Does anyone know any axle thats harder than otk’s HH axle that fits to a otk? Thanks
What specific problem are you trying to fix? If you need something harder than the hardest axle they make, odds are something else in the setup isn’t quite where it needs to be, like seat position or something fundamental like that.
We are experiencing high levels of grip here at our track do to high temperatures and plenty of karts passing by, we ran vortex vlr100 with the sprocket being restricted (z10 with 73 sprocket) and with the new fast levanto krt tyre compound (70 code) so we are trying all the steps to remove grip and make the inside rear wheel pick up (seat foward, harder axles, shorter axles, different types of front torsion bars, caster, etc), some of our guys use a special made titanium axle to free the kart and it has been working but I was wondering if any of you know a after market axle thats harder than otks hh because not everybody can afford making one of those titanium axle.
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For what it’s worth, most rulesets specify that the axle has to be ferrous material… I saw that you move the seat forward… did it get raised at any point? If the track is truly grippy enough the tires can stick (as an adhesive, like a glue) to the rubber on the track if that makes sense. In those situations moving the seat forward will not always have the same effect. Moving it up gives you some more mechanical leverage to actually unstick the tire from he track.
CRG T5 is about the stiffest I’ve come across.
Kart Republic HH is pretty stiff too.
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One trick I used to see ICC/KZ guys do when they reached the stiffest axle but need more was to put about 10 axle collars on the axle near the center to stiffen that area up further. Would be cheaper than a titanium axle.
If you are trying to get the kart to unload more, I would recommend raising the rear ride height. Be wary of stiffer front bars. They will make the kart jack weight quicker but they will set the inside rear down too quickly for sticky tracks. If you are looking to keep the inside rear wheel up longer, you want to probably keep the flat front bar in.
The issue with adding a bunch of weight jacking into the kart under sticky conditions, while it seems like the correct route, is that you run the risk of pushing the outside tire into the track so aggressively it physically binds the tire up and the kart cannot rotate well. This is especially easy to do in an OTK kart where it is already a very front heavy kart that jacks a lot of weight.
What we are really looking for is the frame to twist for a longer duration. Something you might want to try is removing seat stays. Sometimes the chrome stays can just simply force the tire into the track too hard and stiffen up the seat too much for these conditions. Removing the chrome stays will allow for a lot more flex in the center of the kart and will keep the outside tire from being driven into the track so aggressively.
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Ti will have about half the stiffness as a steel axle of the same dimensions (elastic modulus 120 GPa as opposed to 207 GPa for iron, 195-207 for steels). A beryllium, tungsten, or uranium tube is something only a defense contractor would dare to make and would have a corresponding price; those are the only metals that’ll beat steel’s elastic modulus. If you’ve got that budget message me and General Atomics ASI will quote.
I would instead recommend a steel axle with a greater wall thickness than the HH axle’s 2 mm thickness. The stiffness of a tube will go up linearly with wall thickness. Try a PKT 50mm D25 and remember to order the PKT keys. CRG also makes a 2.5 mm axle; call them for the right number.
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