Update: Aged MTB - convert to 1 x 10speed?

[Proto]

Declaration: I know nothing about mountain bikes!

My aged Whyte 905 MTB needs a bit of drivetrain TLC - rings, cassette and chain all need replacing.

Current setup is Sram X9 10 speed shifters and mechs, 39/26 x 11-34. X9 cranks (will accept a direct mount single ring)

I’m considering going single front ring and a wide range cassette. Anyone know the biggest cog the rear mech would cope with? Pretty sure the rear mech is medium cage, and with the current setup has a capacity of 38t. So, does that imply it would cope with 11-42 or even 11-45, or will the cage clout the bigger cogs?

For those running single rings up front, what’s considered sensible gearing for general XC/trail hacking. Deffo no racing innvolved. 🙀

 

[Jody]

Before throwing money at a wide range cassette, try your current set up with a single ring. I've just built up a 26" XC bike and although I bought a wide range cassette, I found the 11-36 I already had coupled with a 36 up front to be ample for all but the very steepest stuff around here.

The wide range was an 11-46 but would need an extender.

Anything over 25ish MPH and it will spin out.

 

[Ming the Merciless]

Sticking with current ring setup will be far cheaper. Any reason you don’t like the double up front?

 

[si_c]

If it's helpful, I recently (last year) converted my 2007 Trek MTB from a 3x9 to a 1x10 (with 32 front, 11-46 rear) setup. I ended up replacing the rear derailleur though as the one that was fitted had had a hard life and was pretty scuffed and I replaced it with a Deore long cage, one issue I had was that I did need to get a sunrace hangar extender to drop the derailleur down a bit as it was rubbing when in the 46t.

 

[Proto]

Sticking with current ring setup will be far cheaper. Any reason you don’t like the double up front?

My CX/gravel bike is single ring and I've got to enjoy the simplicity of a single ring. If the chain rings weren't looking tired I'd probably just replace the chain and cassette.

Since diving in, I've now discovered the BB is knackered, a horrible plastic sleeved SRAM PF30. Looking for better alternatives - Praxis, Wheels Manufacturing offer quality substitutes. There may be others. Grrrrrrr.

Interestingly the BB shell is 68mm wide, had expected 73mm.

 

[ColinJ]

My CX/gravel bike is single ring and I've got to enjoy the simplicity of a single ring.

I bought one recently and enjoy riding it. It only took me a few minute to get used to SRAM double-tap and only having one ring means that all gear shifts are done with just one lever, which I like.

I thought that the gaps between gears might bother me but I do a lot of riding on my singlespeed bike these days so I have got used to using a wide range of cadences. The difference 1x1 and 1x11 is MUCH bigger than the difference between 1x11 and 3x10!

 

[Ming the Merciless]

If it's helpful, I recently (last year) converted my 2007 Trek MTB from a 3x9 to a 1x10 (with 32 front, 11-46 rear) setup. I ended up replacing the rear derailleur though as the one that was fitted had had a hard life and was pretty scuffed and I replaced it with a Deore long cage, one issue I had was that I did need to get a sunrace hangar extender to drop the derailleur down a bit as it was rubbing when in the 46t.

Old rear derailleurs usually just need the pivots unbolting. Clean out the gunk. Grease the spring. Rebolt together. Good as new

 

[si_c]

Old rear derailleurs usually just need the pivots unbolting. Clean out the gunk. Grease the spring. Rebolt together. Good as new

Yeah, I'd done that a few times already, it was properly scuffed though - quite a lot of scratches and the side plates had been bent a few times then re-bent back into place and had become rather plastic. I could have got some spare parts and rebuilt it but it cost less to buy a new derailleur.

 

[Proto]

Update:

Strip down, diagnosed as needing new BB (PF30), new jockey wheels, new chain, as a minimum. Thought the rings and cassette would suffice until I decided what to do. So, new parts fitted. Checked rear mech alignment, minor tweak to correct. Rear mech, minor tweek, working fine. Front mech, not such good news.

I always have trouble with SRAM front mechs, painful to set up (Campag, by comparison, is easy, pretty well plug+play). Cable and stops all set up correctly, but whatever I do, to get the chain to climb from the small to big ring, it just climbs over the top and falls off the outside. If I restrict the movement to prevent this, then the chain won't go onto the big ring. Tried everything, failed.

And then disaster. The cage looked a bit wide, so I squeezed it and 'clunk', it broke! At the 'bridge' between the inner and outer. Whether this was causing my problems is unclear.

So, new X9/X7 front mech, or go single ring? Decision time!

Or new bike?

PS doing a bit of measuring I think the rear mech would handle a 42 cog, so would probably go 32 x 11/42 which gives me the same bottom gear as existing set up (if it wasn't broken! )

 

[fossyant]

Just get a used mech off ebay. Should be more front than rears as they usually get mashed. Not has a single issue with my X9 stuff, nor the kids X4/X5.

Jockey wheels, don't get SRAM. They don't last and are expensive. I bought BBB rollerboys and they are great, much better sealing. The issue with the SRAM jockeys is the end caps trap dirt between the caps and the bearing seals (they are quite large). The BBB just have a small end cap/spacer, leaving nothing round the bearing seals.

 

[FishFright]

Update:

Strip down, diagnosed as needing new BB (PF30), new jockey wheels, new chain, as a minimum. Thought the rings and cassette would suffice until I decided what to do. So, new parts fitted. Checked rear mech alignment, minor tweak to correct. Rear mech, minor tweek, working fine. Front mech, not such good news.

I always have trouble with SRAM front mechs, painful to set up (Campag, by comparison, is easy, pretty well plug+play). Cable and stops all set up correctly, but whatever I do, to get the chain to climb from the small to big ring, it just climbs over the top and falls off the outside. If I restrict the movement to prevent this, then the chain won't go onto the big ring. Tried everything, failed.

And then disaster. The cage looked a bit wide, so I squeezed it and 'clunk', it broke! At the 'bridge' between the inner and outer. Whether this was causing my problems is unclear.

So, new X9/X7 front mech, or go single ring? Decision time!

Or new bike?

PS doing a bit of measuring I think the rear mech would handle a 42 cog, so would probably go 32 x 11/42 which gives me the same bottom gear as existing set up (if it wasn't broken! )

Definitely time for a new bike.