Badly fitting headset top race (updated and now FIXED!)

Giraffoto

I have an On-One Scandal frame, and a Superstar T2 tapered headset. No problems with the bottom cup – it was fairly straightforward to get it pressed into place. The top cup didn’t need any pressing at all, it just dropped into place and seemed to be a close fit. However, when I built the bike up it turned out that a close fit isn’t close enough, and it moved enough that I could feel it moving. To prevent any damage to the frame and stop it moving I wrapped it with loads of plumbing PTFE tape before forcing it back in, but that strikes me as a bit of a hillbilly solution. So the questions are . . .

Is the PTFE tape anything other than a very temporary fix?

If not, and the top race turns out to be fractionally undersized, will there be any issues with fitting, say, a Hope pick and mix top race in there instead (I’m thinking of Hope because I only want the top race)?

nicklouse

sounds like you have the wrong headset. or the frame has been machined incorrectly.

Giraffoto

nicklouse wrote:

sounds like you have the wrong headset. or the frame has been machined incorrectly.

Are there multiple headset standards that differ by less than a millimetre? That's going to be awkward to measure up for.

Bad news if it's the frame - it's brand new and came machined like that. If it is that, would it be terminal or is there any way to fix it that doesn't involve welding?

The Rookie

2 of the integrated headset standards are very close on size, but I thought a Scandal was external of which there is only one, measure and compare to the stnds on Parktools webby.

If it's too big it's terminal, rewelding and machining and painting will likely cost as much as a frame, send it back?

nicklouse

Giraffoto wrote:

nicklouse wrote:

sounds like you have the wrong headset. or the frame has been machined incorrectly.

Are there multiple headset standards that differ by less than a millimetre? That's going to be awkward to measure up for.

Bad news if it's the frame - it's brand new and came machined like that. If it is that, would it be terminal or is there any way to fix it that doesn't involve welding?

contact OnOne and as then what standard the headset is. not which of their headsets will fit as they do not give the standard info on thier headsets.

from what I can see from the grey info give by OnOne the top headset should be and internal/Semi Int./ZeroStack that is to say ZS44mm

Giraffoto

nicklouse wrote:

contact OnOne and ask them what standard the headset is. not which of their headsets will fit as they do not give the standard info on thier headsets.

from what I can see from the grey info give by OnOne the top headset should be and internal/Semi Int./ZeroStack that is to say ZS44mm

The guy I spoke to said that their own Smoothie Mixer headset would be a perfect fit - and if it isn't, I can return it for a full refund. I'm not entirely convinced by this - they don't market their headsets as only able to fit their own frames, and vice versa - but with the promise of a full refund on return if it doesn't fit, I'll give it a go. Then at least I'll have covered myself against a headset seller and a frame seller both claiming the other's product is at fault

nicklouse

but the smoothie looks just the same as the SS T2.

Giraffoto

nicklouse wrote:

but the smoothie looks just the same as the SS T2.

A valid point - I see more than a 50% chance that it won't fit either, and your first suggestion is pretty much what I'd do if I were dealing with local shops. Doing it this way round allows me to say that I've done it their way, and it still didn't work: if it comes to that I can send the headset back for a refund, and send the frame with the original Superstar headset back to them with a request to make sure it fits this time

UPDATE
Well, the On-One headset didn't fit any tighter than the Superstar one, but the good news is, I have a plan B that doesn't involve stripping the bike down to the frame and shipping it back where it came from. An engineer friend has offered to bring the headtube back to the size it should be with some microscopically thin shim stock and a Loctite product that is generally used for seating loose bearings in engines - it's all happening this weekend!

It should be pointed out that this is not On-One failing to stand behind their product - the guy from customer service was very clear on the fact that I could send it back for replacement if it turned out to be at fault. This is a case of the customer deciding he can't face stripping it all down and building it all up again so soon

Giraffoto

As previously stated, On-One offered to take a look at the frame and replace it if there was an issue. The alternative offer from an engineer friend was to do exactly what he does for similar issues in lorry engines etc. - pad it out with microscopically thin stainless steel shim stock, secure it with a Loctite product (that exists for this very purpose) and keep the whole thing aligned for the half hour it took the Loctite to cure. The result is no movement at the top race and a smooth headset. So why didn't I go for On-One's perfectly reasonable offer? Some combination of
Lunacy
I like watching precision work
I'd only just built it and didn't want to strip it down to the frame again
Couple of hours work against a possible week or more to get it turned around

(For the record it's Loctite 660, a gap filling and retaining product)