Scratch built GS

[Urban spaceman]

GS based dragbike build in progress. Nitrous and large cc's

 

[Rob S.]

So far, so good. I'm guessing from that rear Goodyear Eagle you're not planning on doing a lot of cornering. :xsmilie_mrgreen:

Waiting to see pics of the engine!

 

[Steve]

So far, so good. I'm guessing from that rear Goodyear Eagle you're not planning on doing a lot of cornering. :xsmilie_mrgreen:

On the contrary, he'll make a U-turn about every three or four tenths of a mile.

.

 

[steve murdoch]

Welcome aboard.
There are plenty of current and former drag racers on this site who can probably solve any problem you come across.
Looking forward to following your build.
If you put your location in the avatar there could be a helpful GSer nearby.

 

[JTGS850GL]

Are those brazed welds?

 

[dorkburger]

Are those brazed welds?

I was curious about the different color of the welding material also. I spent some time studying the pic and all of the tubing.
Its pleasing to my eye. Nice looking job.

 

[Urban spaceman]

It does have to turn off the track at the end, and there's a corner or two on the way to scrutineering so it does a little bit of cornering yeah! The Goodyear tyre is only for mockup purposes, it'll have a Mickey Thomson on for the track.

The Tube joints are whats known as Bronze welded, or braze welded yeah. A close up....

 

[Urban spaceman]

 

[rapidray]

When I was building racing go cart chassis, they were brazed so the frames will flex, thus becoming the "suspension" in the chassis. On a dragbike frame you DON'T want flex! I am interested to hear how this works out. Good luck, I hope this works. Great looking design. How many inches is the wheelbase, & how big will the engine be?
Ray.

 

[blowerbike]

and what is the crank to axle measurement.
welcome!

 

[Urban spaceman]

I hope it works too - which of course it will!!
I know it in mm
1335mm c to a
2026mm wb
Engine will be whatever i have ready i guess, but i'm building it for a V&H 2V and 1640cc

 

[Urban spaceman]

When I was building racing go cart chassis, they were brazed
Ray.

Ray - Brazed or bronze welded?

 

[Urban spaceman]

This build has been ongoing for a while, i started 11 months ago when i bought the tube. The pics so far have shown it pretty much as it was just a few weeks ago.
I have a LOT of pics from the build, it's all documented on my blog but i thought i'd share some here...... here is another...

 

[Urban spaceman]

and this is back in july

 

[Urban spaceman]

and a bit more recently

 

[rapidray]

Ray - Brazed or bronze welded?

Oxy/acetylene gas brazed.
Ray.

 

[Urban spaceman]

The process i have used is known as Bronze welding, not sure if thats the same, but it differs from brazing in that there is virtually no capillary action. You build up a bead much like a large tig weld. The rods used contain Manganese and Tin giving excellent strength properties and are ideal for use with an inline gas fluxer - which i used. (no messy flux residues to try and clean off afterwards). I use an oxy/propane setup.
Aerial atom car chassis are built that way, Theres some really good videos on YouTube of them using the process. https://www.youtube.com/watch?v=ZlLV0P6uGDw

The joint on a frame can never allow flexing. The design of a frame and the materials used can allow flexing, and in the case of Karts, they have no suspension and run for hours on sometimes bumpy tracks - and so the tube thickness and chassis design will allow flex to absorb the bumps, otherwise - if it was rigid something would break and it wouldn't handle. The reason they are sometimes brazed is that with all that flex welds could crack whereas brazed joints will not. The bronze welded fillet is probably stiffer than a tig weld if anything as it runs further up the tube. It also doesn't embrittle the parent material as theres not much heat put into the tube. So less chance of cracking in the HAZ.
I've chosen it as it's a nice and perfectly suitable way of joining tubes, and not used much these days.

 

[rapidray]

Yeah, I know the process, same as building the cart chassis. I just don't see it as strong as tig welding with steel filler rod. There are NO chassis for drag racing, cars or motorcycles, welded that way here in the USA so not sure if it would even be legal here. When I worked for Gary Hansen Race Cars we did use silicon bronze rod at times for tig welding roll cage mounting plates to existing floor pans. We used it on sheet metal also but that was about it, & the metal is was being welded to had to be SPOTLESS clean! Interesting though. I am waiting to see how yours runs when finished.
Ray.

 

[Urban spaceman]

Your probably right ray, i doubt the join itself is as strong as tig either. The biggest benefit i found is that there's pretty much no movement whatsoever in the tubes while your brazing the chassis up. It required no tweaking, or allowances for movement whatsoever.
In europe i know a few bikes are bronze welded, in the UK Bob Brooks Yellow Metal bike and my own have been running bronze welded steel and ally wheely bars for years with no problems, oh and our UK national tech inspector - his very own race bike also has an entirely bronze welded chassis.

All my racing endeavors are on my Blog and FB page, so i'll copy some of it here and we'll get to see how it works sometime next year hopefully.
Oh, and the tube is also unconventional for you folks, it's T45 not chromoly. Just to break the mold some more.

 

[rapidray]

Cool! I am always open to learning new things! I look forward to seeing your pictures & experience!
Ray.