Sur-Ron - New Mid drive Bike

Adding to what Natas said, an 18 MC rim, even if its a 1.85 x 18 is rim, is way bigger than the standard 1.4 or 1.6 wide 19 inch rims in terms of weight. In this picture of Bomber 143, I have an 18 x 1.85 rim on the rear with a 19x1.4 rim up front. I am running a 2.75-19 SR241 shinko on the front and a 3.00-18 SR241 shinko on the rear. No doubt this tire combo will work with the SurRon, but I don't we can go wider than a 3.50-18 SR241 on the rear.

Offroader said:

Uran93 said:

Offroader said:

You really would need nothing else to install the fox fork other than head tube spacers if you reuse the sur-ron headset. You would have to remove the crown race from your old fork, you would have to be careful, using a razor blade to start it and then slowly wedge larger stuff in there to lift it. Don't knock it out with a screw driver and hammer or you will bend it.

You could use a screw driver to wedge in the space under the crown race to help lift it after using a knocked in razor blade to start it.

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Honestly, I haven't understood anything you wrote in this paragraph. Could you or anybody explain or put in some pictures please?
You just scared me))

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When changing your front fork you will have to deal with the headset. The Sur-Ron headset is a cheap one and has many parts. It also seems to get damaged easily and parts of it bent. Take a look at some of the pictures of the Sur-Ron headset.

Then you will have to remove the crown race carefully from your RST Killah fork and install it on your Fox fork. Care needs to be taken to remove this and probably best to start with a razor blade and knock it in with a hammer to give you enough space to carefully knock in a flat head screw driver to slowly pry it off the fork. Then you need to knock it back down flat on your FOX fork. If you damage it, like if you knock it up with a screw driver at the end of the crown race and bend it like they show on some you tube videos you will have to buy another one. Good luck finding a Sur-Ron crown race, then you will need to install a hope or Cane creek new headset.

Here is the stock Sur Ron headset. Complete garbage but it works, look how many pieces it is. Take careful attention how it comes apart because you will have to remember how it goes back together.

You can see the Sur-Ron Crown Race installed at the very bottom and the bearing is sitting above it.

The Sur-Ron Crown Race removed from the fork, you will have to carefully remove this from your RST Killah Fork using a razor to start it and then knock something a little thicker in to carefully lift it up. You can see mine is dented on the edge from trying to knock it up with a hammer and screw driver from its edges. I didn't care about mine since I bought a new Cane Creek 40 headset. You can use a hammer and screw driver but only to wedge it in under the crown race after you slightly lifted it with knocking in a razor blade to start it.

Just for an example, here is a cane creek 40 crown race installed. You can see its pushed all the way down on the fork and its difficult to lift it up. The only way to get it started to remove it is to use a hammer and knock in a razor blade. Then after lifting it up slightly with a razor blade, knock in something slightly larger like a flat head screw driver to slowly lift it. Make sure to alternate sides while lifting it.

If you want to use another headset, like the cane creek 40. You will have to install headset cups. It is difficult to do without proper tools. If you use threaded rod and wood, which works, it takes a lot of force to get those headset cups pressed into the frame. The cups will go in uneven and you have to keep unloosening everything to try to get them to go in straight. A real difficult not fun job. If you had proper tools it probably would go a lot smoother but I didn't want to buy a head set press. You may just want to go to your local bike store for them to do it for you to be honest as they have the tools.

The cane creek 40 is nice and has a lot less pieces than the stock sur-ron headset. It has just a single sealed bearing.

Below I'm stalling my new cane creek 40 head set cups.

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Amazing! Thank you for very detailed instructions!!!

Joachim said:

Cant wait for a bigger battery and the belt drive kit
Building a 55Ah/3.1Kwh battery to have a good range in sport mode.
Next week i hope to instal the belt drive to make my surron silent.

55Ah wil give me60 to 70% extra range....60/70km in sport and 100/120km in ep mode ?

19P 10mmx0,2mm pure nickel so i can upgrade the controller later for extra power

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Great! Thank you for explanation! Please keep posting!!!

Rix said:

Adding to what Natas said, an 18 MC rim, even if its a 1.85 x 18 is rim, is way bigger than the standard 1.4 or 1.6 wide 19 inch rims in terms of weight. 18x19 Bomber.jpg In this picture of Bomber 143, I have an 18 x 1.85 rim on the rear with a 19x1.4 rim up front. I am running a 2.75-19 SR241 shinko on the front and a 3.00-18 SR241 shinko on the rear. No doubt this tire combo will work with the SurRon, but I don't we can go wider than a 3.50-18 SR241 on the rear.

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Thanks for the feedback guys!

Wow - I wouldn't have guessed that 18" rims are heavier than 19" rims.

I was really wanting a setup just like this (17" rear rim, 19" front):



The only problem with 17" is that the tire selection for 17" seems super limited - so I was thinking about 18" rear.

