Well after 5 days in Spain my Shimano MT68 all mountain wheel started making some nasty grumbly noises and the cassette was all wobbly. We left well alone as thought the freehub bearings had collapsed. So home and strip and check to see a crack the full length of the freehub. I would have expected a bit more than 3 weeks / 100 miles out of it. Has anyone else had the same Shimano issues?

Funnily enough we’ve just had a customer in with exactly the same issue (on an XT wheelset). He’s had three crack now – and asked me whether we had other customers suffering from this (we don’t).

So I’d also be interested in responses to this thread…

… and Thrustyjust, I am certain that Madison/Shimano will sort out your issues for you, if you get in touch with your dealer.

Cheers, I will speak to Pauls Cycles in the morning where I bought the bike. Worrying its gone so soon to be honest.

I’ve done this with a number of Hope hubs over the years, as have friends. I have also killed an XT in a similar fashion.

I also have Hope and Shimano hubs that have lasted forever.

I reckon some will fail as a result of minute manufacturing/metallurgy faults, some due to a massive unexpected force.

In the last month I have also bent a front wheel, snapped a frame and rounded off a set of splines on my XT cranks.

Well, I am now 2 weeks in and still I have no freehub. Bit frustrating. Allegedly the place I got the bike ordered one over 2 weeks ago, as soon as I sent the photo of the part. I am sure Madisons should have stock. I tried to email them today, filled in the query and it then went blank and wanted me to fill it in again. It also stated they would reply within 14 days. Thats really handy……… 🙄

I’m sure somewhere like Pauls Cycles must have another suitable Shimano freehub somewhere in the shop that you could have whilst awaiting delivery of your replacement….

Call them!

Not sure if it relates to your particular model, and I have no personal experience, but the MTBR forums are littered with reports of broken/cracked Shimano rear hubs…

http://forums.mtbr.com/wheels-tires/shimano-xt-m775-wheelset-freehub-fails-465660.html

http://forums.mtbr.com/wheels-tires/shimano-xt-142×12-rear-hub-toast-after-500km-791039.html

Looking on Shimano diagrams, its the same freehub across the board, from SLX to XTR , including Zee ( same part number). Bit worrying, as thats some of the threads I read as well. If you google broken SLX freehub photos, you will see a multitude of broken outer shells on there as well.
If the wheel isnt fit for purpose, then i will reject it and then the shop/ Cannondale/ Madison would have to work out what to do. I cannot reject it on the first breakage, as i have to give them a chance to repair it, although timescale is going against them all.

How many freehubs of that design do you think Shimano has shipped?
How many broken ones have you seen?

Anyway, why hasn’t Paul’s Cycles provided a replacement?

I will call them again today.
http://www.chainreactioncycles.com/shimano-mt68-mtb-rear-wheel/rp-prod82566
Not great feedback here also……….
On another note, in 24 years of riding a bke, also with Shimano hubs, I have only ever broken 2 feehubs on bikes, both after 8 plus years of service, not 3 weeks. One was a hope XC one, which Hope swopped and you could see they had redesigned it , as they had issues and one was a Goldtec one, which was a few weeks ago, which you could see they had also redesigned it, as they also must have noted issues. Both small fish in the world of bikes.
It is obvious, from an engineering perspective that the outer shell on the shimano, which is no more than 1.5 mm thick, which has to support the strains of the ratchet latching into it, is too thin and is creating this issue. Regardless of how much R&D and how many they sell, if they are breaking they arent very good. How many have broken and not come to light, just sent back to the shop and replaced?

Not had any experience of broken ones, but were you running it with a massive low gear (40/42t aftermarket cog)? I can see these causing all sorts of problems in the very near future.

Hi Tim, hope you are well. Nope, just the standard Sram cassette that came with a new Jekyll. Bike was bought , 3 weeks later ridden in Spain. Only did 20 miles before I went as a shakedown.

How so Tim? Is a 32×42 gear system really putting more force/stress through the freehub than a 22×32 gear?

Or is it a chainline thing?

One of these , as is
http://www.paulscycles.co.uk/m1b0s1p5187/CANNONDALE-JEKYLL-3-2013

Biggest sprocket is 36 t. Previous times I had gone, used to try and turn big gears, but decided to spin the week away and no leg pain whatsoever, which was a bonus.

Expected delivery date of the 1st July from Madisons for the part !! FFS. They are stripping a wheel down to take a freehub off. This is weekend 4 of no jekyll. They did offer to strip a wheel down 2 weeks ago, but I didnt expect a 6 week wait for Shimano/ Madisons to get their butt into gear on this. 🙄

Oh, in that case it’s a bad show all round.

I’m thinking more about the folks who are taking the gearing thing outside it’s remit. 28/42 fat bloke, big hill – loads of stress.

Tim, it’s actually a really valid point about gearing and torque going through the freehub body. I know Shimano updated their road hub shells a few years back to deal with the additional torque generated by the larger cassettes.

…and shimano also made a “29er specific” slx hub a few years ago. I scoffed at first, but actually the idea was a poorly-named but honest attempt at recognising the impact of 36t cassettes (on geared 29ers but i guess any bike really) that we had at this time not really seen before. Perhaps there is something about the shimano freehub design that is particularly sensitive to the loads from bigger cassette sprockets. My new slx one has more clicks and doesn’t sound like any of the shomano ones i have had before. It is also bigger- goes about 3mm further into the hub body than the old shape used to.

