Honda S600 – Suspension

S600 RC3

Motorcycle engine, motorcycle suspension.

Miata Parts

The original plan for the suspension was simple: Buy a Mazda Miata with a blown engine, take out front and rear subframes, narrow subframes as needed, weld subframes to Honda S600 frame.

This would have worked out reasonably well if not for the fact that the S600 is SO MUCH NARROWER than the Miata.

Miata Subframes
Miata Rear Subframe Narrowing

With the rear subframe narrowed the appropriate amount, the diff wouldn’t even fit. This lead to plan b: use the A-arms, but ditch the subframes.

Rear Subframe

This approach required a new rear subframe to be designed and built to accept the Mazda suspension arms. Fortunately, the lower control arms were so close together that they could just use a common tube on the bottom. There wasn’t a lot of accurate jigging for this; I 3D scanned the frame (that’s why there’s white powder on the frame in the images), drew the new subframe in CAD, and then cut the tubes as closely to the CAD as I could and hope that was enough to self-jig. It worked pretty well.

Rear Subframe Build 1 Rear Subframe Build 1 Rear Subframe Build 5 Rear Subframe Build 4

There were a few months between beginning this project and finishing it, and it got a little rusty in the interim.

Front Suspension

Unfortunately, the A-Arms on the Mazda were too long to use in the front, so I had to use custom arms that attached roughly to the stock pickup points on the vehicle side and to the Mazda upright on the wheel side.

car motorcycle suspension Car motorcycle suspensio 2Both front and rear use Yamaha motorcycle shocks. The first thing people do when they get a new fancy literbike is to swap out the exhaust and rear shock. This means there are a ton of pretty decent coil over shocks on eBay right now for a fraction of what they’re worth.

Finishing Touches

Frame before powder
RC51 for scale. I miss that bike.

After everything was located and welded onto the frame, I took it all apart and had the frame powder coated. I was going to sand it and paint it myself, but I remembered that I hate both sanding and painting.

powdercoat frame

S600 RC2
S600 RC1DIY car alignmentAlignment was done with this super expensive rig that consists of a 2×4, a creeper a big zip tie and two tape measures.

More about the S600:
Honda S600 – Acquisition and Deconstruction
Honda S600 – Drivetrain

Motorcycle Engine Car Honda S600

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