Second Ride Conversion Kit SR24 for Simson Duo 4, Duo 4/1, Duo 4/2
Please keep your packaging!
To save resources, in case a return shipment is ever necessary!
Requirements
|
Scope of Delivery
|
|
Duo 4, Duo 4/1
M5x Motor Mount
|
|
Duo 4/2
|
|
Required Tools
|
|
Before you start the conversion
The purpose of the conversion kit is to convert the above-mentioned Simson models according to the present assembly instructions, as well as their use on public roads according to the operating manual. Please understand that in developing the conversion kit, we based it on the original condition of the mentioned Simson models. For modifications involving non-original components, or changes to original parts due to accidents, wear, or intentional modifications, we cannot guarantee that the conversion kit will function flawlessly and safely, or that it can be installed at all. If you are unsure about your vehicle, feel free to contact us.
The document provided to you, “Conversion Kit SR24 - SR50, SR80 - Assembly and Operating Instructions,” is issued by Second Ride GmbH and is intended as a supplement to the original manufacturer’s operating manual. Both documents should be seen as a unit. They belong together directly, with the explanations regarding the combustion engine being disregarded.
Please read this document completely and carefully before starting the conversion and taking your first ride. Here you will find warnings and notes, information and advice, emergency procedures, and other important remarks regarding your vehicle. Failure to follow the instructions may result in minor or severe injuries, including life-threatening situations. Furthermore, the vehicle’s performance may be impaired. Please also carefully read the warnings and notes listed next to the symbols, especially regarding the high-voltage area. Only then can proper installation of the conversion kit and proper use of the vehicle be ensured. Ignoring these warnings and notes means you are knowingly accepting possible damage to people and/or the vehicle.
Please note that the disposal of the onboard battery, transmission oil, and fuel-oil mixture must not take place in household waste, wastewater, or the environment. Please inform yourself about the proper disposal of these substances. Used batteries can contain harmful substances that may damage the environment or health if improperly stored or disposed of. However, batteries also contain important raw materials such as iron, zinc, manganese, or nickel, which can be recycled. Please return the seat bench battery to us after use. To ensure safe transport, we recommend using the original packaging. In any case, please contact us.
Some fluids used in vehicles (battery acid, battery coolant, brake fluid, fuel, windshield washer fluid, etc.) are toxic and must not be inhaled, swallowed, or come into contact with open wounds. Always read and follow the instructions printed on the fluid containers for your safety, and observe the legislated handling regulations for these substances.
All technical data and descriptions contained herein were current at the time of printing. However, since continuous improvement is one of our main goals, we reserve the right to make changes to the products at any time. If you notice errors or omissions in this document, please report them in the Discord channel (see footnote).
1. Disassembly
Before you begin disassembly, remove the vehicle’s battery to avoid short circuits.
1. Disassembly: Engine Connections
First, all electrical and mechanical connections to the engine must be loosened. Unscrew the Duo’s shift linkage. Make sure the fuel tap is closed and disconnect the hose from the carburetor. You can now drain the remaining fuel in the tank into a suitable container (e.g., fuel canister). If you want more space in the vehicle interior, you can also remove the tank completely. Loosen the clamp of the intake boot and pull it off the carburetor. Unscrew the throttle and choke cables from the carburetor. Unscrew the speedometer cable from the chain cover. Then remove the spark plug connector and the ground cable from the engine block. Disconnect the cables coming from the alternator from the vehicle.
2. Exhaust
Now only the exhaust should be attached to the engine. It is fastened to the engine with a large nut that can be removed using a pipe wrench or hook wrench.
Tip
If the exhaust nut won’t loosen, you can tap it with an old flat-head screwdriver and a hammer (preferably rubber or wood) into the notches of the nut to loosen it.
The other exhaust mount is at the rear in the form of a clamp, which can be opened by removing the screw.
3. Chain
Before the engine can be removed, the chain must be taken off the drive sprocket. To remove the engine cover, first remove the cover between the driver’s footwell and the engine. To do this, loosen the upper engine mount and another screw on the left edge of the front vehicle wall. Then remove the alternator cover from the engine. Next, loosen the nut of the right rear axle and the axle bolt on the left of the driven wheel. A few turns are enough, as the rear wheel only needs to be moved. The small nuts of the chain tensioners can now be screwed all the way back to the end of the thread. The rear wheel should now be able to slide forward. It’s time to lift the greasy chain off the drive sprocket. We have included disposable gloves in the package for this.
