Spontaneous self-disassembly of Shimano XTR M980 pedal

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IanW
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Joined: 9 Aug 2013, 2:10pm

Spontaneous self-disassembly of Shimano XTR M980 pedal

Post by IanW »

My spouse's right-hand SPD M980 XTR pedal experienced a spontaneous self-disassembly on her way to work this morning.
(she managed to mechanically limp home by approximately re-assembling pedal body to spindle and then pedalling very slowly / carefully)

It appears that the bearing retaining nuts on the outboard end of the pedal spindle came undone which has allowed the spindle to slide free out of the pedal body.

The remaining spindle is straight / true and essentially unmarked, with both spindle end threads entirely intact and the crank end threads still covered in little clean copper-slip grease.

The bearing grease is the clean grey Shimano OEM grease and there was plenty of it. And I have never had cause to disassemble it before.

I have undone the bearing retaining nut from the pedal body I have managed to remove it and the immediately subsequent sleeve.

But, apart from just 3 loose ball bearings that I have managed to retrieve so far, I have been unable to extract any other parts
(i.e. any of the parts mentioned in http://bike.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/PD/EV-PD-M980-3069A_v1_m56577569830818656.pdf )

Does anyone have
a) any idea how I might extract them?
b) any idea whether spare parts are readily avaliable for this pedal, assuming that some of them are missing (when it fell apart at the roadside) or damaged?
c) any opinions, good or otherwise, about this pedal?
(I.e. before I just go and order another pair of the same M980's or a pair of M780's to save a few pennies)

And no, I am not going to buy any SPDs that require a Shimano-specific (or anyone else) plastic tool to disassemble a cheaper pedal
because I want proper servicable components (but preferrably ones that do not self-disassemble)
IanW
Posts: 176
Joined: 9 Aug 2013, 2:10pm

Re: Spontaneous self-disassembly of Shimano XTR M980 pedal

Post by IanW »

Ah, slight correction:

Whilst the outboard spindle end thread *looks* ok.

It looks to be rather *shorter* than the threaded section length displayed in the Shimano parts diagram.

So I *think* that the threaded section has rather cleanly and perpendicularly sheared off.

So a new spindle and probably new ball-bearings and adjustment "cone" and locking / retaining nuts may well be required.

This is sounding less financially viable.

Apparently she got no advance warning of this failure, which is a bit worrrying.
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timdownieuk
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Re: Spontaneous self-disassembly of Shimano XTR M980 pedal

Post by timdownieuk »

I must admit I would avoid buying any pedal that doesn't have flats for removing with a spanner. That looks like an Allen key only type (although it's possible that the draughtsman left them out).
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Redvee
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Re: Spontaneous self-disassembly of Shimano XTR M980 pedal

Post by Redvee »

timdownieuk wrote:I must admit I would avoid buying any pedal that doesn't have flats for removing with a spanner. That looks like an Allen key only type (although it's possible that the draughtsman left them out).


Higher end Shimano pedals have only an 8mm socket on the back, no 15mm flats.
Brucey
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Re: Spontaneous self-disassembly of Shimano XTR M980 pedal

Post by Brucey »

I don't think this is an isolated incident

http://mtbegypt.com/articles/xtr-pedals-are-failing-en-masse-and-shimano-isnt-issuing-a-recall/

so maybe you have a warranty claim there (although UK warranty might be different).

People say that they feel the clip-in, hold and release action are different between the various models of MTB style double-sided SPDs (M520, M540, M780, M980 etc), but personally I can't see it as being a big deal; there are much bigger variations with shoes and cleat than between pedals.

The bearings/spindles on all versions from PD-M520 to PD-M980 are built in the same basic way and just vary in style, materials and finish. Well-used (and correctly adjusted/lubricated) M520s spin as well as the others, even if they don't always feel quite as nice when they are new.

Cash-wise I can't see why I'd spend more than the price of PD-M520s, especially for a commuting bike. They are only a little heavier and they don't seem to have axles that break.

The idea that the full-hex retaining sleeve versions are 'better for servicing' is a bit of red herring; the required 'special tool' TL-PD40 for the pastrycutter sleeves costs less than £2 and works just fine.

