Oh My! I bet this is fun... (KTM 690 RC4 kit)

[Frankienuckles]

This was on sale on ebay a couple (few?) months ago on ebay. Same idea as the KTM just done with an Aprilia. It looks like a lot of fun!

[Orson]

Wasn't there a road race series being proposed based on 450 MX engines in a custom chassis? I remember seeing some prototype photos a couple years back.

I think it wuz Dog Boy who said the 450 engines weren't designed to be held wide open for long periods of time like they would be on a road race track and suffered accordingly, leading to high maintenance costs for racing teams

although, my memory could be faulty

[DogBoy]

The 450 MX engines are not the grenades they once were. They have improved in every way but, as pure race engines, are very far removed from a street bike multi-cylinder. The big knock against the 450 singles races series was the bikes cost nearly as much to build as a competitive 600 supersport for club racing. Most road racers would prefer to ride the 600ss bike on the track.

Back on topic. This KTM kit would be a very fun bike to own. Totally out of place on a kart track but it would compete with an SV650 or similar track bike. HP is close but the KTM has significantly less weight, better suspension and brakes. On a track with long the straights the SV would still have an advantage but on most tracks where club racing and track days take place, a 690 SMC with this kit would work great and be very fun to ride. The 690 engine has proven to be durable.

[phatphil]

 450mototechGP Renner Mototech, a specialist in chassis modifications from Denkendorf has placed in their own a special racing bike on the legs. The Suzuki RMZ 450 RR is based on a standard Suzuki motocross bike! The landing gear was in the fields of geometry, suspension travel, and vote for the reconstructed track. The result is a lightweight 100kg motorcycle racing with 62PS low Tuningmaßnahmem on the motorcycle. Power to weight ratio 0.62 bhp / kg! In the U.S. and in Spain there are already racing series for these vehicles. The conversion costs depending on the scale from 6.000 € and includes cover, dummy fuel tank, seat, 17-inch wheels, brake with 320mm disc and four-piston caliper, footpegs, handlebars, tachometer, triple clamps, DRD exhaust, a simple finish in black or white, and the conversion of the entire chassis. Depending on the selection of the basic vehicle and equipment (you can take almost all 450cc MX bikes) you get a true-super-lightweight racing bike for more than 10,000 € (used or new vehicle, depending on). The power to weight does not move far from a 125 or 250cc GP machines. seat ergonomics and geometry were taken in the first step of the KTM RC eighth After the tests can be very satisfied with the performance.

Power/weight ratio pretty amazing.  Thing would scream...