Your Opinion about the best Racing Chassis for BSR Power Unit?

Hey there, fellow karting enthusiasts! We’re diving into an intriguing discussion today – the ultimate choice of racing chassis for the dynamic BSR Power Unit. :checkered_flag::electric_plug:

We all have our unique opinions when it comes to the perfect chassis – its perks, its gains, and the list goes on. But here’s the twist – we want to hear from you! What’s your insight on the most compatible chassis for these electric racing beasts? :thinking::bulb:

Picture this: slightly heavier karts, packing a punch of higher torque, and a weight distribution that’s flawlessly balanced. This tweaks the chassis dynamics, given that traditional karts are often tailored for internal combustion engines.

To make it even more engaging, we’ve included snapshots from various customers flaunting their chassis paired with BSR’s power units. So, let’s get into the nitty-gritty. Would you go for a stiffer chassis, or do you lean toward a more flexible one? How about the brakes – any thoughts on the ideal fit? And let’s not forget the adjustments – what tweaks do you reckon could elevate the performance?

To see for example how CRG performs in Japan EV Championship:

While electric karting might still be relatively fresh for many, we’re betting you’ve encountered situations where a little extra weight was needed to jazz things up, especially when the weather gets tricky like rain.

Your input matters! Share your thoughts, experiences, and suggestions – your insights could be a game-changer for others hunting the ideal chassis. Ready to rev up this conversation? Let’s roll! :racing_car::speech_balloon:

This should be interesting. My experience is limited to commercial rental electrics and those seem to use wider gauge tubing and are quite stiff. It would be interesting to see how an OTK would feel with big torque.

1 Like

I think Birel/Energy/CRG should all be fine, when I think lots of torque I think of a stiff chassis like one of them. Almost like you drive an Kz, deep in and straight out with plenty of traction.

Nowadays modern braking systems are all good, just different feel with same outcome so that doesn’t matter. All the bigger brands make good brakes.

For adjustability Birel have loooooots of tuning tools, but you need to buy them first… here I think CRG with its sniper system offers the most without buying new stuff. Same as for Parolins EasyCaster system

1 Like

Certainly, for the more powerful category, it’s really worth looking into KZ chassis. What do you think, is it better to have a stiffer chassis with support reinforcements, or rather a softer one that allows more chassis flexing?

Factory is willing to be the OEM chassis supplier to BSR. Our chassis works really well at Masters weight with a 175 SSE already. Contact Billy or Willy to discuss commercial aspects.

1 Like

Could higher torque affect sports chassis and their bearing housings? Is it better to have a chassis with 2 bearing housings at the rear, or perhaps three?

I would definitely be looking at a stiffer shifter-type chassis for sure. Personally BirelART or CRG would be my go-to (well, DR Kart but same family as CRG), although I would imagine an iPK brand would be strong as well. I don’t see any reason why any specific brand would want to be avoided in this scenario, just making sure the chassis model is strong enough to handle the weight and torque correctly.

1 Like

It completely depends on the track, tire, weather conditions… Asking what kart would be best is like asking “what is the best food?” On some days I like ramen, on others I like pizza. Depends.

1 Like

Thank you for your fast response and offer to help with the chassis for BSR customers. What do you think would be the best from your list with BSR electric power unit?

It would almost certainly be based on the “X1” shifter chassis. The cost for modifications will depend on the extent of the changes and the volume of chassis that you’re buying.

1 Like

I was thinking more about the fact that there is a slight additional weight and that it affects the dynamics of a standard kart, so it might be necessary to consider other aspects that differ from the internal combustion experience. Of course, the track factor and weather conditions are other factors to take into account.

I agree that you’ll want a KZ chassis for the stiffness and the torque. Keep the third bearing support so you have the option to tune with it.

1 Like

In the case of BSR, the good thing is that the chassis doesn’t need to be adjusted for the power unit’s requirements. They are designed to fit on any standard chassis without any additional modifications. Plug and Play - you can install it on any chassis in 15 minutes with 0 experience. X1 sounds good for 25kW and 25kW+ models

What recommendations would you have for achieving a high top speed, around 150-170 km/h (up to 105 mph)? Any tricks and tips from Chassis, tires another adjustment perspective?

If you want high top speed you’d narrow the track width, pump up the tires, and lay down the seat.

1 Like

Time to science the heck out of this. I am available for extensive testing. :grin:

Honestly, I would be intrigued to try electric on a conventional race chassis. LMK if that becomes an option in the NE.

1 Like

I think it is less about top speed and overall weight than balance and torque. Ideally with the torque of a KZ and good side to side balance a KZ chassis would probably work best. However, I was told several years ago that even many KZ chassis that were once 32 mm were going to the 30 mm frames, because the had a wider tuning range.

That said, I would guess it depends on the karts balance with the BSR unit mounted to it. Most chassis these days are based on the use of ICE power plants that put more weight on the engine side and offset the driver to compensate. It is clearly evident in the seat placement measurements. My question would be how does the kart scale with the BSR unit? Secondly, nearly all modern chassis have two rails on the engine side and only one on the non-engine side. BSR plants place a large weight in the form of Battery Cells on the non-engine side. How does that effect the flex in the chassis and does it introduce a sag in the long term?

Perhaps there is no winner in this race and like with 4T, the chassis design has to be modified to accommodate the new power plant and its battery bank. I am thinking maybe the traditional 2 rails on the engine side and also 2 rails on the battery side. Maybe mixed tubing. Larger diameter up front to withstand the torsional loads and smaller diameter at the rear, because the loads are distributed over more tubes. Maybe Factory Kart would be a good partner in that they are small enough to accommodate design changes to find the best options in a short amount of time.

Just a thought.

1 Like

Chassis wise, I would imagine something bespoke (based on an existing design) might be best due to the overall weight of the kart.

For 100 MPH+, at long circuits (ie car sized road courses) using CIK bodywork it usually takes something like a TaG engine to just touch that, so you could use an FR125 as a reference point. KZ on the same track would be somewhere around 110 - 115 MPH.

As you might imagine, those speeds are mostly affected by aero vs power to weight. So essentially it’s power to drag ratio.


Yes, this is one of the best ways to understand what works and what doesn’t. Yes, you must try it, I recommend it.

Technically, the electric motor is mounted 1:1 as the internal combustion engine, and together they weigh 30kg. The battery is on adjustable clamps where the radiator is mounted, weighing between 18-32kg depending on the model. Technically, the weight is balanced 1:1 on both sides. The battery mounts and the battery casing are designed so as not to block the chassis, allowing it to flex according to the pilot’s needs. That’s why many pilots so far say that with the BSR electric power unit, it’s even easier to drive, as the kart is technically more balanced.

Perfect can see in this picture:

The weight in the smaller classes is very similar to the weight of internal combustion karts. In the 25kW and 25kW+ classes, when compared to KZ2, the BSR kart is heavier by 10-15 kilograms in total weight. But from the pit stops, we usually hear comments that they don’t really feel that it’s much heavier.

But of course, one should test and feel it for oneself, then perhaps it would be easier to recommend precise adjustments.

Which class do you race in?