2014 EC300 Supermoto Conversions

[3DKevin]

Just picked up this 2014 EC300 a couple days ago. I've wanted to build a street legal 2T to mess around with for awhile now; I was originally planning on going with a KTM or husky, but this deal was too good to turn down. Questions I have:

1.) Has anyone here done a supermoto conversion on this specific year/model?
2.) I know a 4.25" rim with a 140 will fit, is it possible to squeeze in a 5" rim with a 150?
3.) I've seen mentioned in some threads that husky wheelsets are identical to GasGas. For what years is this true?
4.) Gearing recommendations for street riding?

I know this bike will be extremely impractical, but it's a project idea I've had for quite some time. Any feedback or advice is appreciated, thanks!

 

[(F5)]

Tyre choice will be critical. Erm. . . Maybe spikes?

 

[Anders]

Just picked up this 2014 EC300 a couple days ago. I've wanted to build a street legal 2T to mess around with for awhile now; I was originally planning on going with a KTM or husky, but this deal was too good to turn down. Questions I have:

1.) Has anyone here done a supermoto conversion on this specific year/model?
2.) I know a 4.25" rim with a 140 will fit, is it possible to squeeze in a 5" rim with a 150?
3.) I've seen mentioned in some threads that husky wheelsets are identical to GasGas. For what years is this true?
4.) Gearing recommendations for street riding?

I know this bike will be extremely impractical, but it's a project idea I've had for quite some time. Any feedback or advice is appreciated, thanks!

1. My son did something similar to his 08 or 09 model. Although the 14 has a different frame and forks, things regarding wheels and brakes are quite similar.

2. I think he used a 4.5" rim with a 150/70 BT090 tire. I wouldn't use a 150/70 tire on a 5" rim.

3. I don't know about that, but in case it is true, it would be the italian huskys. I know they use the same rear sprocket, but I don't know about the rest. Motocrosscenter sells complete SM kits, https://www.motocrosscenter.com/sho...rmotard-kit-gas-gas-machined-hubs-196601.html.

 

[3DKevin]

1. My son did something similar to his 08 or 09 model. Although the 14 has a different frame and forks, things regarding wheels and brakes are quite similar.

2. I think he used a 4.5" rim with a 150/70 BT090 tire. I wouldn't use a 150/70 tire on a 5" rim.

3. I don't know about that, but in case it is true, it would be the italian huskys. I know they use the same rear sprocket, but I don't know about the rest. Motocrosscenter sells complete SM kits, https://www.motocrosscenter.com/sho...rmotard-kit-gas-gas-machined-hubs-196601.html.

Thank you for the info. I made a typo in my original post; I plan on running either a 140/150 on a 4.25", or a 160 on a 5".

 

[Anders]

Thank you for the info. I made a typo in my original post; I plan on running either a 140/150 on a 4.25", or a 160 on a 5".

I don't think a 160 will fit. I can measure it; as I have a '15 Gasgas and my Supermono with a 5" rear and a 160/60 BT090.
However, it will take some days before I can get it done.

On the other hand; the link I gave you from Motocrosscenter states that their kit has a 160/60 on a 4.25"

 

[Anders]

My son Fredrik's EC300SM

 

[gasser]

Here is a rear 42 tooth rear sprocket that will fit a GasGas hub. 1991 Suzuki dualsport DR250S will fit. Only the "S" model - the regular DR250 is different.

https://www.rockymountainatvmc.com/parts/primary-drive-rear-steel-sprocket-p?v=2578

 

[3DKevin]

I don't think a 160 will fit. I can measure it; as I have a '15 Gasgas and my Supermono with a 5" rear and a 160/60 BT090.
However, it will take some days before I can get it done.

On the other hand; the link I gave you from Motocrosscenter states that their kit has a 160/60 on a 4.25"

I appreciate it. Let me know how that measurement works out... in the mean time, I reached out to Warp9 to see what hubs they use for their GG sumo kit. They said they use a pre-2012 Honda CRF hub on the rear and a KTM up front. I've never seen anywhere on this forum about Honda/GG rear hub crossover compatibility, so now I'm even more confused.

I would just buy the Warp9 kit and call it a day, but I'm dying to run Alpina wheels, which is why I'm looking for a crossover and curious if the 5" will clear with a 160.

