26.4mm Shimano 105 1055 crown race 1" - alternatives???

[Ray_72]

Re:

Thanks for your further experience. I think this is a little more involved than just the crown race. It seems the crown race is 27mm afterall but is worn hence the centre punch mark. I used the painters tape tip and this has tightened up the crown race perfectly.

However, the loose crown race has worn slightly the head tube so the cups can pretty much be pushed in by hand. I used the painters tabe again on those as an experiment and it worked really well but I am a bit reluctant to use tape on the cups long term and think something like jb weld or a loctite product would give me greater confidence. The cups don't fall out so the wear is minimal.

What would you recommend? The headset is NOS 105 (expensive) so would like to use it.

Thanks Ray

 

[Ray_72]

Re:

I have bought some Loctite 680 but before I go ahead and glue the bottom and top cups in does anyone know of a "deep insert" headset I could try before going permanent with the Loctite?

I did read a post somewhere but cant seem to find it now.

Thanks

 

[Ray_72]

Re:

The Loctite didnt work so looks like the frame needs a new headtube and will also therefore need some paint.

I wondered if it is possible to fit a 1 1/8" headtube with a 1" frameset to get rid of all this headset silliness once and for all - realise I will need a new fork but that would open up other possibilities.

Any thoughts?

Ray

 

[Jonny69]

You don't need a new head tube. Before proceeding, I think you need to get a good quality Vernier (i.e. not a £9.99 Chinese digital one off Amazon) and carefully measure the cups and the head tube ends where the cups go in. You need to be sure which of the components are out of spec and by how much.

If it's the headset cups, just get another headset and be done with. It's the least bother.

Assuming it's the head tube though, what I'd recommend is find a trusted bike shop or local old-school engineering firm with an adjustable reamer. From memory, the cups are a press fit into a tube which is 30.2mm dead. Get them to hand ream it up to 30.4mm dead. Then you can get some strips of 0.1mm shim and press the cups in as normal. If they accidentally go a bit over, you can use 0.15mm shim.

This is on my Russian bike which had 30.4mm cups because that's what size the Russian ones are. See where I tried peening the surface to take up the gap, but it wasn't tight enough in the tubes. I dressed it back and used strips of 0.1mm shim when I pressed it in. I installed that in 2015 and I haven't had to touch it since. it's my most used bike in the fleet.

 

[Ray_72]

Re:

Thanks for your detailed response.

It is the head-tube, it appears to be worn front and rear in line with the symptoms of the fork rocking back and forth.

I bought a NOS 105 headset in the hope it would hold but it worked loose after a mile or so, when I tried shims, I managed to damage the NOS headset in the process of inserting them :evil:

In desperation I used Loctite to "Glue" the previous headset in. TBH I am surprised it didnt work - the races are stuck fast and the fork and stem were all installed when the Loctitie was curing so the alignment is right.

I cant think what else can possibly be wrong, fed up with it now which is why I was thinking of the 1 1/8 then I can go aheadset and a more modern fork.

Thanks, Ray

 

[Jonny69]

Re: Re:

I cant think what else can possibly be wrong, fed up with it now which is why I was thinking of the 1 1/8 then I can go aheadset and a more modern fork.

You don't need to do that. You just need to make your headtube bores round again and the correct size to shim up to a press fit. Reaming them will do that.

 

[pigman]

Re:

I agree. That's a severe and costly move to convert to a 1 1/8 head tube. And if its a 1" lugged frame, more complex still.

it's akin to leg amputation because of a dodgy knee