Karizma / CBZ/ Pulsar - Drag Bike?

This was the bike that ran at the Mumbai Speed Run Kharghar 2006.



Set-up by Team Motokraft, ridden by M Muthukumar. It did posted the following quarter-mile result:

2 Muthu Kumar CBZ RACEBUILT 121.63 0.847 16.066 ( Position Name Vehicle Speed Reaction-time Elapsed-time)

Compare this to the stock CBZ quarter mile times as posted in Overdrive at 21.5 seconds . Ofcourse Overdrive tested this at Pune which is not at sea-level, but the correction is ignored here. The figures are approximate anyways.


Let's check out the visible modifications.

- Complete change of plastic parts and fairing. The fairing's been put on a diet. Not even a second round of sheet to form a closed shape. Just a single sheet bent to shape. Perfect. The tank seems familiar, but does look like it's been modified to include a smaller container. Perfect for the drag, where you dont want the excess fuel to increase the weight.

- We can see the VERY lowered seat, and the footpegs which have been pulled way back! The handlebars are lowered and the tank offers perfect accommodation for the rider to crouch down all the way. Notice that the seat has no padding at all, just one thin piece of cloth serving as the cushion (sic). Couple that with the extreme suspension, and you know why these bikes ain't road-legal.

- No chain cover, and the spoked wheels look like 16 inchers. Number of spokes are on the lower side too.

- No front disc brake either, only the basic stopping power provided by drums, saving up on a lot of weight.

- The tyres, single handedly probably affecting the performance the most. Such a thin tyre has got to make even a modest 12.2 bhp bike go a lot faster. Imagine doin that to a karizma. Infact, Team Motokraft have given similar treatment to a Karizma which did a time of 16.954s at the Bangalore run, (where the same CBZ did a 17.818s). The difference in times being a result of difference in altitudes. Now that is nothing short of mind-blowing for a 223cc single cylinder putting out only 17PS. The loss in unsprung weight brought about by the replacement of mag wheels and 18" tyres with those has got to be the most signifcant modification.

Ofcourse the rubber is sticky, but is good only for straight line exploits. In other words, no road use. Couple that with the drum brakes and the stopping power seriously becomes an issue.

- The exhaust is aftermarket devil (dunno, but it does look original titanium), and the bend pipe looks home-made.


- I wonder why they have painted it because that would increase the weight, but if the paint's been put on after removing the original paint, then it might actually be a lighter version.

Note that the above observations are not necessarily 100% accurate, but only to provide a basic insight into how to go about making your four stroke into a drag bike without really touching the engine. Although it's pretty obvious that the featured bikes already have some work goin into them.

Cheers!

Manas Karekar.