The big Stark Varg supermoto information topic

[gewoontim]

Hi all,

Starting this topic as I want to collect all information concerning supermoto'ing the Stark Varg. This is a living document, if you have any additional information please let me know in the comments and I will add this to this topic!


Wheels
Front wheel
Front wheel has a 22mm diameter axle from stock. According to Stark the hub width is 136.6mm. Same dimensions as KTM 450 SXF 2022. The bushings are not interchangeable with KTM wheels. KTM wheels do fit in the Stark but the spacers are different.
Newer Stark models (higher than +/-VIN1000) seem to have different bushings compared to the first version. Changes unknown.

Rear wheel
Rear wheel has a 25 mm diameter axle. The width is 180mm. Same dimensions as KTM 450 SXF 2022. The bushings are interchangeable with stock KTM hubs.

General
When placing KTM wheels in the Varg, they seem to have an offset of 2.5mm compared to each other. Source: VMX Racing.

Suspension
Triple clamps
The stock Stark clamps are spaced 190mm with an offset of xmm. The triple clamps are quite remarkable, as the bottom triple clamp has the bolts on the front. This is mainly due to the frame design, which doesn't allow much steering angle if the bolts are placed in the rear of the clamp. The bottom triple clamp is 59mm, which is only suitable for KYB and Showa. For WP forks, KTM clamps are required, which have a bottom triple clamp diameter of 60mm.

Therefore using KTM clamps is possible, but this greatly reduces the steering lock and this is not recommended. Other problems which arise when using stock KTM clamps are:
- No mount for the numberplate
- Mounting for the front fender doesn't fit
- Steering stops aren't on the same place.

There are several brands working on supermoto clamps for the Varg. A few noted are:
- Erides / MDCparts: 200mm width and possibility for WP forks or KYB forks with adapter sleeve.


- VMXracing: no information yet. Seems to be working on something as well.
- SPS parts: no information yet. Will be working on a kit in the future.

Front suspension
The front suspension is obviously KYB. The length of stock suspension is 953mm (axle to top of triple clamps). Suspension settings can be checked at Racetech.

When converting to supermoto, quite a few people choose to place FS450/SMR450 WP forks (AER or non-AER) in the bike.
Take note that the WP AER forks from >2021 require stock KTM bushings. Forks before 2021 require custom supermoto bushings with wider bushings on one side. The WP AER forks do not fit in the stock Varg as the triple clamps are too small.


Rear suspension
The rear suspension is also obviously KYB. The stock length is 468mm. Suspensions settings can be checked at Racetech.

This is the same length as stock FS450 2021-22 shocks. These need little modification, only the spacer for the top bushings need to be thinner. The 23- shocks are 10mm shorter, but reports have shown that these do not fit(?). Take note that the linkage ratio is totally different compared to the SMR/FS motorcycles, and thus the spring rate of these shocks is not equal to the Stark. Also FS/SMR shocks are also already shortened, and cannot be shortened furthermore.


Brakes
Front
Stock forks: 95mm between holes. Front caliper screws are M8x30mm

----- TO BE CONTINUED -----

 

[Jocke_D]

My story with the Varg and 17" goes something like this...

I got my bike the 15th of September and the 16th it had the 17" from my FC450 on it
The rear was a straight fit but the front needed different spacers since I used shorter/wider clamps on the FC. Had some to spare so was no issue. The offset difference that VMX has reported was nothing I noticed (and don't know if they mean front and/or rear). To me it looked to line up just fine but was not in a particular analyzing state of mind
On the FC I use a Magura 320mm radial set up but had an older Beringer 4 piston axial set up that was a direct fit on the KYB together with stock Husaberg 310mm disc.
Had prepared with a purchase of KTM stock hand guards that was easy to mount.
On the rear wheel there was a 45t and with the stock Varg front chain got a bit long. Since I had no idea what to expect regarding speeds I thought it was a good idea to mount a 14 front from KTM. Better to have higher than lower top speed.
On the 21st I had some graphics (extremely simple in matt finish) made up and on the 23rd I went racing. This was the first time riding the bike besides a couple of times up and down the street.




Supermoto racing was really energy consuming and will vary a lot between different tracks. I topped up as much as I could between every session. Started the day with 93% (had not learned that bike need to be switched on when charging, haha) and ended with 17%. A race day for us is FP1, FP2, TQ, Lunch break, Moto1, Moto2, Finale. Since there are only two classes the breaks between sessions are quite short so little time to charge.
Next year the organizers have started a special electric class that will race together with the others but only get points in the first moto and the finale. This is to be able to charge properly. We are allowed to race all motos of course and get points in the normal standings but that's up to every racer.

