Handling
 

Are these homemade indoor jumps ???

If so its sounds like its maybe the profile of the ramp which is causing the issue, In which case its how you approach it which will help the most.

ie roll it or blip the throttle just before the ramp.

Any pics of the jumps ???

Jumps
 

Yes, they are homemade jumps. No pics. They are not too high, or long but the gradient of them is quite steep.

Sounds like it's the jump, if it's short and steep...it probably bucking the rearend up when it hits the ramp, might have to slowdown, how are other 4wd cars hitting it? Also, are you running a lot of drag brake?

Jumps
 

Most of the other cars that were running were Cat SX', they seemed to have the same problem, but then a couple of cars seemed to clear it Ok, they were better drivers I know, but if it is the jumps then is there a way to take them at pace rather than crawling over them?

I turned the drag brake down after 1st race.

I would either watch those drivers closely that are getting over it or ask them what they are doing different. I would think you might trying letting a few feet before the jump, then blip the throttle right at the bottom of the jump, then get back on power before you land to pull the car back to the ground and keep it from flipping. Anyway, don't think it's a set-up thing, more of a driving thing.

Roundabouts jumps need the throttle blipping on them. My D4 suffers over them just the same. I've biased the weight as far rearwards as possible which helps over the jumps and also in promoting rear end grip on the slippy track, but mostly its in the throttle.

My cat was clearing them last night, had some probs at first, the small single kicker needs smooth throttle take off with throttle applied the same right through flight, the 3 jumps or triple again req some momentum through the corner smooth throttle then shut off just as it takes off, should come down a treat, had to crash my brains out to learn but its great when it works:thumbsup:

I was struggling with those damn jumps with my XXX4 last night to - smashed my rear shock mount the first time I tried to triple them. I finally got em right for the final which was like Si says to get the weight to the rear (just moving the battery back on the Losi) and by gradually accelerating up to full whack before hitting them (trying to avoid wheel spinning as much as pos). I've just got a bmax4 so we'll probably be in the same boat next week!

I had a quick go of chris ridgways bmax and found the
two high kickups free role on to them and a blip of throttle
to keep the nose up

The tripples was fullover the first what let you skip the second
and a blip of throttle on the third to stableise the car

basic rule of thumb is noes down put power on to lift the front
up, nose high use brakes to bring the nose down

Weight
 

How much weight are B-Max drivers adding to the rear of the car to balance it out when using Lipo's?

on hich grip I run no extra weight.
on low grip I put about 40 gr under every pack

I'm adding weight to get to a total 1800g, which was what guys (including yardee) suggested to me. That's about 70g in my case under the Lipos. The car is very well ballanced so far...

im running my bmax for the first time this weekend, ill let you know the best balence after that