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1981 GS450S frankenbike rebuild

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Guest

Guest
So in the interest of creating work for myself and keeping my hands busy, this neglected and poorly maintained GS450 frankenbike is my challenge.
Collected this from a state of neglect and being stored in the open.
At the time of purchase she had been sat for about a year after a minor exothermic reaction as a result of incorrect coil and plug combination (apparently).
So, clearly not a runner. What I managed to determine of this bike is that parts had been sourced from varied locations.
The fork is a variant from GS550 (I think), the front brake a honda version of some kind, etc..
The general state of this little lady was pretty bad, with things having been left open to the elements.
Additionally, some serious bodges had been put into place. The 2 worst being the nuts welded into place and the wiring loom being patched with short lengths of cable of about 10cm length.
It was not pretty. To be honest I thought I might catch a disease from the seat.

As she was on the first day:
Starting_Point.jpg

Once I got her home, it was a complete strip down. Every bolt and nut (where not welded) was removed. With the state it was in, I don't think it would be at all wise to risk leaving anything out.
 
Following the strip down parts were sent for vapour blasting. Figure it's not worth my time to try and sand down all the parts to remove the *@%^$*@%^$*@%^$*@%^$ty paintwork over 40 years. The results were absolutely incredible. What was returned was so good in terms of finish. Much better than I could have hoped for.
This step was followed with learning to paint by rattle can. Perhaps not the best choice, nor the cheapest, but it was a learning experience. There were some false starts and errors made, but then that's the point.
At this stage the engine (save for the crank cases), frame, body parts have been painted and prepped for re-installation. Included in all of this was
- valves cleaned and lapped
- new valve seals
- broken bolts drilled out and/or heli-coiled
- carbs dis-assembled, cleaned (found stripped pilot jets) and reassembled.
- fork legs rechromed and new seals

Not many photos at this point of the results, but I think the wheels turned out all right.
FrontWheel.jpg
 
At the moment I am awaiting new bearings so the crank and balance shafts can be reground. The diagnosis from the engine builder is that the crank is actually in pretty good shape. Just sum scoring and so on you might expect from an old bike.
In the meanwhile, I have busied myself with the tank...
Inside has been cleaned and epoxy coated. I have been spraying the outside and that has been an adventure. Lots of mistakes and false starts, and perhaps a little too much ambition.
After about 4 attempts I finally got a good thick base coast that has flattened out most of the dings. I decided not to try and make a perfect show piece, but rather to leave some battle scars. Also, I'm fundamentally lazy, so maybe that has something to do with it.

With a bit of luck I will be able to complete the tank in the next week or so, at which point I hope some of the outstanding bits will arrive.
 
Looking forward to see how this turns out.
Never had a screwdriver lose a battle to a screw but had many battle scarred screws.

Not familiar with the Michelin Sirac tires. Are you planning some off-roading?
 
The original plan was to turn it into a street tracker style bike. Never been a big fan of the cafe racer thing.
to be honest though, for the wheel sizes there wasn't much choice. Street only I could find Spitfires available, and a few off-road specific options.
The Siracs were the only dual-purpose tyre I could find in stock that was mostly biased to street riding.
Whether I go off-roading or not, will be a question for later down the road. There are many more interesting places to visit off the beaten path, so some ability there will be nice.
 
Street only I could find Spitfires available

the original rims are 18" I believe. But you should be able to easily swap in rims from the T (19 Front and 17 inch rear) or maybe even L models
That said, for my 18" rims, here's a list I made for my GS(X) 400 E...can't guarantee accuracy anymore but I was pretty diligent when I made it.

ON NOW= Shinko Tourmaster 3.00"x18 DURO tubeless 110/90/18 rear
Pirellii SportDemon 90/90 18 TL, Pirelli SportDemon 110/90 18 TL

you might have to "reverse" direction" Avons are notable for this but others can work too where the tread is not obviously wrong.
Avon (AM26)Roadrider 90/90 18 TL, Avon (AM26)Roadrider 100/ 0r 110/ 90 18 TL

IRC Durotour RS310 90/90 18, IRC Durotour RS310 110/90 18

Dual Sport!

[TD="align: left"]Shinko 244(dualsport) 3.0 x18, Shinko 244(dualsport) 3.5 x18[/TD]
 
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the wheels that came with the bike are 18 rear and 19 front. I'll keep the tyre info handy, thanks for that.
Not sure whether these came with the bike originally or not, but it's what I got.
Fairly certain the fork is from a GS550, so maybe the wheel came with it
 
Originally, on the S and the E, the rims were both 18". (The T had 19 front) I'm not sure about GS550 , but on the original forks, a 19" front fits very close to the fender...a 100/90 19 runs so close on my T that mud, snow,gravel grinds up in there with 100/90 19 tires...so if it's true for you, you might want to study the subject...you might investigate lower profile tires , but it gets complicated if you read to much! :) ie: a wide flat tire on the front is not "ideal" with a fat round one on the rear...
 
