HP4 flywheel

I tried out a lightened HP4 flywheel, the verdict (for me anyway) is that it gives "live fast die young" power but not really suitable for touring unless given some thought. I'll be keeping it but I'll only be bolting it on for special occasions.

Pros:
* I managed to rev out to 9200 RPM in 2nd :)
* very responsive i.e. change speed easily
* very easy to kick over

Cons:
* stalls very easily
* engine runs ~20C hotter

The problem is that to reduce the effort that it takes to turn a flywheel, you reduce the weight but also the energy it uses to drive air over the cooling fins (i.e. the HP4 fins look half the size of normal and are less shaped for effecient air pumping). Less energy used to push air = less air, and hotter running temps.

I found that I could get the scooter to perform really well over short distances, however I found I had to sit at 100Km/hr for steady speeds or the temp started to creep up above my comfort zone. In other words it reduced my touring speed!

Though I didn't try it, it probably would have added a few Km/hr to top speed but I'd only want to stay there for a few minutes... so maybe good for land speed records ;)