Yet Another Cycling Forum
General Category => The Knowledge => Topic started by: andyoxon on 10 January, 2019, 01:12:41 pm
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On my main steel bike (531ST) there is a Shimano Deore
DX headset, of early 90s vintage, which I reckon should be checked/lubed/serviced. AFAIA there is no play in the headset, and it feels smooth, but hasn't been looked at for a very long time. Literally the only thing I've done is lift the rubberised bearing cover and added a load of grease.
I've not serviced a headset myself, so after the best way to assess what to do/replace/which tools I need to get. If I take the assembly apart, do the bearings need to be preloaded before tightening?
edit. found the Deore HP-MT60 details on https://si.shimano.com/#/
:)
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If it's not "notchy" I'd probably just leave it be. You've kept it well greased so the races/balls should be fine, and the races aren't brinelled - otherwise they'd feel notchy.
If you do dismantle it, when you re-assemble, tighten it up so the steering is just too stiff, then back it off a bit before tightening the lock nut.
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If it's not "notchy" I'd probably just leave it be. You've kept it well greased so the races/balls should be fine, and the races aren't brinelled - otherwise they'd feel notchy.
If you do dismantle it, when you re-assemble, tighten it up so the steering is just too stiff, then back it off a bit before tightening the lock nut.
Ok thanks. I've only greased the upper bearings/retainer, as the lower head cup is metal and 'sealed', so these will probably be in need of some lube. Will have another close feel of the HS action.
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lower bearing carries most of the load and in addition gets the spray (if there's no front mudguard), so it goes first. my tip for the cartridge bearings, if the are of the same diameter, to swap them around once the lower starts getting less smooth. this basically doubles the service life (and unnecessary wastage) of the headset.
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Be careful - as you undo the threaded portion, the bottom race will loosen up, and depending on how much grease/gunge there is and how good the bearing cage is, the bearings might just fall out all over the floor! If the balls in the bottom part are OK, you probably don't even need to take it all apart - you can just undo the top bolt a bit, drop the fork down a cm or 2, give everything an inspection, clean, and grease, and then push it back up again (if you put the fork ends on the floor then you can do the same with the top race at this point).
So long as you are able to correctly tighten it afterwards, inspecting and re-greasing a threaded headset can be done remarkably quickly.
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If you do dismantle it, when you re-assemble, tighten it up so the steering is just too stiff, then back it off a bit before tightening the lock nut.
Headset maintenance is 10% having the right tools, 5% being good at finding dropped ball bearings and 85% knowing how tight it should be. Unfortunately that's one of those things you need to develop a feel for, possibly by getting it expensively[1] wrong...
You're looking for the point where there's only just no play when you hold the front brake on and rock the bike. Too tight and you knacker the headset. Too loose and you knacker the head tube. Play in the brake or a suspension fork obfuscates the correct feel, and IME threaded headsets are fiddlier.
[1] Cartridge bearings are a good place to learn that you've overtightened it, as the brinelled[2] bit is easily replaceable.
[2] Not really brinelled.
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as others have said, excess preload is the enemy of this headset. Whatever adjustment you have is immensely changed (increased preload) once the locknut is tightened. A good method of getting the correct adjustment is to
a) finger tighten the adjusting race, then back it off 1/4 turn and tighten the locknut down on it
b) check for free play. Hopefully there will be some rather than none.
c) loosen the locknut, then increment the adjusting race tighter, retighten the locknut, and check for free play again.
d) note that each 1/50th of a turn of the adjusting race removes ~20um clearance from the bearings
e) repeat step c) until there is no free play with the locknut tight. If you increment a small fraction of a turn each time you do step c), the first time you get no free play in the bearings, you are done.
IIRC these headsets use chunky 1/4" stainless steel balls but the raceways may not be as corrosion resistant. If the raceways are indented, you can dispense with the clip and fit 17 loose balls instead of 16 in each clip. Subsequent shimano headsets used a proprietary cartridge design, and it is now very difficult to find replacements of this type.
FWIW it takes slightly longer to adjust a threaded headset, but once adjusted such headsets can (as you have found out already) stay in fine fettle for a long time.
cheers
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The only thing I can add, is that if it has loose bearings, or you are not sure, place an old towel underneath to catch the ball bearings as they fall out.
