Sur-Ron mechanical troubleshooting, repairs, adjustments, tips & tricks

[Sebz]

Picking the right front fender for your Sur-ron

The surRon comes with the RST fork or the DNM/fastace inverted forks.

For the RST you can use any mountain bike fender you like, under the cross brace or under the front crown

But if you go for a "under the front crown type" you will need to check if that the cross brace clears the fender when it's fully compressed or you will break it right away,

Picture below is a Topeak Defender FX fender kit, it clears the cross brace fine and installs in minutes.



If you dont like that style you can go for the "under the cross brace type"

like this one from Mark K, he used a Mudhugger Long Front Fender



Here is an installation video on modding mx fender for rst

If you have the inverted type you cannot use a over the tire fender because you don't have a cross -brace, so you will need a fender that is fixed under the lower crown like the Topeak shown. Since you don't have to worry about the cross brace hitting the fender you can use any mini-motocross fender you like but you will likely have to fabricate a mounting plate.

Picture is a Topeak defender on the RST fork, but can be fitted on the inverted forks.



Another option: topeak defender xc1

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DNM Fork users ONLY:

We have stocked this fender which will work and is a more ideal solution than the topeak defender fork:

https://lunacycle.com/sur-ron-x-front-fender/

[Jasdidit]

How to remove the seat from a Sur-Ron

These are the tools you will need.


































Here is my method for popping off the plastic button-head "rivets".

































Here is a picture of the expanding bit, once the button-head is removed.

































Here are both parts of the plastic "rivets", only slightly worse for wear.

































Here is the whole "rivet". You can see how pushing in the pin, expands the inside to hold it in place.

































There are three on each side and two in the front, see below.



Once you get all of those out, the plastic cover just drops down. Then you need to unplug or unbolt the brake light, see above. There are only 4 bolts holding the seat on, but the rear fender bit needs to pushed towards the front of the bike to release it, so the seat can be removed. See below.

























Don't forget the fender bit when you put it back on! It actually goes on after the seat, but before the installation nuts.

[paxtana]

How to change or adjust Sur-Ron primary belt

The following video explains how to replace the main belt. In the video you see a 4 pin socket to remove the mid axle nut, while it's a good idea to get that tool (hint AliExpress ) you can still remove that nut without. I use a long nose plier and fit the tips into 2 notches not turning but just holding that nut while I turn the axle on the left side of the bike!

Now if you want to just adjust the tension, you will have to loosen up the motor (no need to remove the bash guard). Watch the same video at the 37 sec mark, up to 1:01 mark. Skip to the 4:44 mark to adjust the tension on the belt and you're done! The belt should be tight, like if you pinch in right down in the middle (between the 2 pulley) you should not get more than1/8" deflection on each side... Too loose and you will strip the teeth eventually, there is a lot of misinformation out there about riding with a loose belt.

This is another video found on Youtube that you might find helpful, we have no relation to this YT channel, we just though it would be helpful.

[paxtana]

Sur-Ron pedal system

Please read the following if you consider to use the pedal kit.
Sur-Ron made the pedal kit (unbelievable but yes) and it is only a compliance kit, it is not made by any means to be ridden off-road or made to actually pedal the bike on leg power alone for a long distance (or even short distance). It's only goal is to be able to use your Sur-ron on the street (check with you local DMV and such for compliance), and the other purpose is have something to put your feet on them! Let's face it, they are not high quality, bearings are rough, cranks arms are soft, pedal are basic, it may need to be adjusted after a few rides. If definitely needs to be grease and adjusted and will require some modifications to be used off-road. But you can make them A LOT better with simple modifications (things that Sur-Ron should have done from the start).

Yes the freewheel can wobble if you pedal along.. but remember you can't really pedal along if you ride past 5mph anyways... If you do not pedal along the freewheel does not wobble at all. If the wobble bothers you, you may fine tune it to get rid of the wobble and it only takes a few minutes to do. Possibly, you will have to fine tune it again every couple rides if you want it to stay perfect. We have a video on how to adjust it. But warning, we will not replace your bike because the freewheel wobbles or because it's a little rough or not on part with the high quality of the bike. IF you wants to have a real pedal bike were you can go 20mph using your leg I highly recommend you to check the Luna X1! But again that being said, the Sur-Ron is a blast and the pedal kit can be very VERY useful and they can be tuned to work a lot better.

The structure (bottom bracket, mount and spindle) is solid so all you need is better pedals and crank arms to replace these weak links. To make them smoother you can replace the bearing and outside cups and add grease and block the hole in the middle (they use bearings for 3/Piece older style bottom bracket 1.37x24tpi)

For install video see this video

How to fix the freewheel/sprocket wobble :

Also another video on how to adjust the bearing cup to get less spindle wobble :

This covers full rebuild, reassembly and typical pitfalls / solutions.

[paxtana]

Aftermarket cranks for the Sur-Ron pedal system


These cranks are lightweight aluminum with a good offset.
These will fit but they are about half an inch longer than stock, and you may need to move the kickstand a bit back to clear the cranks.



The alternative is the Monty crank arm
https://www.trial-bikes.com/en/monty...-p-537969.html

(update: both these sources are sold out, this crank may also work)

Support notes: these links come from our customers, we have no affiliation with these vendors or tested the products.

