Aksium Bearing/Freehub advice

notsoblue

Morning,

Question for the hivemind. My bike has started to occaisionally make a pretty alarming noise when I lift up out of the saddle when going at speeds over 25mph. First noticed it when coming down Broomfield and it was a very loud grinding/rubbing noise that was coming from my rear wheel. After checking it out the first time I couldn't find any evidence of rubbing on the frame or brakes, the wheel is aligned correctly and theres no play in it.

My only guess is that its the hub and that there may be something wrong with the bearings. Is there a way to tell? Having never serviced a hub or bearings before this is new territory for me!

EKE_38BPM

http://www.parktool.com/blog/repair-hel ... adjustment

I don't know if Aksium rear wheels are cartridge bearings rather than cup and cone, but if they are CandC, the above link tells you all you need to know.

If there is no play, perhaps the bearings just need some lubrication.

notsoblue

Looks like they're sealed (cartridge?) bearings: http://www.mavic.com/en/technology/wheels/QRM

So its just a matter of popping them out and replacing them?

turnerjohn

how old are the wheels ? rough how many miles ?
take the wheels off and rotate the axles...should be smooth with no play and no grindy feeling.
check the spokes are also nice and tight...wheel builder will advise properly.
If its only when you get out of the saddle I'd check all cockpit bolts / headset as this could be the cause...sometimes noises come from totally different locations to where you think they are !
Mavic hubs use cartridge bearings so replacement (although simple press out press in) is far trickier then cup and cone.

mudcovered

Should be easy enough to tell if you have a bearing problem. Remove the wheel from the frame and spin it while holding the axle. If the bearings are not up to snuff it will stop spinning pretty quickly. The other possibility is a broken axle. With cup and cone bearings this tends to make the whole wheel wobble (even when clamped in the frame) but with cartridge bearing designs you might not notice until you take it off the frame and remove the QR skewer (which might be all that is holding things together).

I never suffered from either of these problems with my Aksium which ran perfectly until I wore out the rims but I have suffered from both bad bearings and axle breakages many times in the past.

Mike

notsoblue

turnerjohn wrote:

how old are the wheels ? rough how many miles ?
take the wheels off and rotate the axles...should be smooth with no play and no grindy feeling.
check the spokes are also nice and tight...wheel builder will advise properly.
If its only when you get out of the saddle I'd check all cockpit bolts / headset as this could be the cause...sometimes noises come from totally different locations to where you think they are !
Mavic hubs use cartridge bearings so replacement (although simple press out press in) is far trickier then cup and cone.

Wheels are about 14 months old, and they've done ~4000 miles.
Its definitely coming from the hub, quite distinctive, not the usual random creaking.

@Mudcovered Will check the axle

Thanks fellas. May still need to wander into my LBS and cluelessly ask for next steps though

turnerjohn

I've a set of Ksyrium Equipes (training wheels) that must have done 10,000miles and the bearings are still sweet; just can't kill them ! May just have been unlucky tho...do you jetwash your bike clean ?
Have you checked the axle ? you can pre-load them up...not super tight mind but so their snug...maybe worth a try.
Unless youve had a crash I doubt the axle is broken...their very strong...unless yours had a defect...and just out of warrenty !

raffa cakes

I just recently overhauled some 2010 Aksia after 5,000ish miles but I didn't have any problem like you describe. My problem was an ugly / muddy sound in the freewheel ratchet clicks. To be honest it is difficult to match your symptoms to a problem with the hub - the bearings shouldn't really know or care what speed they are turning or whether you are in or out of the saddle... but you seem to be sure, so I can report that it is definitely possible to get in there and change the bearing cartridges, but it's fiddly and difficult to find the right instructions online.