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Thanks all. :thumbsup:
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If you do dismantle it, when you re-assemble, tighten it up so the steering is just too stiff, then back it off a bit before tightening the lock nut.
Headset maintenance is 10% having the right tools, 5% being good at finding dropped ball bearings and 85% knowing how tight it should be. Unfortunately that's one of those things you need to develop a feel for, possibly by getting it expensively[1] wrong...
You're looking for the point where there's only just no play when you hold the front brake on and rock the bike. Too tight and you knacker the headset. Too loose and you knacker the head tube. Play in the brake or a suspension fork obfuscates the correct feel, and IME threaded headsets are fiddlier.
[1] Cartridge bearings are a good place to learn that you've overtightened it, as the brinelled[2] bit is easily replaceable.
[2] Not really brinelled.
I've been having a close look. There is some play in the front cantis (for some reason) which doesn't help, but if I hold F&R brakes tight on I'm pretty sure I can't feel any play in the headset, There's no notchiness when I move the handlebars, but are other scrapey sensations like gear cable outers contacting.
Leaning towards having a look at the headset bearings and surfaces, regreasing, and attempting to tighten correctly. I should really investigate the front cantis, and also need to shorten the cable outers really, so another job.
Thought headset was DX as my original F&R mechs on the bike were DX, but looks like it's regular Deore
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regular deore may have smaller ball bearings in it. IIRC for a while they only put the model number on the plastic covers, and printed it on in such a way as it soon rubbed off.... Identifying it might be tricky, but it might be that the model number is marked on the top dust seal; worth looking I suppose.
FWIW it is probably worth adjusting it now and seeing how it feels. Then mark the adjusting race (on the metal part, if there is a plastic cover) so that you know where to adjust it to when it all goes back together.
cheers
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Thanks. Yep, for Deore bearings would be 20x 5/32" in a retainer. Lower head cup fairly clearly has printed "Shimano Deore".
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Headsets are best loosened with the bike upright but removed with the bike upside down in a workstand. This stops the balls and the fork falling out.
I have a NOS DX 1 1/8" headset here if you need one, although a Tange Falcon is far superior.
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Headsets are best loosened with the bike upright but removed with the bike upside down in a workstand. This stops the balls and the fork falling out.
I have a NOS DX 1 1/8" headset here if you need one, although a Tange Falcon is far superior.
Thanks Roger. OOI I wonder what features make a better headset - suppose general build quality, materials...
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Anything with cartridge bearings or loose races tends to be immune from "indexing". Also better seals.
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Anything with cartridge bearings or loose races tends to be immune from "indexing". Also better seals.
Not anywhere near a universal truth IME; there are good and bad examples of each.
One thing that does seem to be the case is that cartridge bearings or loose races that are only 'located' on a conical interface need more preload on them before they won't rattle intolerably. This reduces the window of acceptable adjustment/preload values.
There are plenty of 1-1/8" ahead headsets in which the cartridge bearings inside have only twenty-odd ball bearings of 1/8" diameter; this is nowhere near enough for a bearing that sees high service loads and/or high preloads, and these bearings 'index' very easily.
cheers
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One thing that does seem to be the case is that cartridge bearings or loose races that are only 'located' on a conical interface need more preload on them before they won't rattle intolerably. This reduces the window of acceptable adjustment/preload values.
I've found that it helps to do them up quite tight, with a view to pushing the cartridge fully into place, before slackening off and re-adjusting.
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I only have experience of Tange, Cane Creek and Chris King cartridge headsets but I find them trivially easy to adjust and "fit and forget". A Cane Creek S2 lived on my Hewitt for almost a decade with zero attention and I moved it to a LHT this year. It's as good as new. I ran a Cane Creek S6 for 9 years on a neglected commuter and it's still fine after about 20,000 miles and no maintenance. Modern headsets are good. My 90s Shimano road headsets with normal caged balls went notchy after 500 miles.
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i would also concur that since i started cycling (a good decade ago) i haven't had any issues with any of the bikes with integrated headsets, they last years and tens of thousands km. not needing special tools/spanners is a major advantage too.
