yesterday got semi speed challenge at HKZ
only my bro super 2 participated as mine didnt clear the regulations (silap beli 19mm rear roller last2 xmuat dlm pitbox)
TA managed to get 15.31 but didnt key the time in
last 20 minutes time to beat was 15.29 (TA best was 14.17 i think)
tried everything (lessen weight, break in, buy new motor and break in) but no luck as it was faster but tends to stuck momentarily wasting half seconds...
last2 balik rumah terus lol

better buy this

depending on the type of layout, tiny amount of additional weight could render insignificant.

over here, MS mostly rule over S2 in speed races. most don't even use trimmed chassis.

we don't even use ball bearing in our counter gear

S2 yes, should have floating gear.

For speed, always use AO 620 because it has tight tolerance compared to normal round hole or hex hole. If you use hex-hole, the wheel spin is wobbly, there could be some instability there.

All bearings used (including rollers) must be able to spin freely so that it could corner fast

stiff? maybe nut/locknut too tight?

usually the main culprit is roller angle.

at high speed, the chassis could flex, and if the bumpers flex, the rollers could tilt and that will make your car fly at corners

other problems are usually tires, especially when you're using tayar sotong, the tires sometimes go out of shape. that you can see if the car seems to look bouncy during the start.

no need 9mm already. invest in some AO 830.

You will need 2 packs of AO 830 and 1 pack of AO 620 for the rollers.

the setting soulfly is referring to is , the rear rollers top is using 830 and bottom is using the 620 ,front 830  , if i remember something to do with cornering or something which i forgot .

yeah 830 and 620 spacers the same

already did that 3 weeks ago 
liberty emperor looks cool, manta ray on the other hand..

is MA and MS chassis very similar? Planning to get another car, i already have a MS just thought of sharing the parts if i bought a MA.

Would it work?

Semi speed can be sprint dash if straightway more than corners. But power dash after break in, is better than sprint due to high torque. During corner, power dash is faster than sprint.

Do some experiment. Setup sprint dash and power dash super 2 for semi speed. That way you can learn which is more suitable.

35mm diameter max ... nipis is up to you but lebar tayar + reston/sponge need to be 8mm minimum ...