BMAX 4 springs issue
 

Hi guys!

I've an issue with my BMAX shocks. I'm using champ package shocks with 30wt oil, stock pistons and green springs all around.

The car feels extremelly soft, specially at the front. It's not able of handling a 40cm droop without snapping the front end on the floor. :o

Any advice?

try 40wt all round thats what craggy had in at the weekend at worksop

Do you know what springs be was running? Looked like none Yok ones as far as I could see?

I've used Greens too, it is very soft at the front that way, but still very quick!

black front, pink rear, both yok and the champ kit piston 2 and 1

According to Yokomo spring chart, pink ones are just softer than the green and black are the hardest ones.

What kind of surface was it running on? Here we only had dirt tracks.

If they were Yok springs in the back, he'd had the pink removed from all but the very bottom!

Pink is very soft, he had a 1.4 roll bar on the back, and I think was running Lipo (looked it), wonder if it's a way of dealing with the lower weight?

paint was removed

So... c'mon guys... any advice for that soft front end?

very low traction track, so far I've found I need to keep the rear quite soft spring wise to get grip.

Although, for next time was planning on removing all the lead (I run Lipo), dropping to green (or maybe now try pink!) rear springs, putting the stiffer anti rol bar on, and going for thicker oil (I have been on 25wt rear, may try 35 or 40). It may be a terrible idea, but a theory my dad came up with on how to cope with the changed weight distribution from Lipo and the traction issues I've had!

For the front, if you want to go slightly harder on the front, try Orange springs, then the black. Like I say though, I actually went quickest I've been with it while using the front greens and driving around the diving under braking.

I want to get some springs, who stocks them?? Microtech have them to order, I'll try Darren Dms if he has some I know he has lots of yokomo bits

Why not try putting the kit blacks on?

I use Yokomo optional spring set both front and rear. I bought them at rc champ, as everything else.

Regarding black springs, maybe they do the trick, but I'm worried because they are the hardest

They are still quite soft in my opinion.

That's the point! Really there isn't much real tunning options

I've used black, orange and green. The blacks are hard enough, honestly!! If you need more then I would guess other makes of spring will fit, but I don't see you needing harder than black.

The Yok spring set has a very narrow range from their hardest to softest. The front range is soft relative to other manufacturers and the rear range firm.
From what I remember even the blue rears (softest) were harder than AE silver (& i think AE grey). Made the world of difference with the BX when I had the springs measured and realised this. (after the season had finished and just before i changed car though :mad:)
Found the BX transformed on blue rears with green or black fronts.

I've managed to work a few things out about the Yokomo springs.

First of all, the spring chart from Petit RC is a great resource and gets a big :thumbsup: from me - http://www.petitrc.com/reglages/BuggySpringChart.pdf

Secondly, Yokomo's coloured BX springs are very close in rate - they have only 0.25 coil difference between them. This may be a good step for a short touring spring but on a buggy it is far too small to make any difference. A 1/4 coil is worth 2-3% on the rate at these lengths, the AE and Losi springs are at closer to 10% difference between each rate. So as suggested above you need to go right down to a blue or pink to notice any real difference.

Thirdly, the front black springs are quite a lot stiffer than the nearest rate, at 0.75 coils stiffer than the next coloured spring. And are still at best a "medium" spring, similar to an AE silver.

Thank you very much, this weekend I'll try some kyosho springs.

Does your, or anyone else's experience, bear out the petit chart? Just wondering cos if so it could well be worth dropping below the yokomo softest spring on the rear, or harder than the hardest on the front? Say up to AE blue up front, down to AE silver/kyosho yellow at the back?

I tried some AE springs last time out and it pretty much agreed with the Petit chart. Going up to AE blues definitely took the edge off the steering, this was running AE silvers on the back too.