(RS) Steerer tube replacement? Is it the done thing? How safe?
Not my forks, but I'm considering buying them (for next to nothing). My brother was following me a bit close in the alps this summer and rode them into a seesaw while it was still up (not a very big one) but still a very sudden over the bars moment! The (handbuilt by merlin) front wheel remained perfectly true, the front tyre didn't pinch flat (folding tyre + XC tube), the fork still slides very smoothly, there doesn't appear to be any bending in the fork crown/stantions/lowers. Just that the steerer tube is bent, which forced the headset to ovalise the headtube in the bike
Anyhow in the pic below, the steerer tube is NOT snapped, just bashed out (from above) with a hammer as the steerer is just a press fit (the crown hole doesn't appear to have any damage whatsover to it)
I believe it was pretty commonplace to replace steerer tubes on some older marzocchi forks, but anyone any idea about newer (2008) RS (recon) forks?
The steerer tube is a simple press fit, the top cap will make sure it all holds together, I assume the severity of the press fit would stop the fork being able to 'steer' on its own. I mean the 5-10Nm bolt clamping force on a stem works?
Would it normally have some sort of glue/sliding locktight/etc/etc to help stop the steerer from rotating?
Would you consider replacing the steerer tube? Would you ride it? Is it even available as a spare (that one is a steel one, an aluminium one would save weight so would consider).
Or would it better to get new steerer/crown/stantions in one?Posted 7 years ago
The lower end of the headtube is ovalized to be fair (the bend in the head tube forces the headset cups to be at funny angles. The headset cup has been bashed forward again and the gap to the rear has been filled with liquid metal. ie a complete bodge. Under rider wieght the headset cup will be pushing against the intact front edge anyway
A fair few areas around the headtube have got flaking paintwork as a result of it too though, presumably the frame was able to flex/stress more than the brittle paint?
I'm not confident RS will do replacement steerer tubes, but theres an offchance I might be able to get one off another bent RS fork (steerer tube intact) from a friendPosted 7 years ago
I'm not riding the frame, my brother is, so I don't have to worry about that bit ..
If I was to try to use the fork (with a new steerer tube) then I'd have something to worry about. Just trying to find some sort absolute reasoning not toPosted 7 years ago
Its not exactly impossible for the steerer tube to have been deliberatley designed to be the weakest 'link'?
"With your cavalier attitude to safety"
I'm not that bad, other forks have had replacable steerers in the past, and I can't find any damage to the rest of the fork at all? The steerer tube bashed out easily enough to push it from its press fit, a stem is merely clamped up with not loads of force and that works?
I'm just wondering if theres any explicit warning/reason not to?
Cynic-al, you're not quite living up to your name? ..Posted 7 years ago
It'd probably not be ridden over anything 'big' just going onto the XC bike, so no hucks/drops or anything really rocky. Probably some tabletops and some stairs though. Theres always a chance it could end up on the FS if/when the Revelation goes back to the menders again so couldn't really guarantee 'less than big' riding onlyPosted 7 years agospeaker2animalsSubscriber
If it was a case of replacing a steerer because I'd cut it too short or if I was swapping too a bike that needed a different length I wouldn't worry. I'm just worried about this. I'd try to break for parts and get a new one but it's your call.
Good to see your concern for your brother.Posted 7 years agoSlogoMember
you cant buy these parts because its not safe to replace a steerer tube. there could be stress fractures around the top of the forks you cant see! there only recons so pick up a new set £160 ish.
if you use them you will only waste more money repairing them and **** a new frame when they break again and you face plant in to the road/track/mud and need new teeth! then your go visit your brother in hospital after his head tube snaps!
i bet your the kind of person who leaves the shed open or bike unlocked and wonders why its stolen!Posted 7 years ago
"i bet your the kind of person who leaves the shed open or bike unlocked and wonders why its stolen! "
I hadn't really thought about it that much though, the crown potentially being a 'timebomb' waiting to snap. Hmm
So new steerer/crown/stantions would be fine? (depsite being what, £100-150?)Posted 7 years agocoffeekingMember
This can only really be a troll when put in tandem with the errrr tandem thread!