How much would it change the geometry by having an 18" rear (with 3.5" tire) and 19" front? I'm guessing the 17" rear with 19" (like in pic above) doesn't really change it?

And actually; I think I misunderstood Josh. Sounds like he recommending 19x1.85 rear rim and 21" front. How much would that alter geometry? How much heavier than the stock?

An 18x1.85" MC rim running a 3.5 wide tire will have a slightly larger diameter than a 19x1.40" MC rim running a 2.75 wide tire. You dont want this, a 21MC rim and tire combo would be better and if your geometry is a little too slack, you can drop the fork tubes a little in the triple clamps to off set that.

3DTOPO said:

Rix said:

Adding to what Natas said, an 18 MC rim, even if its a 1.85 x 18 is rim, is way bigger than the standard 1.4 or 1.6 wide 19 inch rims in terms of weight. 18x19 Bomber.jpg In this picture of Bomber 143, I have an 18 x 1.85 rim on the rear with a 19x1.4 rim up front. I am running a 2.75-19 SR241 shinko on the front and a 3.00-18 SR241 shinko on the rear. No doubt this tire combo will work with the SurRon, but I don't we can go wider than a 3.50-18 SR241 on the rear.

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Thanks for the feedback guys!

Wow - I wouldn't have guessed that 18" rims are heavier than 19" rims.

I was really wanting a setup just like this (17" rear rim, 19" front):

The only problem with 17" is that the tire selection for 17" seems super limited - so I was thinking about 18" rear.

How much would it change the geometry by having an 18" rear (with 3.5" tire) and 19" front? I'm guessing the 17" rear with 19" (like in pic above) doesn't really change it?

And actually; I think I misunderstood Josh. Sounds like he recommending 19x1.85 rear rim and 21" front. How much would that alter geometry? How much heavier than the stock?

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18" rear rim with 3.5 tire may not fit without trimming the tire side knobs, etc.. that's why they used 17" rim for the trials setup, to run 3.5 tire that fits without trimming.. have also seen ppl running heidenau 3.25 trials tire on the surron 19" rear rim..

Rix said:

An 18x1.85" MC rim running a 3.5 wide tire will have a slightly larger diameter than a 19x1.40" MC rim running a 2.75 wide tire. You dont want this, a 21MC rim and tire combo would be better and if your geometry is a little too slack, you can drop the fork tubes a little in the triple clamps to off set that.

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19x2.75 vs 18x3.5

=)

not really noticeable

sry for rotation of the pic. its the uploader. if you click this link in your browser it should be right aligned
http://185.25.48.125/es/LMX/zz.jpg



shinko 241 2.75/19 - 3.50/18 CST

btw:

iam running tubliss now and iam very very happy with it.
as advertised saving weight it maybe true for normal enduro/cross bikes.

for our lightweight setup it adds 500g on top. (normal moto tubes are 300-350g...tubliss 18" has 800g)

some guy posted here about wobbling not stable rides with low PSI.....
i cant follow that.... i have tubliss only on the rear, but cant imagine it can be that bad on the front.

my front is 26x3.0 bicycle tire and iam running only 1.3bar/19psi
my rear is 18x3.5 moto wheel and iam running only 1.0bar/14psi on street and 0,3bar/5psi offroad.

this gives you grip you dont believe if you dont tried by yourself it climbs like a goat on every terrain.
fluffy and plush like cotten candy over roots and bumps

switching from 19x1.4 - 2.75 Shinko SR241 (5.1Kg rear Wheel)
to 18x1.85 - 3.50 CST 755 (7.0Kg rear Wheel)

so it adds 1.9Kg to the rear. 205 Hub Guys would laugh about. i do either. i notice it only lifting the bike around.
while riding no difference to me in weight. even i would notice it, i wouldnt care because of the fluffy monster grippy ride now.

Pics with weights below. Have no Pic of the Shinko 2.75/19 but it was 2.8Kg.
the CST is easy to put on the rim. its not so hard as other tires.

including rock solid Excel Rim, Tire and tubliss system i think its a very good upgrade for me =)

full bike weight is now 46,5Kg fully charged
(sorry for LMX ing the Thread but its also usable for surron)

our surron has 56Kg Stock and we switched to Bicycle Front Wheel and saved 1.5Kg.

because the Range sucks we both use a 16s5p Range Extender of VTC6. (Backpack as always ~3.8Kg)
now we both can ride full 100km Street and 85Km all other conditions.

