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)
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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?
IIRC the steerer tube isn't replaceable on most modern forks, plus, where are you going to get a replacement steerer tube from? I'd be amazed if you were able to buy a new one.
How on earth did he bend the steerer without totalling the frame?
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 friend
You obviously don't worry about things as much as I do. I'd be looking for a new frame and new fork.
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 to
Its not exactly impossible for the steerer tube to have been deliberatley designed to be the weakest 'link'?
As said above you won't be able to buy one as RS don't sell them as parts. Your best option with those would be to split them for parts that other people need.
If you can get a steerer to swap, why not? If it goes in ok, I'd ride it.
With your cavalier attitude to safety, you might find a bit of old broom handle lying around. They're all 1.125". If not, a bit of insulation tape will make it fit.
"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? ..
Never understood why steerers aren't replacable anyway, surely they're just pressed in?
Am pragmatic when it comes to repairs, most doubters just don't understand how stuff works
yes lots of steerers are/were pressed in. Iirc freezing is used these days
Would imagine the stresses endured by the crown, when the steerer did that, would be enough to cause problems in the future when things get a bit "big"... I'd not ride it.
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 only
New crown steerer time matey, the face plant when the crown snaps on a big landing is going to sting a touch. 😮
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.
Under rider wieght the headset cup will be pushing against the intact front edge anyway
Roflcopter.
That is all.
heat the crown up so it expands stick new steerer in the freezer to contract press fit job dont you need to use a bearing press
AFAIK RS don't sell steerers alone, they only sell the complete crown/steerer/stanchion assembly.
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 ****ing 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!
"i bet your the kind of person who leaves the shed open or bike unlocked and wonders why its stolen! "
Nope
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?)
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.
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 parallel
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..
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
If you can get hold of a new steerer then yes you could fit it. I'd freeze the steerer then press it in.
However I would check the rest of the fork very carefuly as clearly a lot of stress has been put through it. I've seen a lot worse repaired and used though...
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 thickness
I realise the steerer tube could still have bent/slipped within the crown as well
As for stressed metals - we use a special paint to show stress on various things we are working on in our business.
bodge one of these on and hope for the best
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
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.
The old bashed out easily enough with some good whacks with a hammer, I'd assume it'd bash back in again as easily? Though steerer tube in the freezer beforehand and towel around the crown and pour boiling water on would help to get it in more smoothly?
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....
i'd be concerned that the crown was damaged if it popped out that easily, still worth trying the bodge if its only a £5er though
When installing use a [url= http://www.loctite.co.uk/cps/rde/xchg/henkel_uke/hs.xsl/80_UKE_HTML.htm ]Loctite[/url] product to make sure it won't move.
I don't know if James is a troll or Russ Pinder's neighbour but if you have an impact that breaks the fork, bends the frame and breaks the headset then scrap the lot and start again.
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.
"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"
So if it had been near to breaking point then there should/ought to be signs of flakey paint/stressed paint?
I dont know about that, its not like its going to cost a load more to find out, but if your confident there isnt a problem with it, its your call.. They can test it will aerosol crack testing stuff, would take about 10 mins with the paint removed from it.
How does a crack test work then? ie, will it break the crown (if its not already)? Like testing to (or near to) destruction?
Hmm, At least if the outcome of a crack test was favourable enough to ride I could have a unique* silver RS fork crown?
*I assume
[i]Also, cut one of the legs off and fashion it into a lefty.[/i]
🙂
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?
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.
"but would you trust your life to it"
Not at the moment, but am interested in trying to determine how (un)safe it could be made, even if I don't ride it
I could always buy a full face helmet ..
I am I right that 5 mm of press fitted pipe is all that is holding the forks and the frame together? Gulp.
It would have to be a ****ing tight fit wouldn't it?
About 15mm, with a wider bit at the bottom edge
If you think about a stem clamped upto a steerer tube, you're only meant to do the bolts upto about 5-10Nm?
Nick its how wheels are held onto trains, just interference fit, and lots of bits inside your car engine, axle, etc etc..
When I bought my last motorbike the fork stanchions were so bent the wheel was on the frame, i bought it as right off to build into a road/track bike, the stanchions were straightend and I checked nothing else bar going over the bike as best as possible, it was entirely at my own discretion as your repair is for you.
Old nail built up from scrap stuff.
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and after the first track day.