 

[Anders]

I appreciate it. Let me know how that measurement works out... in the mean time, I reached out to Warp9 to see what hubs they use for their GG sumo kit. They said they use a pre-2012 Honda CRF hub on the rear and a KTM up front. I've never seen anywhere on this forum about Honda/GG rear hub crossover compatibility, so now I'm even more confused.

I would just buy the Warp9 kit and call it a day, but I'm dying to run Alpina wheels, which is why I'm looking for a crossover and curious if the 5" will clear with a 160.

I hope I can do the measuremenst over the weekend.

Well, up front you can get away with almost anything. It's just a matter of lining up the disk in the caliper and making some spacers to fit, as long as you find suitable bearings. I (and plenty others) have fitted a GG hub in Yamaha forks, for instance.
Its the rear that represents the problem, as both the chain line and the brakes must fit, while the wheel is still in the centerline of the bike.
People have also used cast street bike wheels from e.g. Aprilia RS125 and I think also Suzuki GS500 if memory serves me right.
I have never built a SM bike, but I did install magnesium PVM Ducati wheels on my Bimota Supermono. Then I had to spend some hours in the lathe and milling machine...
I have never heard of Alpina before, but they look nice.
What part of the world are you in?

 

[pscook]

I appreciate it. Let me know how that measurement works out... in the mean time, I reached out to Warp9 to see what hubs they use for their GG sumo kit. They said they use a pre-2012 Honda CRF hub on the rear and a KTM up front. I've never seen anywhere on this forum about Honda/GG rear hub crossover compatibility, so now I'm even more confused.

I would just buy the Warp9 kit and call it a day, but I'm dying to run Alpina wheels, which is why I'm looking for a crossover and curious if the 5" will clear with a 160.

I don't believe that the CRF and GG hub "crossover," per se; rather that they likely have similar rotor to sprocket spacing and any offset will be factored into the lacing process. As long as your rotor and sprocket spacing is reasonably close to original, you can make up any tolerances with custom spacers and the sliding caliper on the brake side.

 

[gasser]

I have a friend that put a kawasaki rear wheel on his GG 300. It worked well.

 

[3DKevin]

I hope I can do the measuremenst over the weekend.

Well, up front you can get away with almost anything. It's just a matter of lining up the disk in the caliper and making some spacers to fit, as long as you find suitable bearings. I (and plenty others) have fitted a GG hub in Yamaha forks, for instance.
Its the rear that represents the problem, as both the chain line and the brakes must fit, while the wheel is still in the centerline of the bike.
People have also used cast street bike wheels from e.g. Aprilia RS125 and I think also Suzuki GS500 if memory serves me right.
I have never built a SM bike, but I did install magnesium PVM Ducati wheels on my Bimota Supermono. Then I had to spend some hours in the lathe and milling machine...
I have never heard of Alpina before, but they look nice.
What part of the world are you in?

I'm in Pennsylvania in the US. It's a lot easier for me to get Warp9 or excel wheels here, but I love the idea of tubeless spoked wheels, and as far as I know Alpina is the only company that provides that (for a reasonable price). I'm going to reach out to Warp9 again and get details on spacing, and also to my local GG dealer to see if they have any experience on the matter.

 

[3DKevin]

I have a friend that put a kawasaki rear wheel on his GG 300. It worked well.

What year specifically? Alpina does make rears for KX/KXF's, though they don't say for what year range. What spacers did he use, or did he make his own? Any other modifications necessary?

 

[Anders]

Did some rough measurements. A 160/60 BT090 on a 5" rim is 172mm. From then, you can measure the rest on you own bike, but I would think you'll get into trouble with both chain and swingarm. Other tire types will measure differently

 

[gasser]

What year specifically? Alpina does make rears for KX/KXF's, though they don't say for what year range. What spacers did he use, or did he make his own? Any other modifications necessary?

I asked him about the wheel when I saw him at church yesterday. He thinks it was a KX 250 wheel from the early to mid 90s. He couldn't remember about the spacers but said that having only 1 bearing on the sprocket side caused it to wear out faster.

 

[Harry]

OEM GG motard rims. https://www.moradsa.com/

Front rim: Morad (Spain) 17x3.5"
Front Tyre: Michelin 120/70R-17

Rear rim: Morad (Spain) 17x4.25"
Rear tyre: Michelin150/60R-17

Chain just grazes edge of rear tyre.