Racing was easy and hard. Really hard to get good starts. It was difficult to brake properly since the feeling is different compared to ICE. It was an advantage to not have to worry about gears and it was so easy to ride. Power was good but not the kind of advantage I had expected to have. The bike was working great and remember I had not touched anything on suspension etc, not even the clickers. Had some really bad chatter in one corner but other than that it was a really impressive package. This track had no big jumps and a pretty smooth gravel section.

Did try to mount the clamps from the FC together with with the WP forks and tried some flat track. Steering angle was so narrow I crashed on the first lap. But clamps and forks seem to work on the Varg. Will need some more work to get everything in order for racing. There are at least three more, probably a couple more, swedish guys now who have gotten their bikes and are working on getting them ready for next season. Will be really interesting

After the race I've mainly done some enduro practice with stock wheels. Now it's time for ice (the frozen water kind, not combustion).

 

[tymck7]

Thanks for starting this thread! Glad to know ktm wheels fit and all I need to do is swap the spacers. Can't wait to get my bike, Stark is predicting mid January for delivery. I'm hoping I'm not taking this off the intended topic, but I would love to work on adding brake light/headlight so I can street legal this thing (I live in the western US, pretty lax laws for street legal bikes... mostly just headlight, brake light, cheap horn and a dinky handle bar mirror and you're good to go.) I'm wondering if I can tap into the power at the phone mount connection to run 12v (I assume) to some lights and a horn... Anyone have any info on this yet? If not I'll try to figure it out and post my results..
I'm also wondering what my range will be on the street (I commute 24 miles/day anywhere from 40-80mph.. would hope for at least double that range at those speeds). If anyone gets more data on street range, I would love to hear it.

 

[mbw479]

My story with the Varg and 17" goes something like this...

I got my bike the 15th of September and the 16th it had the 17" from my FC450 on it
The rear was a straight fit but the front needed different spacers since I used shorter/wider clamps on the FC. Had some to spare so was no issue. The offset difference that VMX has reported was nothing I noticed (and don't know if they mean front and/or rear). To me it looked to line up just fine but was not in a particular analyzing state of mind
On the FC I use a Magura 320mm radial set up but had an older Beringer 4 piston axial set up that was a direct fit on the KYB together with stock Husaberg 310mm disc.
Had prepared with a purchase of KTM stock hand guards that was easy to mount.
On the rear wheel there was a 45t and with the stock Varg front chain got a bit long. Since I had no idea what to expect regarding speeds I thought it was a good idea to mount a 14 front from KTM. Better to have higher than lower top speed.
On the 21st I had some graphics (extremely simple in matt finish) made up and on the 23rd I went racing. This was the first time riding the bike besides a couple of times up and down the street.


View attachment 10717View attachment 10718

Supermoto racing was really energy consuming and will vary a lot between different tracks. I topped up as much as I could between every session. Started the day with 93% (had not learned that bike need to be switched on when charging, haha) and ended with 17%. A race day for us is FP1, FP2, TQ, Lunch break, Moto1, Moto2, Finale. Since there are only two classes the breaks between sessions are quite short so little time to charge.
Next year the organizers have started a special electric class that will race together with the others but only get points in the first moto and the finale. This is to be able to charge properly. We are allowed to race all motos of course and get points in the normal standings but that's up to every racer.

Racing was easy and hard. Really hard to get good starts. It was difficult to brake properly since the feeling is different compared to ICE. It was an advantage to not have to worry about gears and it was so easy to ride. Power was good but not the kind of advantage I had expected to have. The bike was working great and remember I had not touched anything on suspension etc, not even the clickers. Had some really bad chatter in one corner but other than that it was a really impressive package. This track had no big jumps and a pretty smooth gravel section.

Did try to mount the clamps from the FC together with with the WP forks and tried some flat track. Steering angle was so narrow I crashed on the first lap. But clamps and forks seem to work on the Varg. Will need some more work to get everything in order for racing. There are at least three more, probably a couple more, swedish guys now who have gotten their bikes and are working on getting them ready for next season. Will be really interesting

After the race I've mainly done some enduro practice with stock wheels. Now it's time for ice (the frozen water kind, not combustion).

What top speed did you pull with the 14/45 gearing?

