Yes it is. The Road Rebel just feels mega stiff. Standard caster. 2mm total toe out. 4mm of camber per side.
I’m thinking if I chop the axle down a bit it might help soften the chassis/rear and how stiff it feels. I think it’s a 1060 length axle in it currently. Going a touch less caster. Maybe going even softer on the seat. Our track is so rough it might be exaggerating how stiff the chassis is. I’d like to run it on a bigger smoother track.
17/25 gearing. It’s just about at the top of the rev range in 6th when I brake off the back stretch. Hitting 84-85mph.
It feels great in the two low speed corners and the fast sweeper off the back stretch, but man it’s a handful in the mid speed corners. Very knife edge feeling. It doesn’t feel as bad as it looks in the video, but for sure there is a lot of room for improvement.
A softer seat sounds like an idea with this kind of stiffness. Just to calm everything
Have you tried 18/26? Seems like it would fit slightly better, it’s not an huge difference compared to what you have now. Looks like some time could be gained with a slightly longer ratio. Since it’s so choppy right now
I do have that combo. I’ll give it a try. I bought 17,18, 19 front driver and 23 through 27 rear sprockets so I’d have a nice range.
I have the really stiff adjustable seat strut on the engine side. I might change it out for a normal one and remove the extra on the left hand side. So it’s just one seat strut per side. But that might just remove too much weight transfer versus softening up the feel of the kart.
With that amount of grip I wouldn’t worry about stays if you can adjust your driving to a more V based one. Straight in straight out.
Factory runs 2 each side but with a T11VG seat
Seems like you have a very nice engine to do that. Really think that a slightly longer gearing will calm things down a bit. It will come to you eventually
Right now it’s absolutely about seat time and just calming down the steering inputs and a more v-shaped line. This engine just makes so much power that I think finding the right gearing will really help instead of feeling like I’m stuck in between the 3rd and 4th for most of the infield.
And you are right about the gearing, being stuck between gears is horrible when the engine has so much power at those revs. Makes it very choppy
It’s not always needed to totally wring out the revs on a KZ. If you look at my video when i take the left left corner before the right hander before straight its much better go just ride 4th with lower revs than 3rd at high rpm. Mega choppy otherwise
Yep. There’s a turn that most guys take in 4th at orlando, part throttle. I can turn in and floor it in 5th and it’s perfect every time. If I lose anything in raw accel I gain it in consistency lap to lap.
Cutting the axle will only exacerbate rear instability.
You have fast hands that, coupled with the chassis geometry (at longitudinal tubes), make it so the kart is unstable on corner entry.
There are two solutions:
Slow down your hands and try to limit the corners to a single input (in which case, take a click of caster out and add a couple of degrees of negative camber to help with corner entry)
(my personal suggestion) Move the tie rods to the upper mount point of the steering column and see the effects.
I say this as a KR driver. Our geometries at the front are relatively similar and, indipendent of the type of chassis tube used, display the same corner entry behavior. We run our chassis with the tie rods on the top hole in fast tracks like Franciacorta or Cremona, to calm down the rear.
(Indipendent of all the above, the overarching suggestion is to overdrive a bit less, you’ll go faster )
So the CRG has three options on the steering column. I started at the bottom and the steering was way too fast and heavy. So I’ve been in the middle set of holes.
I’ve got a couple other ideas to soften up the chassis and reduce reactivity. I normally have pretty calm hands and have so many laps around this track. So right now I’m really fighting the baseline setup. I agree after having another think about it cutting the axle might not be the way to go. Caster/camber changes should be a good starting point.
I would also suggest adding more toe out. I work with a tall driver that generates a lot of weight transfer via his body, so we’re always trying to slow down the front end. His chassis has worked a lot better with 3mm/side. We’ve also been going a similar route with drivers on the GP chassis, running 3-4mm/side in some cases.
Struggling to keep the snipers to hold camber. One side or the other keeps moving on me. Camber moves a box or so after a test day.
I loosen the kingpin. Set camber with the inner grub screw since it’s easiest to reach. Lock down the other grub screw. Then tighten the kingpin back down. Set screws are still tight at the end of the day.
As stiff as this bad boy is I don’t think the frame is moving plus I’m being gentle over the single curb I have to hop. Racedays I launch that bad boy and I’ve yet to have a 30mm frame move. Kingpins seem dead straight.
I assume everyone is putting the laser aligners on the rotor carrier and not completely removing the carrier to get the snipers on the spindles. Otherwise the caliper and/or rotor needs removed, which F-that to do an alignment. Then I zip tie down the brake pedal so the carriers don’t spin while I set the alignment.
Struggling to find where the variance is.
Also on the chopping axle I don’t know where/how I measured 1060 it really is the baseline 1040. Maybe I need to hold the dumb end of the tape measure next time
The variance you’re seeing is in the kingpin assembly.
Yeah the lasers will always go onto the rotor slide assembly, no need to remove them. You can either go with zip ties as you’re doing, or just tighten the nut on the end of the spindle until it won’t spin.
That is going to drive me insane if it’s moving a box from where I set it.
I thought about locking the spindle nut, but figured there is a chance I might forget to back it off and cook the bearings. Since the magnets don’t work I found an old inner tube works quite well.
Not to derail the thread, but I think this warants a discussion @KartingIsLife feel free to permaban me or move this reply to a dedicated thread (depending on how you feel)
I propose we elect our favorite front end alignment systems and fight to the death over them.
Mine: Parolin EasyCaster system. Supperior in every way to anything on the market.
Pros:
Intuitive
Indipendent caster camber adjustment
Can be modified on the fly reasonably accuratly without lasers
You can literally stick your impact gun with a 10mm on the caster nut and crank that s*** during an in session pitstop (kingpin tightened and all) for ultimate testing satisfaction