Drilling Forks - 'Standard' Brake Axle Diameter?

[Jezston]

Having the forks of my Dolan drilled for a front brake at the moment, but I'm being asked if I want 5.5mm or 6mm. I didn't realise there were different sizes. Are there?

 

[tyred]

I would have thought 6mm is the standard, with the back of the fork drilled in 8mm if you wish to use recessed brake nuts.

 

[mickle]

6mm obviously.

 

[Jezston]

Cheers, that does appear to be correct.

I should state that the fork is being drilled by a friend who's primary expertise is in drilling holes in things (he's a materials engineer for Rolls Royce), and bicycle maintenance being an additional hobby. Fortunately he's being cautious rather than overconfident.

Are recessed brake nuts a common thing on modern brakes? Should I be asking him to drill 8mm in the back, or leave it alone?

 

[mickle]

Actually I don't know for sure that it's 6mm. I thought it a bit strange that Dolan was asking you this question. Have him measure your brake bolt and add half a mm.

 

[Jezston]

No brake bolt to hand! He's done it to 6mm now. I guess having it a tiny bit too big would be better than too small?

 

[Jezston]

Just heard back from Dolan, they reckon 6mm at the front, 8mm at the back to fit an alan key bolt.

Any reason to disagree with that assessment?

 

[tyred]

Sounds good to me. Any modernish brake I've seen always seem to have an M6 mounting bolt. Older Raleigh made calipers on the R20 and the like are 1/4"

 

[Jezston]

8mm on the back half being drilled as we speak, so I have been texted.

Apparently it's not a big deal if it's wrong anyway, he can make me a shim

 

[Jezston]

Next up, get him to make some titanium sturmey nuts. The ones that come with their modern hubs are made of the most rust-attracting monkey bollocks I've ever seen.

 

[PpPete]

nah - get him to do them in a high strength stainless instead.

 

[buddha]

nah - get him to do them in a high strength stainless instead.

I don't know if >>this company<< still exists. I had them bookmarked, but never got round to getting any, as I got a bag of the normal ones on ebay.

 

[biggs682]

yes 6mm fr and 8 mm rr