[Senor_Martillo]

Removing kickstand cutoff sensor: Since this sensor is very exposed to damage and water intrusion, it can interrupt motor function with the slightest amount of damage (happened to me after riding through a 6" deep puddle) Fortunately its easy to remove:

Step 1: remove bash guard/skid plate
Step 2: cut away rubber/vinyl boot surround wire connectors
Step 3: unplug connector that runs back to kickstand sensor
Step 4: Re-wrap wire connectors in shrink wrap or gorilla tape to protect from water intrusion, replace bash guard/skid plate

Step 5 (the most important step): Don't be a Joey and hurt yourself because you rode off with the kickstand down. You remember the dirtbike you had as a kid? It didn't have a kickstand safety cutoff, and now your Sur-Ron doesn't either.

[paxtana]

Moving the seat back
(for larger riders)



Bolt a strip of metal to the factory mounting points and bolt the seat 5.5” back on the strip of metal.

[Markk]

Aftermarket cranks for the Sur-Ron pedal system


These cranks are lightweight aluminum with a good offset.
Confirmed these will fit but they are about half an inch longer than stock.

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Unconfirmed but also possibly suitable from the specs:

These cranks are also aluminum, little less expensive.
These have not been confirmed yet, but are likely to work (no promises though)

The Jitsies did not work for me. I've written a post about what did work for my cranks:

https://sur-ron.markkitaoka.com/pedal-cranks/

[paxtana]

Thanks for the heads up Mark, I have edited this to point to your page instead :)

[paxtana]

Preliminary docs for installation of the belt kit

https://drive.google.com/file/d/1D5yNL8nVy_HzB0MAyko1Ee1IQtvXeNhM/view?usp=sharing

Backup link
https://docs.google.com/document/d/1...Ic/mobilebasic

[Sebz]

Sur-Ron Black Edition with the RockShox Boxxer 2019 RC fork with Debonair air spring technology.



Rest assured you have one of the best downhill fork that hit the market. Reviewers, blogs, magazines praise that new 2019 RockShox Boxxer series fork ....But it will need proper tuning to work fine on your Su-Ron...

So since your bike is not a 30lbs downhill bike but a 110lbs monster bike you will likely have to tune it like if you weighted 80lbs more.

Your Boxxer comes with the following adjustments:

• Charger 2 RC damper featuring low speed compression adjust
• DebonAir air spring offers a coil-like consistent feel throughout the travel (you will need a shock pump that goes over 150PSI)
• Optional Bottomless air tokens to prevent bottoming out for agressive riders.

So now what?

Open this manual, we edited the manual to reflect the options found on your fork model, please follow the guide step by step to tune your fork.

Tip: You have the right sag and the fork works perfect for most of your riding but bottoms out on drops and jumps? Adding more air pressure will change the sag and also affect the plushness of your fork... So maybe try to add some bottomless tokens to change the air spring rate when the fork compresses further than 50% travel.

[Sebz]

Adjusting / setting the headset and stem.

From the factory the headset will be tight but it's possible that it was not done perfectly so you need to inspect it before your first ride and every few rides.

Checking the headset for any play before each ride is highly recommended. Riding with a loose headset will result in a damaged headset, cracked frame or fork.

In this following video it shows you how to set it with a direct mounted stem but on your Sur-Ron you have a regular stem so just make sure to loosen the stem bolts too!

[Sebz]

Adding a voltage meter to your Sur-Ron,

Please click this link

[Sebz]

Removing the kickstand sensor

You will have to remove the bash guard and access the triangular 3 pin connector and unplug it.



If you are unsure how to remove the bash guard then watch the controller swap video here:

[Sebz]

Replacing the Ignition and battery lock

You will need a new ignition and lock kit, a philips head and flat head screwdriver a 4 and 6mm allen key and a 10mm socket wrench

Ignition:

Remove the 2x 4mm allen heads and lift the ignition and USB assembly from the top.

Use a small flat head screwdriver and press on the 2 tabs to release the ignition barrel, unplug the connector and swap the ignition barrel with the new one. The rest is pretty simple , no need to explain!

Battery lock

Remove the 2x 4mm Allen head on each sides

Remove the 2x 6mm allen head under the lock

Remove the philips head screw holding the 2 plastic part covering the lock assembly

Remove the 2X bolts with your 10mm socket wrench and swap the lock assembly and reinstall the cover back on (follow the steps in reverse)

[paxtana]

Aftermarket sprockets
This goes over what length chain you would need with a given sprocket size.

• 420 CHAIN WITH 1/2" PITCH (NO "O" RING) on the standard LightBee (LB)
• 420 GOLD CHAIN WITH 1/2" PITCH "O" RING on the LightBee "X" (LBX)
• WITH 48T RING REAR AND 14T FRONT YOU HAVE A 106 LINKS CHAIN

All the next measurements are for a 14T front ring

• 102 links 42T
• 106 links 48T
• 108 links 48T + pedal kit
• 108 links 52T
• 108 links 54T
• 112 links 58T
• 112 to 114 links for 60T
• 114 to 116 links for 64T

Chain are ALWAYS an even number, and this is the best way to count a chain: