Replacing cups in a Shimano hub

alomac

I have a M475 front hub with knackered cups (dirt got in, contaminated the grease and worked its grinding paste magic). I know you can knock the cups out and replace them, and I have a donor hub, but I'm not sure how.

Firstly, how do you get the dust caps and cups out? I was thinking of making something like what you use to knock out headset cups by getting a suitable size piece of pipe and splaying one of the ends out, but maybe that's overkill.


Knocking them back in seems pretty easy. Most people recommend using a suitably sized socket to press them in, but not having a socket set l'd probably use a pipe or dowel.

I guess the other issue is whether the faff will be worth it when Merlin, for example, will build a wheelset with XT hubs and EN571 rims for £180, not to mention Superstar and the like.

alomac

Erm, sorry for the double post. That's the second time I've posted to a forum on my Android phone only to have a duplicate post appear some minutes later. I'll have to look into it.

nicklouse

First. They are not a service part so you can not buy them separately.

I just take care and use a screw driver, a tool like a headset race tool IIRC will not work due to the hub shape.

stubs

I have used a M8 bolt just tap at 12 o'clock, 3 o'clock and so on. By the time you have worked your way round a couple of times it should be coming out. To knock the replacement in I used a piece of dust pan handle cut to size.

cycleclinic

I would not bother the same problem will happen again on a M475 hub. they do that. An XT hub will prove far more durable especially if you service it once in while.

I have built up XT hubs with EN521 rims and the customers have found them to be very durable. My old XT M737 hubs are still giving faithful service. My wife's M563 Lx hubs are still giving faithful service after 15 odd years or so.

There ius a reason why the M475 is used aftermarket.

also the Merlin or superatr wheelset for £180 will be using plain gauge spokes and cheap ones at that probably. Better to go for Spaim Race or DT Comps DB spokes for longer spoke life. The EN521 is stiff enough and the XT hub has wide enough flange seperation that the extra lateral stiffness of the plain gauge spokes is simply not required. It i just dead weight in the wheel and sheap spokes with a good rim and excellent hub seems like a waste to me.

alomac

I know you can't buy the cups as a service item, but as mentioned I have a donor hub that I can take the cups from.

I do have the concern that you mentioned, thecycleclinic, that it might be better for my peace of mind just to get a better wheelset. It's probably a topic for the buying advice forum though, so I'll go ask there. Looking online, it seems that M475s are a bit of a lottery when used off-road; some (presumably a majority given how long these things have been kept in production and many of them are out there) get miles of trouble-free riding out of them, while others don't. I have no doubt they'd make a fine on-road hub - the Tourney level RM-30 in my commuter has been spinning happily for almost three years now with only annual replacement of the balls and cones.

FWIW the Merlin build does come with double-butted spokes, but of the ACI brand which I know nothing about. CRC will do DT Swiss butted spokes for roughly the same price.

mrmonkfinger

alomac wrote:

FWIW the Merlin build does come with double-butted spokes, but of the ACI brand which I know nothing about. CRC will do DT Swiss butted spokes for roughly the same price.

ACI have been around for a while, quality is no problem.