Rear Hanger thread size

[DODDY]

Hi,

I have the task of welding up the broken rear hanger on a mates road bike. It is not a replaceable item, it is part of the aluminium frame!

All looks good but I will need to re-thread the hole where the derailleur bolts on.

Does anyone know the thread size. It looks like M10 X 1.0 Pitch. Can anyone confirm this.

Cheers
CRAIG

 

[alecstilleyedye]

that's unusual in an aluminium bike. usually the gear hangar is bolted on.

 

[skwerl]

I'd have thought M8 but that's a guess

 

[spandex]

10mm

 

[DODDY]

Quite supplrised myself that it was all part of the frame, but it is.

The frame is an ALAN!

 

[Swift Dan]

Don't know if this is much help but I've read recently that it's the same size and thread as a rear axle. Apparently if you bend one on a steel frame you can remove the rear wheel, screw the axle end into the hanger and use the leverage of the wheel to bend it straight.

SD

 

[Saddle bum]

Just been looking through the Campag instruction book that comes with a new derailleur. They give the size of the hanger thread as "10x26tpi".

That is a real mix of units. The thread is 10mm major diameter and 26 threads per inch.

26 TPI is a standard for cycle threads taken from BS811. However 26 TPI is so close to a metric pitch of 1.0mm as to make only the slightest difference over the small length of thread used in the gear hanger. (It would not work on a bottom bracket, which is also 26TPI).

When the original Campagnolo gear hangers were first introduced in the late 1940s, I presume Campag kept to the original international 26TPI standard. However I would bet my pension that today, both hanger and screw are made to 10x1 in metric.

 

[spandex]

Don't know if this is much help but I've read recently that it's the same size and thread as a rear axle. Apparently if you bend one on a steel frame you can remove the rear wheel, screw the axle end into the hanger and use the leverage of the wheel to bend it straight.

SD

but do you not need the rear wheel in to gage it off it !!!


BTW how is it in Basildon at the moment I got out of there when I was a kid and just go back for funerals and then run away.

 

[Swift Dan]

B) but do you not need the rear wheel in to gage it off it !!!


BTW how is it in Basildon at the moment I got out of there when I was a kid and just go back for funerals and then run away.

I guess the secret is to borrow a mates back wheel while they're not looking, in case you bend the axle.

I doubt Basildon has changed since you escaped, oh hang on... Woolworths closed.

SD