1990s Raleigh Dynatech headset issue

[Kingsley]

I'm currently restoring a 1990s Raleigh Dynatech 2070 in Castorama colours. The bike came with a Campagnolo super record headset and I want to replace with a Shimano 105 SC 1055 as is the rest of the groupset, however the height of the Shimano headset (50mm, when measured from crown race to top nut) is shorter than the Campagnolo one (76mm). When I fitted the 105 headset there was movement even with it tightened down. Could the difference in size of the bearings between both be a reason for movement?

I have a Raleigh Veloce from the same period which uses Shimano Exage 400 EX and the steerer tube length is shorter (173mm) than the Dynatech steerer (190mm). So this may need cutting down.

Any advice would be most helpful

 

[pigman]

The stack height of the Shimano is less.
Don't cut the steerer down. You will forever then be stuck with sourcing low stack headsets sometime in the distant future.
Just add a spacing washer or two between the top race and the locknut

 

[Kingsley]

Thanks I'm reluctant to cut the steerer tube down but I would need to add around 15 mm of spacers.

 

[gtturbo]

Forget about the top nut for the minute. If you tighten the lower nut does the movement go ?. If not and the nut is tight then it sounds like you may be running out of thread on the fork steerer.

 

[Kingsley]

I take it when you say top nut you mean the top lock nut? Ok if I tighten the lower nut at the top of of the headset, the movement is still there.

 

[Kingsley]

I check out the steerer tube tomorrow. Thanks

 

[gtturbo]

Another thing to check, and I'm assuming its a 1" headset ?, but are they both the same standard either ISO or JIS. Google it and you will find the sizes. If the crown race is a loose fit on the forks that will exhibit movement.

 

[Kingsley]

Both the Campag and Shimano headsets are 1", 24tpi. The crown race is definitely an inteference fit.

 

[sjcprojects]

Could the difference in size of the bearings between both be a reason for movement?

This may be a silly question, but this bit of your post sounds a bit like you've kept the Campagnolo cups in the frame. Just to check that's not the case?

 

[Kingsley]

This may be a silly question, but this bit of your post sounds a bit like you've kept the Campagnolo cups in the frame. Just to check that's not the case?

No haven't kept the Campagnolo cups in the frame, but problem solved, thanks to everyone who commented - I'm an idiot, but one of the Shimano seals was the wrong way round which caused it to lift the bearing cage which led to the movement! It doesn't have movement now although I do need a couple of 5mm spacers