I wanted to discuss this subject because I have been thinking about that subject quite a lot. I drove on many different tracks and many different machines now and I have been thinking the same each time :
Sodi RT8/10 or SR5 are not adapted to such tracks. They are meant to be sturdy, to crash into the tire barriers at full speed without having the frame being damaged. And for that, they are the perfect product.
But such tracks offer plenty of space, which means that you might not hit the tire barriers that much anyway. But you still have to cope with a chassis too stiff and too heavy, which understeers for days and eats front tires like never before. On such tracks, it just makes the driving not as fun as it could be.
Let’s take a look at the competitors :
OTK, Praga, Birel offers a similar product, with a similar weight. They just tried to copy Sodi without getting sued, didn’t offer a better product and obviously it didn’t work, Sodi being first on the market. Praga even calls its rental product “Light” despite being the same weight of the Sodi and the rest.
CRG got sued anyway
Rimo offers a lighter (135kg vs 157kg for the RT8) 390cc rental kart and it offers 13hp 270cc tuned Honda engines but steel frame bumpers, really ?
TB Kart and Tillotson seem to offer the best product for that use but unfortunately I am unable to find a track nearby to try them. Tillotson weights 119kg with a 9hp engine, TBKart seems to be around that mark as well.
To be fair, I think the issue is the engine. The GX390 is too heavy. Its dry weight is 32kg. Add some oil, the wet clutch, and this thing will weight a shit ton. It is also NOT an engine kart, it is not made to offer consistent performance across all engines. It is a shame because IAME does have an engine ready for rental use.
250cc single cylinder, carbureted, air-cooled
16.5hp @6500rpm
Redline at 8500rpm
Tillotson carburetor
250 hours without any maintenance
Weight unknown but is said to be a lot lighter than the Honda offerings
But it was announced during covid, and since then, we heard nothing from IAME
But yeah, honestly I dont understand why we dont get any softer offerings from the brands. Especially OTK and Birel, as they both have the facilities to manufacture rental karts on a large scale. OTK even have Vortex now, they could manufacture their own engine.
Are you saying why not lighter rental karts? I think the answer to that is because they would be more fragile and the vast majority of the public session racers are just plain abusive to the karts, wether by intent or lack of experience.
Keith’s already tired centurions are getting murdered by the pub sessions.
What I’d to see is a (rental) racing club of sorts. Standardize the brand and type, gearing/tires.
Have the members buy a kart of their own. Same chassis/tire/engine package. I’m fine with gx270.
It’s stored at track. It’s serviced by club, we pay for parts and labor as necessary.
We have a set of racing wheels where we get X number of tire changes per year.
We have practice wheels for regular practice. We go on track simultaneous with pub sessions. Call ahead to have kart ready.
We have regular weekly night racing.
I would like a model like this.
Keith says the rentals are too big and heavy to store efficiently in storage containers. I say winch and stackers.
Think about it. Rental operators are running a for profit business. That drives most of the decision making and shortcomings you are pointing out:
Heavy and stiff kart - less prone to damage, more protection around the perimeter of kart, slower corner speeds means less violent wrecks when wrecks do occur. All of this contributes to lower repair bills which equals lower operating cost.
Very hard tires - less tire wear and longer tire life, less grip and slower speeds. Longer tire life is an obvious savings, the lower grip also has the side affect of less speed, so that goes back to less damage.
Heavy Honda GX Engines - very low maintenance, well under the power curve of the motor. This again lends itself to a lower cost to operate vs a higher performance smaller engine.
These things are a tank for a reason. Just sit and watch some rental rounds sometime…even with experienced karters they beat the out of them.
I think that depends. I have found that league folks are pretty respectful of the karts and are generally good enough drivers to avoid sub-optimal trajectories that involve impacts. We have to race the karts on the regular so we try not to abuse them.
So you’re telling that in the 20 years since the Sodi RX8 released (And the all around protection design they patented with it), they were not able to make progress on the technologies used to protect the frame ? Either on the protections or even on the frame alloy ?
Especially when you know that the RX8 was as sturdy but had more frontend grip and you could apply rotation without having the chassis understeering as soon as you release the brakes.
Also, I remember the Sodi GT2 very well. Indeed you would bend spindles and steering columns, because of the lack of front tire protection, but the frame wouldn’t be impacted.
My argument is roughly the same. I think IAME or Vortex can engineer a rental engine that can be as reliable and just lighter, more consistent and more performant. The fact is, IAME already did. It is far closer to a GX390 than a SA250 to be fair. We’ve been using the same Honda engines for 40 years, you tell me there is no way we can’t make it better ?
While I totally agree on the fact that tracks wants to make a profit, I am arguing that we should be able to make the product better now, while keeping the cost the same. The RT8/10 is arguably 20 years old, it is ancient.
