Bicycles Stack Exchange is a question and answer site for people who build and repair bicycles, people who train cycling, or commute on bicycles. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I feel like this is poor design. I have two wheelsets that are less than a year old which have damaged freehub bodys due to cogs digging in to the splines on the freehub. It's so bad that I can't remove the cassette spacer without filing down the splines. I had to use pliers and chain whip to remove the cogs that were embedded in the freehub when trying to remove the cassette.

Most of the damage is on the center of the cassette as the largest 3 cogs are held together by carrier. I'm using a shimano 105 cassette and Novatec disc hub and Velocity ATB convertible disc hubs (which were somewhat damaged in the same fashion, but not as bad as the novatec).

I'm using this bike for cyclocross, offroad exploring, light singletrack use, Rail trails and some road riding.

How can I prevent this damage to the freehub from happening?

my damaged novatec freehub

share|improve this question
    
Just an observation - I find it very surprising that this could happen to a 105 cassette, there must be an awful lot of these out there. If there was an inherent problem, you wouldn't expect to be the only person with it. Presumably there was no play when you first fitted the cassette? – PeteH Aug 13 '14 at 19:12
    
There was no play when it was first installed. There were not gouges in the cassette either. The play is pretty limited, since there is compression from the cassette lockring, so it doesn't really move freely, but I can push it backwards around the hub a bit since the gouges are probably getting to be a 2-3mm deep on the american classic hubs. I found that american classic used to make a pin kits for 105 cassettes that helped immobilize the middle cogs, but are not compatible with newer versions of 105. amclassic.com/download/manuals/clipkit_105.pdf – Benzo Aug 13 '14 at 19:20
    
I had an old mountain cassette that had a long bolt through all the cogs to limit cog movement as well. – Benzo Aug 13 '14 at 19:21
    
A picture is worth a thousand words – Paparazzi Aug 13 '14 at 20:00
    
Added photo and edited description a bit. – Benzo Aug 14 '14 at 13:50

I don't believe there is a lot that can be done as this has to due with the material selection for the freehub body shell (soft aluminum). Below is an image of a Velocity hub (on my commute bike) that had the same problem. I actually had to hammer the cassette off of the hub body. In this case a Tiagra cassette (where most of the cogs are pinned together) caused the damage.

enter image description here

I asked the local bike shop and they said they have seen this before and it is largely a materials issue. A higher end cassette may make a difference. I personally have my doubts, but I will try an Ultegra cassette next and see if the problem continues.

The only solution I can see is replacing the freehub body with one that uses steel or a harder aluminum. Interestingly, Velocity does make freehub bodies in a variety of materials, although I am not clear on the cross-compatibility.

share|improve this answer
    
Mine looks like this, but worse. Gouges are more than twice as deep. – Benzo Aug 13 '14 at 20:57
    
@Benzo - Twice as deep? You must be putting down some serious power. You have put me to shame! – Rider_X Aug 13 '14 at 21:32
    
FWIW, there are newer freehub bodies that have small steel facing edges to help prevent this kind of wear. interbike.mtbr.com/american-classic-mtb-race-29-wheelset/… – Fred the Magic Wonder Dog Aug 13 '14 at 23:31
    
@FredtheMagicWonderDog - Are these sold by velocity or is it another brand compatible with a Velocity hub? A link would be great as I may have to replace mine if it gets worse. Thanks! – Rider_X Aug 13 '14 at 23:33
    
I'd share your scepticism about a higher-end cassette. It's difficult to see how "Tiagra material" would cause this and "Ultegra material" wouldn't. More precise fit maybe? – PeteH Aug 14 '14 at 7:29

By accident I think I came across some valuable information.

http://www.notubes.com/help/frequentlyaskedquestions.aspx

Why is my cassette digging into my freehub body?
... It is necessary to make the lockring extra tight to avoid significant wear on the freehub. We recommend using cassettes with a rigid alloy carrier (XTR, XT, XO, etc. - Figure 1) for the largest sprockets. Cassettes with individual steel sprockets (Figure 2) may mark the alloy freehub, though marks are only cosmetic and will not affect the performance of the hub.

From your picture it appears the freehub takes the hit from the individual sprocket. Need the cassette to act as a unit and spread the load across all sprockets. Tighten down more or look for cassette that has more of a body across the sprockets (rigid alloy carrier).

See how the rigid body (left) shares the force across not just the sprockets but also between the sprockets.

Rigid Individual

share|improve this answer

You can make sure you don't mix and match mountain and road drivetrain parts if you haven't inspected them. Although the spline pattern is the same on both, the spline depth is not. Going with a higher grade cassette will make the problem worse (much worse). Your all titanium Dura-Ace cassette will cut through your aluminum mountain freehub body "like butter". You'll notice the issue fairly quickly since your most used individual gears will turn through the freehub body first, misaligning the shiftgates and causing noticeable issues shifting.

Road cassettes most often contain a high number of individual gears and are short on carriers. The splines on a road hub are much deeper to accommodate the increased force against the splines by a single gear. Mountain cassettes tend to have largely carriers which distribute the force across the spline. Accordingly the splines on a mountain hub are less deep/tall.

I learned this lesson the hard way after my Dura-Ace 10 speed cassette destroyed the freehub body (completely) of my DT Swiss 190 Ceramic Disc hub. Luckily the folks at DT Swiss sent me a new freehub body and I was back in business.

share|improve this answer

Honestly, there isn't anything you can do. As the pressure to make bikes lighter increased, engineers looked a steel parts to replace with aluminum. Your freehub body is a casualty of that fight. For my race bikes I have the same problem with Zipp and Mavic freehub bodies. You just have to suck it up. It's the price of lightness.

A more permanent and satisfying solution is to use a shimano hub that has a steel body (pretty much all of them). I have one on an emonda and it is flawless. I have another on an old Mavic/Shimano combo over 11 years old and it works great.

If you like the aluminum body freehubs, Novatec does have a series of hubs with the "Biteguard" system. Basically, it is a piece of steel that is thin and sits between the cassette body and one of the freehub splines. There is limited effectiveness but it does help some.

Finally, I have found SRAM cassettes to be gentler than Shimano cassettes (105 and up). The cheaper SRAM kit comes as almost one piece while the "better" shimano cassettes are able to be disassembled into each cog. No real engineering reason why, just seems to cause less damage.

Personally, I think that is part of the planned obsolescence movement to get customers in the door buying new parts, or new bikes. But that's my opinion.

share|improve this answer
1  
Most high end Shimano freehub bodies are Titanium, not steel. There is a reason the SRAM one piece cassettes are gentler: the carrier distributes the force along the whole spline, where with an individual cog, the whole force is concentrated on the contact point of the inidividual cog. – Suspended User Jun 23 at 5:06

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.