Personally I'd want to know exactly how the fork was designed before pressing a new steerer in. Even if theres no crown damage visible you may have just shoved it nearer to its failure limit, not sure I'd like that but if I were broke I might risk it on a low-impact bike.Posted 7 years ago
No no, I (was) thinking of how plausible/safe it would be to make the fork ridable again. The crown is probably not worth the risk
I just had 2 thread ideas to put up, so while I was putting one up, I thought I'd put up the other is all
If I was able to get the bent recon from a friend, I might be able to use the complete steerer/crown stantions assembly, though due to the way the fork is bent I think the stantions will no longer be parallelPosted 7 years ago
Okay, so if the crown is/was damaged/stressed/strained beyond/near to its limits, would the more brittle paintwork show signs of this, eg flaking/stretching etc..Posted 7 years ago
I know theres an awful lot of assumptions in asking that, many of which I believe to be false, but I'm interested in the whys
The pic isn't overly clear, but the visual bend in the steerer tube is about 50-60mm up from the base of the steerer tube, ie not where the crown is, it looks as if its bent where the steerer tube jumps to a thinner thicknessPosted 7 years ago
I realise the steerer tube could still have bent/slipped within the crown as well
Hmm altough the thickness should be the same as for the crown race, so the RST steerer tube should fit, I can't help doubt the tolerances would be out (despite it suppoed to be exactly 30mm) to run an RST part in a Rockshox Fork
i think that's the least of your worries! don't the oems use liquid nitrogen to install stanchions/steerers into the crown?
Can't be bad for a £5er. Worth it for the sheer bodginess of it. Also, cut one of the legs off and fashion it into a lefty.Posted 7 years agobommerMember
I'd have thought if you smacked the old one out 'fairly easily' the crown hole is already fairly flared/damaged. Why not fit a new one, then drill a hole through the crown and steerer then stick a nut and bolt through the whole lot? It'll snap around the hole but you'll KNOW where it's gonna snap….Posted 7 years agotinsyMember
James, yes the hot and cold thing is how it would have been fitted at the factory, its just an interference fit part, kinda like a headset cup but with more interference, if you was to take that to an engineering shop I have no doubt they could turn you a nice new steerer, and advise you on the interference fit your after (they will measure the steerer and Crown to work that out, now you might have lost a little of the interference by bashing the old steerer out but thay can make that up on the new steerer, if you are really concerned just crack test the crown too to be on the safe side. (you will have to lose the paint on it to do that though)
It would be cheap enough to crack test and to make a new steerer, if you have any trouble I can get it done for you.
You of course would have to assume responsibility if anything was to go wrong, but if it was me I would definitely explore repairing it.Posted 7 years ago
"impact that breaks the fork, bends the frame and breaks the headset"
The fork isn't actually broken, the steerer tube is 'only' bent at a stress riser* where the steerer tube changes from a much thicker thickness to a narrower thickness relatively suddenly
Only the lower end of the headtube (the unsupported/ungussetted) where the headset sits was slightly ovalised. The headset cup has been refitted into the 'normal' position with some liquid metal filling the little gap behind the headset cup (which isn't as deep as the headset cup)
The headset cup is fine
*I think this is correct?
"if you are really concerned just crack test the crown too to be on the safe side. (you will have to lose the paint on it to do that though"Posted 7 years ago
So if it had been near to breaking point then there should/ought to be signs of flakey paint/stressed paint?wwaswasSubscriber
Also, cut one of the legs off and fashion it into a lefty.
my view: my looks (such as they are) and skull are worth more to me than the cost of a knackered set of donor forks with the steerer still attached and decent set of stanchions.
You may get all this working (but as has been said – if the steerer was fairly easy to remove then suspect further damage elsewhere) but would you trust your life to it?Posted 7 years agocoffeekingMember
Worth a punt if I'm honest, if you can get a second steerer and press it out without damage. Local workshop will do the job for you for £20-30 I suspect. They could, as said above, also probably turn you a new steerer if they're any good, but that would be more pricey.Posted 7 years ago
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