Raleigh wisp headset size

Hi

I'm trying to fit a stronglight a9 to a Raleigh wisp.

My calipers are naff and having trouble measuring if the crown is 26.4 iso or 27mm jis. Not sure about the head tube either.

Before bashing away at the stronglight race I tried tapping an old 26.4 race i had and it didn't seem to want to go on.

Anyone know for sure what size these frames use? And where I can get a jis if it is needed?

Many Raleighs use their own proprietary headset sizes, so beware.

Thanks hamster, that could complicate things even further.

I've refitted the original for now, the crown race was quite loose. Can lift it back off by hand.

Can anyone tell me the effect of a loose crown race?

retro-rich":1n9crvh4 said:

Thanks hamster, that could complicate things even further.

I've refitted the original for now, the crown race was quite loose. Can lift it back off by hand.

Can anyone tell me the effect of a loose crown race?

Click to expand...

Steering will feel "wobbly" much like ground misshapen bearings. If you have access to a blow tourch and basic brazing skills, you can always melt some brass rod on the crown race area to fill it out.

otherself":3jjyvl4y said:

retro-rich":3jjyvl4y said:

Thanks hamster, that could complicate things even further.

I've refitted the original for now, the crown race was quite loose. Can lift it back off by hand.

Can anyone tell me the effect of a loose crown race?

Click to expand...

Steering will feel "wobbly" much like ground misshapen bearings. If you have access to a blow tourch and basic brazing skills, you can always melt some brass rod on the crown race area to fill it out.

Click to expand...

Thanks. Not sure about brazing just yet though, although it could be a useful skill.

I've been and invested in a decent set of calipers, the type with an analogue guage for the fractions of millimetres.

The old headset is a 27mm race with 30mm cups, which according to sheldon makes it jis.

The jis ones are like rocking horse poop on the web, only place I found one was velo orange in the states, but I went back to the lbs and he had one in stock, albeit a cheap one but still better than using the original.

I've fitted the new headset now. The cups went in just nice I think, pushed by hand most the way then used the budget eBay clamp to push them in all the way. However, like the original the crown race is a bit loose, I've read elsewhere on the web about hitting the crown with a centre punch to make a few raised areas for the race to bite into, anyone have any experience doing this?

Did this frequently in the 1950's. Also cut a shim from a bit of suitable tin can. Not for the theorists but we were making bikes rideable if not 100% correct. The cheap components varied, and the cup and cone bearings were intended for light applications which still worked even when mis-matched or badly made.
The loading on the lower head race is probably less than 25% of the total weight on the road. Dursley Pedersen had a small taper casting plain bearing for the bottom head bearing.

Thanks Keith, the shim idea sounds worth a try. This bike is going to be for upright riding as it has sweep back flat bars so shouldn't have as much weight over the front