MidTNBrad

This afternoon I removed the cassette and hub from my rear wheel for servicing. This is the first time I've done it and the wheel has around 8,500 miles on it.

I know the cassette will tend to bite into the cassette body so I'm not worried about that, but I'd like to know about the worn areas between the pawl springs. I'm surprised that they look like they've been digging into the ratchet notches on the interior of the hub. Are these marks something I should be worried about? Is this wear normal?

Andrew R Stewart 

Focus!

I suspect those silver "scrape marks" are from the ratchet teeth and grit. Likely the clearance between the tops of the ratchet teeth and the freehub's ratchet area's OD is very small and any grit in between will abrade the surface of the weaker material (and with all those cog marks that FH body sure is likely Al, not steel that the ratchet ring/teeth will be). Of course there might be a rear metal on metal contact but a FHB that rocks a bit on the axle, within the hubshell end, would close up any clearance too. Count the number of wear marks and the ratchet teeth. I'll bet they are the same.

A pawl might be hanging up and the remaining two pawls would try to twist the FHB off axis. Really worn bearings might provide enough slop too.

As long as the FHB performs well, doesn't have enough wear to cause functional issues than this is still an academic question. Was there any issues causing the take apart? Are all the pawls freely moving and theiur springs strong enough to work the pawls properly? Andy

MidTNBrad

Thanks for the reply. I'm cleaning the hub out because I'm trying to fix a creak. I'm getting a cross between a grind and a clicking noise when I'm in the small chainring and in the upper half of the cassette. I figured I'd clean out the hub, check the bearings and refresh the lube. I've tried other fixes in order of complexity.

To be clear, those marks go all the way around, not just on 1/3 of the body.

There was a lot of dirty grease in there but the pawls and springs were not frozen. All four bearings feel good. Maybe, as you mention, enough grit in there to sand down those areas each time they ran across the teeth. I'll put fresh grease on the teeth but lube the pawls and springs with a little motor oil, put everything back together and hope for the best.

Tawraste666

Those bite marks on the splines caused by the cogs could make those noises.
Each cog is sitting inside those grooves making contact with more faces of each cog than it should.
Depending on the depth, there may be rotation of each cog out of position which can affect how smooth gear changes occur.
In the past, where weight was not an issue I used a stainless steel hub body which resisted this kind of damage wonderfully.
On the bike where weight was an issue, I carefully crafted steel pins to pass through the cogs effectively joining them together and spreading the load (extra 4g in total).
The current bike uses a cog set on a spider which does the same thing but is fiddly to clean.
Personally, I'd be buying another hub body if current funds allow for it.

djb

Boy, how long has it been since we've had to yell that out in a movie theatre?!
Or the scant few times when Mr projectionist fell asleep and didn't get the next reel ready and missed his dot marks for the projector switcheroo?

Younger forum folks (probably not that many!) are scratching their heads at this stuff.

MidTNBrad

A quick update with some better pictures. I put everything back together and the hub is worse now that when I serviced it. Slowly spinning the wheel backwards I can definitely tell something is wrong. The ratcheting noise alternates from light and quiet to heavy and loud throughout the rotation. The pawls do engage although I haven't taken them back out on a proper ride yet.

The pictures show how deep the gouges are in the freehub body so something has gone pretty wrong. I'm hoping freehub body has taken the brunt of the damage and the teeth in the hub are unscathed.

From the part numbers on the freehub it looks like this is OEMed from Chosen hubs. The only reviews for Chosen I found were in mountain bike forums and someone had about the same experience. I saw one review that said that the bearings were undersized which led to the axle flexing which stripped out the ratchets. Sounds like that could be the culprit for me.

I've emailed the wheel vendor with pictures and am waiting to hear back from them.

Andrew R Stewart 

Thanks for the continued follow ups. Those marks on the FH body are deeper and worse than I thought. My earlier "passing" comment about sloppy bearings or rocking about now seems more likely. Please keep us informed. Andy

jgwilliams

I had something similar on my Fulcrum wheel, which was because the freehub bearings were toast. It was also making similar noises to those you are describing.