What the hell, HED!?
 

can anybody tell me what happened here before I call HED in the morning?

This is a NOS 2015 HED Ardennes Plus freehub. I installed a Shimano CS-6600 10-speed cassette using the proper spacer, 2.8mm, as HED advised. I have less than 200 miles on this.

Now, as a side-note (but highly relevant), my son bought a HED Jet 5 (Performance exclusive model) with the same hubs & rims, but with a fairing. Performance installed his 10-speed cassette, but using 3.8mm of spacers (they left on the 1mm that comes with the cassette by mistake). So his 10th cog started freely spinning after a couple of rides. The gear essentially sheared off the ends of the splines. Performance fixed it after some head scratching. To me, it was obvious what the problem was, but two mechanics passed on it and had the service manager (thx Will!) make the call.

As a result of the Performance experience, I decided to take mine off and absolutely verify I had only used 2.8mm, which was the case. But the damned cassette was stuck. I knew it was a bad sign and once I jiggled it off with some pliers, I saw the freehub damage. It was tightened properly and was shifting well - indeed it needed no adjustments relative to the Mavic that preceded it. There was no reason to suspect anything.

So, here's the damage. Any ideas?


https://s26.postimg.org/a7girgh95/HED_freehub_1.jpg

https://s26.postimg.org/hm5uju34p/HED_freehub_2.jpg

Your issue is "normal" - that's what happens with aluminum freehubs, the cassette cogs dig in under the first heavy torque load they encounter. It won't get any worse and only creates an extra step in removing the cassette, IMO/E.

You can look for freehubs with steel anti-bite guard inserts if it bothers you that much.

I mean maybe contact HED and see if their current freehubs have a steel insert but I wouldn't expect much else from them as there's no reason to replace the freehub and it's not defective.

aluminum freehub body vs steel cogs
the cogs win

this is a pretty normal result with that combo

either upgrade to a 1-piece cassette (all cogs CNCed out of a single solid aluminum block)
or downgrade to a steel freehub body

Call HED and ask for help but are you sure the lockring was tightened fully? The specified torque is 40- 50 N-m and that's more than you would use without a torque wrench as a guide.

If you're gonna shave grams, sometimes you get to pay twice. Also, 45Nm is more than many people think. Shout out to my penny-pinching Shimano wheelset, complete with steel freehub.

Or my less-than-penny-pinching Dura Ace FH-7700 hub with it's Ti freehub body and 55,000 trouble free miles.

The only Al freehub body I've had success with was a 2006 Campy Chorus hub but the splines were much taller than Shimano uses so the load was distributed over more area.

Now you know why they combines all but the 2 smallest cogs on a single carrier rather than bolt together the stack of cogs,

And the downside of aluminum driver splines versus hardened steel ones.

a newer cassette as described above will spread the torque out over a wider surface..

Id save the HED for race day, use a normal spoked wheel for training.. if I were You.





.....

The result like many here have said of buying lightweight aluminum freehub. Either buy Campagnolo or Shimano steel or Dura Ace titanium freehub if you don't want this to happen.
Do the homework.

After 10,000 miles, my HED freehub has very small dings in the splines, not nearly as deep as yours.

I did lightly file the edge of the splines to make it easier to remove the sprockets. My tiny gouges had raised edges -- filed those off.


White Industry hubs are titanium, too.

I did not torque it down. I just used my regular approach (with my ginormous 16" crescent wrench) which has always been fine with steel freehubs. I will check the spec and torque it this time. Should I put any grease on the freehub or cassette before assembling?

OK guys, I did not know the freehub was aluminum when I bought the damned thing. Never thought about it one way or the other. I read tons of reviews, everything I could find online, and no one mentioned it. School of hard knocks I guess.

feitsbob - race days don't apply to me. My son, maybe someday, but not me. I just wanted some wide rims.

Yup. See this all the time on aluminum freehub bodies. Sometimes, the easiest way to get the individual cogs to release from the divots is to get two chainwhips out and twist the cog back.
It's usually worse when the lock ring wasn't tight enough.

Torque doesn't make a difference, it's a materials failure due to underspec design.

Torque does make a difference when more pressure on the face of the cog helps to resist the cog rotating in relation to it's neighbors.
I've serviced enough of them to make the observation that insufficient torque on the lock ring exacerbates the problem.

This makes sense to me. So, 40-50 Nm as HillRider suggested? And, do you think the freehub is fine to continue using? In other words: "It won't get any worse" as Spoonrobot suggests.

I've serviced enough of them to disagree. :)

I am going to side with you on this... when you are mashing up a hill the torque on that cog will easily exceed the 40-50nm mentioned.

However, on second thought... the extra tourque may keep the cog better held at a right angle to the spline. If the cog tilts slightly it can push the pointy corner of the cog into the spline, aiding the deformation.

Either way, you lose alot of ground for complaining when you don't follow the mfr's torque specs.

A properly torqued lock ring is certainly no guarantee that the cogs will not bite the splines. All I'm saying is that when I twist off a lock ring that is noticeably undertorqued, I observe repeatedly that the likelihood of a struggle removing the cassette is higher.
Much of this could depend on the rider and which gears get the hardest use.

Some manufactuers address this with narrow steel reinforcement strips at some of the points of contact between cogs and freehub body. This provides most of the weight savings of the aluminum freehub body and mostly eliminates gouging by the cogs. See American Classic freehub bodies as an example.

No.

If the cogs had some sort of side-splines or some other friction-enhancing feature that would facilitate lateral attachment between the cogs (when they are pressed together in a cassette), then lockring torgue would indeed matter. However, we all know that cogs have nothing like that. Cogs are smooth on the sides and don't "grab" each other in a cassette. This means that lockring pressure does not really affect anyhing. Lockring pressure does not "help to resist the cog rotating in relation to it's neighbors" in any meaningful way

Just talked to HED. I mentioned the American Classic, which is another wheelset I considered. He said they tried that also, but had problems with the steel strips falling off. At any rate, the rep saw my photos and said, not a big deal, and I can continue riding with them, just lock down that lockring! Things should not deteriorate.

He also said my older Ardennes had different/heavier anodized alum freehubs, so it is a weight saving game, as suspected. They also made some steel freehubs for cross riders who shift under heavy loads.

I'm not too concerned at this point. I don't think I would have gouged the freehub myself @138# and 63yo. Being a featherweight, I never did have power, not even in my youth. But my son, who borrowed my wheels when his were in the shop ...

Just talked to the mechanic that fixed my son's HED's. He said to do the same, and that this is no big deal.

Well, I'll leave the theories to the theoreticians and continue to report on what I observe with my own beady eyes.
Working as a part time wrench in one of the leading high end local road shops, I see a lot of aluminum freehub bodies, so it's not like I'm telling ya about something I've observed once or twice.

I have similar notches on my DT Swiss freehub.

There has to be a "how many cyclists does it take to change a cassette" joke in here somewhere.

No, what I said above is not "theories" - it is straightforward practice.

Believing that lateral squeeze of the lockring can somehow keep cogs in a cassette "glued" to each other under the immensely large rotating force exerted by the chain on one of the cogs... well, it is like believing that one can repair carbon fiber frame with a chewing gum.

While I have never tried repairing carbon fiber frames with a chewing gum, I know for sure that it won't work.

I would have said that with that cassette, you should be using the thin Shimano spacer along with the 2.8 mm spacer.
Some of the other 10 speed cassettes do not need the spacer but that one does.

Nowhere did I suggest such a thing. I see freehub splines chewed up by the cogs all the time. My observation, over a large sample size is that it's often (usually) worse when the lockring is not properly tightened.