Replacing bottom bracket and headset questions

[daccordimark]

One thing to bear in mind when replacing the bottom bracket is to make sure you get an asymmetrical one. The drive side of the axle will stick out further on yours but modern ones tend to be the same both sides.

Mark.

 

[lorenzo]

Hmm, ok, I didn't realise that. I've gone and bought a tange one now. I'll check when it arrives.

 

[bm0p700f]

I agree in that you will have 1" threaded headset but they come in two kinds. One sort has a 26.4mm corwn race the other has a 27.0mm crownrace. You will need to measure to get the right sort. Some Raleighs used the 27.0mm kind. Most good quality headsets asre of the 26.4mm kind.

If you have a 27.0mm standard then the crown race seat can be milled down but you need the right tools for this. I have them and any LBS should have them too.

The crown race seat for the 26.4mm standard should be 26.5mm and for the 27.0mm standard the crown race should be 27.1mm in diameter. The difference allows for a press fit. When you buy your headset it is important to measure the internal diamater of the crown race and the O.D of the crown race seat and there should be a 0.1mm difference. Any more than 0.15mm difference and the crown race will not press on any less and the fit will be loose.

 

[lorenzo]

And I've got a 27.1 crown race seat...

 

[lorenzo]

Just had a word with the place that's doing my paint job, they can machine the forks down to fit the new headset. Thanks for the heads-up on that.