The lack of pedal spanner flats on the more expensive versions puts me off them too. An 8mm hex isn't enough to shift a really tight pedal; in bike shops they often describe this as 'a crap idea'.

If no joy with the warranty a new axle assy is about £30 (more than the cost of M520s...). It may be possible to use some other axle assy versions if you swap the retaining sleeve over BTW. [edit; removing the old bearing sleeve etc will be a right job; you will need to fit an expanding puller of some kind, or perhaps weld something onto the steel bearing sleeve (very tricky).]

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
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Redvee
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Re: Spontaneous self-disassembly of Shimano XTR M980 pedal

Post by Redvee »

I bought a pair of M520s off Amazon for £14 for the commute bike and apart from some lube where the cleat meets the pedal I haven't touched the internals. I do have a pair of M780s on the other bike though.
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RickH
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Re: Spontaneous self-disassembly of Shimano XTR M980 pedal

Post by RickH »

All three of my bikes have M520s. The oldest set are on my old MTB and were fitted in the 90s. They may have been disassembled once in the first few years but not subsequently - there doesn't seem much point as they continue to run fine. There doesn't seem much point to me in anything else, unless you want a platform for using ordinary shoes or more support because your SPD shoes haven't got stiff enough soles.

Rick.
Former member of the Cult of the Polystyrene Head Carbuncle.
IanW
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Joined: 9 Aug 2013, 2:10pm

Re: Spontaneous self-disassembly of Shimano XTR M980 pedal

Post by IanW »

Brucey wrote:I don't think this is an isolated incident
http://mtbegypt.com/articles/xtr-pedals-are-failing-en-masse-and-shimano-isnt-issuing-a-recall/
so maybe you have a warranty claim there (although UK warranty might be different).


Unfortunately the pedals are just under *4* years old
(I have just found the receipt from Chain Reaction Cycles dated 10-Oct-2010)

Brucey wrote:The idea that the full-hex retaining sleeve versions are 'better for servicing' is a bit of red herring; the required 'special tool' TL-PD40 for the pastrycutter sleeves costs less than £2 and works just fine.


Unfortunately, in my experience, it is precisely the use of plastic parts in these high-stressed components (i.e. pedals)
that just do not seem to stand up to very many service and maintenance operations.
So I prefer the longevity of components upon which you can use a standard (metal) spanner / allen key etc.

Brucey wrote:The lack of pedal spanner flats on the more expensive versions puts me off them too. An 8mm hex isn't enough to shift a really tight pedal; in bike shops they often describe this as 'a crap idea'.


I can entirely understand that viewfrom bike shops / mechanics because they are often on the receiving end of poorly maintained bikes

My / our cycles (bi- and tri-) are best described as "dirty on the outside but clean on the inside"
i.e. all the mechanicals are well serviced and maintained
but we do not necessarily clean our bikes often (certainly *not* after every ride)
So I have *never* had any problem removing the pedals from our own bikes (copper-slip grease used wherever possible / sensible on all threads)

But I can certainly see the merits of the M520's and to then treat them as "consumables" like tyres, tubes, drive-trains, brake blocks and brake / gear cables etc.
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531colin
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Re: Spontaneous self-disassembly of Shimano XTR M980 pedal

Post by 531colin »

I have 4 pairs of 520 going.
Probably about 10 years use on the oldest, I think that's pretty reasonable with just an annual grease-up. (Not that I could identify the oldest, unless its the pair with just one US patent number, the others have 2 US patent numbers)
Brucey
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Re: Spontaneous self-disassembly of Shimano XTR M980 pedal

Post by Brucey »

IanW wrote:
Brucey wrote:I don't think this is an isolated incident
http://mtbegypt.com/articles/xtr-pedals-are-failing-en-masse-and-shimano-isnt-issuing-a-recall/
so maybe you have a warranty claim there (although UK warranty might be different).


Unfortunately the pedals are just under *4* years old
(I have just found the receipt from Chain Reaction Cycles dated 10-Oct-2010)
that is rotten luck.

Brucey wrote:The idea that the full-hex retaining sleeve versions are 'better for servicing' is a bit of red herring; the required 'special tool' TL-PD40 for the pastrycutter sleeves costs less than £2 and works just fine.


