Wanted Wanted engineer or bike mechanic

[Mark south wales]

hiya guys I've got a Raleigh twenty, I need the bb cutting down and retapping, any one around, who can do it? I don't expect it free. but in south Wales valleys I'm buggered and cant find anyone who will or can do it.

if not a jap spec 76mm tapered axle of aprox 130 - 137mm width

 

[peetee]

Are you trying to convert to a standard BB size?
If so, there used to be screw-in adaptors. I used one in a static trainer.
I can find one online that converts from US BMX size and if that’s the same as the old UK BMX it might do the job.

 

[bikeworkshop]

I can do it
I live in Monmouth, take stuff to the shop Saturdays
Tom

 

[Siish]

@danson67 will be able to do it if you can get your frame to him

 

[Mark south wales]

ive found an engineer in Blaenavon that can do ger guys, thanks for the input

 

[Mark south wales]

I can do it
I live in Monmouth, take stuff to the shop Saturdays
Tom

hiya tom, i didnt see your post there, your only half hour away fab

 

[Mark south wales]

Are you trying to convert to a standard BB size?
If so, there used to be screw-in adaptors. I used one in a static trainer.
I can find one online that converts from US BMX size and if that’s the same as the old UK BMX it might do the job.

yup, ive tried and tried, o know the one you mean, tom below is just around the corner from me, ill have a chat with him, once he sees my message

 

[Mark south wales]

@danson67 will be able to do it if you can get your frame to him

i need the bb shaved my 5mm 78mm to 73 and the threads retapped to 24 tpi from 26tpi, as i can fit a modern lighter crank and alloy arms instrad of the steel things, spread the rear forks to take a modern axle and casette, then onto a custom fork then with cantis, and either extend the steerer and braze on some rear canti mounts, then a respray and build her up. wont be in time for the next retro raleigh ride in milton keynes though. but maybe next year.

 

[bikeworkshop]

Do you think it's safe to retap 26 to 24? By my calcs you'll be missing over 50% of the thread material.

Of course if it pops out, you can return to using a self- tightening square taper...but I think I'd go straight there.

I can reset the back and braze canti mounts but I would suggest disc tabs - so much cooler, same price.

A "Twenty" with canti bosses is leading you into rohloff/long grey beard territory- are you ready?
(I do have a Rohloff kicking around though, oh, and a grey beard, but that's not for sale)

Could you find a new fork, canti or disc? - I don't like increasing the braking forces on a fork blade beyond what they were built for.