1981 GS450S frankenbike rebuild

[salty_monk]

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..)

[supertorro]

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

[salty_monk]

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?

[supertorro]

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.

[supertorro]

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:



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?

[steve murdoch]

I like the term "manually edit".
A very large hammer usually comes into play if i am using that term.

Are the shocks facing forward because of a frame clearance issue with the reservoir?

[pete]

Excellent, that's always a great milestone to hit! I do have to second the question on the shocks though, the reservoirs typically face backwards... looking real good though!

[salty_monk]

I had quick measure after I had mounted the wheel. Its about 270mm.

That's about the same as stock. The CBR ones are 295mm. It's going to be pretty tight with those. You will likely need to space them out from the hub. What's the offset of the disc and how much space is there between your fork legs?

Congrats on getting to a roller!!

[supertorro]

Yep, the shocks are facing forward temporarily. I loosely mounted the shocks and found there is a lot of length on the mounting studs left over.
Checking the diagram there are about 4 washers required on each of the top studs and I think 2 on each of the bottom studs. So it might still be able to work facing backwards.
They are a cheap ebay purchase I thought would be a good learning curve to the innards of shocks.
Turns out the piggy back reservoirs are purely ornamental; there is no path from the shock body to the reservoirs
So perhaps later on these will be used for something else and be replaced by another brand, preferably a version that can be rebuilt.

[supertorro]

Today was an entertaining day fabricating some caliper adapters, or at least a template to use. More than just the adapters were worked on though. As a result of checking clearances I realised I had incorrectly assembled the front wheel axle spacers, forcing the fork legs to compress towards each other. After a lot of searching and trying various things I eventually fashioned an extra thick washer from an extra spacer I had. So now the forks are straight and not being forced together by clamping down the nut. As an aside what is the correct process for installing a fork like this? The version where the bottom of the fork leg can be removed and the whole axle and wheel can simply drop out? I took the approach of assembling the axle, spacers, speedo drive and wheel all together and clamping lightly into place with the fork legs. Satisfied the forks were clamping the axle in place I clamped down the axle nut, and then the fork legs.
Any thoughts?

Anyhow, once this was done I measured the distance from fork leg to disc and found a 1mm discrepancy, and thought but why? Remembering the spacer that is used with the one disc, I hauled it out and tried to insert it. Man: what a struggle. I recall dis-assembly was equally painful and ended up cutting off the portion that would sit between the disc and the hub center. With this editing done, the discs are now equi-distant from fork legs, so happiness ensued.

The caliper adapters were some fun to do. With some flat aluminium bar I had lying around I shaped and drilled some suitable brackets. So far I think they'll do, but would not mind some feedback. Doubtlessly there is something I have gotten horribly wrong. Sorry for the pics, but my phone really really doesn't like the dark.

Version 1


Some clearance visible in this shot. Pity I don't have new pads.




View from the back of the caliper


Caliper and adapter in a slightly better light


And the adapter plate as it stands now


I ended using a single spacer to bring the caliper a little closer to the disc. This gives me some measurements to work with.
From the inside of the fork caliper tab, I reckon about 11mm thickness takes me to the end of the nut you can see in the pics.
The caliper mounting plate is 6mm thick, so will need to offset the plate by 6mm to the outside to bring the caliper in line.

How thick should the plate be to provide adequate safety and rigidity? Any recommendations on material. Some brief internet searching basically came down to aluminium, but there are many voices yelling for a particular alloy. Help a numpty out here, too many opinions from too many folks.

And lastly had another go at mounting the decorative reservoir shocks on the traditional way, but no dice. The right side will foul on one of the tabs. Perhaps that tab will be scheduled for removal, but I'll just keep it for now.

Looking forward to this now. Much excitement in the air

[pete]

Nice work! I can't really offer advice on how to ensure the brackets are safe, but when I researched what to use for my rearset adapters it came down to two types of aluminium being suitable which was marine grade 5083 or 6061 T6. Either of those are suitable for my application, but the 6061 T6 was easier to get and my understanding is the 5083 gets quite pricey.

For your application the 6061 T6 should be a good grade also (I believe it's good structurally full stop) but would definitely like some verification from someone else more "in the know" on that.

My rearset adapters use 12mm thick 6061.

Dan (salty_monk) will be your best bet there I think.

[supertorro]

Some more work done yesterday, was to strip, clean and repaint the starter motor. As with previous items on this bike, some bits are broken, missing or worn out.
A new brush kit is absolutely required, and one of the bolts is missing. Any ideas where I could find a 5mm x 12mm bolt?

[pete]

M5 x 12mm long? Any hardware store I would imagine...

[2BRacing]

Some more work done yesterday, was to strip, clean and repaint the starter motor. As with previous items on this bike, some bits are broken, missing or worn out.
A new brush kit is absolutely required, and one of the bolts is missing. Any ideas where I could find a 5mm x 12mm bolt?

Not sure exactly where you are situated, but in Paarden Eiland there is Bolt & Nut Centre, and Topfast Engineering Supplies. In Radnor Street, Parow there is Parow Bolt & Tool. Nesco Engineering is in Voortrekker Road opposite Sanlam in Bellville. In Epping there is Bolt Fast near the Cape Mail Centre.

Alternatively Suzuki South in Wynberg for OEM parts like the brushes etc and maybe the bolt as well.

Congrats on your progress so far. I second asking Salty Monk (Dan) for suggestions on the type of material to use for the bracket, he developed the twinpot brake upgrade conversion brackets.

PS: Those brake pads do look quite worn!

[supertorro]

M5 x 12mm long? Any hardware store I would imagine...

Damnit. That was supposed to be M5 x 125mm
It's one of the bolts that runs through the starter motor and holds it together. Of course one is missing.
After having inspected the diagram for the starter I realise I have a few pieces missing. Notably washers/spacers internally, o-rings, bolt. And of course the brushes are well worn.
Think I will see what it would cost to rebuild or replace. Whatever makes economical sense really