gs450 re-build

[mlc216]

3/16/11
So I just picked up this little chopper so I'd have something cool to run around instead of a silly sport bike.


It's a GS450 motor (not sure what year), with a 16" comstar, 18" spoke disc wheel (no brake), with some cheap off the shelf chopper parts thrown on a crazy long hardtail. I think the guy who built it was something like 6' 6" tall, so I guess I understand it.... but when I sit on it the mid-controls feel like forwards haha.

Plans: I am going to cut it up this weekend and improve the proportions. We'll shorten up the hardtail section to a suitable wheelbase and I'll probably cut out the triple backbone and put in a nice new single top tube. The comstar's offset is HORRIBLE. It's millimeters away from the tire rubbing on the non-drive side and inches away on the drive side. I forgot to take pictures of how bad the offset was, but I've already started on a solution to get the wheel a little more centered. Between the both of us we have some random wheels that we might be able to switch to if needed. As of right now I think I'd like to run the comstar in the rear with ripple moon discs and a 19 or 21 up front. Probably make a rigid tuck and roll seat conformed to the shape of a new fender/sissy bar arrangement.

Stay tuned, this one will get changed up pretty quick and then ridden A LOT.

[mlc216]

3/19/11
A guy from work turned down the "cush drive" and now the offset on the wheel is perfect!


The guy who chopped this bike didn't exactly think like I would...



With the nasty triple backbone...


Took 5" out of the hardtail and here's a mock-up

[mlc216]

And here's the new and improved frame with a single backbone...

The side supports have engine mounts in them, so I didn't want to cut them out all together. I debated what exactly to do with this area... I've seen people put a crossmember just above the motor mounts, but those supports aren't even with each other from the factory so the crossmember just looks crooked. So instead I pie cut the supports and bent one forward and in to the backbone and one back and in to the backbone. Looks pretty clean IMO.

More mock-up


Got it back together and went for a ride...




It died during my neighborhood test ride... Tried to start it back up, but it started to backfire from the carb.... so I guess I need to check into a few things before I ride it anymore. Also, I still have to find a fender, make a rear tank mount, and a front seat mount. Plenty more changes in the next couple of weeks like a decent headlight and tail light and some t-bars soon.

P.S. I started at arond 10am this morning and went for a ride at 6:45pm... I think I got a lot done for one day.

[Go Mifune]

[QUOTE=
P.S. I started at arond 10am this morning and went for a ride at 6:45pm... I think I got a lot done for one day.[/QUOTE]
I think it took me longer to read this thread than it took you to do all that work.
Looks better , nice.

[pete]

Not exactly a fan of the hardtail/chopper/bobber thing, but you've done an amazing amount of work in such a short time!

I will say it looks tons better than it did in its stretched out form, it was quite bizarre before you shortened it. Now it looks rideable.

I also love the shape of that car behind it there. I love old American iron but there's no chance of me ever owning one, so I just drool occassionally instead...

[mlc216]

I think it took me longer to read this thread than it took you to do all that work.
Looks better , nice.

Haha yeah I had a few days of work to think about all that I wanted to do this weekend... Well I knew I wanted to take 5-6" out and 5" even seemed to be the easiest. It was the triple backbone that took some staring to try and figure out how to tie it into the side supports. Pie cut and bend. Done.

Not exactly a fan of the hardtail/chopper/bobber thing, but you've done an amazing amount of work in such a short time!

I will say it looks tons better than it did in its stretched out form, it was quite bizarre before you shortened it. Now it looks rideable.

I also love the shape of that car behind it there. I love old American iron but there's no chance of me ever owning one, so I just drool occassionally instead...

It's much more ridable for me being only 5'7"! A lot more changes to come too. And hardtails aren't nearly as bad as most people think, so give it a try!

That's a '52 chevy fleetline in the background. Body is off the frame while I notch and z the frame to get it low. That's my baby and consumes most of my time... just taking a break to get a little bike on the road.

[pete]

It's much more ridable for me being only 5'7"! A lot more changes to come too. And hardtails aren't nearly as bad as most people think, so give it a try!

That's a '52 chevy fleetline in the background. Body is off the frame while I notch and z the frame to get it low. That's my baby and consumes most of my time... just taking a break to get a little bike on the road.

Nice one... still not sold on the hardtail... but you never know, if an opportunity arises...

Chevy's havta be my favourite I think. I've always had a thing for Chevy's even when I was a kid, not sure why, must be the lines or something. I always thought a pillar less Impala would be nice...

That Fleetline should look real good when you're done, nice flowing lines on that shell.

[mlc216]

Yeah the fleetline is going to be straight late 50's kustom. Trying to do it using only parts that could've been had pre 1960...

[pete]

Sounds good!

[scottychop]

Nice work man! I DO like chops, unlike some people....

What size backbone did you go with? IT might just be the pic, but it looks a little on the smallish size DIA wise?

[pete]

Nice work man! I DO like chops, unlike some people....

Just not my thing, but I definitely do appreciate quality workmanship

[mlc216]

Nice work man! I DO like chops, unlike some people....

What size backbone did you go with? IT might just be the pic, but it looks a little on the smallish size DIA wise?

It's 1" .120 wall DOM tubing. Would've liked to use 1.25", but couldn't find any. I lugged it into the original back bone and built a neck support underneath it as well. It's plenty strong, I made sure of that

[mlc216]

Removed all the stupid crimp connectors and soldered all the joints tonight so now it cranks without hesitation and doesn't randomly die somewhere in the neighborhood. Still running pretty lean, so I'll address that very soon. It was fun to ride around the neighborhood without it dying on me though. A good bit quicker than I imagined a 450 being. :-)

[pete]

Sounds like an excellent idea! The 450's are definitely quick enough around town etc., they just get a little squirrely on the highway.

[mlc216]

I like pictures, so I'll keep them coming...

stopped at a friends while out on the test ride.


Came around a familiar corner to find two teenagers walking down the middle of the road...swung wide, found a little grass while avoiding the ditch, back tire slid a little, dragged a little pipe apparently and rode it out like it never happened haha.

Never hit the brakes during all that.... Not sure why. I race mountain bikes? Maybe that has something to do with it?