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

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    Placing the dust cap on DNM fork

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    This black piece on the left is the dust cap. This goes into the other piece on the right. Use something plastic to push seal into place , and hold it firmly in place for about 30 seconds to allow the ribs to settle in place.


      Equipment to change from belt drive back to chain


        Programming Sur-Ron Controller,

        Support notes this only works if you have the X controller pre-installed. IF you bike came with the base controller and added the x controller later this will not work. Please note it is not promised or guaranteed that all X controllers have this capability, but if you want to give it a try, go for it!

        Note the factory bike comes programmed at level 3 (which is max regen)

        Level 1 regenerative coasting = 2 short brake pull, 1 long
        Level 2 regenerative coasting = 3 short brake pull, 1 long
        Level 3 regenerative coasting = 4 short brake pull, 1 long
        Turning off the regenerative coasting = 7 short brake lever pull
        Turning off the e-brake sensors = 8 short brake lever pull
        Turning ON the e-brake sensors = 9 short brake lever pull and 1 long
        Last edited by paxtana; 11-30-2020, 09:54 AM.


          Aftermarket Sur-Ron forks

          Stock forks are fine for normal riding but for the hard core motocross rider you may find the stock fork a bit soft and hard to tune to you pro riding style ;)

          The Stock Sur-ron uses a standard downhill (DH) mountain bike forks (called double crown or triple tree forks) 200mm of travel, for 26 inch MTB wheel and a straight tapered steerer 1 1/8". The Sur-Ron front hub is a non-boost 20mmX110mm. . If you find a newer model fork with the new boost 20x110mm axle system you can still add a 5mm brake disk spacer and the Sur-ron wheel will fit. If you find a fork with a tapered steerer (called 11/8" to 1.5") then you will just need to replace the lower headset with a cane creek headset like this : . Click here for more info on headsets

          So what model you should buy? That is up to you all the different model out there have different adjustments and properties, but
          • Fox 40 (do not put a Fox36 on your bike, stanchions are not strong enough) this one is likely the best fork available but it's not cheap and often is over 1600$ It's plush, rigid and almost any rider will find the perfect setting for their style of riding.
          • Manitou Dorado pro or expert, 26" or 27.5". Probably the best bang to the buck if you can get one at 700-950$. it is one of the "plushest" fork out there when tuned properly! Killer inverted motocross looks too.
          • DVO Emerald, another amazing fork, probably one of the top 3 best forks out there, and if you can get your hands on one they are often in the 1100-1300$ range
          • DVO Onyx, a new fork built just for Sur-Ron
          • Marzocchi boomber or any 40mm stanchion model, this fork can be found used for cheap and it's pretty easy to get it serviced.
          • Öhlins DH38 m.1... OHlins makes the best suspension period but this one is only 38mm... might not be as rigid as the Fox 40.
          Last edited by paxtana; 10-15-2020, 05:24 PM.


            Removing the jackshaft castle nut and replacing it with a standard Nyloc nut

            The easy way is to get the right tool.. but then if you have the tool you don't really need to change the nut?!? Right? Well some like to be able to fix their bike with standard tools so it's not a bad idea to do it.

            Sur-Ron tool :

            You will need a Nyloc M10 x1.0 nut
            You will need a washer 20mm OD with a M10 hole :

            Tools, you can buy the Sur-ron official 4 prongs nut remover (if you can find one) or you can just use a long nose plier (vise-grip preferably) and a allen key on the other end to hold the axle in place (dont spin the allen head) while you apply force to the castle nut and remove it. You can also use a flat head screwdriver (or a punch) with a hammer on one of the 4 notches and hammer/spin it counter clockwise

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            There is also the flat head screwdriver and hammer technique that works wonderfully, but be careful not to scratch the frame!

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            Last edited by Sebz; 07-20-2022, 02:23 PM.


              Aftermarket upgrade parts

              Aftermarket pedal system - This is not connected to the drivetrain so it is far less likely to break, and if it does it will not affect the operation of the bike unlike the normal pedal system. A nice upgrade.

              Tail Tidy - This updates the area behind the rear seat so you have more options for mounting stuff

              Seat extender - This raises the seat

              Foot peg bracket - This replaces the original cast foot peg brackets with something that is nicely machined for enhanced durability

              Suspension linkage upgrades and other stuff
              Last edited by Sebz; 05-24-2021, 02:03 PM.


                Changing the brake lever blade

                1) loosen the set screw on the lever, the one holding the main pin, not the reach adjuster

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                2) Push the main pin out from the bottom of the lever. You can use a nail, a punch, screwdriver...

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                3) Turn the adjuster with an 2mm Allen wrench until it comes out of the lever

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                To reassemble, slip in your Allen wrench in the new blade threaded hole and reach the adjuster 2mm hex head and turn till you get the threaded adjuster all the way in. Push the main pin in and don't forget the set screw or the pin will fall out eventually.

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                  How to replace the RST fork spring with a firmer spring to make it not bottom out.

                  1. Get this spring here. Click me. Make sure to get the blue firm one.

                  2. Just unscrew the top cap of the left leg on your fork and replace with new spring. Note you'll need
                  to remove the Hex bolt and the aluminum disk at the bottom of the plunger as in the picture below and replace that with a socket that's roughly the same diameter as the plunger piece) What I did was drilled a hole large enough
                  so that the plunger piece slides on the shaft (see pics) This way the jig becomes the perfect diameter.

                  3. You do not need to add grease you can just take the grease from the
                  stock spring and transfer to the new one. It's an easy 15-20 minute job.

                  4. If you want to make the spring preload adjustable, get a length of metric all-thread, size #8 x 1.25, and cut a 6-7" piece off. Then get 3 x #8x1.25 metric nuts, and 3 large #8 washers. Unscrew the aluminum rod from the top cap, and screw the all-thread in instead. Slide one of the washers against the cap, and thread one of the #8 nuts down against the washer on the cap.

                  5. Now for the adjustable part. Thread one of the #8 nuts a few inches down the all-thread, place another washer on it, the slide the aluminum disc down against the washer. Slide the last washer against the aluminum disc, and thread the last #8 nut down to the washer. This traps the aluminum disc between the nuts/washers.

                  6. With the front wheel/forks in the air, slide the cap/adjuster down into the fork leg. The amount you have to push in before the threads engage, is the amount of preload you have. Adjust the nuts/washers on each side of the aluminum disc to adjust how much preload it gives. If you have more than a 1/4" of preload, Use a 13/16" socket to screw the cap in, because it's too hard to start the threads with a wrench.
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                  Warning this procedure is a modification (AKA; hack), warranty on the fork will be voided.
                  Last edited by Jasdidit; 06-28-2021, 07:57 AM.


                    How to fix the battery latch or remove it.

                    First step it to remove the seat off the bike, please click here for instructions.

                    Once you have the seat out of the way you will have to remove the latch plastic cover

                    1 Allen head bolts on each sides and one philips head on top.

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                    Under the latch you have 2 Allen head bolts to remove to be able to remove the 2 plastic covers.

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                    IF the battery is still in the bike and the battery door is locked then you have to remove the 2 plastic cover that you just uncrewed, might have to pull on each end that way tou will be able to see the latch (bronze color)

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                    Use a small screwdriver or a pick to move the latch

                    Then it's time to remove the latch assembly, just remove the 2 main bolts and you can remove the latch

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                    The next step is to fix the latch if your key does not catch the latch, so follow the procedure below:

                    (with thanks to Robert from Facebook)

                    This is a fringe case that has only been seen a few times so in most instances you want to check the latch is not caught on something and that the cylinder does not need lubricating.

                    What is happening here is the mechanism the cylinder fits into is not working. This is the mechanism that sits between the latch and the lock cylinder. If you can turn the key in the lock but it does not turn the latch then this may be the issue.

                    You have to dismount the lock mechanism and then open it up. Inside of the lock-mechanism there is an axle going through the entire mechanism. In the end of this axle there is a nut and this nut has become unscrewed. This then causes the hook that locks the lid to slide off the spline of the axle. Hmmm... difficult to explain but start with opening up the mechanism and then you'll see. I was lucky because my battery was not in the bike when this happened to me. This made it easier to dismount the lock mechanism.
                    Red straw points to small Phillips head screw that backs off shaft letting latch disengage from turning shaft

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                    Solution: Drill hole in end of casting just large enough to get a Phillips screwdriver in but small enough that screw can not fit through hole in case. Unscrew screw to expose threads, apply lock tight to threads, screw back in tight.

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                    If you can wiggle that gold colored metal latch that hooks your battery cover down, if it is not centered in the mechanism, the screw is backing out. It is a very tiny Phillips head screw with no lock washer or lock tight on the end of the lock shaft furthest from the key. I drilled a hole in the end of the case so I could get at it with a screwdriver, backed the screw out until it hit the case (twice) and dosed it with blue lock tight (twice), running the screw in and out a few times. The screw can not fall out because it hits the case first, but the gold latch can get out of its purchase on the lock shaft notch and not unlock anymore. If that gold metal latch is loose it's only a matter of time before you won't be able to open the lid.
                    Last edited by Sebz; 01-18-2021, 10:13 AM.


