TOPIC:

the "gold lines" are where they were brazed.
alot of japanese and europeans braze there frames.

thanks for the kind words buddy.you know me i just want to help people keep these old bikes on the road and their knees in the breeze.

leon

testarossa wrote: Actually, I believe that it is a piece of tube that has been sectioned and bent to follow the main tube. It's welded to the underside of the tube to create a double walled section IIRC.

kinda like this






leon

Not sure if I'm opening a can of worms here, but anyone got any strong opinions on chains? 530 seems to be the common one.

I'm a 530 guy myself. It's the same width and strength as your old 630, and it offers more gear ratio flexibility due to increased number of teeth. There is a marginal wear advantage due to the load being spread amongst more teeth. It's also more common these days than 630. If you ever need a master link clip, most shops will stock a 530 but have to order a 630 as an example.

testarossa wrote: I'm a 530 guy myself. It's the same width and strength as your old 630, and it offers more gear ratio flexibility due to increased number of teeth. There is a marginal wear advantage due to the load being spread amongst more teeth. It's also more common these days than 630. If you ever need a master link clip, most shops will stock a 530 but have to order a 630 as an example.

Good to know - especially for field repairs.

531blackbanshee wrote: the "gold lines" are where they were brazed.
alot of japanese and europeans braze there frames.

thanks for the kind words buddy.you know me i just want to help people keep these old bikes on the road and their knees in the breeze.

leon

Thanks, Leon. I've been kind of fascinated with brazing for a while. From my understanding all the BSA and Norton factory racer frames back in the 70s were brazed. Good enough for them...

I'm currently on the market for an oxy/acc setup, and once found and purchased, I might see if I can braze the gussets at the head tube.

Use your old 630 to make an ultra-cool chain mailbox post! Less links to weld.

testarossa wrote: Use your old 630 to make an ultra-cool chain mailbox post! Less links to weld.

...or maybe an arbor for the missus.

So a little progress this weekend on the gussets (at the head tube).

I've been looking at other builds and was curious about how to get the fold-over with a concave curve. So I tried it two ways: one to bend it over with a custom jig, and two, cut the triangle and the 'return', then weld, grind and sand.

here's the jig.


and the bent piece

problem with the bend method was two fold...one the curve was not great and two the work piece showed the tell-tale signs of being handled by an amateur panel beater.

So I went for the second method...

which came out a lot nicer.


as long as you don't look at the disgusting weld on the backside.



Still side by side, the difference is pretty stark.



And fitment is spot on.

I've got the other side cut, I just have to finish it off. Slow and steady we're getting there...

Also, had a bit of a setback on Saturday.

I like to keep the garage door open when it's warm, but the dog always wants to take off and find something disgusting to eat in the alley. So I used the car, the trash can, and a crate for a barrier.

It was getting late and we were heading out for a beer as Sunday was my birthday. I closed the garage door without thinking that the crate (full of parts) was still on the other side.

Got home, went into the garage and realized my carelessness. Fuck - I coulda punched myself in the face for that one! We live 3 blocks from Broadway here in Denver and the alley gets a lot of traffic from the Magpies (guys looking for metal scrap) and homeless folks. Needless to say, the crate was long gone.

Good news is that most of the gear in there was not going to be kept (like the old chain, the stem and old rear axle. Unfortunately the clip ons (and controls) from the ZX-6r front end and a NOS stator cover were also in there. There was proably other gear in there too, which I'll figure out as I go on.

It's a shitter, but also means that I'll a) be more careful and b) have to find/make some fresh clip-ons, which will likely be better that scavenged ZX units.

Life goes on.