Author Topic: SRAM MTH-506 R hub, query RE bearings & hubs  (Read 329 times)

SRAM MTH-506 R hub, query RE bearings & hubs
« on: April 08, 2021, 10:36:49 pm »
I've got a SRAM MTH-506 R(ear) hub which started to grind on my last ride. When I got back I noticed play on one side of the hub i.e. the drive side. Taking hubs apart is not one of my favourite tasks as I'm visualizing bearings escaping left, right and centre. Anyway this didn't happen but upon disassembly I noticed the drive side bearing grease was pretty cruddy whereas the other side was clean as a whistle. The drive side cone is done for and the cup doesn't look great but I'm pretty sure I can clean it up (though I'll probably replace the whole core). Now I can get a core (the bit that the cassette mounts onto and includes the bearing cup) but where my knowledge runs out is where do I get replacement ball bearings (and possibly cup if the very clean non-drive side is also a bit worn), ball bearings tbh are the priority right now. I've looked up SRAM service docs online and nothing tells me what I should be looking for. I'm also aware I'm going to have to get the Freehub Body Removal tool (11mm).

I'll soon be replacing these wheels and wanted to ask would I be better off getting hubs with cartridge bearings rather than the traditional cone & bearing setup. I imagine cartridge offers a lot of advantages.

Last question, I have a 1x12 speed setup so with my new wheels I'll be sticking with this. Which of the following gives me the best options Shimano freehub, XD drive or Microspline?

Re: SRAM MTH-506 R hub, query RE bearings & hubs
« Reply #1 on: April 09, 2021, 11:52:34 am »
Essentially I know I can get a core just need to source the bearings (no idea what size) and a cone (no idea where to get a SRAM replacement) and by the time I've bought these and the Freehub Body Removal tool I'd be close to what I'd have to pay for a new hub. I can rebuild the wheel myself so may just get a new hub as it's less hassle.

Tim Hall

  • Victoria is my queen
Re: SRAM MTH-506 R hub, query RE bearings & hubs
« Reply #2 on: April 09, 2021, 12:30:13 pm »
For the ball bearings I'd just take a sample along to my local bearing supplier, as found on industrial estates all over the country.  Halfords and other similar outlets sell loose balls in the bike spares section too.

SJSC in Bridgwater would be my first place to look for replacement cones, than maybe Spa Cycles.

My understanding is that cup and cone bearings, being a type of angular contact bearing, are better at resisting lateral forces than regular cartridge (deep groove) bearings. You'll get lateral forces on the bearings when you start going round corners.  I reckon cartridge bearings are easier for the wheel manufacturer to install and don't need/don't allow any adjustement by a user.
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)


  • Whimsy Rider
Re: SRAM MTH-506 R hub, query RE bearings & hubs
« Reply #3 on: April 09, 2021, 01:04:50 pm »
Cups are comparatively forgiving of minor imperfections, unlike cones.

Perhaps another manufacturer's cones are a close enough match to your SRAM

Ball bearings are trivial to find. Small 'grade numbers' (e.g. 25) are rounder and more evenly sized than large (e.g. 100) and prepackaged balls in bike shops are usually the worst.
Wheel meet again, don't know where, don't know when...

Re: SRAM MTH-506 R hub, query RE bearings & hubs
« Reply #4 on: April 10, 2021, 12:46:17 am »
Yea I guess the BBs are pretty standard but the cone is shot. They are a crappy low grade SRAM hub I inherited when I bought the bike, so I'll be treating myself to a new set of hubs. I'm embarrassed to admit I don't maintain and never have the hubs on my bikes :facepalm:  But now I'm building my own wheels that will change  ;D