Watsonian Sidecar Resto

Need technical help - Restoration help and tips, engine rebuild or just offer your knowledge or services - drop it in here.

Watsonian Sidecar Resto

Postby Allein » Mon Dec 23, 2013 4:11 pm

Hi All,

I'm currently renovating a Westonian Monza Sidecar.

Have stripped the hub down and cleaned it all up I decided to loosely assemble it whilst I do some other work.

unfortunately I had problems refitting the hub nut onto the shaft, I may have damaged the lead thread on the shaft I'm not sure. I have filed back the end of the shaft to clean it up but the nut is now damaged so I'd like to replace it.

I haven't had to deal with anything other than metric for sometime so have no way of identifying the thread and size, it does look like quite a fine thread...whitworth??

The manufactures site is largely useless, does anyone know what the right size is, thee original but was also nyloc.

many thanks
Allein
 
Posts: 2
Joined: Mon Dec 23, 2013 4:02 pm

Re: Watsonian Sidecar Resto

Postby Welsh Wizard » Mon Dec 23, 2013 9:36 pm

you may have to measure the number of threads per inch to find the thread, have you got a ruler that has inches on it, if so count the threads over a 1" distance and post the result up, as Watson could have used Cycle thread, BSF, or as it was made after the War UNF, or even some American fine thread.
User avatar
Welsh Wizard
Global Moderator
 
Posts: 1400
Joined: Wed Jun 17, 2009 4:28 am
Location: Far Side of the World

Re: Watsonian Sidecar Resto

Postby Tman » Mon Dec 23, 2013 10:29 pm

Watsonian....I'd be surprised if it was anything other than BSF or BSCY unless this chair was made very recently. If you have a Nyloc nut on there then it must be fairly recent or someone's whanged the wrong nut on.
If you're confident that the nut is a good fit then take it to any half-decent nuts and bolts shop and match it. Failing that you really need a thread gauge (cheap enough on Ebay) to measure TPI. Armed with that info + the diameter use Google to find thread specs and away you go.

(Incidentally Whitworth is anything but a fine thread...)
Tman
 
Posts: 564
Joined: Sat Nov 07, 2009 10:38 am

Re: Watsonian Sidecar Resto

Postby Allein » Mon Dec 23, 2013 11:33 pm

Thanks guys, I will measure tomorrow and find a local fabricators or similar.

I don't know the age of the sidecar but due to the state of it and the styling of the mudguard I had assumed 70s but most of the fittings seemed metric ?

The thread is very fine, but the nuts look original and are nyloc, I'm hoping a new nut will do the trick or it will have to be turned down and a new thread cut.
Allein
 
Posts: 2
Joined: Mon Dec 23, 2013 4:02 pm

Re: Watsonian Sidecar Resto

Postby Welsh Wizard » Tue Dec 24, 2013 3:36 am

you can also get fine threads in metric, if no count is even over an inch , check distance from thread to thread, see if it comes out as 0,50 mm , 0,75 mm , 1,00 mm , 1,25 mm , 1,50 mm it can also be outside of this range in metric.
User avatar
Welsh Wizard
Global Moderator
 
Posts: 1400
Joined: Wed Jun 17, 2009 4:28 am
Location: Far Side of the World


Return to The Classic Bike Workshop

Who is online

Users browsing this forum: No registered users and 3 guests

cron