Sur Ron - who's got one

[hawaiidirtrider]

3 hours ago, dentvet said:

I have not tried the 18 wheel modification but i would guess that adding an inch or two of additional sidewall at 5 psi is going to more than make up for added stress on the shock in terms of ride quality.

I have changed most things on mine and the last flaw is the rear's harshness over trail trash.  I'm up to about 150# but with 18 hp and 3kWh of battery.  150# is still another world in comparison to 250# so i will continue down this path.  I'm strictly DIY so I'm around $1500 in upgrades

Guys are talking about 0 pressure. I wonder how that is ...... later. I got enough projects with my regular dirt bikes..

[mr.skywalker]

11 hours ago, dentvet said:

I have not tried the 18 wheel modification but i would guess that adding an inch or two of additional sidewall at 5 psi is going to more than make up for added stress on the shock in terms of ride quality.

I have changed most things on mine and the last flaw is the rear's harshness over trail trash.  I'm up to about 150# but with 18 hp and 3kWh of battery.  150# is still another world in comparison to 250# so i will continue down this path.  I'm strictly DIY so I'm around $1500 in upgrades

I assume your response is addressing my posts. Im not denying the improvement of the larger wheels such as the improved traction, the larger sidewall for better shock absorption and flex, etc. I just think it could have the same benefit going to a 16" as you can get gummies, or just about any good mx based tire and a few enduro tires but you dont add a massive weight penalty. It seems to me like a good compromise.

As for riding conditions I have a feeling where I am has some of the worst mud anywhere in the world, one of our trails is 100% unrideable with any rain over 1/2" in a 24hr period as we have very slimmy clay type mud there. I think its pretty similar to Hawaii but you probably have more rock which is just another form of slippery so it makes sense there to go with more traction oriented setups. Ive started riding some other trails that have way more sand but I tried one hill there this weekend that still had that nasty slime and couldnt get past half way(big root in the middle) where a friend on a ktm 250 made it about 3/4 just because he could carry momentum better as the surron got stuck on the root and it was a really steep climb. I want to go back when its dry and see if its even possible then again with the 16" rear when its not ideal.

[mr.skywalker]

7 hours ago, hawaiidirtrider said:

Guys are talking about 0 pressure. I wonder how that is ...... later. I got enough projects with my regular dirt bikes..

Yea I wonder if its bc the bike is so light or are they running tubliss? One other benefit of the 21/18 wheels is that is an option 

[Woods_Rider]

A 16” to 18” side by side comparison would be very interesting. I would be concerned the 16” would want to go in and out of every little hole on the trail, kind of like a mini bike like a 110 tends to do. On the other hand, as mentioned, the 18” may eat up power on a bike that doesn’t have any to spare. 

Please keep us posted as you guys experiment. If I was normal height, I’d have a Light Bee X in the garage already. I may still get one, waiting to see if the Storm Bee or any other regular size e-dirt bikes ever hit the market. 

[dentvet]

maybe we can get the weights of the 16 inch tires, too. 

I measured sidewall heights in my shop.  The current 19 rear I have is 2.2 inches.  A 16 " rear is 2.5 inches.  An 18' is 3 inches sidewall

[hawaiidirtrider]

Local shop is prepared...

 

[NatetheNewbie]

On 10/29/2020 at 6:35 PM, dentvet said:

I have not tried the 18 wheel modification but i would guess that adding an inch or two of additional sidewall at 5 psi is going to more than make up for added stress on the shock in terms of ride quality.

I have changed most things on mine and the last flaw is the rear's harshness over trail trash.  I'm up to about 150# but with 18 hp and 3kWh of battery.  150# is still another world in comparison to 250# so i will continue down this path.  I'm strictly DIY so I'm around $1500 in upgrades

can you post up some details on your mods? I'm really curious about your battery and controller specs!

[hawaiidirtrider]

One more mod evolving. 
 

 

[hawaiidirtrider]

On 10/30/2020 at 3:22 AM, mr.skywalker said:

I assume your response is addressing my posts. Im not denying the improvement of the larger wheels such as the improved traction, the larger sidewall for better shock absorption and flex, etc. I just think it could have the same benefit going to a 16" as you can get gummies, or just about any good mx based tire and a few enduro tires but you dont add a massive weight penalty. It seems to me like a good compromise.

As for riding conditions I have a feeling where I am has some of the worst mud anywhere in the world, one of our trails is 100% unrideable with any rain over 1/2" in a 24hr period as we have very slimmy clay type mud there. I think its pretty similar to Hawaii but you probably have more rock which is just another form of slippery so it makes sense there to go with more traction oriented setups. Ive started riding some other trails that have way more sand but I tried one hill there this weekend that still had that nasty slime and couldnt get past half way(big root in the middle) where a friend on a ktm 250 made it about 3/4 just because he could carry momentum better as the surron got stuck on the root and it was a really steep climb. I want to go back when its dry and see if its even possible then again with the 16" rear when its not ideal.

Video? Always love some video 

[mr.skywalker]

32 minutes ago, hawaiidirtrider said:

Video? Always love some video 

Unfortunately my SD card had a formatting error that day so I didnt get any footage of it. I'll be sure to get some next attempt though

[mr.skywalker]

43 minutes ago, hawaiidirtrider said:

One more mod evolving. 
 

 

The seat is for sure something needed of moto riding but if you go with bigger battery you may have to get creative. I heard race spec sur ron was making one and Ive been pretty impressed by a few of his things. 

Edit: looks like he already has the seat on his site now.

Speaking of, for you Hawaii riders, may want to look into his 2wd setup lol

 

Edited November 3, 2020 by mr.skywalker

[hawaiidirtrider]

7 minutes ago, mr.skywalker said:

The seat is for sure something needed of moto riding but if you go with bigger battery you may have to get creative. I heard race spec sur ron was making one and Ive been pretty impressed by a few of his things. 