 

[Jocke_D]

The app reported some 125km/h at the end of that tracks longest straight.
The app is not a very reliable source for top speed and that speed probably was not the maximum for that gearing. So hard to say

I did do a short improvised test with stock gearing and stock wheels (18"). The app said 135 and my Samsung phone said 145. At that time the engine maxed out.

 

[mbw479]

The app reported some 125km/h at the end of that tracks longest straight.
The app is not a very reliable source for top speed and that speed probably was not the maximum for that gearing. So hard to say

I did do a short improvised test with stock gearing and stock wheels (18"). The app said 135 and my Samsung phone said 145. At that time the engine maxed out.

Thanks, I get mine in January apparently, I will be putting a 14/40 on it not long after that to see if I can get 190kph for an event later in the year.

 

[Jocke_D]

Thanks, I get mine in January apparently, I will be putting a 14/40 on it not long after that to see if I can get 190kph for an event later in the year.

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.

 

[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.

I'll be replacing that chain for the tall gearing and putting a joining link in the standard chain.

 

[tymck7]

My story with the Varg and 17" goes something like this...

I got my bike the 15th of September and the 16th it had the 17" from my FC450 on it
The rear was a straight fit but the front needed different spacers since I used shorter/wider clamps on the FC. Had some to spare so was no issue. The offset difference that VMX has reported was nothing I noticed (and don't know if they mean front and/or rear). To me it looked to line up just fine but was not in a particular analyzing state of mind
On the FC I use a Magura 320mm radial set up but had an older Beringer 4 piston axial set up that was a direct fit on the KYB together with stock Husaberg 310mm disc.
Had prepared with a purchase of KTM stock hand guards that was easy to mount.
On the rear wheel there was a 45t and with the stock Varg front chain got a bit long. Since I had no idea what to expect regarding speeds I thought it was a good idea to mount a 14 front from KTM. Better to have higher than lower top speed.
On the 21st I had some graphics (extremely simple in matt finish) made up and on the 23rd I went racing. This was the first time riding the bike besides a couple of times up and down the street.


View attachment 10717View attachment 10718

Supermoto racing was really energy consuming and will vary a lot between different tracks. I topped up as much as I could between every session. Started the day with 93% (had not learned that bike need to be switched on when charging, haha) and ended with 17%. A race day for us is FP1, FP2, TQ, Lunch break, Moto1, Moto2, Finale. Since there are only two classes the breaks between sessions are quite short so little time to charge.
Next year the organizers have started a special electric class that will race together with the others but only get points in the first moto and the finale. This is to be able to charge properly. We are allowed to race all motos of course and get points in the normal standings but that's up to every racer.

Racing was easy and hard. Really hard to get good starts. It was difficult to brake properly since the feeling is different compared to ICE. It was an advantage to not have to worry about gears and it was so easy to ride. Power was good but not the kind of advantage I had expected to have. The bike was working great and remember I had not touched anything on suspension etc, not even the clickers. Had some really bad chatter in one corner but other than that it was a really impressive package. This track had no big jumps and a pretty smooth gravel section.

Did try to mount the clamps from the FC together with with the WP forks and tried some flat track. Steering angle was so narrow I crashed on the first lap. But clamps and forks seem to work on the Varg. Will need some more work to get everything in order for racing. There are at least three more, probably a couple more, swedish guys now who have gotten their bikes and are working on getting them ready for next season. Will be really interesting

After the race I've mainly done some enduro practice with stock wheels. Now it's time for ice (the frozen water kind, not combustion).

Hey, rear wheel width 4.25” i assume? No way to fit a 5” rear, right?

 

[Jocke_D]

Hey, rear wheel width 4.25” i assume? No way to fit a 5” rear, right?

Yeah, 5" rear!
Using 4.25 with slick tires is no good. And in my experience also road tires on 4.25 gets wider than on 5" if using 150/160 wide. Have never tried 130/140 though.

 

[tymck7]

Yeah, 5" rear!
Using 4.25 with slick tires is no good. And in my experience also road tires on 4.25 gets wider than on 5" if using 150/160 wide. Have never tried 130/140 though.

Sweet! I'm not racing and hence not doing slicks, but I do want the biggest tire that will fit without rubbing. ... but I'll admit ... mostly for appearance purposes. So I'll pick up a 5"x17" rear tubeless wheel and grab some contiattack SM 160/60s I think.

 

[Kurlon]

Wish those MCD clamps were 205mm apart, my 06 SMR setup would drop in. At 200mm my caliper will be eating spokes. Good to see the market is already spooling up though.

