Yeah, time off really hurts. I'm 20-sec/lap slower now having taken 2-yrs off due to covid & moving. It's coming back, but slowly. Although I'm starting over with 100% street bike...
Quote:
Originally Posted by petrolhead
I saved weight by shortening the chain
Seriously. I looked at Moto3-bikes. They have a very short wheel base, the rider's butt is almost above the rear wheel center. Shorter wheelbase can't hurt on go-kart tracks where the bike does most of it's action. My son maybe better able to keep up with Supermotos and Mini-GP bikes.
Racing circuits in Finland are on average slow speed with very little fast turns.
Google says that a Moto3 bike has 17cm shorter wheelbase than a stock Ninja.
I grinded the swing axle holes a bit to move it forwards enough.There's now 9mm between tyre sides and swing arm.
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I went little further:
- grinded 5mm off protruding edges of shock-bracket at front of swingarm
- removed 10mm from rear of swingarm to move axle-adjusters forward
- extended axle-slot in swingarm 10mm forward
- grind inner sides of swingarm for tire clearance at widest part, 3-5mm gap
- removed 4 chain links
This allowed me to slide wheel forwards more. Reduced wheelbase by 3,2cm to 135,7cm!
Previous race-org didn't allow removing wiring brackets and other tabs from frame. New one only limits displacement to 350cc. So I'm going to strip frame over summer break and cut off all extra brackets and tabs. Will also make 2-arm V-shaped fairing bracket (original is monster!). Should be able to remove another 3-4kg.
Not having any luck finding titanium axles, or hollow chromoly ones. Might just make them myself. Ordered some 12mm ti ones to replace shock & linkage bolts. Also making dog-bones from aluminium. Another -1-1.5kg there...