Page 1 of 1

B25ss Goldstar.

Posted: Wed Apr 10, 2019 9:51 pm
by lathejack
Well I have taken on another project, a 250ss. I couldn't resist having a go at it, and I do quite like the 250 motors. It's all registered and is a UK bike, although it doesn't really bother me which country a BSA was originally registered.
image.jpg

It doesn't have any forks or yokes, all I've managed to get of them so far is a pair of legs. So I have been making a few parts myself, using the B50 fork internals as patterns before I reassemble them.
First I machined up a new pair of fork top nuts From Stainless Steel, the genuine item is on the right.
image.jpg

I also machined up a new set of fork damper valves and associated parts such as the main tubes, Pistons, beveled nuts and the stanchion bottom alloy nuts that contain a floating bush. Both images show the parts I made on the left, genuine on the right.
image.jpg
image.jpg

Re: B25ss Goldstar.

Posted: Wed Apr 10, 2019 10:00 pm
by lathejack
I had to machine the fork damper tubes from solid bar, here the oil slot is being cut.
image.jpg

All the newly made parts befor assembly, they were more time consuming than I imagined. I did buy the short rebound springs.
image.jpg
So I have made a bit of a start, although it is a somewhat odd way to start a project, but needs must!

Re: B25ss Goldstar.

Posted: Wed Apr 10, 2019 10:20 pm
by koncretekid
You might want to read this from the Britbike forum:
http://www.britbike.com/forums/ubbthrea ... rks#UNREAD
Tom

Re: B25ss Goldstar.

Posted: Thu Apr 11, 2019 4:49 pm
by kommando
Lathejack if you need any info on my BMW SS1000R insert re-engineer KK has added the link to then ask here or PM me. For someone with a lathe and mill its not hard to do especially based on what pics you have posted, beats my turning attempts. As the cartridge inserts are upgraded as soon as the bikes were bought its not hard to pick up surplus standard ones. On Gavin's A65 my mod for preload adjustment was covered by the handlebars so no need for that bit unless the B50 is different. I will not be making any more but happy to pass on how it was done.

Re: B25ss Goldstar.

Posted: Thu Apr 11, 2019 8:53 pm
by Ian Hingley
koncretekid wrote: Wed Apr 10, 2019 10:20 pm You might want to read this from the Britbike forum:
Interesting to see familiar names on an unfamiliar forum!

Hats off to both Tom and Kommando for their in-depth knowledge. Didn't know you were such a suspension expert Kommando!

Ian

Re: B25ss Goldstar.

Posted: Fri Apr 12, 2019 9:10 am
by kommando
Not an expert at all, just looking for ways to cope with our potholed roads and came across digressive damping which both promised and delivers if tuned correctly. I have CBR600RR Showa cartridges with shim stacks in my Commando so knew it worked but then found if you fitted them to OIF then you end up relying on 2 bolts with drilled out centres to hold the wheel on. I then found a way to fit the SS1000R cartridges to OIF which I had as I had bought them incorrectly thinking they would fit the pre OIF bikes but when they turned up found them much larger in diameter than the Showa 20mm ones.