Interesting headset problem (tapered steerer, carbon 456)

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Interesting headset problem (tapered steerer, carbon 456)

98 posts & 22 voices | Started 1 year ago by PeterPoddy | Latest reply from Rusty Mac

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PeterPoddy - Member

I built my C456 with 1 1/8 forks and a reducer head race. All perfect.

When I added the tapered steerer Revs, first ride the headset came very loose and I tightened it, but next ride it was making an odd 'cracking-clunking' noise but there was little or no play in it. I took the HS apart and thought it might have been something to do with the split tapered ring in the O-O headset. I checked it all, and put it back together as tight as possible, and also added a taller spacer above the stem just in case the top cap was grounding on the steerer.
Next ride, after a few miles and some bumps the cracking/knocking noise was back, I cranked the HS down as tight as I dared and it seemed to stop, then it came back again!! No play at all at this point, and I was worried the alloy insets the HS presses into were moving in the frame by now...

So I stripped the HS down again and the tapered ring in the HS was so tightly wedged between the steerer and the bearing I had to pry it out with a screwdriver, as I did so I could hear and feel the crack/creak noise! But no movement anywhere in the assembly.... Deffo the ring causing it...

So after a bit of examining it turns out the headtube on the frame is too short for the taper on the fork steerer! The tapered washer is not fitting between the bearing and the top of the taper on the steerer properly, and as it's not parallel with the taper of the steerer, and that's what's creaking

Crap pic to try and show the problem

Untitled by PeterPoddy, on Flickr

So, I've filed the inside of the tapered washer to a knife edge taper (Almost) itself, to match the steerer, and reduced the flange under the taper you see there to half that height, refitted it all with plenty of grease. In a garage test it seems OK, but another Peaks ride tomorrow will show if I'm right.

Anyway, the only real fix I can think of is a top headset race that's taller to move everything up higher away from the taper, but I'm wondering what might fit instead, it's just a normal top race, right???

Posted 1 year ago #
PeterPoddy - Member

Bump for the weekday crowd, being as I seem to have stumped the weekenders!

UPDATE
The mods I made seem to have made a difference. I'm not 100% sure the headset is staying tight, but the crack/clunk noise didn't return after a days riding in the Peaks yesterday....

Posted 1 year ago #
DezB - Member

Surely the headtube on the frame is incorrectly made and therefore should be replaced by warranty?

Posted 1 year ago #
wwaswas - Member

I had some issues with the on-one smoothie and a standard 1 1/8" steerer - difficult to get it go tight and stay that way.

I did wonder whether the Alu inserts in the frame were slightly the wrong size (or the headset cups where the bearings rest in them). I did seem to have to tighten the top cap more than I have on other frames/headsets - not to the point the headset is 'tight' though.

Do they do a +10 or +20 bottom cup version of that headset - woudl adjust the geometry a bit but woudl solve the problem?

Posted 1 year ago #
PeterPoddy - Member

Surely the headtube on the frame is incorrectly made and therefore should be replaced by warranty?

Dez, I'm not 100% sure that's so. I can imagine the conversation:

Me - Mr On One, your headtube is too short for a tapered steerer
Mr O O - No it's not. The taper on the steerer is too big

Me - Mr Rockshox, your taper is too long for my bike
Mr O O - No it's not. The headtube is too short

etc etc ad infinitum!

So, I'm in 2 minds as to weather to contact On One or not.....

Posted 1 year ago #
brant - Member

Me and Cy@Cotic both noticed that there is not actually a specification for the taper on a tapered fork. There's a spec for the diameter at the base and the top, but not a spec for the length of the taper.

Ouch.

A better fix would be an "external" top cup?

Posted 1 year ago #
julianwilson - Member

Sounds like the short on-one headtube is just a teeensy bit too short for the steerer/headset combo. Although i see it is an on-one branded headset If you managed to rectify it by filing the inside of the wedge, there must have only been a few mm in it...

I wonder if manufacturers anticipated this arising?

Is there a 'standard' length of taper already set?
ie steerer returns to 1.125" by x mm above the crown, to allow frame and headset makers to plan their own parts.

Peter, what is the length of your headtube? How does that compare to short headtubes on 'normal' frames? Millie has had (small or laydeez) frames with 90-100mm headtubes before, it would be a shame to lose the option of making them so short becasue you wanted to put a tapered steerer in.

[edit] oh, i see lots of you beat me to all that. ^^ Must type faster.

Posted 1 year ago #
PeterPoddy - Member

wwaswas, as far as I can see, I'm 100% sure that gold headset taper ring is grounding out on the top of the taper of the steerer.

The only fix I can think of is a taller headset in one way or another, but I don't really want to do that as it'll cost £££ and I have a 7-8 ride old headset already in there.

I do have a King headset knocking around and I'm considering trying the top race from that (No expander wedge in it see!) but I'm a tart and I have a nice looking bike, and I don't want to have a clumpy looking mixed headset and then there's the old 'King HS score steerers thing' as well, and these are 150mm Revs.....

