racebike charging system

I didn't want to hijack, so I just copied the image. I have seen many racebike pics thanks to kzz1p, and many of them have the alternator seemingly removed for weight savings/turning clearance reasons. How does the charging system work on these bikes? Is there a belt for a magneto somewhere that I am missing? I would think that a battery would weight more than a stator and some magnets...

thanks for the noob Q&A!

some have a battery just to provide the twelve volts to the coils and some have a little magneto on the alternator/stator side ...the one in the picture had a kx80 dirt bike magneto to provide juice to the coils in a total loss igntion system....

this is a butchered version of what i have found ...

the battery losses charge but lasts 20-30 laps???

With regard to the weight difference, you can't just compare the static weight of the charging system and battery.

The rotational mass of the rotor has much higher performance consequences than it's simple static weight. Removing the rotor reduces the mass of the crankshaft significantly making the engine rev quicker.

Another factor which has only a small effect is that the stator applies an opposite force to the rotor (to make electrical power) which consumes some of the engines power that could otherwise be used to make the bike go faster.

Plus, like you said, it does free up some ground clearance on the left.

Keep in mind, this is mostly just speculation by me based on recent physics courses.

You got it, removing the reciprocating weight is free horsepower. Dragbikes get a charge between rounds to keep up the volts that MSD or Dyna need. Lots of folks are going to lightweight hi power lithium batteries that will make 2-3 passes without requiring a charge.

so Jack, a lightweight battery is the way to go then?? A little magneto sounded interesting