Thursday, July 7, 2016

SS50 race bike, still shaking down

The new season has started, heck, it's almost halfway over already, and I've been busy with work, and getting the bikes running that I'm forgetting to blog about it.

Well the main focus has been on the SS50 racebike, as this is the biggest technological challenge.
Over the winter, changes have been made, footpegs were moved back, fairing was added, tachometer was changed... and changed back again.

And then the season started and a lot more changes and tweaks were made.
-Because of the footpeg relocation, the front forks needed stiffening.
-The new mechanical tachometer couldn't keep up over 13k rpm, so the electronic unit was fitted again.
-The inner rotor ignitions weren't functioning correctly, so the old outer rotor battery ignition was refitted.
-The newly made 24mm carburettor turned out to be too small, so back to the 26mm
-The new 5speed dry clutch engine wasn't delivering what it should.

The dry clutch although looking and sounding cool, was a step back in handling, this combined with the last event in Gramsbergen, where I swapped the 5-speed motor (because of strange noises) for the old 4-speed before the second heat (which also developed some strange noises after that) meant that both motors were opened up fully and examined.

As it turns out, the 4-speed motor had a better cylinder head as i had been more cautious porting the other head.
So now a new engine has been built, with the 5-speed gearbox, wet clutch and cylinder head off the other engine, combining the best bits. In a small testrun it displayed 16k rpm on the tacho, while still pulling, so I'm looking forward to the next race, to see what it actually does.

Saturday, March 5, 2016

4 speed close ratio gearbox

Decided to take some gearboxes out, known for not being so good, S50 and S65, combine with a little SS50 and some more modern parts, and create another 4-speed close ratio.
Not as close as the racing gearbox, but nice for a spare racing engine, or any other future build.


when installed in a racing engine, I might even replace 1st for a 14/33 or 14/32 with long shaft for mounting a clutch.

Seen in the picture, the special tool for shimming the gearbox and checking if all the gears line up correctly, a must when combining things like this, as only the 4th gear shift drum really worked for this setup.

Thursday, February 25, 2016

replica CR93 parts

So busy, and forgetting to update, so here's a quick one

Original parts were borrowed, and copied 6 times.
Replica CR93 foot rest brackets, in raw form.