what's the lightest anyone's ever got a bone stock CB350 frame down to?

My stock framer weighs 300 w. 1gal. in the tank. Cut off the frame behind the top shock mounts & all the spotweld seams (& re-welded), no electric start or alt., dinky little Yuasa gel-cell batt. Boxed the upper rear frame channels & welded on the outboard swingarm pivot plates. We'll see if it needs any bracing later. You can't brace the swingarm & I figure that's where most of the flex will be. The main frame may not be a stiff design, but it's made of really heavy shit.

 

Jeez Dave....lets not clog this thread up with actual data pertinent to the OP's question. ....I mean, there are nerf nuts and titanium cranks goin on up in here!

I need a decent scale. I've been wanting one for awhile. I've got a decent 100lb hangar scale....but I need some type of platform.

Glad to hear the bike is coming along.:up:

I've been to Steves shop....the man has some stuff.

 

Sounds about right. Take off 6 lbs for the gal of fuel and you're at 294 lbs dry. What wheels, etc do you have?

I got 286 lbs for mine w/Dunlops on aluminum rims and thinned/drilled disc in front. Wild numbers I hear for some 350GP bikes sound a bit optimistic.

 

Avon tires, Guzzi Eldo fr. brake laced to sum rim w.bigger spokes/nipples, 73' CR250 rear wheel w.bigger spokes/nipples, Jemco race exhaust, stock 73' tank, EX500 forklegs in Guzzi LM/G5/T3 triples. Oh, and the swingarm is SL350. I guess my point is, on this stock-framer (GP350) CB, most of my weight removal came off the motor. If I were looking to build a really light one, I'd look into an SL350 double downtube frame. I don't know for a fact, but the SL looks like it could be lighter. The swingarms are identical except for the brackets out on the end, which moves the axle & lower shock mounts back about an inch.

 

I spent hours one night helping my tuner grind and drill everything we could think of to save a few ounces. The next day I started running and watching what I was eating and lost 15 lbs in 3 weeks. I have already started losing weight for racing in the spring. Grinding off the factory welds and rewelding should help stiffen the frame. It worked on car frames when I was building dirt trackers. Or maybe I shouldn't mention that I did the roundy round thing on here, I here there are some haters lurking. Good luck with the project, it sounds great.

James Stewart
"using stumbling blocks for stepping stones"

 

Ain't nothin' wrong with roundy-round on dirt. Been to Springfield a couple times.You wanna talk about racers w. huge balls of ice, them boys got 'em!

 

I got the wife to drive a 4 cyl car down at Modoc. They want me to drive a crate late model down there.

 

A good handling dirt car was fun to drive but after roadracing bikes the thrill just wasn't there. We used to run Cherokee and Riverside Speedways in upstate SC and won so much that we had to have a police escort out of the track some nights. Sold all the dirt stuff and ran the Hooters Pro Cup Series for about 5 years, until we were all broke and finally just quit the cars.

 

Car guys get all worked up when they lose. It's crazy. I didn't like getting dirty just to watch. She had a blast and got some cash after the carnage was over. She wasn't fast, but she was just far enough back to avoid the mid pack carnage. She just kept moving up.

My neighbor used to build cars. Jay Mckinney. It seem's his family raced dirt for a long time.