I’d noticed a bit of play in my cog and spacers on the singlespeed the other night so took it off this morning to investigate.

(can’t seem to get a link to embed a photo at the moment)
https://goo.gl/photos/cUxqFu8ShpRWG3Wa7

Looks like using a wide based cog hasn’t prevented the alu freehub from getting eaten!

Anyone seen this happen before? I thought the wide cogs were supposed to stop this…

a particularly cheesy freehub body?

I use wide footed cogs, and a standard 52″ gear inch. Even at 95Kg and honking up the Malverns I rarely put that much of a dent in the freehub on my Superstar or XTR hubs.

Whats the hub in yours?

Probably due to not being torqued up enough, especially looking at the grey fretting all over the contact zone. Shouldnt cause you any problems though. You could always adjust the chain line to use a fresh bit.

Stoner – looks like a hope.

cassette lockting torque wont have much bearing on the torque put through the splines really. The cg will always slip to the contact face on the first bit of grunty climbing.

Hope freehub possible the cheese factor.

Yup, it’s a Hope Pro2

…although having just had a look at my XTR hub, and passed a magnet over it, it’s faint magnetism might suggest its actually a steel alloy 😳

Yup, it’s a Hope Pro2

Yeah, don’t like to diss hope, but their alu freehubs are a bit like french cheese, I’ve made a right pigs ear of mine using it for ss.

cassette lockting torque wont have much bearing on the torque put through the splines really. The cg will always slip to the contact face on the first bit of grunty climbing.

I disagree. There looks to have been quite a bit of fretting going on the condition of the whole area the sprocket has been in contact with. Could be that the lock ring was bottomed out on the thread but not fully compressing the spacers and sprocket if the spacer stack was not quite big enough.

The interface area of a properly clamped sprocket that big should be absolutely fine to take the load. It’s less than the whole area a sram XD cassette uses and they are on the edge and don’t shear off the splines unless something is loose.

…although having just had a look at my XTR hub, and passed a magnet over it, it’s faint magnetism might suggest its actually a steel alloy

Sure it’s not titanium and the magnet is picking up the bearings inside?

for there to be any fretting there the lockring would have to actually be loose – there’s not enough tension in a freehub pawl spring to pull a cog back off the spline unless it’s floating free.

may well be a Ti alloy on the XTR – was that normal for M965? Cool 🙂

for there to be any fretting there the lockring would have to actually be loose – there’s not enough tension in a freehub pawl spring to pull a cog back off the spline unless it’s floating free.

You are thinking rotational fretting. What about radial and axial (as in wobble in the is case)? There is a tolerance to the fit over the splines that is pretty loose. Everytime that wheel rotates the tension in the chain will try and shift the sprocket around just a little bit and fret a little bit each time if it’s not clamped in place with sufficient force.

*cough* stoner *cough* http://singletrackworld.com/forum/topic/xtr-freehub-body-titanium

I missed this in the OP:

“I’d noticed a bit of play in my cog and spacers on the singlespeed the other night so took it off this morning to investigate.”

Does sound like either not torqued up or incorrect spacing.

The lock ring was nice and tight.

I think the play was mostly the cog shifting back and forward in the groove it had carved in the freehub.

Although there may also have been a fraction of a mm side to side play (it’s hard to say with the forward/backward play being there too). I’ve found a slightly wider spacer to replace one of the ones that was on there just in case.

andyl – Member
*cough* stoner *cough* http://singletrackworld.com/forum/topic/xtr-freehub-body-titanium

Well that’s it. Im officially old enough that I forget shit now.
Anyone got the phone No. for Dignitas? The red lamp in my hand is going off 😳

also, XTR freehubs are pretty tough then. Since Ive been riding almost entirely SS on these hubs for the last 7 yrs, and they look like this now:

i use the singlespeed specific hope offering

though mine is gold bling has stainless steel freehub thingy and more pickups on the ratchet. I think that just means it sounds like an angrier wasp than usual 😉

steel freehub pricey and heavy but should last

Stoner
Well that’s it. Im officially old enough that I forget shit now.

😆 Well I was going to say something similar but my equality training at the place I am contracting at these days pointed out that age jokes are not a laughing matter… 😀

Ti is generally quite good at resisting wear and has a high shear strength so freehub bodies are actually one place it is good. Except I would avoid using a Ti lock ring to a Ti freehub without a good anti-seize.

verses – Member
The lock ring was nice and tight.

I think the play was mostly the cog shifting back and forward in the groove it had carved in the freehub.

Although there may also have been a fraction of a mm side to side play (it’s hard to say with the forward/backward play being there too). I’ve found a slightly wider spacer to replace one of the ones that was on there just in case.

Does sound like even though the lock ring was tight it wasnt fully clamping the sprocket. Shouldn’t be any play at all. Add a thin shim like spacer somewhere in the stack and see how it feels.