                      Installing the seat extenders

                      1. Remove the rear light/bracket from underneath the seat.

                      2. There's a zip tie that holds the cable that goes to the rear light which attaches the cable to the seat brackets.
                      CUT the zip tie so that the cable is free.
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                      3. Follow the instructions on the website which screws go where:
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                      4. There's 2 screws holding the lock and bracket to the rear of the battery tray.
                      Remove the 2 screws and then the bracket will be free like this:

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                      5. Installing the Spacer/Battery holder I will include couple of pictures of that here:

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                      6. Some times the plastic piece will be too long and will not allow you to close the battery cover because it's hitting the battery strap
                      but if that happens you can use an angle grinder or a file to remove some of the plastic material like in the pictures above.
                      It's not hard to remove the material this is 3D printed piece.

                      After you're done installing the seat extenders you can then re-connect the rear light and bracket to the under-seat.

                      Congrats you're done!!!
                      Attached Files
                      Last edited by intramorph; 09-27-2021, 07:46 AM.


                        Changing the spring on a Sur-Ron Shock

                        DNM takes a Fox sized coil 36mm inner diameter, 3.5" stroke spring, but the shock itself does not have more than 3" stroke
                        FastAce takes a RockShox sized coil 38mm inner diameter. As per the specs it's apparently a 3.25" stroke spring.

                        For the DNM, you can just remove the shock and loosen up the lock ring til you can move the spring enough so you can lift and slide the lower cup. If you need a higher spring rate you can buy it at Luna (click here)

                        For the FastAce it's not as easy. The spring that is mounted on the shock needs to be compressed a little to be able to remove the lower cup, you can use super heavy duty zipties to compress it, go to a local bike shop to have it removed or make your own using some old wood working clamps like I did. Getting it off is only part of the trouble... Finding a 36mm coil with 3.25" stroke that has a spring rate of 500-550 or 600lbs is quite hard.

                        The good part is that the shock itself is not a 3" stroke and does not need a 3.25" coil. I measured the stroke and it's 2.5" stroke till you hit the bump stop and maybe another 1/4" stroke left for a total of 2.75" stroke. I put the shock in a vise and got a hair over 2.75"

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                        First step is to remove the rebound adjustment knob:

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                        Next step, take out the spring. This is my jerry-rigged spring compressor, if you do not have anything that you can use to safety compress it I recommend to use 100lbs heavy-duty zip-ties. If it can be done on a motorcycle it can be done done a Sur-Ron!

                        Jerry-rigged spring compressor:

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                        Zip ties compressor:

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                        Now that the spring is compressed you need to lift and slide out the lower cup

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                        Slide out the spring and slide in the replacement, put the cup back in and tighten the lock-ring a little. Install the rebound knob and your done! Just need to adjust the spring pre-load to your liking.

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                        Hint this is a Nukeproof 550lbs X 3" 38mm RockShox spring and it fits like a glove. Yes it's shorter but it's made for 3" stroke shocks. Inside the box it says good for 2.75 to 3.2" stroke. You can find them at "chainreactioncyles".
                        Attached Files
                        Last edited by Sebz; 08-17-2023, 05:49 PM.


                          How To fix spongy brakes Or fix sticky pistons.

                          3 different trick to fix spongy brakes:

                          Last edited by Sebz; 05-12-2023, 07:40 AM.


                            How to replace the rear hub bearings.

                            These do wear out as the stock bearings are pretty cheap.

                            Now you don't need a pretty bearing puller and pricy bearing press. All you need is a threaded rod, spares and nut , basic tools like a wrench hammer and punch.

                            Note I'm using an impact .. because I have one and want to do it quickly, but you needs plier, wrench or ratchet.

                            washers needs to be between 34 and 36mm or 1-3/8" . For the threaded rod I've use a 1/2" with nuts. You can get away with a just hammer and a socket that is between 34-36mm OD (but you can mess it up so I prefer the threaded rod technique.

                            The bearings are basic NSK 6202 so I replaced it with 6202 2ZR C3 high quality FAG german bearing, about 5$ each , you need 2. (thanks to Joel for the find)

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                            First remove the motor seal , you will need to wedge a screwdriver inside and pop it out . If it's stuck you can heat it up, just watch the video down below at the 56sec mark.

                            You will simply have to tap out the first bearing with a long punch, tap the inner bearing sleeve with the punch and tap it all around the ring. Do not hammer just a one spot, you want the bearing to pop out evenly. I didn't need to heat up the hub, the bearing it was not pressed in that hard. If yours is stuck watch the video down below it might help you.

                            flip the wheel and do it again,

                            install one bearing at a time if you can, I had a very big socket (bigger than the bearing hole) so I didn't need to buy other spacers. you could press both bearings at the same time , but you have to make sure that the go in square! I've added a tiny amount of grease on the hub so the bearing would slide in smoothly.

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                            Here is a video found on the internet about a street motorcycle.. it's pretty much the same on your Sur-Ron.

                            Last edited by Sebz; 01-06-2022, 08:47 PM.