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Originally, on the S and the E, the rims were both 18". (The T had 19 front) I'm not sure about GS550 , but on the original forks, a 19" front fits very close to the fender...a 100/90 19 runs so close on my T that mud, snow,gravel grinds up in there with 100/90 19 tires...so if it's true for you, you might want to study the subject...you might investigate lower profile tires , but it gets complicated if you read to much! :) ie: a wide flat tire on the front is not "ideal" with a fat round one on the rear...

My guess is various manufacturers are going to have differences in overall diameter.
On my bike the Kenda k761 dual sport had that exact issue but the Shinko777 that replaced it has plenty of clearance, both are 100/90-19. You can loosen the fender bolts and cheat it upward a bit to gain a small amount of added clearance.
 
I'm keen to follow along here, interesting to see the front end swap there, the dual disc setup is definitely not stock 450 and the 19" should actually make tyre selection easier. Finding good tyres in 18" front and rear is tricky although are some out there (I run Avon Roadriders which I find good).
 
a Weeks progress

a Weeks progress

Some progress completed over the weekend:
- painted and clear coated crankcases
- clear coated frame
- cleaned and rebuild brake system
- cleaned and inspected a bunch of bolts, fasteners, nuts, etc
attachment.php

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attachment.php

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Now I can start to figure out how the majority of the frame, swing-arm and fork gets re-assembled. Stupidly I put all the fasteners for the frame and associated bits in one single bag....
At any rate at least that pile is clean now.
Hopefully by the end of next weekend it will be a rolling chassis
 
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Nice work, looking very good indeed! Getting to a roller is always a satisfying step!
 
???..I put all the fasteners for the frame and associated bits in one single bag....

Well done, you are doing a nice neat job there!

If you look at a OEM parts fiche like the one on Partsoutlaw, the bolt sizes are coded into the part number eg. in the frame picture below, the part number for bolt #4 is 01500-0860B.

Looking at the last part of the number, the "08" means an M8 bolt, and "60" means 60 mm long. Using this method, you can make sure to put bolts of the correct thickness and length in the correct places. This holds true for all bolts on sidecovers and all other places on the bike.

https://www.partsoutlaw.com/oemparts/a/suz/50d3f0bdf8700230d8b4b97f/frame

Good luck!

 
If you look at a OEM parts fiche like the one on Partsoutlaw, the bolt sizes are coded into the part number eg. in the frame picture below, the part number for bolt #4 is 01500-0860B.

Looking at the last part of the number, the "08" means an M8 bolt, and "60" means 60 mm long. Using this method, you can make sure to put bolts of the correct thickness and length in the correct places. This holds true for all bolts on sidecovers and all other places on the bike.
Now that is a piece of info that will go down as some of the best I've heard yet
 
Those brakes don't look stock but I don't know what they're off... Very weird slider arrangement with that pin going in the opposing direction. I'd love to see a pic as you put them back together. You must have forks off of a different model too (unless SA 450s came with two brakes..) :)
 
Those brakes don't look stock but I don't know what they're off... Very weird slider arrangement with that pin going in the opposing direction. I'd love to see a pic as you put them back together. You must have forks off of a different model too (unless SA 450s came with two brakes..) :)
Brakes are from a 2012? Kawasaki EX650. I got them on ebay for about $30, so I thought what the hell, maybe I can make it work.
Will need a bracket to fit them up, as the mount points are not the same. A problem for later down the line.
The forks are not stock, and I think they are from a GS550, but I am not certain
 
Yeah that makes sense. There should be room for that caliper. You may need to space the disc/rotor further out from the hub & cut down the speedo drive dust shield. You'll probably need a 4 bolt bracket. I hope there is room.

Those discs look like the CBR ones but I haven't seen a solid set like that before. What diameter are they?
 
Yeah that makes sense. There should be room for that caliper. You may need to space the disc/rotor further out from the hub & cut down the speedo drive dust shield. You'll probably need a 4 bolt bracket. I hope there is room.

Those discs look like the CBR ones but I haven't seen a solid set like that before. What diameter are they?

I had quick measure after I had mounted the wheel. Its about 270mm.
 
A milestone has been reached. Yesterday I got the rolling chassis done. Quite a few little niggles along the way. Because the wheels and fork are not stock items, some of the bits I had bought for them didn't fit. I had to manually edit the cush rubbers to fit into the wheel. After a bit of work and referencing diagrams it eventually turned out like so:

attachment.php


Now to discover exactly which bolts and fasteners I actually need from my pile of well used originals.
I'm happy with the build, and it's good to have something that actually resembles the end product.
is it weird that I can hear BRAAAAP-PAP-PAP-PAP already?
 
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