SimonAH

It couldn't be rim flex graunching against a brake or something could it? Are you sure it's from the hub? It seems to me that anything catastrophic in the hub would manifest itself all the time rather than in specific circumstances only....?

notsoblue

SimonAH wrote:

It couldn't be rim flex graunching against a brake or something could it? Are you sure it's from the hub? It seems to me that anything catastrophic in the hub would manifest itself all the time rather than in specific circumstances only....?

I'm not certain actually. Which is why I'm going to take it to my LBS for a second opinion before doing (or commissioning) any fettling.

Slightly OT - Its kinda ridiculous that Condor always has a two week backlog in their workshop. London Bicycle Workshop can usually sort you out same day if you get in early enough. Shame they're not a Mavic dealer.

markshaw77

As a recent sufferer from the what sounds like the same problem, it is most likely the freehub (if you google "mavic death squeal" - you will get plenty of hits!) - that is assuming it is happening when you are freewheeling

It is an issue with the mavic freehub design used on their aksium/ksyrium wheels for the past few years - generally, a quick remove/clean/mineral oil/replace will sort out the noise, but it is only a short-term solution as the noise comes from the plastic bushing getting worn and dry, so generally by the time you get the noise, it is a sign that it is on its way out anyway. That said, since I first got the problem and cleaned it up, I have done another 1000miles with only minimal squeaks and none of the horrible screeching noise, so it can't be all bad

The removal and replacement is a relatively easy process (there are some youtube videos around) so easily doable yourself if you have the time/inclination. Otherwise, it is a 20-30 minute (max) job for your LBS

Hope that helps

notsoblue

@markshaw77 Deathsqueal is the perfect description! Thanks for the steer, I think that might be it.

markshaw77

Cool - drop me a PM if you need any further help

notsoblue

So I just had a word with the chaps at LBW and they seem to confirm Mathshaw77's suggestion about the freehub being the cause of the squealing. Their recommendation was a hub service and to replace the pawls. The bearings were also pretty worn so they'll be replaced in the same service. I'm concerned that, as you say, the bushing may be on the way out anyway. But with a service, new grease, and new pawls I may be able to squeeze another 1000 or so miles out of it before the freehub body needs replacing entirely. I'll probably have a new rear wheel built when that time comes.

Thoughts?

raffa cakes

Interesting... seems like I might have just caught mine before this problem developed, the bushing was pretty filthy inside the hub. So it sounds like you've found the culprit, I think I'd agree that if it came to replacing the freehub that might be the time to get a new wheel - presumably the rims are quite worn too.

Out of interest, markshaw77, did you do this on an Aksium? I had a hard time figuring out how to get into the freehub on mine.

notsoblue

raffa cakes wrote:

Interesting... seems like I might have just caught mine before this problem developed, the bushing was pretty filthy inside the hub. So it sounds like you've found the culprit, I think I'd agree that if it came to replacing the freehub that might be the time to get a new wheel - presumably the rims are quite worn too.

Funny how it seems to be such a common problem with the full range of Mavic wheels, even with the likes of high end ksyriums. From what I've read/heard they chose performance over durability in the freehub design. Looks like they may not be the best choice for commuting wheels.

Are nylon bushings a common part of freehub design in other brands?

optimisticbiker

notsoblue wrote:

raffa cakes wrote:

Interesting... seems like I might have just caught mine before this problem developed, the bushing was pretty filthy inside the hub. So it sounds like you've found the culprit, I think I'd agree that if it came to replacing the freehub that might be the time to get a new wheel - presumably the rims are quite worn too.

Funny how it seems to be such a common problem with the full range of Mavic wheels, even with the likes of high end ksyriums. From what I've read/heard they chose performance over durability in the freehub design. Looks like they may not be the best choice for commuting wheels.

Are nylon bushings a common part of freehub design in other brands?