Posted 1 year ago #
TheBrick - Member

Contact them they may have a suggestion.

Posted 1 year ago #
PeterPoddy - Member

Brant, thanks for the advice, I think you're on the same lines as my thinking, but I'm not too familiar with different types of headset. Is that a semi-integrated? What headset are you thinking of? Hope?

Posted 1 year ago #
PeterPoddy - Member

Brick, I think I'll drop O-O an email at some point...

I can't believe I'm the only person to have this problem, surely not????

Sounds like the short on-one headtube is just a teeensy bit too short for the steerer/headset combo.

Yep, that's it. I reckon there's 2mm, maybe 3mm in it....

Posted 1 year ago #
cy - Member

Sorry to see you're having trouble. As Brant says, there's not actually any industry standard as far as we're aware for this. I guess Trek must have tied something down when it was developed, but it's not in the public domain. Only thing I've seen are Fox fork drawings which has a maximum taper length of 95mm from crown seat to taper top. I've not seen any Rock Shox drawings, so I don't know if they conform to this.

With an external cup headset like that with a stack of around 12mm, your head tube would need to be at least 90mm long to fit a Fox fork once you account for top cup clearances. How long's the head tube on that frame?

Posted 1 year ago #
chiefgrooveguru - Member

Me and Cy@Cotic both noticed that there is not actually a specification for the taper on a tapered fork. There's a spec for the diameter at the base and the top, but not a spec for the length of the taper.

Was this new 'standard' created by the same remarkable brains that put together the latest CEN tests?

Posted 1 year ago #
PeterPoddy - Member

Cy, I don't know how long the HT is and I'm 100 miles away from the frame until tomorrow night, so I can't measure it quickly...

But it's a 16in frame which equates to a medium on this table here:

http://www.on-one.co.uk/i/q/FTOOC456MIX/on-one-carbon-456-stick-n-mix-frame-bundle

So it SHOULD be 105mm......

Forks are 150mm Rockshox Revelation RLTs

Thanks for the help, there's no need to say sorry though, it's not your design!!!

Posted 1 year ago #
wwaswas - Member

Just measured my 18" frame and it's 105mm.

Posted 1 year ago #
PeterPoddy - Member

wwaswas, yes the 16 & 18in frames are listed as 105mm headtubes, so mine should be the same....

Posted 1 year ago #
DezB - Member

Me and Cy@Cotic both noticed that there is not actually a specification for the taper on a tapered fork.

Man, that is moronic. Trust the bike industry to bring in "standards" that have no standards!!
So glad I have no desire for a new bike (yet)!

I guess Brant is saying that any external headset cup on the top would be high enough up the steerer and mean the 1 1/8th wedge would then fit. Seems to make sense.

Posted 1 year ago #
PeterPoddy - Member

Dez, so that's a semi-integrated top cup I have in there yes?

I can just see it looking like a right old lash-up, but I do have a spare FSA top race I can try I think....

It's not good, is it?

I bloody love that bike, it's a flipping hoot to ride, and this is really taking the shine off it right now, but as far as I can see, it's not On One's fault and it's not Rockshox fault. It's just a bunch of arse.

Posted 1 year ago #
DezB - Member

Pretty sure it is - as far as I've worked out (only ever actually used external headsets), integrated means the bearings are mounted in the frame, semi-integrated have a low pro cup with the bearings 'inside' the frame.
Could be wrong about integrated though!

Posted 1 year ago #
TooTall - Member

You can't go having a thread on here and not flame someone in a pointless and improper manner! There are standards to uphold around here you know. Get with it and pick a target - any one - you have mentioned a few!

Posted 1 year ago #
andyl - Member

The easiest solution would probably be to get a thicker crown race made up. On One really should release a solution to this themselves.

Posted 1 year ago #
DezB - Member

Flip, there are 5 types now!
http://www.canecreek.com/tech-headsets?view=standards

Posted 1 year ago #
LoCo - Member

ok tootall, I dislike the radius on the piping in the background of the picture, there, happy now?
Interesting issue pp not some thing I've come across as yet but then my frame are of the 'gate' variety being a lanky begger.

Posted 1 year ago #
PeterPoddy - Member

I dislike the radius on the piping in the background of the picture,

That's my Brother's cellar! How VERY dare you!!!

Andyl, yep, you're right. Where the hell do I get one of those then?

I'm gonna try a different top cup and see when I get the chance, which will be at least Friday, sadly.

No point in effing and jeffing about this, it won't fix the problem. I'm sure it's doable though. I just want it to look neat!

Posted 1 year ago #
PeterPoddy - Member

Dez, thanks for the link.

This headset covers 2 of those standards!

I think the top cup is a 'Zero Stack' from the description:

The Zero Stack design offers a low stack height and the security of bearing cups that are hidden inside the head tube. ZS cups are compatible only with specifically machined head tubes and cannot be retrofitted to an existing bike with Traditional headset cups

I'm now wondering if a normal top cup will actually fit?

Posted 1 year ago #
DezB - Member

Yep: zero-stack = Semi-integrated (hey, why have naming standards if we can't have size standards!)