Unfortunately, in my experience, it is precisely the use of plastic parts in these high-stressed components (i.e. pedals)
that just do not seem to stand up to very many service and maintenance operations.
So I prefer the longevity of components upon which you can use a standard (metal) spanner / allen key etc.


in general terms I'd agree with you but in this case I have found out that my suspicions were ill-founded. After very heavy use the pastrycutter part on the pedal can certainly wear or be damaged. However I have removed them quite easily even when they have never been disturbed before and half the teeth are missing; unlike a metal part they don't corrode into position in the same way. I have only once seen these parts stuck in the pedals so badly that they had to be melted out, and that was when some joker (not me BTW!) had put the wrong ones in each side (tip; service the pedals one at a time; that way you can't get the parts mixed up.... :roll: ). If you do think they are a bit manky then they cost less than £2 each to buy as spare parts.

With the plastic retainer, you can't easily overtighten the parts, which with metal ones is a real possibility. Nor do they work loose in service, where with the metal ones they need soft Loctite to completely exclude this possibility.


Brucey wrote:The lack of pedal spanner flats on the more expensive versions puts me off them too. An 8mm hex isn't enough to shift a really tight pedal; in bike shops they often describe this as 'a crap idea'.


I can entirely understand that viewfrom bike shops / mechanics because they are often on the receiving end of poorly maintained bikes..


that is a fair point. However in addition to this I have also heard of instances where the pedal spindle cracked lengthwise, with the crack starting in the corner of the 8mm hexagon. The exact circumstances are unknown to me but it seems that this axle design is a little less reliable. A possible benefit is that the seals may be better, and may have a little less drag.

But I can certainly see the merits of the M520's and to then treat them as "consumables" like tyres, tubes, drive-trains, brake blocks and brake / gear cables etc.


However the idea that PD-M520s (and PD-M515s before that) are in some way 'consumables' is just not the case. Some people may treat them like that because they are so cheap to buy but they are actually one of the most durable pedals made IME. As Colin says an annual service (for road use, more than this for MTB use) seems more than adequate, and I have yet to see a properly maintained pair actually wear out. I've seen some where the cleat interface has worn very badly (and here the expensive versions have no advantage BTW), and the bearings have never been adjusted or lubricated etc. On examination the bearings have still been quite serviceable. I have several pairs using this bearing system that are over 15 years old and they are still going strong. If anything, they just get smoother and smoother...

The only major issue that I have with SPD pedal bearings (and this applies to all of them with the retaining sleeve type bearing system) is that the locknuts are not always set tight enough in the factory to prevent the bearings from going out of adjustment. When this happens the right pedal bearing slackens, and the left pedal bearing tightens as the cones precess on the threads. I have seen a few pedals where the left bearing was prematurely worn because of this effect, and I've 'rescued' many more that were going that way.

If it is the left pedal that is broken BTW, it may be that the cone moved thus and applied an additional load to the bearings; with intrinsically smooth bearings as found in the M980 model the end load could be very large and you might not notice.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
IanW
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Re: Spontaneous self-disassembly of Shimano XTR M980 pedal

Post by IanW »

Hi Brucey,

Thanks for all that really useful information.

I have never actually tried the cheaper end of the Shimano SPD pedal range, precisely because of my doubt of plastic pedal components.

But with your experience and observations I might just take a punt on a pair of M520s when they next become "on-sale" (i.e. at a discount).

Thanks very much.
Ian
Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Spontaneous self-disassembly of Shimano XTR M980 pedal

Post by Brucey »

you have got little to lose by trying them; it is only about a fiver more to buy M520s with cleats than it is to buy cleats alone.

[ Edit; both wiggle and CRC have them (with SH51 cleats I think, but check this) for £14.99 a pair right now, unless you want silver ones from CRC in which case it is £15.99 for some weird reason... :roll: ]

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
Brucey
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Re: Spontaneous self-disassembly of Shimano XTR M980 pedal

Post by Brucey »

531colin wrote:I have 4 pairs of 520 going.
Probably about 10 years use on the oldest, I think that's pretty reasonable with just an annual grease-up. (Not that I could identify the oldest, unless its the pair with just one US patent number, the others have 2 US patent numbers)


I just checked my PD-M520s and the most recent set with a single patent number is date code FA which makes it Jan 2007. The newer ones all have two patent numbers on them.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
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