Shimano FH-M525A - buy spare or another?

[rogerzilla]

7, 8 9 and 10 speed rear mechs are interchangeable.

Front mechs are a bit of a mess (only an issue because Shimano decided we needed indexed front shifting...really adds value to a double chainring setup!). The front pull was changed sometime during 10 speed, I think, and road and MTB front mechs had different pulls, probably because underbar MTB STI only has a weedy little lever to push compared to a huge road brake lever.

If you are lucky enough to have a non-indexed LH thumbshifter on an MTB, you can run a road front mech...but, by $DEITY, it's stiff!

[mikeymo]

7, 8 9 and 10 speed rear mechs are interchangeable.

Thanks. Perhaps I'm thinking of shifter compatibility. As in, can a 10 speed MTB shifter change a 10 speed road derailleur?

the internet says:

https://www.mtbr.com/threads/2011-10-sp ... st-7343607

Which might be relevant to me if I want to use any of the stuff from the spares box to make up a flat bar bike.

Front mechs are a bit of a mess (only an issue because Shimano decided we needed indexed front shifting...really adds value to a double chainring setup!).

I've never had non-indexed front shifting, so wouldn't really know. As it happens I have a shiny new pair of DA downtube shifters. Sometime I might fit them and see how I get on. If nothing else when I eventually go on tour they can go in the bag as backup.

But despite the various negative comments about indexed front shifting, as a relatively new cyclist, I have to say I like mine. And haven't really found it problematic to set up. This is the first bike I've ever made, and also the first derailleur bike I've ever ridden. As you might expect, the initial build took a bit to get right, gears wise. But now I've had a couple of years to learn and tinker, the front shifting is fine. In fact, now I understand the trim positions, and a sensible approach to changing, I would say it's perfect. The only aspect that "worries" me (and not that much) is Brucey's comment about how much strain there is on the STI when changing down from the big ring to the middle.

The front pull was changed sometime during 10 speed, I think, and road and MTB front mechs had different pulls, probably because underbar MTB STI only has a weedy little lever to push compared to a huge road brake lever.

Yes, something like that was what I understood. Though to be fair, I haven't paid that much attention. Basically I sort of ignore anything bigger than 9 speed. I suppose I should learn, but there are limits to how much knowledge I want or need, about things I don't even own or intend to buy.

[531colin]

I think road and MTB front mechs. have "always" been different cable pull....there used to be specific "flat bar road" shifters for this reason, I think.
Road and MTB rear mechs. (apart from some early Dura Ace, I think) were all the same cable pull up to and including 9 speed. Then, 10 speed Deore got its own special cable pull ratio, and now I believe there are all sorts of complications like Tiagra 10 speed with different cable pull ratios for different incarnations of the "same" groupset.
Oh, Brucey!

[zenitb]

Just checked, and my hub hoard all appear to be M756; thats XT 6 bolt with a steel axle.
Its in my mind that at the time I started buying them up, XT hubs for RIM brakes had gone over to alloy axles to shave a bit of weight, with the downside of smaller bearings as mentioned previously, and also some questions over the freewheel mechanism at least in early alloy axle hubs.......

yes definitely around 2008 there were problems with the "alloy axle" XT hubs freewheel mechanism. The freewheel design had been "squeezed" with the thicker alloy axle and problems resulted

To quote Brucey "..When these hubs were launched they had a disastrous reputation for reliability, with freehubs blowing up right left and centre. It appears that all models FH-M77x (and higher) may be afflicted." (from viewtopic.php?t=108592 )
.... and one of the primary sources I think he used ( https://www.peterverdone.com/wiki/index ... ub_Failure )

Broken FH-M775

Broken FH-M785

Broken FH-M788

broken fh-m788.JPG (33.06 KiB) Viewed 873 times

All that said one of my friends had his "steel axle" XT hub replaced by the "aluminium axle" FH-T780 (specified and built into a wheel by Paul Hewitt in Leyland) a few years ago and (despite my "doom and gloom" predictions) he has had zero issues.. so maybe this was an issue that has since been fixed ? The culture of Shimano is to "silently change" components so it doesn't surprise me there is no recall announcement.

