Sur-Ron - New Mid drive Bike

[Rix]

I went ahead and ordered one. The only complaints I've run across are that front brakes might be a tad weak and rear sprocket could be bigger. Any comments on those issues? Also any parts compatibility?

I'm guessing that "light bee" comes with downhill mtn bike style brakes with 8" disc rotors.. for more front brake leverage and bite (to endo, lift the rear wheel like trials) you could probably run larger diameter 9" / 224mm rotors such as from Hayes.. i think some ppl on here are even running 10" rotors on some of their ebikes (Rix) ???

Yah Natas, I have both 9" and 10" rotors and have ran them. The 10" is fuqn huge and heavy. The 9 inch with an Avid BB2 Mechanical caliper is more than enough for a 100 pound 50+mph Ebike. Thats my favorite and the old Hayes 9" are getting harder and harder to come by.

 

[madin88]

Recently i came over those Santana 10" rotors which were made for tandem's:

Not sure if they are worth the 180USD, but they look awesome with the cooling fins.
Otherwise i would swap the entire front braking system for a Hope tech 3 V4 with a vented 203mm rotor.
Thats the best brakes i ever used and it is no problem to lift the rear wheel even with 13kg hub drive. I can do this with a Shimano ZEE or Saint as well, but it needs much more finger force.

 

[efMX Trials Electric Freeride]

nice find on the 10" tandem brake rotors..

I got my Hayes brakes with 9" rotors from motocruzin.com (9" hayes brakes still come stock on motopeds) but they don't sell just the rotors alone..

as for the primary drive chain conversion.. one nice thing about the jackshaft / concentric swingarm pivot is that chain tension is not affected by suspension travel and the chain does not contact or drag across the swingarm.. but if your using a 420 chain (for strength and durability) i think the smallest sprocket you may be able to use would be 12 tooth? but 13 tooth is very common on pit bikes so this should work well since light bee has similar power levels.. (you could probably go a bit smaller with a racing cart chain but it wouldn't be quite as strong)..

for those that already have light bee, what is the tooth count on the secondary drive small sprocket?? that is probably the smallest you could also use for the motor sprocket.. of course the smaller the sprocket, the less the chain wrap and therefore the more chain and sprocket wear..

 

[Rix]

one nice thing about the jackshaft / concentric swingarm pivot is that chain tension is not affected by suspension travel and the chain does not contact or drag across the swingarm..

Thats great, I was hoping that would be the case, like the Quantya design. Still I would rather run a bigger rear sprocket.

 

[Rix]

Recently i came over those Santana 10" rotors which were made for tandem's:

Not sure if they are worth the 180USD, but they look awesome with the cooling fins.
Otherwise i would swap the entire front braking system for a Hope tech 3 V4 with a vented 203mm rotor.
Thats the best brakes i ever used and it is no problem to lift the rear wheel even with 13kg hub drive. I can do this with a Shimano ZEE or Saint as well, but it needs much more finger force.

Cheaper option

https://www.bicycledesigner.com/bike-parts/bicycle-brake/monster-disc-brake-rotor-255mm.html

 

[Marksteamnz]

What size chain/sprockets are you thinking of for the primary reduction?

with the primary drive chain and sprocket conversion you may want to keep the same sprocket outside diameter as the stock belt drive to maintain the same reduction without having to use a huge sprocket at the rear wheel.. but since chain drive does not need as much chain wrap on the sprocket as belt drive then you could go down to ~13 tooth (420 chain) for the motor sprocket (don't go much smaller or it will wear faster) with a bit smaller diameter second sprocket..

This is true, I am guessing that Sur-Ron has some kind of Delron guide that protects the chain from grinding on the swingarm. Running a 12t or 11t would cut into that deeper causing accelerated wear.

No no no The small rear chain sprocket is on the swing arm pivot. It is a brilliant set up.

 

[Rix]

What size chain/sprockets are you thinking of for the primary reduction?

with the primary drive chain and sprocket conversion you may want to keep the same sprocket outside diameter as the stock belt drive to maintain the same reduction without having to use a huge sprocket at the rear wheel.. but since chain drive does not need as much chain wrap on the sprocket as belt drive then you could go down to ~13 tooth (420 chain) for the motor sprocket (don't go much smaller or it will wear faster) with a bit smaller diameter second sprocket..

