Birel ART Set Up : Questions


I have questions about Birel ART and the set up.

They recommend in high grip condition to put short F axle (1000 mm) and widen rear (1400 mm) = softer axle (?)
But i think i have to put stiff axle in high grip condition.

In low grip condition they recommend to put B axle = soft axle

So in two opposite conditions they say to install soft axle ? I don’t understand

Other questions :

  • Do i have to make my frame stiffer (tight rear bumper …) in high grip condition and softer in low grip ?

  • Soft seat or stiff seat ? In high or low grip

  • what about seat struts ? Do i have to put seat struts in low grip (2+2) and remove them (1+1) when track goes grippy ?

Thanks for your help

The F axle is the standard axle that should work in most conditions. Widening the rear track in high grip is not necessarily to soften the axle, but to keep the kart from transferring weight as easily, as you are relatively lowering the center of gravity compared to the driver.

In low grip they recommend the softer B axle to help the kart flex and keep the tires in the traction limit with less effort, since there is less grip available.

I would not tighten the rear bumper in 99% of conditions. It will really limit your chassis flex and keep the kart from rotating properly from apex to exit.

Seat strut number is not a big adjustment and not super important. As you can see they recommend 1 or 2 in all conditions. There is not a big difference between 1 or 2.

I always tell my drivers that you cannot tune the kart from home. It’s difficult to recommend making a change when you aren’t at the track knowing what the track is doing in real-time.

The biggest thing to think of the setup sheet is a recommendation of potential changes in those conditions. We’ve raced on both high and low grip tracks, and the biggest change I normally make is to tire pressure. I watch the attitude of the kart, and take the driver feedback to determine what changes are needed. I’ve also adjusted rear width, front width, occasionally ride height, and caster. I run 1 strut on both sides, have never changed the axle, never tightened the rear bumper, and never removed the front stabilizer. We do run a NEK Modulate seat. For size comparison, my driver is 5’7" and 150 lbs.


Chassis model? Class? Weight? That’ll help us help you.

Thanks :slight_smile: ,

I drive a RY 30 (2016) - Iame X30 - weight : 144 lbs and global weight : 348 lbs -> French senior regulations.

And next year I will drive in a cheaper category with Rotax Junior - hardest tires than X30 (without rain tires) and 330 lbs.

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