Edit: looks like he already has the seat on his site now.

Speaking of, for you Hawaii riders, may want to look into his 2wd setup lol

 

Thanks for the vid.. got lots of development all over the world. It’s a new thing. As far as all wheel drive? Christini just didn’t pick up like I thought it might locally. It had its issues in drive and how it worked turning too. Seems more still gravitated toward rear wheel drive after the initial hoopla of awd for dirtbikes. Im not confident on tech to make it work on a smaller scale for surrons. Maybe but I’ll watch and see. 

[mr.skywalker]

I think the Sur ron has better potential to use awd if someone with some real expertise in control systems gets a hold of it. Add a few wheel speed sensors(similar to ABS) and when it detects a certain amount of tire spin it sends power to the front wheel(this could be configurable by the rider for different conditions or preferences). It was funny bc I came across the 2wd kit after thinking to myself, the SR has mtb front wheel and they have front hub drives, why not add that to the front? and sure enough its in the works haha

I actually rode a Christini 450 after working on it for a friend about 2 months ago (just general maintenance as he just bought it). It was just so big and HEAVY(top heavy at that) and the fact that you have to manually switch was a bit of a hassle but not difficult. The big thing for me was working on it, I never would own one(except maybe the 2 stroke) bc it was impossible to work on anything with the shaft running over the carb and head. Its a very well engineered setup but its just too much weight penalty on an already heavy and outdated chassis.

Where I think the surron could actually be really easy if you could have one controller drive both motors then the only added weight for a basic system would be the front hub drive and it helps the SRs biggest down fall on climbs.

If you cant tell I'm a bit of engineering tinkerer. Comes from being a mechanical engineer that got hooked on trying new things on a FSAE team lol

[dentvet]

On 11/2/2020 at 1:26 PM, NatetheNewbie said:

can you post up some details on your mods? I'm really curious about your battery and controller specs!

I used a mobipus 200 amp controller and built a 60v 50a battery out of some bmw EV cells.  The controller keeps track of data and says it bursts over 16 kW which makes the bike climb very well compared to OEM.  Oem is a good enough bike unless you like hilly terrain

I have a couple of nucular controllers being shipped as we speak so I'm anxious to see if they are any better. 

I think the surron is light enough to make 2wd not that attractive.  I have a christini ktm which i love but its 100 pounds heavier so 2wd does come in handy at times

[mr.skywalker]

12 hours ago, dentvet said:

I think the surron is light enough to make 2wd not that attractive.  I have a christini ktm which i love but its 100 pounds heavier so 2wd does come in handy at times

I actually think its the opposite, the bike suffers for traction due to the light weight in nasty conditions. It maybe just the controller putting too much down right on applying throttle as I often find when I get stuck it helps to switch to EP just so it doesnt light up the rear wheel. In flowy terrain 2wd is not needed but in hard enduro setting I think it could be a real improvement. I dont think everyone would benefit form it but I think if it only adds about 10-15lbs it could be a worth while add on. Maybe if I get another I will play with making a 2wd version.

On another note my hub is finally supposed to arrive Thursday so by this weekend I should be able to get some spokes ordered.

Edited November 4, 2020 by mr.skywalker

[NatetheNewbie]

4 hours ago, mr.skywalker said:

I actually think its the opposite, the bike suffers for traction due to the light weight in nasty conditions. It maybe just the controller putting too much down right on applying throttle as I often find when I get stuck it helps to switch to EP just so it doesnt light up the rear wheel. In flowy terrain 2wd is not needed but in hard enduro setting I think it could be a real improvement. I dont think everyone would benefit form it but I think if it only adds about 10-15lbs it could be a worth while add on. Maybe if I get another I will play with making a 2wd version.

On another note my hub is finally supposed to arrive Thursday so by this weekend I should be able to get some spokes ordered.

One of the advantages that Alta Motors was experimenting with in the context of extreme enduro and mx was traction control and hill hold. The traction control possibilities on electric bikes are mind boggling, and a massive competitive advantage in hard enduro. Far more precise than is possible with ICE, and way less weight penalty than 2wd. 

But won't help you in truly sloppy conditions, where 2wd would rule, of course. 

[mr.skywalker]

1 minute ago, NatetheNewbie said:

One of the advantages that Alta Motors was experimenting with in the context of extreme enduro and mx was traction control and hill hold. The traction control possibilities on electric bikes are mind boggling, and a massive competitive advantage in hard enduro. Far more precise than is possible with ICE, and way less weight penalty than 2wd. 

But won't help you in truly sloppy conditions, where 2wd would rule, of course. 

Yea I think with the right people working on it you could have the best all terrain bike at the expense of a little weight with an electric bike(less weight penalty than a gas bike that needs all the drive components to the front) but I agree for normal conditions some contols for tract and hill assist etc is very easy to implement.

Have you seen the surron storm bee reviews? They have done just that, traction control, reverse etc. A bit heavy bike though as its looking close to 300lbs 

 

[NatetheNewbie]

looks like it has potential but that rear shock placement is..... strange. I know they have to fit a battery in but still. 

 

[mr.skywalker]

I thought the same but no reason it couldnt work as long as the kinematic ratios were designed right. They did good on the light bee so maybe they have good engineers(other than the suspension being at the limit of its valving)

[Turn,TheScrew]

That rear shock angle is wrong and I don't think you could ever make it work right. As it approaches full compression,  the spring rate is going to start decreasing. The spring will start to be at a mechanical disadvantage as soon as the shock is perpendicular to the swing arm. 

Unless there is some really fancy linkage we can't see, or perhaps the suspension travel just doesn't get to that bad zone.