S90 Update 4 – Prepping for Sandblast

Lots of things have happened since my last post ten days ago. Five days ago I picked up the seat and brought it to a upholster who removed the foam and showed me this.


Clearly it’s a mess. I’ve decided I need to compare it to a TMX seat and see if I can use that instead. I just need that hook thing at the top and those two bolts to the rear that connects to the frame.

Three days ago I picked up the two chassis, both the donor and the original. I also picked up the rear fender, fork, swing arm and the broken up engine crankcases from my mechanic.

The donor 1964-68 chassis.

I brought both to a nearby trusted welder to do three things. Take it all completely apart ready for sandblasting and powder coating, fix the bad welds at the center stand area and weld a missing floor at the battery area.

Here they all are previous to breaking apart.

Once apart we can now see the specific differences between a 1964-’68 and ’68 onwards chassis.

1969 chassis on the left, ’68 and earlier on the right. Notice the middle part connecting the seat and tank.
’68 onwards.
’64 – ’68
’68 onwards on the right, ’64 – ’68 on the left.
’68 onwards at the front ’64 – ’68 at the rear.
Fixing and strengthening an ugly weld at the center stand.
The finished weld which will hopefully look better when painted. Yes I know it looks horrible but we were going for strength not beauty.
Here’s the bottom part of the donor chassis which is in great shape. Notice the floor of the battery compartment.
Here’s my chassis with the battery floor rusted out.
Here’s the same battery area for my chassis top view after welding with a floor welded in and holes to allow wiring.
I put sacrifice bolts in every hole to make sure the powder coat doesn’t paint over threads. I’ve learned from that mistake.
And finally here they all are resting on the floor of Republic Powdercoating, ready to be processed.

Other than the rear taillight bracket which I added later on here is the complete list. The correct name of ‘Tpost 2’ is Butterfly Latch aka Steering Stem, and the ‘Swing Arm Part’ is ‘Arm Rear Brake

The colors are RAL-9066 for Aluminum Silver, PRD037 for Red, and A-1533 for Jet Black.

The color choices are bewildering.

There was practically no discernible difference between XP8276 (flame red) and PRD058 even when I held them up to the light. Choosing was made simpler when XP8276 was out of stock, so PRD058 it was.

That’s it! It will take 8-10 working days to get them back. In the meantime I received a fork+ignition+gas cap key set I ordered. It is new old stock (NOS) and it’s always amazing to see these as they’ve probably been sitting in some shop for decades.

If you’ll notice I didn’t have the gas tank and the engine with me.

The old engine has turned out to be an issue because the crank case where the engine number is stamped needs to be replaced because previous owner in his great wisdom welded stuff in it. I have a donor crankcase but obviously if I use that the numbers on the registration won’t match anymore. This is a terrible development as the whole reason this bike appealed to me was that it had matching numbers. I had been thinking about this a lot and was hoping to get it also sandblasted and painted along with the tank when I had the solution.

HOWEVER there is a new very recent news with the engine! I’ll keep that under wraps for now as it is still too early but if it pushes through it will definitely save my ass. Till next!

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