4. Engine
Duo 4, Duo 4/1
After all this preparation, the engine is now ready to be removed. It is fastened with a long M8 screw at the frame mount point and an M8 screw at the cylinder head. Removing the engine can be fiddly—support from a second person can be very helpful now. Loosen the nuts and try to pull the bolts out of the holes. It helps to lift the engine slightly. Now you can take it out of the mount. Congratulations! Your Simson is no longer a combustion vehicle!
Duo 4/2
After all this preparation, the engine is now ready to be removed. It is fastened with two long M8 screws in the engine mount (10). Removing the engine can be fiddly—support from a second person can be very helpful now. Loosen the nuts and try to pull the bolts out of the holes. It helps to lift the engine slightly. Now you can take it out of the mount. Congratulations! Your Simson is no longer a combustion vehicle!
5. Handlebar Attachments
On the handlebar, you can now remove the starter/choke cable and lever behind the left grip.
6. Other Attachments
To install our new seat bench, you should now remove the lead-acid battery along with its holder, as these mounting points will be used for the seat bench holder.
Et voilà! The moped is now ready for the electric conversion kit!
Assembly of the Conversion Kit
When assembling the conversion kit, only screws of size M4, M5, M6, and M8 are used. To ensure the parts hold as intended and are properly tightened, you should use the following torque values:
M4: 2.9 Nm
M5: 5.7 Nm
M6: 9.8 Nm
M8: 24 Nm
1. Drive Module Installation
Duo 4, Duo 4/1
Before installing the drive module in your Duo 4/1, you must loosen the two upper pan head screws that connect the controller to the drive module at the top front. Now take the two M6x90 screws included in the kit and screw them into the freed holes, leaving a thread overhang of about 10 mm.
Now take the parts listed under “M5x Motor Mount” in the scope of delivery and assemble them as shown in the following figure. Screw the M8 nut only 2-3 full turns onto the M8x70 hex bolt. Leave the two M6 nuts aside for now and set the pre-assembled M5x motor mount aside.
The drive module is mounted on the vehicle in the same way as the original engine. Here too, you should get help from another person. First, place the drive module under the vehicle. Lift the drive module and guide it between the frame mounts (10).
The supplied M8x100 hex bolt is for the upper hole in the engine mounting plates. Using a ratchet with extension and 13mm socket, and a 13mm open-end wrench for counter-holding, tighten the nut so that the drive module can still rotate around the bolt axis. You can now rest the drive module in the engine mount.
Next, take the pre-assembled M5x motor mount and install it as shown in the figure, so that the thick washer sits inside the upper engine mounting plates and the thinner washers outside. Depending on the condition of the original mounting plates, the inner washer may be omitted.
Now push the drive module upward so that you can insert the upper thread overhangs of the controller screws into the lower two holes of the M5x motor mount. Screw the M5x motor mount to the drive module with the M6 nuts.
As a final step, tighten the two M8 nuts of the rear and upper engine mounts firmly. Use a ratchet with extension, 13mm socket, and a 13mm open-end wrench for counter-holding.
Duo 4/2
To fit our drive module into the Duo 4/2, you must make a small adjustment to our drive module. The adapter block (31) must be rotated 30° along the motor axis.
Unscrew the 4 socket head screws (32) and Schnorr washers (33) with a SW6 Allen key from the drive module. Put the adapter block aside and unscrew the two M8 set screws (34) from the motor. There may be some damp silicone on the screw ends—don’t worry, the fumes are not toxic, just harmless vinegar.
Now screw the set screws, as shown in the following picture, into the two lowest holes of the motor so that they sit slightly below the motor surface. Take the adapter block and screw it back onto the remaining motor holes. Tighten the screws with a torque of 15 Nm. If you don’t have a torque wrench, tighten them firmly by feel, but not too much, otherwise the threads could be damaged and the motor would have to be replaced.
The drive module is mounted on the vehicle in the same way as the original engine. Again, you should get help from another person. Lift the drive module and guide it between the engine mounting plates (10). The supplied M8x100 hex bolt is for the upper hole, and the M8x90 hex bolt for the lower hole. Using a ratchet with extension and 13mm socket, and a 13mm open-end wrench for counter-holding, tighten both bolts firmly with the supplied M8 nuts. To complete the engine mount, the front support must now be attached as shown in the following figure.
2. Chain
Remove the chain guard from the drive module by loosening the three M4 screws and set everything aside. Time for gloves again! Locate the master link on the installed chain and open it. You may need to get under the Duo to reach the chain link with the master link. The master link can be opened with needle-nose pliers or a flat-head screwdriver. Remove the old chain and lay out the new one. Place the new chain over the drive sprocket and close the master link. You can now pull the rear wheel back again and turn the chain adjuster nuts forward for a rough pre-adjustment.