[rogerzilla]

I think road and MTB front mechs. have "always" been different cable pull....there used to be specific "flat bar road" shifters for this reason, I think.
Road and MTB rear mechs. (apart from some early Dura Ace, I think) were all the same cable pull up to and including 9 speed. Then, 10 speed Deore got its own special cable pull ratio, and now I believe there are all sorts of complications like Tiagra 10 speed with different cable pull ratios for different incarnations of the "same" groupset.
Oh, Brucey!

You're supposed to buy a whole new bike every time. It's like Microsoft telling you the best way to get the new version of Windows is to buy a new computer. Feeds the consumer economy (and the landfills).

[Jamesh]

To be fair to Shimano they have been pretty stable in terms of groupsets and trickle down tech.

Serviceability is good and straightforward compared to their makes...

Ok they gave made a few poor designs along the way see above but in the whole quality is pretty good compared to other manufacturers stuff and esp compared to other sectors of consumer mechanical tech....

Cheers James

[531colin]

To be fair to Shimano they have been pretty stable in terms of groupsets and trickle down tech.

Serviceability is good and straightforward compared to their makes...

Ok they gave made a few poor designs along the way see above but in the whole quality is pretty good compared to other manufacturers stuff and esp compared to other sectors of consumer mechanical tech....

Cheers James

Yeah, the stuff works, but they don't do compatibility do they?
Brake cable pull....not just Road and MTB, but road splits into NSSLR and whatever the previous acronym was.
If you want road STIs, rim brakes and 40mm tyres and mudguards, you can whistle!
Or a triple chainset, hydraulic brakes and road STIs
(Pretty soon, no triples at all, I reckon)
Road STIs and touring triple chainset, say 24, 34, 46T...? you have to use a F. mech. made to fit 52T?

[Jamesh]

Agreed if you are wanting to cross genre then it becomes a minefield.

Thanks for pointing that out.

Cheers James

[mikeymo]

Buying lots of old stuff is my strategy.

So far, so good.

[colin54]

For what it's worth, I think it's a good idea to settle on one kind of gear set-up for future proofing as the OP has (and makes buying spares whilst you can, straighforward, and at reasonable prices). My own bikes have variously 559-26'', 700c wheels 126/130/135mm wide frames and 7&8 speed hubs, it can get a bit mind-bending from a spares point of view, what is compatible with what. I wish I'd thought about standardising a bit with hindsight - (or making do with one bike...).
I've bought and used spare hubs or their internals over the past few years, a lot of the time it's been to replace a pitted cone whilst having the hub apart to re-lubricate, having struggled to get the wheel to spin nicely with the damaged cone (picture), note pitting.

Having taken a few of these apart over the years which have done a few miles with the factory tight set-up (once it's been built into a wheel), nearly all have had cone damage, it doesn't take long, luckily the cone seems to fret first leaving the cup, (pressed inside the hub undamaged, tricky if not impossible to remove if damaged) . If the cone is not replaced the surface hardening will eventually start to flake of the ball-bearings as well.
I've had freehubs start to make the cracking noise on occasion indicating trouble (adjustment/lubrication with the pawls.
I've had a slightly bent spindle on a rear hub making adjustment problematic.
Most of this is down to set-up from new (and a surprisingly small amount of grease from new from Shimano) and can be largely avoided by early correct set-up & lubrication as I've learned from posts on here, and my own subsequent experience . I've also had thread strip on a spindle whilst servicing it. Shimano hubs do however seem to rumble-on for a good while with any of the above issues, I only found (caused sometime!) whilst servicing them.
Luckily, and here's my point, I was glad to have almost all the spares to hand when these problems arose having bought them when I could, and at a reasonable price.
I bought a set of wheels from Spa a while back and re-greased/adjusted the hub before I put it in the bike, I didn't / don't expect them (or any other wheelbuilder) to do this. I imagine it would (a) invalidate their warranty from Shimano (b) add to the cost of a wheelbuild. I think they're an inherently reliable design and will roll way past the warranty period as built.
The only one I've seen totally fail was the other day, I stopped for a bloke whose rear derailleur was swinging forward as he tried to freewheel down a hill, when we took the wheel out the free-hub was seized up, quite rare ?
I was looking at those RD-M772's the OP uses on ebay the other day and one sold for £108, what were they new, 50 or 60 quid ?
Going back about 6 years, 7-speed RX100 down tube levers could be had new for about £15-£20 on ebay, not any more, £40 is a not uncommon price.
Edit, picture added: a clearer picture of typical cone damage from a different hub, front this time.

