The big Stark Varg supermoto information topic

[gewoontim]

I also did my first session on the Varg on the supermoto track. Had a lot of fun, but noticed some really heavy engine braking (as in: locking up rear wheel) after closing the throttle on the straight. Got a new powertrain from Stark, so will be installing that this week and do a second test next Sunday.

My conclusions were:
- Equal fast to 450s, maybe a bit faster.
- My laptimes were 3s slower, but that might also have something to do with the fact that my last proper session was 3 years ago.
- Didn’t notice any thermal limitations.
- The battery lasted 3 sessions of approximately 15 minutes each. I traveled a total of 42km. Power goes only noticiably down at only 10% SoC or so.
- The bike didn’t feel as fast as on the parking lot, but might have something to do with the fact that you use less throttle when going out of the corners.

 

[Kurlon]

What gearing are you running, and what map setup if you don't mind sharing?

 

[gewoontim]

What gearing are you running, and what map setup if you don't mind sharing?

Stock gearing and 80hp map with 100% regen. But I used the 60hp map in the corners, as I find the throttle curve too steep in the 80hp map. It is about time they release the throttle curve adjustment, because I feel like that is the main reason people don’t like the 80hp.

 

[Beagle]

Just going by what the commentators noted, and you can see he didn't have as much motor as he was being chased down on the last lap of the B heat. He could have dropped modes to save battery?

Indeed they said that on live commentary though I think he lapped 1'22-1'24 all race long.

Actually his last 5 laps in race 2 are quite steady:
1'23.9
1'23.3
1'23.9
1'24.0
1'24.3

However his pace did drop by a couple of seconds for the 3rd race. Hopefully we'll get more info but it's not obvious his bike had any issues (in race 2 at least).

 

[Fukenfast]

I had some free time today and a spare WP rear shock from a 2018 KTM 450 SXF. I removed the bushings and replaced them with the one's from the Stark's KYB shock. The tolerance in the WP shock's bearing requires the bushing. to be pressed in, where the KYB shock's tolerance allows the bushing to almost fall out. When measured with calipers The diameter of the internal bushing is ~1mm off. I used a little grease and the dust seal from the WP shock to seat the KYB bushing and buttoned everything up.

The WP shock requires the use of a KTM lower shock bolt.

The only noticeable issue is the size of the shock bladder. The bladder is mated against the plastics and may require some modification. I'll refrain from cutting until I move the xact pro over from my 450.

 

[ducatidesmo]

I may have missed it, but does anyone have just a parts list (part numbers) needed to get on the track? I've got KTM/Husq Alpina wheels, and tires but things like the fork bottom to put a radial brake on, spacers, etc?

Thanks!

 

[Beagle]

Some infos there

 

[Kurlon]

Depending on the track, pace, etc you don't HAVE to go all in with radial mount fork bottoms, etc... A stock MX brake will go a decent ways, if you're not warping rotors or melting pads skip the spend to start? If I can ever GET my bike, I'll document the details of converting.

 

[Theo]

I've never used a MX bike converted to SM; my SM bike was already like that from factory, but typically people complain about MX forks being too soft and diving too much when braking on asphalt; well, if the Varg fork is too stiff for motocross, maybe it will be right or at least acceptable for SM.

 

[Fukenfast]

For the front, I ordered the MDC triples to run my WP cone valve forks with KTM Alpina Wheels. This setup requires the xtrig 200mm axle, wheel spacer and front rotor spacer. I got those parts from toxic Moto racing. I installed beringer stage-2 kit (axial mount). I also installed slidemoto axle slider from toxic that fit the KTM trig axle. Basically, moved my whole front end over from the KTM 450 SX-F I was racing.

For the rear, I modified the rear bushing to install my wp xact pro shock. I took 2mm off the outside of the bushing for the shock to fit inside the frame mount on the stark. The alpina from my KTM moved over with no parts needed (just KTM wheel spacers). I will say the stock rear brake is a PITA, so I mounted a beringer 2-piston caliper with beringer rotor on the stock brake line. I also picked up a set of custom made sliders from Toxic that replace the stark axle blocks for a clean fit. I have a beringer clutch lever I'll move over once I get a custom line for the rear brake from coremoto...need to measure the line na order one, but the stock setup is working for now. The stock setup uses a 8mm banjo at the lever.

I also added a guts seat cover and switched to a 15 tooth front and 45 rear. I race with a guy running 15/39 and he's turning crazy fast laps still. I'll stay with the 15/45 as it allows a swap without having to break the chain.

For what it's worth, the kick stand works with SM wheels. I was told warp9 is working on a longer kickstand that will actually work for dirt duty, as the stock one is way to short.