I had a 40 mile old slx free hub arrive cracked on a bike I bought last week. Looks like tightening the cassette lockring was enough to shear off the threaded part of the cassette and split it down the middle. I’m no metallurgist but it looks to me like it’s made of a really poor steel alloy. It has that sort of grainy look that I’ve seen before when cheap tools snap.

Fortunately the guy I bought the bike off is being super helpful.

Today I have a replacement freehub from another Jeckyll from Pauls. Helpful chaps, i must say. But this doesnt help them or us, if Madison cant keep stock of items which may well fail or wear out and expect people to wait near on 2 months for a replacement. Its all bolted on and fine again, but for how long ?

ike it’s made of a really poor steel alloy. It has that sort of grainy look that I’ve seen before when cheap tools snap.

It may well be rubbish material but that grainy texture just means that it failed suddenly. Any metal part that has let go without warning will show that.

Thanks Robin – I never realised that.

Well on friday, I had an email from Madisons. There isnt any known problems with these freehubs, so no new version is available. They also said they had stock , so not sure why the delay in getting it to Pauls. Pauls said they had ordered it on the Wednesday , a day before I sent the broken freehub, on seeing the photo I sent them. A month for delivery , something isnt right. It has survived so far, the new one, so fingers crossed.

How many broken ones have you seen?

I’ve pretty much given up on Shimano hubs, as just about every one I’ve had in the last few years has failed, from Deore to XTR. Compared with older hubs pre-1998 or so, the more recent ones simply aren’t anywhere near the quality in terms ofmaterials and manufacturing, that the older ones were. In fact, this is true of pretty much al of Shiman’s output, sadly. They don’t make anything to last any more, wanting you to ‘upgrade’ far more frequently than you should have to.

I know several others who’ve experienced Shimano freehub failures too, as well as broken axles. They are simply poor quality.

Well to bring this back up, seems I have another freehub failure. I don’t ride this much, perhaps 40 miles since the last failure. It hasn’t cracked this time round, but has so much play in the freehub, that as soon as you put pressure on it, it sounds like a cement mixer and crunches and cracks. Checked the cassette was tight. Took the cassette off and the wobble is quite noticeable in the freehub. More so than my road bike shimano hub. So back to contacting Pauls again, but must admit to loosing any form of confidence in these freehubs. Thing is, I like the bike, so rejecting the bike because of a second hub failure is daft, but I cant keep feeling I cant trust it. What options are there for 142mm through axle hubs?

Cup and cone hubs often work themselves loose so check that first. They’re easy to maintain you just need some cone spanners. Plenty of vids on how to diy. If you’ve only done a few miles you shouldn’t need to replace bearings, just pack in some more grease whilst you’re at it.

Cup and cones fine and smooth. Nowt wrong with that. Its definitely the freehub gone wobbly. You cant go wrong with these freehubs for fitting them, as they actually screw into the hub body and tighten as you ride ( I put a cog on and a chain whip to tighten) then fitted bearings and greased and set up as cup and cone is done. Wish is was the bearings being loose on the axle !!

Buy a set of Hope Hoops, and keep the Shimano’s as a spare (once repaired).

Do it now, and you’ll be back on your bike in a few days.

I am weaning Hope stuff from the fleet as other than XC hubs, the pro’s have been never ending grief. I may speak to Goldtec and see if they do a rear hub in 142, although being an AM bike, doesn’t go out often and rely on the 3 other bikes in the fleet, although a day to BPW was planned in a couple of weeks and with fitting my new Zee brakes yesterday for that, is going to have to be put back, like a ride had to be the last time it failed. Also just built a 650B Turner Burner for a mate with Stans rims and Schwalbes and we could not get them to seal, so he has tubes in them. Not had any issues with the Shimano or Mavic rims on other bikes.

Shimano free hub bodies don’t screw directly into the hub body. They are held in by a large hollow bolt that require (usually) a 10mm Allen key. My money is on this has come lose.

Number 9.

Won your money 😀
Same freehub as this. I have swopped one already, so know how it goes together. Same part no for this to XT for through axle hubs

http://www.sjscycles.co.uk/shimano-zee-fh-m640-cassette-freehub-body-3ts-9806-prod31405/

Dammit. :-).
Should have said ‘most shimano’. I have a set of mt68 wheels that are as per the tech docs.

Aha aha mine is qr. yours are 12mm. TAXI!

😀 I guess yours are QR wheels. With the through axles, the freehub is different, which is possibly its downfall. I have an email from Madisons at work, so apart from speaking to Pauls again in the morning, may question the ‘fit for purpose’ scenario with them and see what they say and will email Madisons as well.

I’m surprised you’ve had issues with madison. I deal with them most days with one thing or another and they’ve always been spot on. One of the reasons I use them so much.

I have to go back to Pauls first. Last time they offered to strip a bike to get a freehub. I don’t use it that often, so said I would wait for a freehub from Madisons. I don’t know why after 4 weeks for a replacement, as in the end they stripped a wheel for me. Looking on the web, there is plenty of cracked freehubs similar to my first one, yet there is nowt wrong according to Madisons. I’ll update when I get answers here, as I cant be the only one with issue at some point.

Spoken to Pauls. Well Paul, actually.He has spare ones, which are Shimano packed ones ready to send. Advises that he has sold lots of Jekylls and had a half dozen broken freehubs, so not been problem free. He hopes the latest ones will solve the issue. Lets hope so, as the wheel wont be going back on if it breaks again. Allegedly the last batch took so long, as the shipment got lost from Japan, hence the delay.