I have tried to upload my proposal here buy it is too big. Here it is without any of the charts:http://motocrossactionmag.com/Main/News/WE-BUILD-A-KTM-300SX-BIGBORE-MOTOCROSS-BIKE-6884.aspxThe gain in horsepower of this project raises the 250 two horsepower from 49 to 51, but it rises over the whole power curve which translates into less needed precision and effort from the rider to stay competitive with a 450F.
The main benefit of racing a 2-stroke vs. a 4-stroke is the lower cost and ease of maintenance. Listed below is an article on the comparison costs of 2 vs. 4 strokes:
http://www.lasleeve.com/galleries/2-vs-4-cost/DirtBike606-p102-104-lores.pdfPro-Circuit -
...Pro-Circuit cost chart from their website for 4 and 2-stroke motor work...
Overall, the costs of racing a 4-stroke are much higher than a 2-stroke, not to mention the actual cost of the motorcycles themselves.
Honda CRF 450 $8099
Honda CRF 250 $7199
YZ 125 $6090
YZ 250 $6990
KTM 250SX $6598
KTM 150SX $6198
Most 4-strokes are about $1000 more than 2-strokes, with maintenance and racing costs causing this figure to be more than what most privateers and smaller teams can handle. This $1000 difference will primarily fit into any big bore kit available today. Listed below is a spreadsheet with the current 2-stroke production bikes with the most widely available big-bore kits available: (Excel Spreadsheet pretty jumbled on here)
Bikes: Bike Cost /Mod. Displac/KTM parts/ GYTR/ LASleeve/Eric Gorr/MaxRPMs
KTM150 $6,198 n/a
KTM250 $6,598 300 $799.00
YZ125 $6,090 144 $859.95 $495.00
144 stroker $1,125.00
YZ 250 $6,990 265 $900.00
270 $660.00
275 $500.00
285 $600.00 $900.00
295 $600.00
TM 125 $7,499 144 $475.00
TM 144 $7,699 n/a
TM 250 $7,799 275 $550.00
TM 300 $7,999 n/a
LA Sleeve 800-822-6005, Eric Gorr 630-825-5645, Max RPMs 608-224-2524
While there is no evidence of attendance dropping in Supercross and Motocross events, the brunt of the motorcycle industry will be felt in the coming years and months. Listed below is an article on motorcycle sales from the first quarter of 2010 compared to 2009:
http://www.motorcycle-usa.com/4/7033/Motorcycle-Article/Motorcycle-Sales-Down-First-Quarter-2010.aspxThat's pretty much it so far.