The pic below was before suspension swap.

 

[ducatidesmo]

View attachment 11162

I also did my first session on the Varg on the supermoto track. Had a lot of fun, but noticed some really heavy engine braking (as in: locking up rear wheel) after closing the throttle on the straight. Got a new powertrain from Stark, so will be installing that this week and do a second test next Sunday.

My conclusions were:
- Equal fast to 450s, maybe a bit faster.
- My laptimes were 3s slower, but that might also have something to do with the fact that my last proper session was 3 years ago.
- Didn’t notice any thermal limitations.
- The battery lasted 3 sessions of approximately 15 minutes each. I traveled a total of 42km. Power goes only noticiably down at only 10% SoC or so.
- The bike didn’t feel as fast as on the parking lot, but might have something to do with the fact that you use less throttle when going out of the corners.

@gewoontim, Which sliders did you end up using? Do you happen to have a link to where i can find them?

Thanks!

 

[Fukenfast]

@gewoontim, Which sliders did you end up using? Do you happen to have a link to where i can find them?

Thanks!

Not gewoontim, but these are the one's I just received from Jeff @ Toxic Moto Racing. The rears are pictured below, but aren't on the website yet. Call and Jeff can hook you up. I'm using the slidemoto fronts for my Xtrig KTM axle, this link takes you to the Stark Slidemoto Fronts.

 

[mbw479]

I used 15t front this weekend with the studded tires. It's a bit of a stretch but seems fine.
16 won't make it. That one (and the 17t) will stay in the sprocket box

Without anything custom made 15/38 is the tallest gearing you'll be able to put on. Remember the chain is riveted.

Did you use a ktm front sprocket?

 

[Jocke_D]

Did you use a ktm front sprocket?

KTM front and rear

 

[mbw479]

KTM front and rear

I have used the KTM front but it was a tight fit....much tighter than the stark standard sprocket.

 

[BeardyTroll]

Some great info in this thread, but wondering if you guys are seeing the chain slider getting chewed up with 40t rears? I was testing a 14/40 setup and found the chain slider was getting eaten pretty quickly...is there a harder UHMW option or just let it eat and replace as needed? or is it lower shock preload and let it squat a bit more? Anyone else seeing an issue with small sprockets?

 

[mbw479]

Some great info in this thread, but wondering if you guys are seeing the chain slider getting chewed up with 40t rears? I was testing a 14/40 setup and found the chain slider was getting eaten pretty quickly...is there a harder UHMW option or just let it eat and replace as needed? or is it lower shock preload and let it squat a bit more? Anyone else seeing an issue with small sprockets?

My chain slider did wear pretty quickly with 14/40, however I never ran it for long because it would not pull that gearing to full rpm. How did you go with that gearing? Apart from the slider wear.

 

[BeardyTroll]

My chain slider did wear pretty quickly with 14/40, however I never ran it for long because it would not pull that gearing to full rpm. How did you go with that gearing? Apart from the slider wear.

Didn't really get an opportunity to find the top, was just messing around and hadn't put much thought or research into gearing. Noticed the slider wear and started looking into fixes. But even if it couldn't pull that gear at the top it was still ridiculous at 80hp, throttle curve still too sensitive for corner finesse, didn't seem to hobble the acceleration at anything under 60-70 mph as that was all still wheel lift limited.

 

[mbw479]

Didn't really get an opportunity to find the top, was just messing around and hadn't put much thought or research into gearing. Noticed the slider wear and started looking into fixes. But even if it couldn't pull that gear at the top it was still ridiculous at 80hp, throttle curve still too sensitive for corner finesse, didn't seem to hobble the acceleration at anything under 60-70 mph as that was all still wheel lift limited.

Mine with 14/40 below, it still accelerated quickly but I suspect it was doing just over 12000rpm rather than the 14200rpm it can do with appropriate gearing.

 

[BeardyTroll]

Mine with 14/40 below, it still accelerated quickly but I suspect it was doing just over 12000rpm rather than the 14200rpm it can do with appropriate gearing.

I wonder how the sand/water surface and knobbies affect things. In my case I'm running 17's on street tires on hard pavement. I'm pretty sure the reduced rolling resistance would let it pull all the way to redline with 14/40. Just based on the numbers I would think 80hp should be good to around 210kph or 130mph depending on aero and drag...It sounds like some of the sumo guys have been trying down to 38t...

Really curious if anyone has intel on the slider or swing arm protection, not interested in the chain sawing through the slider and then it getting balled up in the front sprocket causing a lock up at speed. I suppose it would be possible to mount a roller back in the hoop of the swing arm, but that is starting to feel complicated. Probably going to stick with 15/45 until I get bored at that pace.