Are new Shimano XT hubs a bit rubbish these days?

[N/B]

Recently bought a pair of M785 XT hubs for an upcoming 26" build, and a few mechanics are telling me these hubs are crap.
Tales of rapid failure of the freehub, badly-set-up bearings from the outset, and a generally more fragile nature than the simpler Deore hubs.
I haven't laced these up yet (or even ordered the spokes), and this talk has me thinking of returning them.

What say Retrobike?

 

[FluffyChicken]

Re:

I have the 770, same as 775 but with out the disc mounting.

I think these are also pretty much the same as the T780//M785 but I thought they where suppose to have the improved freehub?

Anyway my freehub is working fine and so are the bearing. But they are a bit rumbley just cannot find out where.
So the 780/785 thought may be legacy info from the nearly 770/785 problems?

I do know a few people using the 780 with no problems.

 

[hamster]

Long distance tourers gave up on XT when they went to aluminium axles. To get them to fit they undersized the bearings. As a result the hubs last only a couple of thousand miles before the bearings grind out - just like Hollowtech bottom brackets really.

Deore continue with the same bearing and seal design that Shimano has had for 20 years, which works brilliantly well and is just about bombproof. I've got a rear with over 20,000 miles on it and nothing more than a couple of squirts of grease for maintenance.

To keep freehubs lasting, avoid spray lube as it works its way into the freehub body and washes out the grease in the freewheel mechanism. Use a drip lube directly onto the chain instead. I've not had to replace a freehub body in 15 years since learning this trick.

 

[N/B]

Long distance tourers gave up on XT when they went to aluminium axles. To get them to fit they undersized the bearings. As a result the hubs last only a couple of thousand miles before the bearings grind out - just like Hollowtech bottom brackets really.

Deore continue with the same bearing and seal design that Shimano has had for 20 years, which works brilliantly well and is just about bombproof. I've got a rear with over 20,000 miles on it and nothing more than a couple of squirts of grease for maintenance.

This is pretty much what the mechanics are saying to me. It's either buy a Deore rear, or up the budget significantly and go DT 350 / White Industries.
Is the SLX FH-M675 hub a steel axle, or aluminium?

 

[hamster]

Looking at the exploded view, SLX still have the good design and steel axles.
http://cycle.shimano-eu.com/media/techd ... 805676.pdf

Below is the exploded view of the XT: note the higher number of smaller balls and (even worse) that the LHS side have them caged, further reducing the number available to take the load.
http://cycle.shimano-eu.com/media/techd ... 753751.pdf

 

[FluffyChicken]

Re:

Cages are no always bad, it stops them bunching and keeps an even load over the axle with reduced friction. Shimano bottom bracket always use them (you just can't see them) and they last for ages, mavic headset similar. Also nearly all cartridge bearing use cages (and metal not a nice plastic) at that.

It's not those bearings that are the problem though, it's the freehub that needed to be redesigned to take the the bigger axle (and hugh Allen key to get the body off). That was always the problem mentioned in the early M770/775 hubs.

Not heard or read anything bad about the 780/785 hubs or XTR for that matter.

 

[N/B]

I've already decided to downgrade to Deore M615 for this build. It's made it easier to get the spokes I wanted anyway.

 

[Sketchyxup]

Re:

Iv got 785 on 2 bikes and both have had freehub issues, one just locked solid and one split along one of the splines. My LBS said there was a new part number for the freehubs to fit those hubs indicating they have updated them in some way, not had any issues since but it might be too soon to tell.

Iv not actually had any bearing issues but im one of those saddo's that enjoy stripping and greasing hubs so they are in fine fettle.

One of my XT hubs was running a 12mm thru axel so i dunno how that affects anything?

How has XTR been affected?