Good point - the cup might actually be too small. Blimmin flip, what a palava!

Posted 1 year ago #
wwaswas - Member

angle grinder on the fork steerer time?

Posted 1 year ago #
andyl - Member

The C456 top is 44mm so it is too big for a 'normal' ie 1 1/8th headset top cup.

I wonder if one of the new 44mm external fittings might fit though?

Nukeproof do a range: http://www.shedfire.com/2011/02/19/nukeproof-warhead-headsets/

They have external lower and upper cup options - no idea if they will fit. The external upper would be for 1 1/8th steerer section but look to have a chamfer, the external lower are flush fit which might be better and you would need the straight 1 1/8th tube one but that is a lot of money to splash out to fix a problem which should not exist.

A crown race should be pretty easy to get made, you know the angle on the bearing fitting (written on the bearing) and the internal diameter should be standard (or give the place the old one to measure and tell them it is a press fit). I would get it made out of aluminium though instead of steel to save weight and get it made +5mm.

Another option would be a ring that fits over the existing crown race with a lower inner taper and upper external taper so it works as a crown race spacer. I was messing around with the crown races on my superstar headset (comes with both 1 1/8th and 1.5" lower crown races) doing something similar. Would want a properly machined one to use it though. A bit of Loctite bearing fit would probably be wise on the crown race to spacer interface too.

Posted 1 year ago #
PeterPoddy - Member

Dez, yes, I suspect you are right.

--------------------------

New Question:

See that gold alloy taper ring in my pic up there? Well it seems the problem is that it can't seat properly becasue of the small vertical flange below the taper. I've already modified that flange, but whaddaya think would happen if I removed it entirely?

My thinking is that there would ne nothing to get jammed between the bearing and the steerer, and the taper would sit properly where it should on the bearing, with the only issue being (still) the inside face of is not sitting squarely on the steerer.

Can anyone think of any downfalls of removing that flange entirely?

Posted 1 year ago #
PeterPoddy - Member

Andy, thanks for confirming my suspicions!

Another option would be a ring that fits over the existing crown race with a lower inner taper and upper external taper so it works as a crown race spacer. I was messing around with the crown races on my superstar headset (comes with both 1 1/8th and 1.5" lower crown races) doing something similar. Would want a properly machined one to use it though. A bit of Loctite bearing fit would probably be wise on the crown race to spacer interface too.

This has crossed my mind too. I reckon to be safe I'd need to pinch 3mm in total. 1mm spacers under each cup and a 1mm spacer under the crown race would do this, but again, I need to get the spacers. And I'm not 100% sure it's a good idea to have the headset not fully inserted into the frame either....

Posted 1 year ago #
wwaswas - Member

any downfalls of removing that flange entirely?

it's designed to fit between the bearing shell and the steerer - if it's not there the steerer would be 'loose' in the shell and you'd be relying wholly on tension fromt he angled bit to locate the steerer in the bearing which doesn't sound like 'a good thing'.

I'm sure on-one must have fitted some tapered forks to one of these frames (albeit that the complete bikes run std tubes) - might be worth just calling them?

Posted 1 year ago #
DezB - Member

This though:
"Me - Mr On One, your headtube is too short for a tapered steerer
Mr O O - No it's not. The taper on the steerer is too big

Me - Mr Rockshox, your taper is too long for my bike
Mr O O - No it's not. The headtube is too short"

You - well which fork can I fit? And why wasn't I informed I couldn't fit RS forks?

Doesn't help, but it's bloody ridiculous! On-One need to know so that other purchases are informed.

Posted 1 year ago #
PeterPoddy - Member

Just called O-O, waiting for a call back

Posted 1 year ago #
andyl - Member

Yeah you could use 1mm spacers between the frame and the cups top and bottom but I would prefer a thicker crown race.

As for the top ring thing - you need that for the bearing pre-load - this is an important part of the headset.

IMO On One should remedy the situation by releasing an updated part - either a thicker crown race, a deeper lower cup or a slightly less flush upper cup.

Did you get the headtube faced at all? The On One documentation for the C456 is pi$$ poor and they have really annoyed me about it. I did eventually see a mention (either on their site or on their facebook page) that there is no need to face the BB and headtubes - I didn't anyway as my reasoning was they are purpose made fittings so not just tube as part of a welded frame. There is still the chance the head tube fittings are not square though as they are 2 parts. But I don't fancy letting anyone loose on my carbon frame with a serrated facing tool!

I tried asking On One on their frame page (in the comments) if a top swing front mech was okay to use. The guy replied about bottom cable runs acting as though I was a bit special in asking if it was top or bottom pull - what I actually asked was if you had to use a conventional mech or if I could use my top swing one. I have the top swing on but I am not convinced the frame is the right diameter that close to the BB area.

Posted 1 year ago #
PeterPoddy - Member

Did you get the headtube faced at all?

No, thank God!

As for the top ring thing - you need that for the bearing pre-load - this is an important part of the headset

Yes I know that. I'm asking if I can modify it, not remove it!

Posted 1 year ago #

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