For fine adjustment, start with the right chain tensioner: turn the nut forward until the chain has only 2 cm of play up and down. You can test this by grabbing the chain in the middle between the rear wheel and the drive sprocket and moving it up and down.
Once satisfied with the chain tension, adjust the other chain tensioner. With this, you align the wheel with the chain. When both chain tensioners are correctly adjusted, tighten the rear axle and nut again. Finally, reattach our chain guard. Now the wheel alignment must be set so your Duo drives properly.
Measuring the Alignment
The alignment is measured at the inner rim edge at the same height above the floor. First measure in front of the axle in driving direction from the right to left rim; then behind the axle at the same height. There should be 0–1 mm clearance.
Adjusting the Alignment
The alignment is only adjusted at the right rear wheel behind the axle bolt. Provided the left rear wheel runs in line with the chain, the chain is correctly tensioned, and all bolts are tightened, the alignment can be adjusted at the right axle by gentle hammer taps. Taps in the driving direction enlarge the toe-in, taps in the opposite direction reduce it. The clamping bolt on the stabilizing bar must be loosened for this.
3. Electrical
Duo 4, Duo 4/1
You can secure the thick cable from the drive module along the bottom of the frame with cable ties, routing it up to the former lead-acid battery mount.
Attention! Make sure the cable does not hang too loosely or interfere with the steering linkage!
The onboard system (lights and horn) is supplied by a voltage converter in the drive module. Under the drive module, a black cable with a white 2-pin connector comes out. Route this to the top of the motor. We supplied you with two red-black cables. Connect the cable with the white 2-pin connectors on both ends to the 2-pin white connector from the drive module. At the other end, connect the second cable, which has a matching white connector on one side and multiple flat plug terminals and a ring terminal on the other.
For connecting the flat plug terminals, it is easier to remove the Duo instrument cluster by undoing the two Phillips screws. Now connect the red cables of the Second Ride cable to the ignition switch at the following contacts:
59, 59B, 30, unmarked triple connector
The black wire can be connected to the ground distribution point at the handlebar (16, page 19), located to the right under the turn signal switch. You do not need to use a fuse, since the power supply automatically shuts off in case of a short circuit until the fault is cleared.
At this link you can find the wiring diagram for your vehicle. It shows which components can be removed. Don’t worry about making mistakes—our drive module has short-circuit protection, so the lights will simply remain off until the error is corrected.
If your vehicle is still equipped with 6V electrics, you must replace all bulbs, the flasher relay, and possibly the horn with 12V components. Now is the time to replace the headlight bulb and the dashboard lighting bulb at the ignition switch.
Good to know
The 12V bulbs are much brighter than the 6V versions, and the horn is also louder with 12V. After the conversion, you’ll be safer on the road.
Now you can reinstall the ignition switch and lamp mask, and set the original ignition switch to the headlight or “II” position (the third position clockwise).
To ensure your 6V windshield wiper also works with the 12V onboard system, we included a 12V-to-6V converter. First, remove the yellow-black cable from your wiper and connect the yellow cable of the converter there. Then unscrew the brown ground cable from your wiper and attach the black cable from the converter (next to the yellow cable) in its place. Now connect the yellow-black cable to the red cable of the converter by fastening both ring terminals with an M4 screw. Do the same with the black cable and the brown ground cable. It’s best to insulate the screw connection of the ring terminals with electrical tape. You can fasten the converter to the nearest frame tube with one of the supplied cable ties. Now your wiper motor works as usual.
Finally, you must connect our brake contact cable. With this cable, the drive module detects whether you operate the rear brake (or also the front brake, if it has a contact). As long as the brake is applied, it will not be possible to accelerate. The package includes an 80 cm long black cable with a white connector housing on one side and a flat plug terminal (22) on the other. Connect the white plug to the white connector on the underside of the drive module and route the cable under the left cover behind the padded panel on the driver’s side to the brake light switch. Here, connect the brake contact cable with the flat plug terminal with extra tab to the side of the brake light switch that leads directly to the brake light.
We designed this function because there is no longer a clutch, and therefore no way to disconnect power transmission if a throttle fault occurs. For example, the throttle grip could get stuck in the open position. Such a scenario is no longer dangerous if you just press the brake to cut off motor power.
Duo 4/2
You can secure the thick cable from the drive module along the bottom of the frame with cable ties, routing it up to the former lead-acid battery mount.
Attention! Make sure the cable does not hang too loosely or interfere with the steering linkage!
