SURRON LB: RESEARCH & DEVELOPEMENT

[thoroughbred]

I have an ancient Sheldon lathe to make spacers etc. I should have specified my riding ; its all trails and stuff like a harescrambles course. Rocks, roots, ledges, edges and the occasional log.

How much travel does the rear wheel actually have? Its tough to estimate just by looking at the bike.

 

[efMX Trials Electric Freeride]

you could certainly improve on the stock suspension with tuning or an aftermarket coil dh fork such as fox etc but for trail riding, mx suspension would just be more weight and under utilized imo.. for bigger jumps I would try a small mx fork (but then the frame may break instead).. also the bike in the race was completely stock? and probably didn't bother tuning the suspension specific to the rider and course.. and air suspension is not as plush as coil and inconsistent under hard use due to heat affects on an air spring..

 

[thoroughbred]

Yes I obviously need to put some miles on the bike and learn about mountainbike suspension capabilities and tuning. Its very possible that youth mx suspension is inappropriate.

The bike in the race video had the rock shock debonair forks which Luna touts as a $1500 upgrade. Thats twice what I paid for my crf so I'm getting sticker shock in considering upgraded mountainbike suspension... Same bike shown here:
https://www.youtube.com/watch?v=AqxTokziqNg

I'll start by taking the forks off the honda to see what will be required to adapt the triple clamp onto the Sur Ron.

 

[fechter]

How much travel does the rear wheel actually have? Its tough to estimate just by looking at the bike.

Spec is 200 mm.

 

[Grantmac]

Lowering and raising links are common in the motorcycle world and usually inexpensive. Lowering generally reduces effective spring weight, so raising would have an added benefit there.
I don't have a Sur-Ron so no idea how feasible that is.

CRF150RB forks shouldn't be that much heavier and certainly might be worth a look if a person is also adding weight via batteries etc. Plus you get a whole lot more front brake.

Bicycle forks, no matter what their spec, are really on the limits in this application.

Edit:
If I had a 150RB chassis I'd just convert it to electric rather than trying to stick the pieces on a Sur-Ron. Those are the best "mini" chassis made and a lot of adults have used them.
The QS3000 motor is about perfect direct drive with that wheel size.

 

[pipeking]

Bicycle forks, no matter what their spec, are really on the limits in this application.

I'm not sure what your application is, I looked back and only found some talk about a video doing the rounds of some guy with rokshoks on a hare scramble but here's my thoughts:

1. like that other guy said, the rake will be way off, this will mess up your geometry and also increases the risk of snapping the headset off the frame on a big bottom out.

2. Like you pointed out, there are guys who are using fox40s etc already and having zero issues with these doing some fairly big jumps and getting upside down

3. Cost vs practicality vs getting real... how big are you planning to go on this thing?

Have a look at the Alta Redshift instead, that things a beast.

 

[pipeking]

Hey what do you guys know about these asi controllers ??

 

[thoroughbred]

Yes I was talking about the harescrambles application where you get constant rocks, ledges, edges, roots and logs. A couple more inches of properly valved travel might allow you to plow through more of this stuff more plushly without getting jarred and worn out over a couple of hours. Not talking about huge mx jumps where the bike can be broken in half.

I'm doing my first serious offroad ride today with all my regular dirtbike buddies so I'll know more about the need for any upgrade.

The crf150r steering stem turns out to be thinner and longer than the Sur Ron stem so the transplant should be pretty easy with some shims and spacers. Steering lock issues might be problematic

 

[skyungjae]

Hey what do you guys know about these asi controllers ??

They're great, but there's a long wait if you want the ERT plug and play version. I don't think you can even make orders at the moment due to the back order on ASI's end as well as Alan (ERT) catching up on getting current orders to customers.

I think it's well worth the wait if you do plan on upgrading the battery.

 

[Grantmac]

Smooth well designed jump tracks aren't the same kind of workout for suspension as slamming through a pile of roots or rocks in a harescramble.

DH bikes have more suspension than a freeride or park bike not because of the jumps but because of the rock gardens etc. Similar situation.

 

[thoroughbred]

My offroad research this weekend leads me to believe that an increased rake angle for this bike might actually be a good thing in some scenarios.

Very steep downhills were hairy as this is a small bike and it was difficult as a tall rider to get far enough rearward. It might also increase stability through chatter bumps and stones where I found the bike to be a bit too twitchy and harsh.

 

[pipeking]

Hey what do you guys know about these asi controllers ??

They're great, but there's a long wait if you want the ERT plug and play version. I don't think you can even make orders at the moment due to the back order on ASI's end as well as Alan (ERT) catching up on getting current orders to customers.

I think it's well worth the wait if you do plan on upgrading the battery.

Do you have any links to who has them, or will have them, please? Yea would like to upgrade battery too more power and range please haha

Yes I was talking about the harescrambles application where you get constant rocks, ledges, edges, roots and logs. A couple more inches of properly valved travel might allow you to plow through more of this stuff more plushly without getting jarred and worn out over a couple of hours. Not talking about huge mx jumps where the bike can be broken in half.

I'm doing my first serious offroad ride today with all my regular dirtbike buddies so I'll know more about the need for any upgrade.

The crf150r steering stem turns out to be thinner and longer than the Sur Ron stem so the transplant should be pretty easy with some shims and spacers. Steering lock issues might be problematic

what fork do you have on your bike now? I hope to god you don't have the 'do not moves' any fork will be better than those pos things...

 

[pipeking]

What was he doing when it broke?

I was jumping mate, 3/4ft

We'll see if anyone else manages to break one. It's possible yours had some kind of material defect. Also if the shock isn't dialed in right, it may have bottomed out causing a sharp spike in the forces. From what I can tell, the part is forged, so should be even stronger than a part that's just CNC machined from a billet.

