car seems to be very fast.

R4 is absolutely faster than the RRR ...many options for set up , not just camber toe roll center , but much more that the new cars should have so as to be competitive , ... if you find the right compination that car with the apropriate hop ups that unfortunately are necessary , R4 is really faster

This car is much faster and alot more stable than any of the R's i haqve driven and i havent even started to mess with setup as yet

Hello everybody:
I´m a bit dissapointed of still reading complains about R4 diffs, because the eal thing is that that´s a past matter. Since i´ve been running the hard cases, i´ve spente more than 10 L of blend whith the same rear diff, and i´ve had no issues. I agree that Kyosho made a big mistake whith the first design, but soon or late, they´ve solved the problem.
Fot those who wonder if the car is faster than the RRR, i can tell them that at least in Spain (we are 3 Kyosho sponsored drivers), we´ve beaten all our past track records in every track we´ve raced at, and at least me, in my hometrack, i´m 1,5 tenths faster per lap whith the R4. May be R4 is not as relyable as RRR, but concerning the speed, believe me,...is faster.

is it possible to come down to 1550g with the R4?

I'm trying to go down to 1650... 1550 is imposible. With low profile servo, titanium pivot balls, titanium screws and a light motor you can go close to 1630-1650.

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what about body and wheels?battery?

life battery cruiser body and wheels !!with!! foam. 60mm-62mm.

xm,there is not a lot that you can do to go under 1650gr.

lightweight rear and middle axles?

R4 have already lightweight front axle. If you put rear light axle maybe have proplem with transmition. Light is easy to brake and cut gears because you make axle softer. 1650 is ok...

have you see any rear titanium or hollow axle broken?or cause gear problems?

Gear problems... See mtx5... hollow rear axle... Do you want to have problems for 3 gramms?? I dont want! Before 2 years i had problems with gears because of a titanium rear axle. When i change it problem solved...

i have a titanium rear axle in my rrr for some years now and 10gr less.i hadn't any problems since now.maybe i am lucky.

Are you using the steel crown gears? I bought some recently and they are absolute rubbish. I bought 4 sets at $25 a set and they are only the 2 main crown gears.

Well I ran these at our recent nationals and munched through 4 diffs as they do not mesh properly with the old small bevel gears.

I just got the hard diff cases this week and spent 2 nights trying to build a decent diff. The steel gears just wouldnt work no matter what I tried.

I eventually built the diff with all of the original internals and shimming to get it to be smooth.

I have yet to run the diff yet so I dont know if it will hold up but I have to say after running Kyosho for the last 10 years I am so over the rubbish they have bought out with this car.

If I have diff issues again this weekend I will be selling the lot and moving to a more reliable brand.