Cheers for the thoughts guys. As I said, this can be a problem for another day, it’;s not stopping me from moving forwards with the rebuild so plenty of time to mull it over.
Gearbox time 🙂
I had seen a video of the bike riding in 1st and 2nd, so I knew at least 2 of the 3 gears work. But's its pretty rough looking and I also know the kickstart return spring doesn't work, so I knew it'd be coming apart.
I opened the gearbox expecting to find a broken kickstart spring in there... but there was no sign of one! Just some gears and a couple of selector forks!
In my naivety I presumed that the spring would be inside the gearbox, as I've never experience anything else, but it's actually an external spring which had probably rusted through over the years and was now completely missing. I did manage to find the correct spring for sale, on a small website based in Germany for quite a large sum... I also found a very similar spring, for one of BSA's other 30's bikes, for sale in the UK at a more appealing price, so thought I'd chance that. Obviously it didn't fit... but I bent it and cut it and have something that for now seems to work. 🙂
You can see the inside of the gearbox was pretty dirty, and the side cover had been broken and welded up at one point.
You can also see that most of the gears and internal components looks to be in pretty good condition, all except for the kick start pinion. The teeth of this were heavily worn, not an uncommon issue apparently. I would guess having a broke kick start spring may have let the kick-start drag against the teeth? Still the kickstart seemed to work 'ok', so I left it all alone. From what I've read I will have to watch out for the kick start jamming and possibly slipping with a pinion this worn. At least it shouldn't be too hard to bump start being only a 250!
While the box was apart I noticed that there was a sizeable crack across the top of the gearbox casing, so I welded that up.
The gearbox is now all back together, filled with fresh Castol 120w gearbox oil, and I was ready to put it on the 'finished' pile...
... but then I chanced upon a NOS kickstart pinion on eBay. I'd come across stories online of people having new ones made, at quite some cost, and this was reasonably cheap so I snapped it up, and the gearbox is currently waiting for me to pull it apart again to fit it.
Frame next time 🙂
Gearbox time 🙂
I had seen a video of the bike riding in 1st and 2nd, so I knew at least 2 of the 3 gears work. But's its pretty rough looking and I also know the kickstart return spring doesn't work, so I knew it'd be coming apart.
I opened the gearbox expecting to find a broken kickstart spring in there... but there was no sign of one! Just some gears and a couple of selector forks!
In my naivety I presumed that the spring would be inside the gearbox, as I've never experience anything else, but it's actually an external spring which had probably rusted through over the years and was now completely missing. I did manage to find the correct spring for sale, on a small website based in Germany for quite a large sum... I also found a very similar spring, for one of BSA's other 30's bikes, for sale in the UK at a more appealing price, so thought I'd chance that. Obviously it didn't fit... but I bent it and cut it and have something that for now seems to work. 🙂
You can see the inside of the gearbox was pretty dirty, and the side cover had been broken and welded up at one point.
You can also see that most of the gears and internal components looks to be in pretty good condition, all except for the kick start pinion. The teeth of this were heavily worn, not an uncommon issue apparently. I would guess having a broke kick start spring may have let the kick-start drag against the teeth? Still the kickstart seemed to work 'ok', so I left it all alone. From what I've read I will have to watch out for the kick start jamming and possibly slipping with a pinion this worn. At least it shouldn't be too hard to bump start being only a 250!
While the box was apart I noticed that there was a sizeable crack across the top of the gearbox casing, so I welded that up.
The gearbox is now all back together, filled with fresh Castol 120w gearbox oil, and I was ready to put it on the 'finished' pile...
... but then I chanced upon a NOS kickstart pinion on eBay. I'd come across stories online of people having new ones made, at quite some cost, and this was reasonably cheap so I snapped it up, and the gearbox is currently waiting for me to pull it apart again to fit it.
Frame next time 🙂