Sur-Ron mechanical troubleshooting

[Sebz]

Mechanical Troubleshooting

Looking for electrical troubleshooting? Click here.

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Key not working

Battery compartment is pressure released and if you press down on the battery compartment the key works fine this is the first thing we would recommend to check.
Key will not fit the lock if it is the wrong key. Likely if it fits the lock it is the right key, they are formed in such a way that if its wrong key it won't fit.
If key opens the battery door it is the right key, typically if this issue comes up it is relating to closing the battery door. If it opens it then it's the right key for both ignition and door. Keeping in mind that the issue is not so much the door per se but more like the seat itself, which has a pressure-release latch. If this latch cannot do its job due to battery not pushed all the way down, battery strap getting in the way, or wiring getting in the way, then the key will not lock the door.

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Brakes are spongy or lack of braking

See bleed your brakes post

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Pedal Kit is loose or grinding:

https://electricbike.com/forum/forum...age2#post78992

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I feel the front fork is loose

You headset might be loose or damaged.

First would be to loosen the top cap of the stem, loosen the stem and the top crown clamp. Try to wiggle thefork a little to make sure it seated correctly and then tighten the top cap of the stem first, this will compress the whole assembly together. Try to wiggle the fork again to see if you still have some slack. If you do please repeat again. Once the front is solid you can start by tightening down the top crown first (do not over tighten the clamp bolts) then move toward the stem and tighten the clamp too. You should be done.

If it still does not feel right replace it, please see this thread to know how it looks like and to replace it with what.

Sur-Ron headset info and replacement

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Removing the bolt on the fork for assembly
You unscrew the right side bolt "clockwise" and then unscrew the axle counter clockwise, lift up on the fork to release pressure and pull axle out

If you are facing the bike. Take the left cap off. Then unscrew the right side. Take the battery out, so that you can lift the front of the bike easily. Lift, wiggle and pull out the axle. There are arrows on the axle for unscrew direction. For a visualization please see the assembly walkthrough video linked from the main documentation page.

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Stripped hex bolt on fork during assembly

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If disc brakes are rubbing, check the rotor is not bent. If it is flat proceed to this

[paxtana]

Battery door key not working - In depth failure analysis
(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


Here is another view of the problem

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.

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.

[Jasdidit]

There is a tapping sound coming from the bike when the motor spins the wheel.

Often this is caused by a loose jack shaft nut. Before replacing the jack shaft, I recommend tightening it up first. The jack shaft has a four notched nut keeping it tight. Pretty hard to tighten, or torque to proper spec. I recommend replacing it with a Hex nut, so it can be torqued with conventional tools. First hit it with a hammer and screwdriver to loosen it, then just spin it off with your fingers. Take it to your local hardware store, and find a matching hex nut, or nylock nut, and a washer so you can tighten it without gouging the frame. Then torque it down to 26 ft lbs, or 35Nm of torque, and ride it for about 50 miles. Re-torque it after several rides, because as the bearings are pushed back in, they create more slack under the jack shaft nut. The tapping noise should just go away as the bearings move back into position. If the tapping noise doesn't go away after replacing the nut and re-torqueing it, then send an email to support@lunacycle.com, and ask for Joel.