.

[mikeymo]

For what it's worth, I think it's a good idea to settle on one kind of gear set-up for future proofing as the OP has (and makes buying spares whilst you can, straighforward, and at reasonable prices).

Thank you for confirming that my approach isn't crazy.

I was looking at those RD-M772's the OP uses on ebay the other day and one sold for £108, what were they new, 50 or 60 quid ?

I think I watched the same one. Like I said, I bought the last retail NOS RD-M772 in the UK (I think) for £80. As I've not fitted it yet I was tempted to sell it at a profit.

To be accurate, I don't actually "use" the M772, yet. I bought three of them, in a hurry, as I could see they were on their way out. I've got the NOS one, and two decent condition used ones. Given their reputation for longevity, used ones are probably fine. I've just serviced the jockey wheels on the better used one, and will fit it when I do the big annual bike service. As it means cutting the cable shorter (I've got a Sora on at the moment) I'm in no hurry. There's every possibility that in 20 years I won't have managed to destroy the two used ones I've got, in which case the NOS one will either be worth a small fortune, or nothing at all.

Some of the parts I'm buying to squirrel away haven't exactly been at "reasonable prices" as you put it. The NOS Ultegra 6510s definitely weren't.

I should really narrow my focus even more perhaps, and decide if I'm storing up pre or post NSSLR levers. But to be honest I've probably got enough now. Though I keep my eyes on the ebay and similar.

There are other places now I need to consider in terms of longevity - "if this tiny often ignored component breaks, can I get another one, or will it mean a wholesale replacement" - type of thing. As I said, I'm new to bike fettling, so wasn't really aware that freehubs might wear, for instance. There's a whole unused hub on it's way to me, so that's hopefully covered.

[colin54]

I spoke to soon about freehub reliability, I met a bloke this afternoon scooting an MTB along the towpath with a no drive free-hub, he thought the pawl springs had gone. I didn't see if it was Shimano, it had what looked like one of those 40 odd tooth bottom gear sprockets.

[mikeymo]

- If you were going on a long tour and just wanted to refresh the hub you could swap the freehub and internals (so three of the four bearing races) giving you a "nearly new" hub for the tour.

Thanks.

And if I wanted to replace the fourth bearing race (NDS cup), how easy would you say it is to drive that out and drive the new one in?

[Cyckelgalen]

Replacing the NDS bearing cup is not feasible these days. Hubs are not designed to have the cups replaced, if you managed to pry it out of the hub shell, where would you get the replacement new race?

Even cones, that luckily wear wear first because the support the same load spread over a smaller surface, are getting difficult or uneconomical to source. If you can get both cones as separate spares plus fresh bearings you are often looking at a price similar to a whole new hub. To me it makes a lot of sense buying spare hubs to use the cones, axel, bearings, freehub, seals etc as spares. And only if you are unlucky to get a NDS race damaged, quite unlikely if you take reasonable care of your hubs, would you have to replace the hubshell and rebuild the wheel.

[mikeymo]

Replacing the NDS bearing cup is not feasible these days. Hubs are not designed to have the cups replaced, if you managed to pry it out of the hub shell, where would you get the replacement new race?

Even cones, that luckily wear wear first because the support the same load spread over a smaller surface, are getting difficult or uneconomical to source. If you can get both cones as separate spares plus fresh bearings you are often looking at a price similar to a whole new hub. To me it makes a lot of sense buying spare hubs to use the cones, axel, bearings, freehub, seals etc as spares. And only if you are unlucky to get a NDS race damaged, quite unlikely if you take reasonable care of your hubs, you would have to replace the hubshell and rebuild the wheel.

Thanks. As I said earlier up thread, I have indeed bought a complete new hub, which is in the post as I write.

Edit: This chap seems to remove a NDS cup relatively easily.

https://www.youtube.com/watch?v=Tv-3rkO6rNA

Admittedly he wasn't bothered about damaging the shell, though after he'd done it he claims that there wasn't any damage. Which, given that he was using a tool that is actually designed to "damage" things is maybe a good sign. If I were doing it I'd take care to find/design/make a suitable drift. And some sort of suitable press to get the cup back in (combined with fridge treatment).