This is true, I am guessing that Sur-Ron has some kind of Delron guide that protects the chain from grinding on the swingarm. Running a 12t or 11t would cut into that deeper causing accelerated wear.

No no no The small rear chain sprocket is on the swing arm pivot. It is a brilliant set up.

Yep, thats what Natas was saying.

 

[fechter]

It's hard to find a good picture of the swing arm pivot. From what I can tell, it seems the chain has plenty of clearance.






On the primary reduction, a 420 chain seems pretty big. I would think something more like a #35 go kart chain would be more like it.

 

[madin88]

On the primary reduction, a 420 chain seems pretty big. I would think something more like a #35 go kart chain would be more like it.

Yes such large chain would be overkill.
A 219 chain should work well too with it's high number of teeth (so lower wear).

I wonder what belt it is exactly? Seems lik 8mm pitch, but what kind would be interesting.
From Gates there are very good belts avilable like the Poly Chain GT Carbon which would be also a nice upgrade i believe without making it more noisy.
Also for regen (in the case if SurRon would add it one day) a 2-stage chain drive would not be optimal because of the slackness.

 

[efMX Trials Electric Freeride]

cart chain would probably work well with the stock power levels but what about increasing the power levels with higher voltage or controller upgrade.. how much power and torque are these cart chains rated for?? would you have to use mechanical sympathy or more frequent chain and sprocket wear replacement?? I know that 420 light weight motorcycle chain is good for up to ~20+hp..

with the jackshaft design the chain/ belt tension remains constant tight so that drivetrain slack should not be an issue with regen motor braking.. seems like that could be more of a possible issue with the belt drive by putting a lot of stress on the belt teeth for minimal efficiency gains.. I think that i remember seeing the stock belt type listed somewhere on the Sur-ron website.. can't remember exactly what it was but it wasn't a Gates belt..

On the primary reduction, a 420 chain seems pretty big. I would think something more like a #35 go kart chain would be more like it.

Yes such large chain would be overkill.
A 219 chain should work well too with it's high number of teeth (so lower wear).

I wonder what belt it is exactly? Seems lik 8mm pitch, but what kind would be interesting.
From Gates there are very good belts avilable like the Poly Chain GT Carbon which would be also a nice upgrade i believe without making it more noisy.
Also for regen (in the case if SurRon would add it one day) a 2-stage chain drive would not be optimal because of the slackness.

 

[DanGT86]

219 is used in 125cc 2stroke kart racing. It should be good for 50hp if the rpm is high enough. Its ideal for a primary reduction.

 

[madin88]

with the jackshaft design the chain/ belt tension remains constant tight so that drivetrain slack should not be an issue with regen motor braking.. seems like that could be more of a possible issue with the belt drive by putting a lot of stress on the belt teeth for minimal efficiency gains.. I think that i remember seeing the stock belt type listed somewhere on the Sur-ron website.. can't remember exactly what it was but it wasn't a Gates belt..

I believe i have read somewhere that it is "8m HTD" profile.
The Gates Polychain should be at least twice as capeable from what i know, but it has a different teeth profile so it isn't compatible.

Regarding regenerative braking i think a belt drive would be the optimum, but it has it's downsides when riding in dirt and gravel.
With a chain there will be always a little slack if the direction of the torque is alternating, while a modern carbon belt should be smooth as a hubdrive

219 is used in 125cc 2stroke kart racing. It should be good for 50hp if the rpm is high enough. Its ideal for a primary reduction.

+1

 

[Marksteamnz]

So If you loose one of the keys of the pair that Sur-Ron provide and want to get another one cut, what blank does the locksmith use?
I figure others might want to know.

"So whats it orf mate, I need to look it up in the book"

 

[Fieldmatt8]

Hello Sur Ron owners. I just received my bike from Luna cycles yesterday the grey 60v and it seems to have shipped with the Killah RST fork. Seems decent but I’m a big guy at 6’1 220lbs. I thought I read that all the bikes were now shipping with the race ace forks. Any input or thoughts would be greatly appreciated.

Matt

 

[RemoteRoad]

Hello Sur Ron owners. I just received my bike from Luna cycles yesterday the grey 60v and it seems to have shipped with the Killah RST fork. Seems decent but I’m a big guy at 6’1 220lbs. I thought I read that all the bikes were now shipping with the race ace forks. Any input or thoughts would be greatly appreciated.

Matt

When inquiring about FF options, I was told all Luna's bikes were ordered with FastAce forks. Mine arrived yesterday so equipped.

