So, i’ve found a unique headset compatibility problem which even FSA say there is no part for. Any (useful) suggestions welcome, although I don’t want/can’t afford a new fork!

The problem is with the lower end only. I have a Pinnacle Arkose ‘cross frame with a tapered headtube, lower OD of 56mm. Designed for a ‘normal’ tapered fork. In my ignorance I bought a cheap but decent second hand carbon disc only fork with a tapered steerer. Sounds fine, but the taper in the fork is 1.1/8″ – 1.1/4″. There is no bearing that will fit, and no appropriate crown reducers either…

How i’m loving the proliferation of ‘standards’

If you can’t find a 56mm to 1.1/4 headset or cannot find a 1.1/4 to 1.5 steerer tube adapter then you might have to get something like a hope HS136 1.1/8 to 1.5 adapter and get someone with a lathe to bore it out slightly. Do you currently have a suitable 1.5″ lower headset, bearing and crownrace?

I would give Works Components a shout- they seem to do this sort of non standard stuff

Thanks both –

I do have the appropriate 1.5 bearings and crown race and a hope adaptor from the previous fork…i’ll try Works components to see what they say.

There must be so many generic bearings around that there’s one with a 52mm OD and a 32mm(+/-0.1mm) / 1.1/4″ hole in the middle!?

I’d say milling out the hope adaptor would be the easiest option, a generic bearing wont have the 45 or 36 degree chamfer that a head set bearing will need

a quick search on bearingshopuk.com shows no options either

If the fork is second hand, what was the previous owner using?

Hmm, it would seem that milling the adaptor might be the easiest/cheapest option..

I’m assuming the previous owner had a different headtube lower size – OD 52mm, 47mm bearing seat, which you can get a headset for (FSA No.44 E/CD). I think the design is based on Giant Overdrive (Mk 1) for road bikes.

Thanks for the input…