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Sur-Ron Modifications, adjustments, tips & tricks

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    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.

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    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

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    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.

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    Another option: topeak defender xc1

    DNM Fork users ONLY:

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


      How to remove the seat from a Sur-Ron

      These are the tools you will need.
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      Here is my method for popping off the plastic button-head "rivets".
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      Here is a picture of the expanding bit, once the button-head is removed.
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      Here are both parts of the plastic "rivets", only slightly worse for wear.
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      Here is the whole "rivet". You can see how pushing in the pin, expands the inside to hold it in place.
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      There are three on each side and two in the front, see below.

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


        How to change or adjust Sur-Ron 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!


          How to service Sur-Ron pedal system

          This is typically useful if the kit develops play at the spindle. This covers full rebuild, reassembly and typical pitfalls / solutions.

          For a more in-depth technical overview of the pedal system, see this page:

          For install video see this video


            Aftermarket cranks for the Sur-Ron pedal system

            Please follow this guide:

            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.

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            The alternative is the Monty crank arm from Mark's blog.


              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.

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              Attached Files
              Last edited by Senor_Martillo; 12-23-2018, 08:11 AM.


                Moving the seat back
                (for larger riders)

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

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                  Originally posted by paxtana View Post
                  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.

                  Click image for larger version Name:	image.png Views:	1 Size:	2.12 MB ID:	79095

                  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:


                  • paxtana
                    paxtana commented
                    Editing a comment
                    Thanks for the heads up Mark, I have edited this to point to your page instead :)

                  Preliminary docs for installation of the belt kit

                  Backup link


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

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                    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.


                      Are you guys sure that TR-4 70/100-19 is the right tube size? I just tried two and they seemed way big and I got instant flats probably because they were too floppy and big in there. They seemed much bigger than the stock tubes.


                      • Sebz
                        Sebz commented
                        Editing a comment
                        Yes the "TR-4" is jus the valve size and the rest is the tire size.. I can confirm that the stock tire is a 70/100-19 and you need a 70/100-19 tube for it and that the valve is a TR-4 (or TR-6 is good also , just longer). Some are super heavy duty tubes and it's possible that they wont fit..



                      My light bee X came limited at a way too slow speed of 20 km/h and unlimited is too fast. I think a speed of 25 to 30 km/h is more reasonable.

                      Is there a way to adjust the speed limiter of the sur ron?

                      Thanks in advance!



                      • paxtana
                        paxtana commented
                        Editing a comment
                        Best would be to just change to a larger rear sprocket. This will optimize for torque over top speed.

                      • jugon666
                        jugon666 commented
                        Editing a comment
                        Yes, switching to a larger sprocket trades top speed for torque... but then how can I calibrate the speedometer? :/

                      • paxtana
                        paxtana commented
                        Editing a comment
                        You can't. But you can use an aftermarket speedo. There are bike speedos, gps speedos, even your phone can show how fast you are going by simply loading google maps or using one of many free gps apps.

                      Adjusting / setting the headset and stem.

                      From the factory the headset should be tight but it's possible that it was not done perfectly so you should check before your first ride.

                      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!


                        Adding a voltage meter to your Sur-Ron,

                        Please click this link

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                          Removing the kickstand sensor

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

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