Hondacati GSX-R CL350

Luke Manion

Luke Manion

Active Member
**Just a funky name we were joking about when I started brainstorming this project...
But it's a better name than Frankenstein, or some other clever iconic time-machine reference bike name. LOL

Anyway, the recipe for the project:

(1) '72 Honda CL350 pulled from a shed with 4k original miles.
(1) '07 Suzuki GSXR front end.
(1) '10 Ducati Streetfighter S 1098 rear end.
(1) mid-60's CB160 toaster tank.

Combine ingredients, mix well, add chrome, powdercoat, along with many handmade and/or aftermarket parts...then DTT!
 
Yes! This sounds AWESOME. Can't wait to see it. Make sure to gusset and brace the frame to accept the stiffer GSX-R/Ducati parts.
 
The first part to arrive...the bitch-o-neat-o Cognito Moto Retro Clamp!
Now reworking the bottom clamp to match this beauty.
Removing the old casting marks, cutting tabs, and grinding a bit more radius on the lower tree...
then plenty of sanding and polishing.
:)
 

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  • Cognito top clamp.jpg
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Here's a peek at the lower GSXR tree. Sanded down to 600 grit so far.
As I mentioned before, I removed all the nasties, and even drilled an extra hole in the face
to match the factory one. I will use this later, for an accessory mount or badge mount.
A few more hours, and she'll be clean as a whistle.
Nothing fancy to write home about, just the boring preliminary stuff that has to get done.
:)
 

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  • GSXR lower clamp 2.0.jpg
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I wondered how much the varied fork offset would alter the trail...
fork length obviously controls rake too.
I must sneak off to the garage to do some math.
(I'll be back to scratch my head and spout out some numbers.)

I'm curious to see if I remain in the 8% trail factor.

-Luke
 
Okay, after much deliberation on this rake/trail issue...
See if you educated-types agree with my train of thought.
I'll spit out some numbers:
First off, stock---> 26.5 rake, 2.08" (53mm) offset, 52in. wheelbase, typical 18" rubber.
I calculated the trail should be 4.04". I went to the garage and applied the math to an actual stock CB...on the floor..I was about 4 3/16".
I felt that it was close enough to double-check my trig. That yielded a 7.76% trail to WB ratio.

Now for the theoretical alterations---->
Taking into consideration the 26.5 rake, 1.81" (30mm) offset, and smaller 17" rubber...it left me with a 4.8" trail, TOO MUCH!
by shrinking the rake accordingly to reach similar stock measurements, I was de-raked into a 24 degree neck on paper.
After adding the added swingarm length (3.25"), and subtracting the offset (.905") to obtain a new altered wheelbase of 54.25",
I was left with a 7.68% trail to WB ratio, and a final trail of 4.17".

So the proper amount of de-raking to resemble stock handling characteristics would be about 2 1/2 degrees.

Rather than de-rake the neck, if I set up the new swingarm ride height to over-correct for this 2.5 degree variation lost in the new fork offset,
wouldn't it achieve the same thing?? Instead of placing the forks at the stock 63.5 fork angle, if I engineered the rear to force the neck into a position to relocate the forks at a 66 degree angle...making for a more aggressive stance...would that solve the trail issue.

Also to consider...suspension sag, shortening the forks into the trees, ride-height adjustment rod fine tuning, etc.etc.

Open to any form of discussion on this. This is new territory for me.

Thanks in advance!
-Luke
 
sounds great the only issue is radical chain slack with increased swinger angle
you could lower the pivot to help
 
With double checking the numbers, and swapping a few emails with Devin at Cognito...
From the CL's 19" to the new 17" will also help the cause.
(I had calculated from a CB that I also have in the garage, with an 18".)

If I can achieve 2 degrees from altering the rear...I'm golden.
I'll move the pivot accordingly to aid in preventing massive chain slack.
Still open to anyone's advice...I'm like Stevie Wonder directing traffic here...LOL
 
Here she is in all her glory. Complete with '79 inspection sticker, and '82 plates.
Teardown started about 3 seconds after this pic was taken,
all is ready for the front end swap by now.
4k on the motor, and it will clean up nicely!

-Luke
 

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  • '71 CL350.jpg
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BSA Nut said:
With double checking the numbers, and swapping a few emails with Devin at Cognito...
From the CL's 19" to the new 17" will also help the cause.
(I had calculated from a CB that I also have in the garage, with an 18".)

If I can achieve 2 degrees from altering the rear...I'm golden.
I'll move the pivot accordingly to aid in preventing massive chain slack.
Still open to anyone's advice...I'm like Stevie Wonder directing traffic here...LOL
Click to expand...

I did the same thing on my T500 (add slightly more angle to the swingarm) to get the correct rake I was aiming for. I was going to cut off the neck and re-weld a new one on at a different angle. Then it was pointed out to me (by Teazer on here) that if I increased the swing arm angle along with the new extended swing arm length I would not need to cut the neck off. I ended up with about 11* of angle on the swing arm.
 
Thanks for the input johnu...

That's the direction that I'm heading.

Set up the front. Place the forks. Raise the rear of the frame to get 66* on the tubes. Set the swingarm up with the rear wheel on the same plane as the front. Weld up the shock linkage.

and yes, Nail it Ryan.
 
hopefully you dont have to drop the swingarm too much
the problem with the cb350 is the distance from swinger pivot to c/s is substantial enough to cause huge chain slack as you increase the swinger angle and the pivot is already somewhat high so the chain will rub
a well placed poly skate wheel up under the front chain run will help
the best solution is moving the pivot forward as much as possible and down as well
good luck
 
Yes, forward movement is limited, maybe down and 'around' the corner a bit would be helpful.
Im hoping with the fatter Ducati swingarm it helps with the chain slop, too.
A roller tensioner IS always an option.
Im hoping it isn't a real radical angle change. I think the stock CB is about 6*,
not sure mathematically how much it will change. I will have to wait until I mock it up.
Swingarm length is almost exactly equal to fork length, so I'm hoping is in perfect conjunction.

I double checked the numbers...at a 24 degree rake, and switching to 17" from a 19" wheel yields almost exactly the same trail.
Again, 66* legs are the target.

Thanks to everyone who chimes in...

I promise, cool pictures in the future, less math blah blah blah.
-Luke
 
Here is my NOS toaster tank I picked up two weeks ago.
(I had to source the panels separately.)
Some fab work is needed to make it fit, the frame is a little fat toward the back half of the tank.
Not a big deal.
 

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  • CB160 tank.jpg
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I moved my pivot point forward and level with the counter shaft centerline. I only have 1mm between the engine case and swingarm! I just used a delrin skid on top of the swing arm to deal with the chain rub (which is not major) all MX bikes do this. I look forward to more updates.
 
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