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….. My 90s Shimano road headsets with normal caged balls went notchy after 500 miles.
there's only one reason for that to happen; you may not agree but that is because they were not installed/adjusted correctly.
My experience is that if correctly installed etc, threaded headsets can be extremely reliable. I personally have some that have been in daily use for over 35 years, on bikes that live outdoors.
By contrast Ahead headsets are not properly weather proof; water gets into them from the top more easily (via several routes) and/or causes more corrosion problems, under identical service conditions.
cheers
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My old headsets (1055, mostly) died from false brinelling. I'm with Jobst Brandt on the causes of that, and cartridge headsets are immune to it because there are extra surfaces to take the rocking motion. I know you don't agree with the theory.
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HP-1055 is very similar to many other shimano headsets around that time. I have used one on an MTB and once it was set up right it didn't need anything doing to it for at least a decade (of hard use with a rigid fork). I have seen dozens of similar knackered headsets and they all had one thing in common; they were not adjusted correctly (as per the method I described upthread).
Brandt's reasoning re false brinelling is quite false; one of the things that he didn't mention (or apparently consider) is the extraordinary length of his steerer tube; this would flex far more than normal and this greatly alters the loading on the bearings. If you have a long/flexy steerer then it is possible that having some extra freedom in a headset is not a bad idea. However like many other things having a long flexy steerer probably also narrows the range of correct adjustment, too.
cheers
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Both cartridge and cage bearings can be restored / made more robust with a bag of loose balls a pot of grease and tweezers. Fill the race with grease, push in balls n-1 and assemble. For cartridges the shields can be popped out, the cage punched out and balls replaced in the same manner.
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That does temporarily fix the "indexed steering" problem but the headset will still be rough, i.e. it can't be adjusted so there is zero play in every position. I have done it in the past when ICBA to clean out retainers but I have a bag of bearing balls.
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if you replace balls in clips with loose balls they are spaced differently. This means that an indented headset cannot have more than one or two balls sitting between two indents at the same time. The load per ball is less because there are more balls.
If you also remove one of the lower races and turn it by half the angle between indents, and refit it, there cannot be any balls sitting between two indents in the straight-ahead position. Once you have done this the headset will work perfectly; leastways that is how it has worked out when I have saved the dozens and dozens of headsets I have done this way for other people who damaged them....
You just have to be careful to adjust it properly, not like it was adjusted before, which was almost certainly the thing that knackered it.
cheers
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update...
The other day, at the end of a commute, and having been apparently blissfully unaware of headset play (and done nothing), I had my front wheel against a wall and pressing down on my handlebars repeatedly, I felt clear play in the headset. Normally because the canti brakes have a certain amount of play themselves, it seems I haven't been able to feel the play in the headset.
Tonight I dropped the forks 2" and had a good look, cleaned & regreased. The bearings in this Deore headset are in retainers, and looked clean and shiney, the races looked fine. Perhaps it's a testament to the Deore dust seals, but I haven't greased the lower bearings at all*, and there was still a bit of grease in there, no corrosion etc.
So I hope I can tighten it all up correctly, at least I'm reasonably confident at feeling play without using the brakes. :)
* bike did go through a substantial period of under use though.
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depending on how long and flexible your steerer is, you may find that the status quo is to have a tiny bit of slack in the headset bearings; if so, this mostly doesn't manifest itself when you ride, except when the front brake is used.
cheers
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Thanks Brucey. I've decided to go for no play, but with the last of the play removed with the final tighten of the locknut (I think). As close to the 'threshold' as I can manage, with tyre against wall, and wiggling the bars. Hopefully all good.
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Adjusting a threaded headset is a bit of an art. Once you know how it all goes together and you've figured out the effects of small adjustments, you'll probably get a feel for just how much to tighten the adjustable part, and just how much you need to compensate for the lock nut difference. Might take a few goes, but you get it in the end. Helps if all the gubbins are really clean. A speck of grit can mess it up. Always been impressed by the seals on Deore kit. A headset spanner makes the job slighly easier (easier than using an adjustable spanner).