Sur Ron chain length information for various sprocket sizes:

Chains
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 YOU HAVE A 106 LINKS CHAIN
104 links 42T
106 links 48T
107 links 48T + pedal kit
108 links 52T
110 links 54T
112 links 58T
114 links for 60T
MASTER LINKS FOR A 420 CHAIN
O’Ring chains will require a O’Ring compatible master link
If you have the pedal kit installed, you need one extra link.
Belt drive model: Contitech HTD 560 8M, 15mm wide

I can verify that the RK 420 chain 110 link, fits the Sur Ron sprocket well. I purchased this chain to use with the Super Moto with pedal kit rather than the chain Luna Cycle provides with the SM kit.  The SM kit does NOT anticipate being used with the pedal kit option. Also the cost of the chain (because it is not an o ring chain) is very inexpensive. I plan to purchase another one to use with a chain breaker if I need additional links for other applications.

My change to an O ring chain

I also opted to change to an O Ring chain to keep chain maintenance to a minimum. I found that the noise of an O ring chain reduces chain noise by about 50% to my ear.

10 Comments

  1. Mark – have you considered the belt drive to reduce drivetrain noise further? I haven’t explored it, so I’m curious about the pros and cons that you’ve encountered.

    • I have not considered the belt drive regardless of the brand or noise. Based on where I ride I do not want to limit where I ride due to sand or mud. Everyone is different.

      • I’m confused the 110 link o chain would be good to use for the sur on lb x with pedal kit and 48t sprocket or should I size it down to an 107 link?

        • Eli 107 with the pedal kit. Since no one sells a chain in a 107 you simply cut the chain to the length you need. If you want your bike to handle a bit faster, you can move the rear axle forward which will then require removing a link(s) or moving the axle further back for a more planted feeling will require adding a link or two. It’s all about how/where you ride. Do what’s right for you.

        • You think I can use a non o ring chain on the LB-X it’ll just be noisy I guess right ?

          • Sure a non O ring chain works fine. Just a bit more noise and more maintenance needed.

  2. My sur ron should be coming in a couple weeks. I ordered the 54 tooth sprocket and pedal kit from luna. Do you know what length chain I will need for this configuration? If the chain is only a couple links too long, will it be okay by setting back in the adjustment range?

    I am new to the Bay Area (San Jose) and dirt biking and would like to get out and ride with you sometime and/or get some info on good spots to ride. Let me know.

    • Bradley I’m not sure how many links would be needed for a 54 tooth sprocket with the pedal kit. I’d ESTIMATE that it would be 3-4 more links than the 107 with the 48t sprocket, BUT I AM NOT CERTAIN. If the chain you’re using is a little long then yes, you can move the rear axle toward the most rearward part of the adjustment.

      In terms of riding it really depends on what/how you want to ride offroad. I find that my bike is just right for vacant lots or Bump City where I live. Although with COVID it’s a bit more difficult so I go out at night now. Investigate on Google Maps areas around where you live to find great spots. Welcome to the Bay, it’s a wonderful area.

  3. Hello Mark, sorry to bother you.
    I’m a new LBX owner located Vallejo. I just removed the stock pedal kit. (I should have heeded the warnings, but had hoped it would help me be an ebike)
    I have the 19″ stock wheels with the stock 48T sprocket.

    With 28mi on the new bike, it seemed the pedal kit was ready to self destruct and seize the rear wheel, obviously not a happy thing. The grinding noises and wobble of the crank arms indicated it was not suitable / unsafe at any speed …

    My confusion is about the small sprocket (label stamp reads WLJF 25-420) that came with the gold o-ring chain shipped with the bike from Luna. Am I supposed to mount it on the drive shaft in order to use the gold chain ?
    (I hope not, looks very difficult to do)
    If I just get a master link for the gold 420 chain, count 106 links and join, will that be roadworthy?
    Thanks in advance for any advise.
    I’ve learned a lot from the posts you’ve done for the sur Ron.
    Sincerely, GL

    • Hi Gary I’m sorry about your experience with the pedal kit. I have ideas why you had those wobbling experiences, but no need since you removed it. I am unfamiliar with the part number WLJF 25-420. If you are running the stock 19″ wheels and the 48t rear sprocket there would be no need to use that sprocket with the O ring chain. I have no idea what that part/sprocket is. 106 links for the 48t rear sprocket, no pedal kit. And yes be sure to use an O ring master link which includes rubber O rings for each side of the master link. Have a great time on your bike in the Bay Area and thanks for your kind words. I’m happy this site has helped you. It’s the only reason I built it.


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