I have a lot of play in the linkage on mine now, I am looking to replace the bearings soon, has anyone else noticed this yet?

 

[pipeking]

onto my new Sur Ron with the DNM forks. Same 19 inch wheel but more travel, weight and brakes. is this a waste of time and effort? I have not ridden my bike much to know if the forks even need upgrading but I am coming at this as a dirtbike rider rather than a bicycle rider.

oh sorry I just read this.

Look bro, take that crappy DNM (yes it stands for DO NOT MOVE for a reason) fork off your lovely bike and put anything, I mean anything on it other than that fork!

Honest, a nice pair of second hand Fox 40s will be all you need, get a new rear shock too an RC2 or something and trust me that thing is gonna feel like a new bike :lol: I had the dnm at first too...they caused me so much pain, the front would wash out on anything, I come from a mx background but I also ride DH

 

[thoroughbred]

onto my new Sur Ron with the DNM forks. Same 19 inch wheel but more travel, weight and brakes. is this a waste of time and effort? I have not ridden my bike much to know if the forks even need upgrading but I am coming at this as a dirtbike rider rather than a bicycle rider.

oh sorry I just read this.

Look bro, take that crappy DNM (yes it stands for DO NOT MOVE for a reason) fork off your lovely bike and put anything, I mean anything on it other than that fork!

Honest, a nice pair of second hand Fox 40s will be all you need, get a new rear shock too an RC2 or something and trust me that thing is gonna feel like a new bike :lol: I had the dnm at first too...they caused me so much pain, the front would wash out on anything, I come from a mx background but I also ride DH

I don't have any Fox 40 s at the moment but I do have some Showa 37 s

 

[Merlin]

nice handlebar height now....
how is the handling :lol:

 

[Grantmac]

Have you verified wheel clearance at full compression?

Definitely time to think of a raising link.

 

[pipeking]

onto my new Sur Ron with the DNM forks. Same 19 inch wheel but more travel, weight and brakes. is this a waste of time and effort? I have not ridden my bike much to know if the forks even need upgrading but I am coming at this as a dirtbike rider rather than a bicycle rider.

oh sorry I just read this.

Look bro, take that crappy DNM (yes it stands for DO NOT MOVE for a reason) fork off your lovely bike and put anything, I mean anything on it other than that fork!

Honest, a nice pair of second hand Fox 40s will be all you need, get a new rear shock too an RC2 or something and trust me that thing is gonna feel like a new bike :lol: I had the dnm at first too...they caused me so much pain, the front would wash out on anything, I come from a mx background but I also ride DH

I don't have any Fox 40 s at the moment but I do have some Showa 37 s

Hmm does the Showa only have 37mm stanchions? :?

You realise the 40s have 40mm stanchions right? And that USD forks flex WAY more than conventional forks do...

and that the valving in that Showa fork will be set up for a 100kg dry weight bike such as the CRF150... as others have pointed out the obvious geometry issues but how about centre of weight? The stock sur ron is perfectly balanced and you can feel this in the air too, its easy to flick around...

The extra weight alone would be the main reason I wouldn't attempt what you have done, I want to go faster on my sur ron so I have taken any and all extra weight off mine... no stand, headlight, tilt sensor (god I hope you pulled this off if your racing it!) I would love to see a weight comparison of fork, bars, headset, wheel, tyre and brakes.. I think you would be surprised!

Na, I'm sorry but I really thing your barking up the wrong tree, guys are upsizing the front wheel to 29" for handling purposes and getting good results with a good fork like the Fox... I understand if you don't want to shell out for a new fork but that franken bike will be problem after problem in my honest opinion.

 

[thoroughbred]

I'm just doing some Sur Ron R&D here, nothing is irreversible.

15 pounds heavier
rake goes from 24 degrees to 27
wheelbase increased from 49 inches to 50

Riding it feels pretty good initially. Cockpit ergonomics improved significantly for the stand-up style I prefer. I can feel the weight difference but all the changes listed above contribute to decreased twitchiness. Brakes feel stronger. I'll ride and tweak it for a little while before I declare boom or bust.

 

[smdub]

Does anyone know the name/style of small connectors that Sur-Ron uses? Looking to mod the throttle box but can't find the stock 3-way triangular connectors.

 

[Rix]

nice handlebar height now....
how is the handling :lol:

One things for sure, its probably very comfortable standing up on the pegs now. :thumb: :lol:

 

[thoroughbred]

nice handlebar height now....
how is the handling :lol:

One things for sure, its probably very comfortable standing up on the pegs now. :thumb: :lol:

Good news Bad news.

The forks work really well. The bike felt much more like a normal dirtbike to me and was very confidence inspiring today. The tall handlebars are so much nicer for the way I ride. I could hold a straight line over all the roots much better.

The front end now makes the rear feel really weak. The front was floating over stuff that was hammering the rear. I was running 20 psi and I pinch flatted after only a mile and a half. :x

When I switched back to my normal bike, I could no longer keep my buddies in sight so its possible I was faster on the not-so-light bee

 

[Grantmac]

There are limits to what a bicycle rim can handle on a heavy bike.
Oset wheels should fit easily, or else just lace on a 19" MC rim.

 

[efMX Trials Electric Freeride]

SR LB has 19" 1.4 moto rims stock.. I would do a tubeless conversion plus rim lock on the rear tire..

 

[Grantmac]

SR LB has 19" 1.4 moto rims stock.. I would do a tubeless conversion plus rim lock on the rear tire..

Do they indeed? Seems like a tube and tire issue, plus as he says the rear suspension is perhaps beyond its limitations.