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175TS rear hub

Posted: Wed Mar 21, 2018 9:01 pm
by ranton_rambler
I stripped the wheels down a couple of weeks ago so I could measure up and order new rims/spokes. I've realised that the rear hub is maybe an unusual one. It looks like the illustration in the manual for the smaller brake fitted on bikes up to the 175TS, and the drum measures up at 136mm. I think the 175 Sport and above had a bigger brake. Front brake is bigger.
Any thoughts on where I might source new cush drive rubber inserts, and a new sprocket? None of the places I've looked at so far list these type.

DSCF5445small.jpg

Re: 175TS rear hub

Posted: Thu Mar 22, 2018 12:08 am
by Jordan
If cush rubbers are not available, you could try making some. Rubber is easy to shape by grinding.
First get the rubber block of suitable hardness (Durometer or Shore). Take a sample of some similar to the rubber supplier.
Roughly cut to shape with a cutting blade in an angle grinder.
Grind to finished shape on the outsides, using a bench mounted abrasive belt machine, or bench grinder. Supreme accuracy shouldn't be needed.
The inside hole would be more challenging. Maybe use a diamond abrasive burr bit in a drill. Some jig could be made, to "mill" it more accurately.
Just suggestions!
Having said all that, the ones you have don't seem so bad in the photo.

For sprocket, if you have the original you can reband it with a blank sprocket, available from industrial suppliers.
Or use the blank to make one from scratch.
Care to keep it concentric with centre hole.

Re: 175TS rear hub

Posted: Thu Mar 22, 2018 9:44 am
by Ventodue
ranton_rambler wrote: Any thoughts on where I might source ... and a new sprocket?

Hi Ian,

Try Jane at Sprockets Unlimited (just down the road from you ...)

http://www.sprocketsunlimited.com/

01386 831341.

EDIT
Otherwise, on sale by Italian Motorbikes in Italy. Go:

http://www.italian-motorbikes.com/Pagin ... %20ita.htm

Re: 175TS rear hub

Posted: Thu Mar 22, 2018 7:29 pm
by ranton_rambler
Thanks both, I have done some looking around and I think I should be able to get a sprocket made. Stafford Show coming up in a few weeks.

Re: 175TS rear hub

Posted: Fri Mar 23, 2018 12:03 pm
by Eldert
italian motorbikes dont have the correct sprocket . you need one with 4 pins .

Eldert

Re: 175TS rear hub

Posted: Sat Mar 24, 2018 8:48 am
by Ventodue
Eldert wrote:italian motorbikes dont have the correct sprocket . you need one with 4 pins . Eldert

Eek :o !

175 sprocket.jpg

Good spot. I trust you'll let them know, Eldert ;) !

Re: 175TS rear hub

Posted: Sat Mar 24, 2018 9:02 am
by ranton_rambler
That's the one. I have the old one to use as a pattern, or I could cut the middle out and weld/bolt a new outer to it.

Re: 175TS rear hub

Posted: Sun Jul 08, 2018 8:12 pm
by ranton_rambler
Just for interest, I was at the Festival of 1000 Bikes at Mallory Park this weekend and there were quite a few small Italian bikes there. Now I'm a bit more familiar, I can see there was a lot of component sharing between the manufacturers.
There were a couple of Guzzi Stornello 125's there and I reckon the rear hub is the same as my 175. Might offer a few more options when searching for bits.
Ian

Re: 175TS rear hub

Posted: Thu Jul 19, 2018 5:08 pm
by Samurai
Hi Ian,

Funnily enough I recently had to fit a new chain and sprocket set to my 175TS for it's MOT. It was the first time that I'd had cause to take the sprocket off (too much other stuff to deal with!) and found the same problem e.g. the unusual four posts on the back of it that locate in the cush drive.

Speaking to Nigel Lacey, apparently the early 175TS used smaller Gremica hubs as you have obviously found. Apparently these were used on other small Italian bikes as well, but he doesn't know which ones, or even of anyone that sticks replacements.

I'm going to have a word with Talon Engineering as they are just down the road from me in Yeovil. They make all manner of bike stuff from sprockets to replacement trumpets for Dellorto carbs. Nigel has spoken to them previously about making some suitable sprockets but at the time they didn't seem keen.

Anyway, I'm going to have another go and perhaps they may have more interest if another person is also asking for a small batch to be made? If there is any interest on this forum let me know, so I can get a realistic quote for a special batch.

In the meantime I'm going to see if there is a source for sprockets listed for similar period MVs or Guzzis etc.

Hope this is of interest?

Jason.

Re: 175TS rear hub

Posted: Thu Jul 19, 2018 6:53 pm
by ranton_rambler
I talked to Sprockets Unlimited at Stafford Show and we concluded my rear sprocket was OK to re-use.
They were not able to make a replacement as it's not flat, but they recommended someone that could weld a new ring of teeth on. I have the details somewhere if you want them.
Barry Jones told me most people rebuild the wheel onto a later hub, with bigger brake.

I have a new front one from Nigel.

There were a couple of complete Stornello hubs on US eBay recently.