Bultaco Astro m163 1976-1977

[steve234]

I'm rebuilding my #106 to run 19 x 2.15 front and back and run a front tyre on the back. The newer swing arm might be wider than mine so you probably could run a 2.5 and a rear. The pre 78 clamps would also be wider. If you can get 2.5's and they fit go for it.

[RW490]

As you can see my rebuild is just starting. I am borrowing a mates Astro so that we are comparing two frames and then getting the cost for jigging and manufacture. The guy that will be doing it for me is an aeronautical engineer and currently makes featherbed norton chassis.

I will work out pricing one I have spoken to him and presented him with the two examples.

What I would like to know is the type of steel required as I think the originals were like a Reynolds seamless tubing but some of the last ones were chrome moly ?? He can do it either way. If someone has some more info on the materials used it would be very helpful.

This guy can also CNC triple clamps to suit, so I am very interested in the dimensions for the wide front end.

Also can the front brake be a disc or is that not allowed.

Appreciate the help guys.

[RW490]

G'day Rick,
I know somebody that would be very interested in one or two frames if you went ahead with your
plans. Keep us posted. The Astro is a great looking bike. Do you have the fibreglass? If so,... that same person would be keen to do some moulds/forms. Hmmmm,,.....
regards  Mark

Hey Mark
Yes I have the glass as per the photo and would love to start a match and build through forum members. That is a great idea.

[RW490]

why dont you just get the finished product from forum member matcho mick(moto tumbi fiberglass)he has molds for most things
jim

That's the go Jim, as I said to Mark we could have a match and build through forum members at good pricing so that someone could take their motocross motor out and slip it into an Astro copy for a flat track meeting.

Sounds like a plan to me.
Rick

[SON]

Great Idea Guys
About 10 years ago I imported a Champion Bultaco Flattrack frame and sold it to a friend
He was very into VMX / VFT at the time and lots of forum members know him
I have a few Champion single and double down tube frames
As much as I love Astros and Bultacos I think a Champion is the frame to copy as a Universal
I would gladly lend them all to you if that will help
Whilst on jigging a Universal frame
I have a Brand New Trackmaster in pieces for the XS 650 and have Firkos adjustable TT frame as a template that needs to be copied as well

[yamaico]

Hi Rick,
This is a set of triple clamps I made for my Astro. They are 195 between centres which is the norm for USA flat trackers.

[jerry]

Mark are you talking about Steve? J

[steve234]

Guys I am salivating with all this talk of building frames etc! Let the short track revolution begin!

Anyway, there are plenty of guys in the state doing cnc bits & bobs, but if can do it yourself all the better (It's about time). To cut out the trial and error it might be best adopting the Chinese business model and getting some that are proven performers and replicating if you wanna do it yourself.

Clamps, quick change hubs, swing arms bla bla bla.

My favourite aftermarket frame id the knight, love those things for some reason.

Cheers,
Steve

[Tomas]

As you can see my rebuild is just starting. I am borrowing a mates Astro so that we are comparing two frames and then getting the cost for jigging and manufacture. The guy that will be doing it for me is an aeronautical engineer and currently makes featherbed norton chassis.

I will work out pricing one I have spoken to him and presented him with the two examples.

What I would like to know is the type of steel required as I think the originals were like a Reynolds seamless tubing but some of the last ones were chrome moly ?? He can do it either way. If someone has some more info on the materials used it would be very helpful.

This guy can also CNC triple clamps to suit, so I am very interested in the dimensions for the wide front end.

Also can the front brake be a disc or is that not allowed.

Appreciate the help guys.

Reynolds is/was CrMo tubing manufacturer. Originally manufacturing tubing for bicycle frames. A would think that majority of Reynolds tubing is CrMo.

[RW490]

why dont you just get the finished product from forum member matcho mick(moto tumbi fiberglass)he has molds for most things
jim

Can you supply me a phone number contact please Jim.

[SON]

Champion Astro frame on its way to my shop, I will email Jim the photos
he can post them

[RW490]

Champion Astro frame on its way to my shop, I will email Jim the photos
he can post them

I haven't been able to get the other Astro frame yet. Hopefully this week coming. I will be interested to see the pictures of the Champion frame.

As my Astro originally had no brakes do I fit drum style or can I fit a disc as I want to try and ride this bike at the titles next year. If the bike must stay period is what I mean so that it is legal.

[yamaico]

As my Astro originally had no brakes do I fit drum style or can I fit a disc as I want to try and ride this bike at the titles next year. If the bike must stay period is what I mean so that it is legal.

The rear disc will be OK as it was standard equipment and I would think that as it had no front brake from the factory that you would be able to use a period disc brake off anything on the front. Having said that, if it was me I would still go for the conical Yamaha hub on the front.

[RW490]

Thanks for the reply Pete. I will do the same as yours I think.

[yamaico]

No worries Rick, I reckon that's the way to go. You should be able to find any number of hubs and backing plates at your local wreckers. You could probably find a magnesium one if you look hard enough.