Frame strengthening exercise?

[DeathFromAbove]

Like ruwfo said that rear loop is not right, even the diameter is wrong. Probably so they could put it in the original frame. I would remove it all and start with a known rear section. Got a veiw of this from the rear? Even the shock mounts look suspect. Chris

 

[Brad-in-STL]

... I would remove it all and start with a known rear section. Got a veiw of this from the rear? Even the shock mounts look suspect. Chris

Thanks Chris!

Thing is, sourcing the correct rear loop could take years... I get that it's not original, but I really just want a rider for some local vintage MX racing. I'll cut the vertical tabs off, weld on some barrels, slap on some paint and off we go!

I really do think the shock mounts are OEM, but see what you think, below:

 

[motomwo]

Shock mounts are original.

 

[DeathFromAbove]

Thanks Marty, the welds look redone.

 

[motomwo]

Thanks Marty, the welds look redone.

Can you take a closer picture of the shock mounts? Can't really see the welds in the above picture but look like the mounts are in the original location on the swing arm. Although it only takes about 1" difference to make a big change in the suspension travel.

 

[ruwfo]

I'll take a look. Since it's already been modified, I feel more free to cut off these vertical tabs and start over. It would be simple to weld on some barrel style tabs to get the seat closer to the rest of the frame.

Thanks,

Yeap, cut off the old stuff & make your seat you got work

How's the weather ?, SNOW i'm betting, it's coming my way, 10F for a high Sat, here in NW NJ

Those look like, stock rear shock mounts, same as my 80 390CR. And those are way too skinny 35mm forks, and shocks are cheapy -Progressive's, sort of junk.

Some up grades you can do, is 81-83 40mm forks, & same years rear shocks, make a huge difference. 15-1/2 shock length stock on WR

 

[Brad-in-STL]

Can you take a closer picture of the shock mounts?

Sure Marty... Here they are. I think they are original, but let me know what you think. (left then right)

 

[Brad-in-STL]

Some up grades you can do, is 81-83 40mm forks, & same years rear shocks, make a huge difference. 15-1/2 shock length stock on WR

So I would also need the triple clamps for the 40mm forks, right? I'll keep a look out for those. Those are Progressives and the shafts are pretty rusty, totally roached. When I rise up off of the seat they bang at max extension, so the bumpers are gone too. (my wife's gonna kill me! )

Thanks John.

 

[Brad-in-STL]

Here's something I've tacked-up for keeping my boot out of the CS sprocket:

 

[motomwo]

Those are the original mounts.

 

[ruwfo]

So I would also need the triple clamps for the 40mm forks, right? I'll keep a look out for those. Those are Progressives and the shafts are pretty rusty, totally roached. When I rise up off of the seat they bang at max extension, so the bumpers are gone too. (my wife's gonna kill me! )

Thanks John.

Yes ,complete 40mm fork set with triple clamps, will bolt right on. Those 35mm are way too long, MX action, bent them back in the day on the magazine test. After i read that, i went with 40mm, not that i'm anywhere near as good as their test riders. Always felt like a chopper, with the stock length shocks, so i went with a slightly longer, for a more level feel

 

[Brad-in-STL]

... Always felt like a chopper, with the stock length shocks, so i went with a slightly longer, for a more level feel

That's exactly how I refer to this bike's current stance... "looks like a chopper". That's why I was sure that the 15" shocks were too short. Now I know better... We'll I'll keep an eye out for a 40mm front end, but since that will likely take a while, I can at least lower the triple clamps a bit, right?

Is eBay my only choice for both the front end and longer rear shocks?

Are you buried in snow?!
Thanks John!

 

[ruwfo]

Is eBay my only choice for both the front end and longer rear shocks?

unfortunately that maybe your only choice

be careful on shock lengths, i'm 6' 2" so i can use all the height i can use.

NOT as much snow as forecasted -only 3"

 

[DeathFromAbove]

https://www.ebay.com/itm/274989723314?hash=item4006aa2eb2:g:HGcAAOSw~-JhbNaG

 

[Brad-in-STL]

https://www.ebay.com/itm/274989723314?hash=item4006aa2eb2:g:HGcAAOSw~-JhbNaG

Only 3.5 hours away... I drove further than that to pick up this bike in Kansas City.

So the '78 frame is how close to the '80?
Thanks DFA,

 

[ruwfo]

So the '78 frame is how close to the '80?

78 has metal airbox, vs 80 plastic, 78 seat with lower mounting stud

But i'm pretty sure the motor mounts are different, so that maybe a bigger can of worms & in my opinion NOT worth it

 

[DeathFromAbove]

Just keeping my peeps open. May be he can use the rear frame segment?

 

[motomwo]

The frame Chris pictured is a 79.

 

[Brad-in-STL]

Just keeping my peeps open...

Hey Chris, I appreciate all the help I can get! Keep those peeps open!

Especially where that 40mm front end comes into play...

 

[ruwfo]

If your looking for a frame stay away from any that have a "u" shaped plate, like in this picture,
as that's how the 75-78 mount the seat in the front


78 seat