Well neither the Alex Wheels (ball/cone) nor the Fulcrum (cartridge) freehubs appear to have any plastic parts other than the internal and external rubber seals.

markshaw77

I guess it a question of relative costs - a new mavic freehub unit is about £35 and a set of cartridge bearings £10 which isn't too bad on a Ksyrium wheel costing £250+, but when you can get a brand new pair of Aksiums for £150 a pair it doesn't take long for it to be uneconomical (especially if you are paying LBS labour too)

The nylon bushing seems to be a uniquely Mavic design choice and likely works well if maintained regularly, but Mavics are mostly sold as "fit and forget" wheels, so the two don't necessarily fit together - particularly as commuting wheels

@raffa cakes - I did indeed do it on an Aksium - the modern wheels just need a 10mm allen key in one side (you need to remove the plastic 'cap' first) and a 5mm in the other; whereas on the older style, you need to use a (16/17mm?) spanner on the hex nuts on each side. Once removed, you can ease the freehub off, taking care not to lose the small pawl springs that come loose. After that clean it up, a few drops of mineral oil and put it back together

raffa cakes

markshaw77 wrote:

@raffa cakes - I did indeed do it on an Aksium - the modern wheels just need a 10mm allen key in one side (you need to remove the plastic 'cap' first) and a 5mm in the other; whereas on the older style, you need to use a (16/17mm?) spanner on the hex nuts on each side. Once removed, you can ease the freehub off, taking care not to lose the small pawl springs that come loose. After that clean it up, a few drops of mineral oil and put it back together

That's the same process I saw laid out everywhere, but mine had the 17mm nut and I ended up disassembling the entire axle to get in. I suspect there is an easier way though. My wheels are from 2010 which seems pretty 'current' to me for a wheel that needs servicing... It does seem odd that there isn't more information out there on how to do this fairly simple maintenance operation on a hugely popular wheelset.

Oh and I'm not sure how big a deal this is notsoblue, Mavic are very insistent that you use mineral oil on the freehub interior but when I went to my local bike shop to try and find some they were adamant that it was grease that I needed, and that they use grease to do the same thing. I have zero expertise on whether it actually makes a difference - insitinctively it makes sense, you want a light oil in there rather than gunky grease - but I don't know. Maybe someone else here does? but you might want to watch out for that with your shop.

Butterd2

Agree with all MS77 has said, I did the same to my Aksiums a while back. I go the nylon bush off eBay for c.£10 though it was from the US. Swapping it out was pretty easy but the new one was a little tight so the freewheel did not "freewheel" but a gentle sanding with some very fine sandpaper sorted that out and it been going strong since. Admittedly on my wife's bike as I took the failure as an excuse to get some Ksyriums.

markshaw77

@raffa cakes - when disassembling, you only want to undo the drive side nut. There is then a washer (don't lose it!) and after that, with a bit of a tug, the freehub should come away - just be careful not to lose the 2 pawl springs as you do it. After cleaning, you definitely want some mineral oil (or similar - I used 3in1) rather than grease - grease will be too heavy in the winter, will attract dirt and will "gunk-up" the pawl springs over time which will cause much the same issues you have now or, worse, will stop the pawl engaging and preventing any drive at all.

HTH

raffa cakes

markshaw77 wrote:

@raffa cakes - when disassembling, you only want to undo the drive side nut. There is then a washer (don't lose it!) and after that, with a bit of a tug, the freehub should come away - just be careful not to lose the 2 pawl springs as you do it. After cleaning, you definitely want some mineral oil (or similar - I used 3in1) rather than grease - grease will be too heavy in the winter, will attract dirt and will "gunk-up" the pawl springs over time which will cause much the same issues you have now or, worse, will stop the pawl engaging and preventing any drive at all.

HTH

Good advice, hopefully someone else doing the same google trawl as me in the future will find that. I mentioned the oil / grease thing as I suspect it might be common to other bike shops, I guess from a traditional view of 'grease for hubs & bearings'. I ended up using halfords cycle oil, which I had lurking on a dusty shelf, and the wheel has been running fine and sounding sweet since. Moral of the story: keep an eye on your rims and an ear on your clickies!