 

[Theo]

Thanks, I get mine in January apparently, I will be putting a 14/40 on it not long after that to see if I can get 190kph for an event later in the year.

As far as i know, top speed of vehicles is mainly affected by their power and by their aerodynamic drag.
I think that a vehicle having comparable power and drag to the Varg is the Husky 701, which exceeds 190 indicated kph.

 

[Kurlon]

For comparison, road racing Supermotos at NHMS (Loudon NH) we're seeing 105 to 110mph out of FS 450s by turn one, if not a little faster. My 2016 500 XC W could muster the same on our 1.6mi road course with 60hp. Same aero, similar weight to the Varg. The advantage my 500 has is a gearbox, I'm wondering if the Stark will need to be overgeared to keep it's RPMs down a bit on top to stay in the meat of it's efficiency, trading even more acceleration at lower speeds for more ultimate top speed?

If a 3.5:1 reduction in the primary is accurate, and a 14k RPM motor limit, the Varg is going to need to be geared 15/38 to match the top speed potential of my old 500 with 13/42 gearing. That's pretty similar to what the 450s run so that kinda tracks? If it will pull it with any kind of authority will be interesting. This is a track where I'm going down to 3rd on the 500's wide ratio box, the 450s drop to 2nd for Turn 3, and there are a few built motors I'm sure are near 70hp.

The other interesting thing to monitor will be tire life. Big thumpers are pretty easy on tires, the torque is delivered in large lumpy, well spaced pulses. The Stark however is pure linear torque, the tire won't get any rest. I saw this while racing a built FZR400, same HP as built SV650s (85hp) but their slower revving twins could get multiple races out of a test Pirelli 165 SC0 rear, I couldn't go 8 laps before my machine's inline 4 ate the tire, and my bike was lighter to boot.

 

[mbw479]

For comparison, road racing Supermotos at NHMS (Loudon NH) we're seeing 105 to 110mph out of FS 450s by turn one, if not a little faster. My 2016 500 XC W could muster the same on our 1.6mi road course with 60hp. Same aero, similar weight to the Varg. The advantage my 500 has is a gearbox, I'm wondering if the Stark will need to be overgeared to keep it's RPMs down a bit on top to stay in the meat of it's efficiency, trading even more acceleration at lower speeds for more ultimate top speed?

If a 3.5:1 reduction in the primary is accurate, and a 14k RPM motor limit, the Varg is going to need to be geared 15/38 to match the top speed potential of my old 500 with 13/42 gearing. That's pretty similar to what the 450s run so that kinda tracks? If it will pull it with any kind of authority will be interesting. This is a track where I'm going down to 3rd on the 500's wide ratio box, the 450s drop to 2nd for Turn 3, and there are a few built motors I'm sure are near 70hp.

The other interesting thing to monitor will be tire life. Big thumpers are pretty easy on tires, the torque is delivered in large lumpy, well spaced pulses. The Stark however is pure linear torque, the tire won't get any rest. I saw this while racing a built FZR400, same HP as built SV650s (85hp) but their slower revving twins could get multiple races out of a test Pirelli 165 SC0 rear, I couldn't go 8 laps before my machine's inline 4 ate the tire, and my bike was lighter to boot.

Good info thanks. I have just put 14/40 on it, planning on taking it to the beach next week

 

[RJS]

I have a 2016 KTM 300XC that I made a supermoto. The wheels and tires from that fit the VARG. Same spacers, etc.

 

[Beagle]

In competition there's a team which participated at one round in France championship last season, more info on their modifications here (interestingly they report 20% use battery for 20 min session): La première course de la Star Varg en supermotard



Also last weekend there were a couple Vargs racing in British championship, take a look at Andy Mitchell Supermoto B race 2, starts at 2h49:

Round 1 of the TRIPZ.UK 2024 British Supermoto Championship

The 2024 BSM season has arrived in style! New bikes, new riders, new thrills, catch it all at Round 1 from Three Sisters, Wigan. Use the timestamps to enjoy ...

www.youtube.com

 

[Kurlon]

Looks like Andy was having thermal issues on the last couple of laps of the B heat, so no way I'd get a full race at Loudon, bah.

 

[Beagle]

Looks like Andy what having thermal issues on the last couple of laps of the B heat, so no way I'd get a full race at Loudon, bah.

Did you find any info about his races and his bike? There's nothing yet on the championship website, did he or his team put anything on socials?

 

[Kurlon]

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?