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The frame your forks were on is prebably a week point to be honest and I would keep a close eye on it.
5mm?
It's an unknown as to whether the frame/crown will have been weakened - and you may not find out until you experience similar forces again - in which case you are crashing badly anyway.
Who replaces the frame after bending forks?
If the steerer goes in easily I don't think I'd ride it as the crown will have stretched.
A fair few areas around the headtube have got flaking paintwork as a result of it too though
So if it had been near to breaking point then there should/ought to be signs of flakey paint/stressed paint?
Just throw it away
cynic-al, but you could ream the crown hole and go up a size on the new steerer if he was to go down the route of getting one made. Were only talking hundredths of a mm here.
The thing is, if in doubt bin em out. Give you postage for them 😉
"bin em out"?! What's this, making up phrases to fit a ryhme 🙂 ?
"Just throw it away "
Its not my bike to throw away, its my brothers, I don't think he wants to have to drop £1200ish on a new frame when he 'can' still ride this one. Plus you can't get a QUAD-link frame frame-only
"but you could ream the crown hole and go up a size on the new steerer"
As new, the part of the steerer tube that press fits into the crown is the same outer diameter as the part where the headset crown bearing race sits, (presumably 30mm as per that RST one, so that all crown races fit all forks), then tapering back to 1 1/8" for the rest of the fork? (the bend is above this transition point, probably about 40-50mm higher
Yeah pretty much.. I am very bored. 🙂
My mate fitted an alloy steerer to some single crwon Marzocchi shivers. The original was steel and way too short. He did the heating the crown up trick and then freezing the alloy steerer tube. Thus making a press fit. He even used a different steerer tube, think it was a Rockshox one he bought cheap. Bike has been running no problems, hes a fairly burly lad too. I doubt the crown strength will have been compromised. Just dont go too much with the heat on the crown, boiling water will be enough. Heating it a lot with a blow torch too much would compromise the crown strength though.
I would ride with that no problems.
[i]which forced the headset to ovalise the headtube in the bike[/i]
[i]Bike has been running no problems, hes a fairly burly lad too. I doubt the crown strength will have been compromised[/i]
😯
talk to Marin about a crash replacement front end.
I can't belive people (particularly 'burly' people) treat their own safety with quite so much contempt...
whats a Marin front end got to do with the price of fish?
The most annoying thing about the whole thing, is that had the bike not had a handbuilt front wheel and some poorly tensioned with some miles under its belt factory built front wheel, the front wheel would probably have pringled and left the frame and fork completely unaffected. Thanks merlin!
seth-enslow666 - he said it was a quad link frame - aren't they made by Marin?
yes but I thought he said the headtube had gone oval after the crash? Why not just hit the headtube and make it round again. Stick a bit of round pipe in it for a guide and hit it until the headtube is round again, a bit like a blacksmith!
Above comment was facetious and should not be takem literally!
Marin do make Quad-link bikes, but they're not the only one ..
I will sell you a new CSU at trade if it helps you NOT press in a new steerer.
Please don't mess about with stuff like this. An impact that has damaged your headtube and split a set of forks could easily happen again and you will not get lucky twice.
If you want some help then please drop me or Colin and email to mdownie@thebikechain.co.uk with the exact model and i will sort you a price.
_-_-Mods - please feel free to delete this if deemed inappropriate-_-_
Whats a CSU?
I'm not thinking of riding it (anymore), mostly interested in the detail
The fork hasn't split, just bent lots. The pic is after the steerer tube has been forced out of the crown
Steerer assembly. The upper legs basically.
Steerer, Crown + Stantions. Oh I see, CSU, stantions being uppers
Erm maybe yes, I don't need to get the fork off of my brother, just that if rideable would be better than the MX pro on my HT
Its just that the costs could be a bit preventative, though I'd be prepared to swap at home with the help of the rockshox manual
A complete 'CSU/SCU' assembly would put my mind at ease
Drop me an email on above address and i will find out the costs for you.
YGM
Ta - will get back to you soon.
Mate, your brother is gonna die on those!
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And that looks like a "soft" landing too!
I'd be more worried about the frame and the headtube than the forks. Forks can definitely be fixed and the best way is with complete new upper section. Frame on the other hand sounds like it needs the attention of someone with experience of aluminium fabrication at the least (e.g. fix by welding and re-machining headset cups), and may be destined for the bin.
What's the worst that could happen?
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