The Licence Plate holder cracked offroad.(sometimes hard terrain, but only my girl rides it-54kg)
It took some weeks to get exchange. As most parts in EU...."Not available" so our dealer send us
a new one from a bike he had in stock. (thx for this)

we think about doing also tubliss on the surron but not sure about right now because our bikes are in the living room and SHE must lift the bike 6 stairs above on every ride on every day. Remember she is 54Kg and the bike has also 54kg. he has worked out her own technic to get the job done.
sometimes after a hard ride i have to help her. but when she rides alone no one could help so adding 2 kg can be (heavy)important for her.

we will see =)

stock surron controller will be swapped for nucular or adaptto. i dont know if its only her controller stubbon like a horse or if this is normal that you get a 0/1 throttle on very low speeds. i rode an X Controller and its way better.
ASI4000 sounds also good but she dont need the power and i dont hear only good things about....time will show.

because the Range sucks we both use a 16s5p Range Extender of VTC6. (Backpack as always ~3.8Kg)

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Are you saying you carry around the battery in your backpack? Riding with anything heavy in a backpack really kills the ride experience for me. I rode to work today with my backpack and I could tell it threw everything off with the handling of the bike.

I guess some of the stuff I do really requires a lot of balance and a backpack that isn't even that heavy is enough to really throw you off balance. I assume you will get used to the added weight but it will never be as good as not having it.

i dont know where your limit is where "heavy" starts and i also dont know where you ride but i have 90% of time a backpack. some tools, something to drink, replacemnt tube, thin jacket. we ride offroad. not in front of civilisation or some stairs up/down in the city.
flat tire /defects means a loooong pita walk of shame back to the truck =)

the battery extender is 16s5p and it weights 3.8Kg only. MY GIRL HAS THE SAME *lol she is 54kg.
i agree, without a backpack you feel more free. But useless when you lost offroad.
i didnt see any enduro rider without a backpack. even the MTB dudes have same equipment on tours.
early times without qulbix,stealth,eeb etc we had normal DH Bikes with "not so easy" frames and it was normal using backpacks for the battery.
edit: look ego kits still have backpack
https://www.ego-kits.com/shop/double-ego2400-kopie/#master-egokit-2400W-batterie

do you know what the erzberg rodeo is? biggest hard enduro race on this planet. looks like balance of a backpack isnt that important.
really dude. i know you since years and we both rode that heavy fat ass hubs and we both know -now- that a 40lbs rear wheel is the baddest idea for offroad riding.

i will make some pics on the next tour. then you have something to see....not the trial...my riding buddy with his surron.
he has a 2nd STOCK SURRON BATTERY in his backpack + 2liters water + tools.

yea man ....THAT IS REALLY frocking SICK
and he rides both empty on a tour :lol:

Merlin said:

.my riding buddy with his surron.
he has a 2nd STOCK SURRON BATTERY in his backpack + 2liters water + tools.

yea man ....THAT IS REALLY frocking SICK
and he rides both empty on a tour :lol:

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Why he hates his body this much? :wink:

Did this backpack battery thing for 20000km with my bbs01 setup and im sick of it.
Even my tool bag is on the bike at my raptor now.

You wont notice it so much till you have back or shoulder problems, but i guess the young guns will do it anyways, like always.
Its not like extra body weight, its on your back.
Long term you WILL notice it, maybe for the weekend ride your body can compensate it, i commuted with this shitty setup.

Young guns.... Thank you so much. Made my day :lol:

Merlin this 16s5p extender sounds like a decent idea! 3.8kg isn't "that" bad, beats carrying a spare battery by a lot.
Got any pics on how the thing and its cabling looks like?

ziltoid81 said:

Long term you WILL notice it, maybe for the weekend ride your body can compensate it, i commuted with this shitty setup.

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How many cells pack was it?

80 cells, even that was bothering me in the end, i cant imagine what it means to carry a whole sur ron pack period.
I noticed slowly increasing shoulder and back pain.
Its not just the battery, on top you add your normal stuff.

ziltoid81 said:

80 cells, even that was bothering me in the end, i cant imagine what it means to carry a whole sur ron pack period.
I noticed slowly increasing shoulder and back pain.
Its not just the battery, on top you add your normal stuff.

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From my research, it is 20% item weight and 80% how it is worn. Similar to a perfect saddle being a PITA even if you get it a few degrees wrong.
I am building a 80 pack and got a backpack like this.


From the reviews they say it has a 3kg water capacity and it dissapears when riding because the pack is on your hips and not on your shoulders. The shoulders serve as a balancing point.
I do plan on alternating between wearing it and not, and I carry no gear in addition to the battery.

I can't imagine riding with that much weight in a backpack.

This has worked out extremely well so far. 2X range and power:

fechter said:

I can't imagine riding with that much weight in a backpack.

This has worked out extremely well so far. 2X range and power:

Img_1147A.jpg

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Yea the sur ron battery is about 11kg... It is torture.

Duncan75 said:

Merlin this 16s5p extender sounds like a decent idea! 3.8kg isn't "that" bad, beats carrying a spare battery by a lot.
Got any pics on how the thing and its cabling looks like?

