The Lekkie Pacemaker is a CNC-machined aluminum throttle that comes in two shapes: a full twist grip for your right hand and a thumb lever for your left. Lekkie designed both around the Bafang BBS01, BBS02 and BBSHD, and they're also listed for CYC, Tongsheng and most other kits that use a standard 3-wire, 5V throttle. On a Bafang it connects like the stock throttle, usually with an extension cable. On other systems you may need an adapter or some rewiring.

This guide covers which version to get, what to check before you order, how to install it, and how to fix two common problems: Error 04 at power-on and a throttle that never reaches full power.

Full twist or thumb: which Pacemaker to get

All of them fit 22.2mm OD handlebars, have a blue LED that shows when the throttle is live, and have sealed electronics for riding in rain and mud. The full twist now ships with the soft black grips installed.

If you run a twist shifter on the right, a twist throttle would compete with it for the same spot on the bar. That's the main reason the thumb version exists.

Will it work with my motor?

The Pacemaker works like any standard 3-wire throttle. It needs a 5V supply (Lekkie gives 4.6 to 5V) and puts out a signal of roughly 1 to 4.2V. Here's how that plays out on the systems we see most:

• Bafang BBS01, BBS02 and BBSHD: this is what Lekkie built it for. It uses the same 3-pin throttle connection as the stock Bafang throttle.
• CYC: listed as compatible. Throttle plugs aren't identical across every CYC generation, so if you're not sure your plug matches, send us your motor model before you order.
• Tongsheng: listed as compatible.
• Sur-Ron: get one of the Sur-Ron versions. They come with the adapter cable, so there's nothing to rewire.
• Anything else: if your controller feeds a steady 5V to a 3-wire throttle, the Pacemaker can usually work. The catch is pinout. Two plugs can look the same and still have the wires in a different order.

For non-plug-and-play systems, Lekkie's manual gives the pinout the Pacemaker expects on the bike side, a 3-pin male Higo/Julet plug:

Don't go by wire colors. With the bike powered on and the old throttle unplugged, use a multimeter to find the pair of pins that reads about 5V (those are supply and ground; a positive reading means the red probe is on supply). The remaining pin is signal. If your system doesn't supply a stable 5V, or expects a different signal range that you can't reprogram, the Pacemaker won't work on it.

What you need before you start

• A 2.5mm hex key and a little PTFE grease.
• Enough clear bar. For the full twist, Lekkie asks for at least 150mm on the right (throttle) side and 130mm on the left (grip) side.
• A smooth, round bar end with no burrs. A rough edge can damage the rotating parts.
• An extension cable in most cases. The 140mm lead rarely reaches the controller by itself. On a Bafang build, a Bafang 3-pin extension cable does the job.
• For the thumb version: lock-on grips with hard (metal or plastic) inner ends. Lekkie warns that slip-on rubber grips can stretch and jam the throttle.

How to install the full twist Pacemaker

1. Remove your old grips and throttle, and clean up the bar ends.
2. Spread a thin layer of PTFE grease on the inside of the throttle grip.
3. Slide the throttle onto the right end of the bar. It should go on with very little friction.
4. Turn it to the angle you like. Make sure no lever or shifter pinches the cable. Lekkie suggests the top-rear of the bar so you can see the LED.
5. Fit the matching lock-on grip on the left side.
6. Tighten the clamp screw with the 2.5mm key, 2 Nm maximum. It's a small screw, so don't lean on it.
7. Twist the throttle and let go. It should turn smoothly and spring all the way back to its start position.
8. Route the cable, plug it in (through the extension if you need one) and tie it away from anything that moves when you steer.

The thumb version goes on the left. Take off the left grip and loosen the brake lever so you have room. Slide the throttle on with the sensor side up and the cable pointing inward, then refit a lock-on grip with a 1 to 2mm gap between the grip and the moving part of the throttle. Lekkie also asks for at least 30mm between the grip end and the brake mount. Set the angle, tighten to 2 Nm max and check that it springs back on its own.

Test it before you ride

Put the bike on a stand with the rear wheel off the ground, then power up and check three things:

• There's a little free play before the motor starts.
• The throttle returns to zero on its own.
• The motor stops the moment you let go.

If the motor keeps running after you release the throttle, don't ride it. Check the troubleshooting section below. Lekkie also recommends brake levers with a motor cutoff sensor on any throttle build.

Fixing Error 04 and other common problems

Error 04 on a Bafang display is a throttle fault at startup. The controller doesn't like the throttle signal it sees when it powers on. Work through these in order:

1. Make sure the throttle is fully back at zero, then power off and on again. Don't hold the throttle while you switch the bike on.
2. Check that the sensor is seated all the way into the aluminum housing.
3. Check that nothing (a lever clamp, the cable, the grip) stops the throttle from rotating freely.
4. If it still shows Error 04, the throttle voltage settings in the controller may need adjusting.

Our Bafang error codes guide covers the other codes if you're seeing something different.

If the throttle works but never reaches full power:

1. Check the sensor seating and rotation as above.
2. Make sure your controller is set to give 100% throttle in every assist level.
3. If it's still short, lower the throttle's top voltage setting a little at a time. Lekkie suggests steps of 0.05V until full throttle is reached. On a Bafang UART controller this is done with the programming cable and config tool or an EggRider. Our Bafang programming guide shows how to get set up.

If the throttle keeps running after you let go, check that the grip returns fully to zero and that the sensor is seated correctly.

If nothing happens at all on a non-Bafang install, look at the LED first. No light means the throttle isn't getting power, so check the plug and cable. Light but no response usually means a pinout mismatch or a signal range the controller doesn't accept, and the wiring needs to be redone. The sensor can be replaced on its own, so a damaged sensor doesn't mean a whole new throttle.

Care and grip replacement

If the throttle starts to feel sticky or rough, take it off the bar, wipe it clean and put a small amount of PTFE grease into the internal spring area. Lekkie recommends Rock'n'Roll Super Web grease.

Grips wear out long before the throttle does, and you can swap them without replacing the mechanism:

1. Unplug the throttle and slide the assembly off the bar.
2. Push a small flat screwdriver into the recess at the base of the grip and twist to release it. Do the other side if needed.
3. Add a little PTFE grease to the internal spring area.
4. Clip the new grip on, lining it up with the locating lug.

Frequently asked questions

Does the Lekkie Pacemaker work with a CYC motor?

CYC is on Lekkie's compatibility list. Plugs vary between CYC generations, so send us your exact motor model and we'll confirm whether it plugs straight in or needs an adapter.

Do I need an extension cable?

Usually, yes. The standard cable is 140mm (200mm on the Sur-Ron full twist), which rarely reaches the controller on its own.

Will the full twist fit with my shifter?

It's compact enough to sit under most trigger shifters. If you use a twist shifter, the thumb version is the better choice.

Why does my Bafang show Error 04 after installing it?

Most of the time the throttle wasn't fully at zero when the bike powered on, or the sensor isn't fully seated in its housing. If both check out, the throttle voltage settings may need adjusting.

Is the Pacemaker waterproof?

All the electrical parts are sealed for riding in rain and mud.