Deore hub failures

[peetee]

I have come across a lot of Deore M525 8/9/10 speed hub failures where the seals have failed to keep the water out and the cones have worn or pitted. Usually, but not exclusively rears. Sometimes at quite low milage for what should be a reasonable quality hub (or perhaps Deore doesn't amount to much these days?)

My search for a replacement part has lead to genuine items at an eyewatering £5 each plus postage. Can anyone suggest a source of spares or an alternative replacement cone?

[gaz]

One oft quoted source of spares is to buy a whole NOS hub. You get the part you want now and some more parts for stock or re-sale.

[Gattonero]

One oft quoted source of spares is to buy a whole NOS hub. You get the part you want now and some more parts for stock or re-sale.

+1, I've always said that it seems a waste of money, but with a complete new hub one gets a bargain with new axle, cones, ball-bearings, skewer and especially new steel hub races that are not an available spare part

[andrew_s]

I have come across a lot of Deore M525 8/9/10 speed hub failures where the seals have failed to keep the water out and the cones have worn or pitted. Usually, but not exclusively rears. Sometimes at quite low milage for what should be a reasonable quality hub

I've found that you've got to service the hubs before riding on them. New hubs out of the box frequently have the bearings adjusted too tightly, and ay not have an adequate amount of grease.

[Brucey]

....My search for a replacement part has lead to genuine items at an eyewatering £5 each plus postage. Can anyone suggest a source of spares or an alternative replacement cone?

Shimano have recently increased their spare parts prices on small stuff like that. Some items have doubled in cost. This is a dumb move on shimano's part; why bother buying a rebuildable hub if the spare parts cost so much that repair is uneconomic?

In terms of making the hub work, almost any rear shimano cone will do; the cone profile is usually the same. But the length may be wrong and seals won't be compatible in very many cases. If the RH cone in the rear hub is worn, it is often easiest to fit a different cone and a (matching) replacement seal in the freehub body.

The reason for the bearing failures is nearly always the same; bad adjustment and bad lubrication. Shimano's grease is 'not at all resistant to salty water' and since that is what we get all winter long the bearings are bound to suffer unless you put something better inside the hub. Shimano's grease is also not fluid enough to replenish itself at the seal lips, so the seals are also bound to fail.

Apologies if this is obvious but if there is no slack in the bearings (with the QR loose, which just disappears when the QR is tightened), the bearings are set too tightly; this alone will wreck hubs in a few hundred miles that ought otherwise last for years.

As Andrew says (more succinctly than me) these hubs need to be serviced when new. They just won't last otherwise.

cheers

[recordacefromnew]

I have come across a lot of Deore M525 8/9/10 speed hub failures where the seals have failed to keep the water out and the cones have worn or pitted. Usually, but not exclusively rears. Sometimes at quite low milage for what should be a reasonable quality hub (or perhaps Deore doesn't amount to much these days?)

One oft quoted source of spares is to buy a whole NOS hub. You get the part you want now and some more parts for stock or re-sale.

If only one could easily/cheaply. The M525 hub has essentially been out of stock (NOS or otherwise) for a couple of years - I have a number of orders from UK as well as German vendors and the resulting returns to prove it. What happened, is that Shimano quietly withdrew the FH-M525, and replaced it with the FH-M525A, a rather different, more cheaply made (surprise surprise ), and imho poorer hub in terms of seal against elements. Unfortunately, many vendors (including ones I bought from and had to return M525A's supplied) are still marketing these M525A as M525 today - so watch out, and make sure you make them check the marking on the hub shell and confirm in writing before ordering. If you bought a M525A, and use the incompatible parts on the older, imho better M525 hubs, chance is you are going to end up with sealing problems.

Parts, on the other hand, are still mostly available for the FH-M525 afaik. They are worthy of and will reward proper setup and maintenance as suggested above.

You can see the differences below:

[peetee]

Thank you Recordacefromnew. I was unaware of the detail difference or that there were variants of the 'same' hub. Your explanation answers another question I had - that being why one retailer listed more than one type or right hand rear cone.
As I never know what's appearing from day to day it looks like stocking replacements for these hubs is going to be a costly business.
That's Shimano for you. Why did I ever think otherwise?

[Gattonero]

Seems it's the distributor's fault.
I.e. a friend of mine is supposed to wait up to July for the "converter plate" of an Ultegra front mech, is a £2.99 small part but the mech is unusable without

[Brucey]

for correct PNs use;

FH-M525A EV techdoc;

http://www.sjscycles.com/Drawings/Shimano/Shimano_Deore_FH-M525-A_Tech_Doc.pdf

FH-M525 EV techdoc;

http://bike.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/FH/EV-FH-M525-2067B_v1_m56577569830728349.pdf

cheers

[recordacefromnew]

for correct PNs use;

FH-M525 EV techdoc;

http://bike.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/FH/EV-FH-M525-2067B_v1_m56577569830728349.pdf

cheers

Yeah, that link gives you the "correct" part numbers. That is not to say using those part numbers will necessarily give you the correct parts from Shimano's parallel universe... For the freehub e.g., the part number leads to:

https://forum.cyclinguk.org/viewtopic.php?f=5&t=112398