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yea on a normal ride stock battery gives me only ~50km offroad. at 40km sometimes eco mode kicks allready in. then you cant climb anything and fun is lost. with this extender you can ride another 22-25km. thats the juice i need to completly forget about battery. (on street with normal (real) speed around 50kph we reach 100km.

its 2 x 8s5p battery in series w/o BMS. i use it only on tour and have a junsi RC charger. so i can balance charge the pack.
even without a bms i didnt see a problem. if something goes wrong you can throw it away

a pic while welding is here:
https://endless-sphere.com/forums/viewtopic.php?p=1472929#p1472929

somebody above allready talked about it. your backpack should fit.
i didnt agree that a backpack will damage your body in any way if your are normal healthy and use a fitting backpack.
all soldiers, trekking guys, mtb riders, hill climbing guys, 2 wheel commuter and even growing kids use a backpack for maybe 10 years visiting school.
well experienced trekking or artic expedition guys mostly between 40-50 years old, loving his sport/hobby and used backpacks some decades without shoulder or backpain.

i think backpain is the most illnes on the planet and if you ask a doc its mostly because we sit too much on our asses and have weak back muscular.
(iam still with everyone that a whole stock surron battery + water + tools is out of normal using riding offroad :lol: )

he is near 50, all beard an hair is grey or white, he is riding mtb, ebikes, surron of course and also 350 2 stroke KTM. looks like he is pretty healthy.
on a tour he just sits 10% of riding time and 90% standing while riding. slowly, technical up or down.

i sit as much as i can and stay as much as i need 50/50.

btw: wire comes out of the backpack on the right side under my right arm in front of my seat and goes inside left side frame.
doing this you have no wires swinging around and you can move in every way you like on the bike.
connectors simply XT90. wire inside fixed with zip ties. in a crash wire disconnects easy. (twice done)
no Problems at all.

i do pretty much everything with my bike(s)...riding to work, going out with my dogs, shopping food...all with a backpack. if i need more, i ride twice =) i like to ride and my car sometimes stays in the garage for weeks/months. (except of driving to offroad spots with a van)

fechter said:

I can't imagine riding with that much weight in a backpack.

This has worked out extremely well so far. 2X range and power:

Img_1147A.jpg

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i saw this. and it is very nice. perfect for street riding/commuting.
but offroad on step terrain(downhill) my ass moves and hits the rear fender. i dont know if the cases on both sides allow those movements.

also when a narrow trial ends unexpected(too big trees or simply not rideable) the common "turn-around" is flip the frontwheel 180 degree straight up, slide to the rear with one or both legs to switch direction 180° on the spot you are standing. i dont know how to explain.
will search a video.

edit:

found it. "pivot turn"

@22 seconds
https://youtu.be/o_hYZQRxLuk?t=23

[youtube]o_hYZQRxLuk[/youtube]

Merlin said:

i saw this. and it is very nice. perfect for street riding/commuting.
but offroad on step terrain(downhill) my ass moves and hits the rear fender. i dont know if the cases on both sides allow those movements.

also when a narrow trial ends unexpected(too big trees or simply not rideable) the common "turn-around" is flip the frontwheel 180 degree straight up, slide to the rear with one or both legs to switch direction 180° on the spot you are standing. i dont know how to explain.

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Yes, my setup is great for street riding and mild off road but not good for those radical maneuvers, jumping, etc. The rear part of the frame is pretty sturdy and can probably handle the weight of the extra battery well enough. I was also looking at something that resembles a pair of Shark batteries, one on each side. You could possibly get them much closer together and not stick out so far.

Another thing I looked at was to make a seat riser battery that just goes between the frame and the seat and raises the seat by a 18650 or so. I have long legs so raising the seat would be good.

Those rear batteries really aren't much difference to the exhaust cans on a gas bike. Not enough to really impact movement.

A "long ride" seat would also be a very good idea. It's one I'm looking to implement on my next bicycle build.
The width of the Sur-Ron in front of your knees is fairly narrow compared to a gas bike as well.

3DTOPO said:

And actually; I think I misunderstood Josh. Sounds like he recommending 19x1.85 rear rim and 21" front. How much would that alter geometry? How much heavier than the stock?

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What 21" tire will clear the factory RTS fork?

good question but 21" frontwheels will add serious weight to your bike and handling.
at least i think 3Kg more to the Stock Wheel or nearly 5Kg if you dont go the Bicycle 26" way.

Need a little help please...can anyone tell me how many teeth are on the front and rear of the belt drive and how many teeth are on the front of the chain drive side?

I want to calculate the overall reduction for various rear sprockets and need the tooth count for the other sprockets to do so.

Why....well I want to see how much overall reduction is possible with a 60 tooth rear sprocket and compare it to the BBSHD.

Thank You Thank You