It is too slow for Grade 1 tracks to be fair. Even the 390cc is too slow IMO. Remember AMP, the 270cc was slooooooow
EDIT : To show my point :
SODI RX8 :
SODI GT4R :
SODI RT8 :
On the RT8, you can’t get rotation under braking, the front tires just give up, resulting in screeching. Doesn’t matter how clean you are, you end up killing the front tires. Compared to the older ones, you don’t have the same freedom and it is a shame.
It’s a chicken and egg thing. If you build a kart with appropriate protection for rental karting, you’re going to need a stiff frame to support it.
If you add rental kart protection to a racing chassis, well you know what that’s going to be like. Maybe my Rx7’s are not a great example… but holy hell that bodywork and brackets etc are HEAVY! For us , I think adding a smidge of caster would help and I hope to install some pills at some point.
I do get what you’re saying though, a compromise of sorts. The “right” amount of protection and handling for more experienced drivers.
From memory, it’s been attempted a couple of times…. But I’m struggling to remember the vendors. I remember the CRG Maximo being something like this in the late 90’s.
Club 100 might be close? But to Chuck’s point, it’s a very small market. I think it would almost need to be a bespoke offering, designed and developed by a series… for themselves
I don’t really think it is that niche anymore. Most of the grade 1 tracks face this issue. In my area, I have 5 tracks in a radius of 250km that are grade 1 (Mariembourg, Spa, Genk, Ostricourt, Mirecourt) that could benefit of such product.
Would they benefit to the point that it would justify buying and maintaining a separate fleet though. Especially considering that they won’t be used as much since the fleet will run a fraction of the time by a small group of racers.
I think that’s the key point… There’s limited commercial viability (IMO).
If drivers still turn up for their existing fleet, there’s not much incentive to change or add to it for a small group. I guess you could make it work by charging a premium for those events but still making those numbers work would be hard. I’ll admit I’m not good at math though.
Would I like to drive better handling rental karts? Sure! But I’m also barely even 1% of a typical track’s customer demographic. From a commercial standpoint, I don’t matter.
Insurance. If you make the karts faster, that equals more dangerous. At that point insurance premiums will increase, or possible coverage not even offered.
Which is why a club model is interesting. Bespoke karts for “advanced” drivers who own the kart and are ultimately responsible for keeping it out of walls. Financial responsibility as well. Probs impractical.
Well, I see your point. Still, for example, Mariembourg is always selling out on each of its endurance events (48 karts) and the sprints gather at least 25-30 drivers, with some categories being sold out (36 karts * 4 categories). They even had to organize two 4 hours races on the same day because of the amount of people interested. And it was sold out as well.
That’s 14 regular events (7 endurances and 7 sprints) + 1 24h race.
Genk is sold out as well on their events, same for Ostricourt or Spa. I feel like the SWS made rental racing a lot more popular and sought after. Maybe that’s not the case in the US though.
So that combined, plus the fact that you have track with a lot of space before the tires and no turns with massive speed change, I think it could work. But in the other hand, I don’t manage a track, that is pretty much an enthusiast, but outsider POV.
An issue indeed in the US, not so much in Europe, we are lucky
A mechanic’s wife thought of opening a rental kart business without most of their protections to make them lighter but the problem was if the track they managed to get was small it would be pointless.
Also the local public for rental kart tend to crash a lot so the protection would be necessary. There’s a local karting club who races in different rental kart establisments but only a half of them are respectul drivers.
This, and also tracks where you won’t crash in the tire barriers that easily. On big tracks, kart on kart contacts are less violent due to the lower speed differences (small track or indoor track have tight hairpins for example) and due to the higher width of the track.
That is why I am talking about grade 1 track, CIK tracks
I’m guessing the market is too small for super light rentals. Not many takers for league racing although it would be sweet if they had a league only fleet.
For now I guess yes. But I talked with many owners and mechanics, and they are unanimous about the RT/SR Sodi karts. Those are a pain to maintain because of the sheer amount of plastic everywhere. Not only it makes maintenance time consuming, but it makes the exhaust and the engine overheat. Many of them regret the days of the Sodi GT4R and how easier they were to work on.
I mentionned it in my first post, alongside TB Kart. Indeed one of the most compelling offer. Unfortunately 11hp is not enough for longer/faster tracks. 15-18hp would be great
Yeah there are ways to output 20hp or so from the 270cc, if you go ham with the mods. Just simples mods like valve spring, carb jet and aluminum flywheel can make the engine rev a lot higher.
While https://affordablegokarts.com/ have all the parts in stock for such mods, it is not possible to source such tuned engine on a big scale (50+ units)
out of them.
