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Projects: Racing Sidecars

Building a Single Cylinder R25S Dynamo Vintage Sidecar Racebike
(Also visit: Building a 500cc Racing Sidecar)

Note: If you want custom fabrication information, you can contact Dean Paulus at paulusbrothersenterprises@gmail.com. This is a photo journal of our project. The images start at the bottom - if you are a new visitor, you may want to start there. You can read up about this project by going to our blog entries.

250cc BMW Vintage racer with nosher fairing

Arminius, our 250cc racer, outfitted with the Knosher fairing and custom hub-cap from Matthew Wilson installed onto the polished aluminum three-spoke front wheel. This was printed on a 3-D printer and serv.es to cover up the labyrinthine structural reinforcements built into the hub and prevents the salt from building up inside.

250cc Vintage Motorcycle Racing Rig with custom seat

Arminius with Cory Burkhead on board. He upholstered the custom seat designed and fabricated by Kevin and Dean.

250cc Vintage Motorcycle Toolbox lid with Flying Fox Racing Team Logo

View of 250cc Vintage Motorcycle Toolbox lid, with the Brooks Motor Works Flying Fox Racing Team Logo.

250cc Vintage Motorcycle Racing Rig

Arminius in foreground, and Dave headed out to test his R65 in the background.

250cc Vintage Motorcycle Racing Rig with wing- rear view

Front view of 250cc Vintage Motorcycle Racing Rig with wing- rear view.

250cc Vintage Motorcycle Racing Rig with wing and dustbin

Front view of 250cc Vintage Motorcycle Racing Rig with wing and dustbin mounted up.

250cc Vintage BMW with wing

Kevin working on 250cc BMW vintage racing machine- another view.

250cc Vintage BMW bars and tank top

BMW motorcycle bars and tank.

250cc Vintage BMW front wheel

Front wheel of Arminius with fender.

250cc Vintage BMW Dustin faring built by Paulus Brothers Enterprises with Kevin Brooks, another view

Another view of the great dustbin for Arminius, our 250cc streak of greased lightening.

250cc Vintage BMW Dustin faring built by Paulus Brothers Enterprises with Kevin Brooks

Dustbin faring with wonderful paint job by Bob at Puget Sound Autobody.

Placing metal on the sled.

Bottom of sled.

Close up of wing bottom.

Wing standing on end.

Side view of seat.

Rear view of seat.

Close up of seat.

Front view of seat.

Ballmount for frame and racing sled.

R27 fuel tank, wing, and really cool 3 spoke mag wheel from a different angle.

R27 fuel tank, wing, and really cool 3 spoke mag wheel.

Bike seat: maybe a little rough now, but Dean plans to give it a new life in the fast lane!

Front fender.

Another shot of aligning the racing sled with the motorcycle frame.

Preliminary aligning of the sidecar body and motorcycle frame.

Dean lays out all the parts in preparation to weld the wing.

Dean set out the parts for the racing wing.

Remember, when you want custom fabrication, Dean Paulus is your man. He has excellent design skills, and is technically proficient in welding and fabrication. Plus, he is a super nice guy to work with!

Dean shearing metal for the sidecar.

An Aluminum alloy fuel tank! Holding a whopping gal and a half; but how big a gulp of fuel will it take to rocket an R25S down 3 miles of Salt?

R25S Complete chassis with front wheel and sidecar frame and wheel

R25S Partial chassis with front wheel and sidecar frame and wheel. NOTE- If you are a little uncertain about traction on the salt surface of Bonneville, you'll want to add a training wheel to be sure you don't fall down ( always an embarrassment ). So you get a hold of Dean Paulus - Fabricator Extraordinaire - and lay out some plans for a little something on the side.

The lattice/box section design.

Long shot of translating lattice box section.

Translating the forms to metal.

Wooden template to set the dimensions.

R25S Frame on a crate.

Headstock.

Build an aluminum flywheel ( 4lbs ) to unshackle the tiny motor from the mill-stone of the stock 20lb barbell of a flywheel!

Crankshaft on bench.

First, find yourself an old unused crankcase with all its innards and take it apart. Rebuild the crank with a new rod, crankpin, and bearings.

Take a good look at what we start with!