram 9 speed is 2.1 actuation, so should work with shimano 9 speed shifter.......i think.

3) Is SRAM 9 speed compatible with Shimano 9 speed?

The cassette spacing is the same but I'm pretty sure the mechs and shifters aren't cross-compatible between brands. Could be wrong though.

http://blog.artscyclery.com/science-beh ... atibility/ - useful info here, top marks to Art's Cyclery.

I have an 11-40 Sunrace cassette (1x9) on my spare/loaner fat bike. I dunno if it'd run okay with a 2x, 9speed rear mech but I am curious to try it on my bikepacking hardtail 29er (which is 2x9). FWIW the aforementioned bikepacking bike is currently running a 22/36 chainset and 11-34 cassette and I find it fine for it's intended task.

jameso wrote: ↑Sun Nov 29, 2020 8:31 pm

3) Is SRAM 9 speed compatible with Shimano 9 speed?

The cassette spacing is the same but I'm pretty sure the mechs and shifters aren't cross-compatible between brands. Could be wrong though.

http://blog.artscyclery.com/science-beh ... atibility/ - useful info here, top marks to Art's Cyclery.

Good read. Thanks.
What about the splines on the casettes? I think I remember 20years ago a SRAM cassette would go on a Shimano free hub body. Is that (still) the case?

Yes, fitting and spacing was the same until SRAM XD 1x11 and Shimano 12s microspline.

The good ol' days..

jameso wrote: ↑Sun Nov 29, 2020 8:56 pm Yes, fitting and spacing was the same until SRAM XD 1x11 and Shimano 12s microspline.

The good ol' days..

Yep.
It does make me very glad to run Rohloff

Another 9spd sun race sprok user here - 11-40. Works fine with an old type non shadow 9speed rear mech. If you use such a wide range cassette with a 2x up front you may run into capacity problems with the mech but may be a case of not using certain combos.

lune ranger wrote: ↑Sun Nov 29, 2020 9:03 pm

jameso wrote: ↑Sun Nov 29, 2020 8:56 pm Yes, fitting and spacing was the same until SRAM XD 1x11 and Shimano 12s microspline.

The good ol' days..

Yep.
It does make me very glad to run Rohloff

I'm sticking with my rohloff. I've moved over to oval chain rings, now, double Chainring at front to select on road /off road gear ranges. Ideally it would have a 16T+15T double sprocket at the rear instead, to do faster shifting... Also lighter & less complicated.

Have a look at box components. Just got the box 2 for the Hunt. Maybe if I like it I'll switch that to the fatty and get swish box 1 for the mtb.

ledburner wrote: ↑Mon Nov 30, 2020 12:51 am

lune ranger wrote: ↑Sun Nov 29, 2020 9:03 pm

jameso wrote: ↑Sun Nov 29, 2020 8:56 pm Yes, fitting and spacing was the same until SRAM XD 1x11 and Shimano 12s microspline.

The good ol' days..

Yep.
It does make me very glad to run Rohloff

I'm sticking with my rohloff. I've moved over to oval chain rings, now, double Chainring at front to select on road /off road gear ranges. Ideally it would have a 16T+15T double sprocket at the rear instead, to do faster shifting... Also lighter & less complicated.

Do you use sliding drop outs or a chain tensioner? Id love a Rohloff, but I use ovals.

Original Chain tensioner circa 1999 on a cube 29er frame. Hub #001351 so waiting for it to bed in! (chain) Tensioner has new spring kit.

I ran 11-36 and 11-40 sunrace on a 1x9 commuter for year or so using a long cage XT mech. Worked but the 40 didn’t shift as well as I’d hoped.

Good simple budget options though

ledburner wrote: ↑Wed Dec 02, 2020 2:19 am Original Chain tensioner circa 1999 on a cube 29er frame. Hub #001351 so waiting for it to bed in! Tension has new spring kit.

Nice old Rohloff. My oldest is #002775.

It was the original cc type quick release converted to disk 3yrs ago and free overhaul in the 'mother land' - internal springs& seals update. Not bad after 15+ years. Original shifter, new rubber from a gripshifter is more comfortable. I just need heart, legs & lung upgrading., it was relaced on a 29er rom.
ALL'S good. It was, also stolen an neglected. & recovered 10 years later.. . A excellent of top class cycle engineering..

Snap
All except mine had the CC -DB conversion in 2007 and is mounted in it’s 3rd rim and 4th frame.
Wonder how much of this 2x9 will last that long?

SRAM and Shimano 9 spd aren't compatible. 9, 10, 11 spd cassettes will fit. If using friction shifters, take your pick, up to 11*50T.
EDIT - but probably need new mech for 36+