 

[jph3]

Hello Sur Ron owners. I just received my bike from Luna cycles yesterday the grey 60v and it seems to have shipped with the Killah RST fork. Seems decent but I’m a big guy at 6’1 220lbs. I thought I read that all the bikes were now shipping with the race ace forks. Any input or thoughts would be greatly appreciated.

Matt

That’s concerning. You speak with anyone over there? Or what’s your plan?

 

[Rix]

Hello Sur Ron owners. I just received my bike from Luna cycles yesterday the grey 60v and it seems to have shipped with the Killah RST fork. Seems decent but I’m a big guy at 6’1 220lbs. I thought I read that all the bikes were now shipping with the race ace forks. Any input or thoughts would be greatly appreciated.

Matt

When I ordered mine, there was the option to select the fast ace or the RST. The RST was auto populated. I selected the Fast Ace and thats what arrived.

 

[RemoteRoad]

Mine seems rather loud. Asked some observers and got mixed feedback. What serial/bike #s did you recent receivers pull (headset area)? Mine ends in 1065.

 

[Rix]

Mine seems rather loud. Asked some observers and got mixed feedback. What serial/bike #s did you recent receivers pull (headset area)? Mine ends in 1065.

Mine was loud as well, however, the chain was banjo string tight. I loosened and its just a tad quieter. That said, there is no way getting around the mechanical noise of a mid drive.

On another note, I am trying to dial in my suspension. Got the rear dialed pretty good. I really should re spring it with a 500# coil for my bodyweight, however, I got ball park with turning the spanner preload compression ring to down 1/3 on the shock tower, shock compression settings are 4 turns out from all the way stiff, and the rebound was left stock from factory setting. Its still a tad soft, by I will work as long as I am not dropping off or landing air from more than 4 feet high or so. Now moving on to the fork, on the left fork leg, I got a schrader air valve on the top, and bottom of the fork. the right fork leg has settings for rebound speed. So through my initial observations, I have determined that the fastace forks on these machines are a "separate function fork" design, not that dissimilar from the 2012 KXF250F. I have no experience with separate function forks so my question is, are the schrader valves used for suspension set up, or are they used for bleeding the forks when air PSI increased due to hot weather and hard moto sessions? My internet researched has yielded negative results for guidance on the issue.

 

[RemoteRoad]

Mine was loud as well, however, the chain was banjo string tight.

Ah, awesome, mine is too. I'll set it looser when I install this pedal kit, which will require me to lengthen the chain. Luna was meant to install it but didn't.

I could use a guide to the FastAce FF too. This is my first motorbike, or even full suspension bike, so the rear shock eludes me a bit as well. I want to set it to be softer and slightly lower. Want to accomplish the same with the FF.

 

[dirkdiggler]

Got new bars installed. I went with the Answer protaper 810 with 3" rise. Now the bike is perfect for me.
Only issue, was I pulled a wire putting on the brakes. I am unaware of how the electric brakes work on this. I noticed that the grub screws weren't tightened all the way on the brake wires. The bike doesn't move with them tightened. Any one else know how they are set-up? If I have the wires loose the bike works.

 

[jph3]

Got new bars installed. I went with the Answer protaper 810 with 3" rise. Now the bike is perfect for me.

What fender are you running? Looks good imo.

 

[stonezone]

Got new bars installed. I went with the Answer protaper 810 with 3" rise. Now the bike is perfect for me.
Only issue, was I pulled a wire putting on the brakes. I am unaware of how the electric brakes work on this. I noticed that the grub screws weren't tightened all the way on the brake wires. The bike doesn't move with them tightened. Any one else know how they are set-up? If I have the wires loose the bike works.

https://www.sur-ronusa.com/changes-for-the-better

 

[Aebrennan]

You can find the manual for the Fastace forks on the www.aebikes.com.au website under downloads.
Do not attempt to add air pressure to the forks without reading the manual first, you may do a Hyena.

If you remove the key switch surround, you can unplug the brake sensor cables and prevent unwanted brake cut/safety when using the throttle. I have removed them completely on 2 of my bikes.

Out of the box the chains (Choho brand) are poorly lubed, a good clean a proper MX chain lube will get a quiter chain instantly.

Hope this helps a few new owners.

 

[Aebrennan]

Here are some pics of the newly fitted primary drive chain conversion, 13-30T sprockets.