The onboard system (lights and horn) is supplied by a voltage converter in the drive module. Under the drive module, a black cable with a white 2-pin connector comes out. Route this to the top of the motor. We supplied you with two red-black cables. Connect the cable with the white 2-pin connectors on both ends to the 2-pin white connector from the drive module. At the other end, connect the second cable, which has a matching white connector on one side and multiple flat plug terminals and a ring terminal on the other.
Now the red cable ends must be connected wherever your vehicle needs 12V. Typically, this means:
Contacts 59 and 30 must be supplied.
The black wire can be connected to the nearest ground distribution point. You do not need to use a fuse, since the power supply automatically shuts off in case of a short circuit until the fault is cleared.
At this link you can find the wiring diagram for your vehicle. It shows which components can be removed. Don’t worry about making mistakes—our drive module has short-circuit protection, so the lights will simply remain off until the error is corrected.
If your vehicle is still equipped with 6V electrics, you must replace all bulbs, the flasher relay, and possibly the horn with 12V components. Now is the time to replace the headlight bulb and the dashboard lighting bulb at the ignition switch.
Good to know
The 12V bulbs are much brighter than the 6V versions, and the horn is also louder with 12V. After the conversion, you’ll be safer on the road.
Now you can reinstall the ignition switch and lamp mask, and set the original ignition switch to the headlight or “II” position (the third position clockwise).
To ensure your 6V windshield wiper also works with the 12V onboard system, we included a 12V-to-6V converter. First, remove the yellow-black cable from your wiper and connect the yellow cable of the converter there. Then unscrew the brown ground cable from your wiper and attach the black cable from the converter (next to the yellow cable) in its place. Now connect the yellow-black cable to the red cable of the converter by fastening both ring terminals with an M4 screw. Do the same with the black cable and the brown ground cable. It’s best to insulate the screw connection of the ring terminals with electrical tape. You can fasten the converter to the nearest frame tube with one of the supplied cable ties. Now your wiper motor works as usual.
Finally, you must connect our brake contact cable. With this cable, the drive module detects whether you operate the rear brake (or also the front brake, if it has a contact). As long as the brake is applied, it will not be possible to accelerate. The package includes an 80 cm long black cable with a white connector housing on one side and a flat plug terminal (22) on the other. Connect the white plug to the white connector on the underside of the drive module and route the cable under the left cover behind the padded panel on the driver’s side to the brake light switch. Here, connect the brake contact cable with the flat plug terminal with extra tab to the side of the brake light switch that leads directly to the brake light.
We designed this function because there is no longer a clutch, and therefore no way to disconnect power transmission if a throttle fault occurs. For example, the throttle grip could get stuck in the open position. Such a scenario is no longer dangerous if you just press the brake to cut off motor power.
4. Instrument Cluster
Now screw the speedometer cable to the newly installed chain guard. The plastic thread for this is located in the same place as on the previously removed combustion engine. This way, your original speedometer continues to function.
Attention
Due to the use of the DUO speedometer drive, the indicated speed is about 9% higher than the actual speed. At 60 km/h, the speedometer will show nearly 66 km/h.
Duo 4, Duo 4/1
The instrument cluster (13) with button (17), charge indicator (15), and ignition lock (14) must be installed under the original cluster. The instrument panel is fastened with the two large flat-head screws that also hold the original instrument panel. The original panel must be unscrewed if this has not already been done for wiring. Now place the Second Ride instrument panel under the original Duo panel and fasten both together.
Finally, route the cable along the handlebar tube to the drive module. There you can connect it with the matching connector and secure it with cable ties to the frame. Both connectors have arrows indicating the correct orientation. Make sure the cable connection allows enough slack for steering.
Duo 4/2
The instrument cluster (13) with button (17), charge indicator (15), and ignition lock (14) must be installed in place of the starter button on the right side of the handlebar, replacing the electric starter button. Unscrew it and install the supplied cluster in the same spot.
Finally, route the cable along the handlebar tube to the drive module. There you can connect it with the matching connector and secure it with cable ties to the frame. Both connectors have arrows indicating the correct orientation. Make sure the cable connection allows enough slack for steering.
5. Battery / Seat Bench
To mount the battery holder on the bulkhead, take the frame clamp and the mounting plate and loosely screw them to the crossbar of the former lead-acid battery holder as shown below. Apply the edge protector to the inner edge of the frame clamp and place it as shown below over the two upper tubes leading to the handlebar tube. Again, only loosely fasten the two M6 screws with the mounting plate.
Now take the battery/seat bench and place it upright against the bulkhead while inserting the lock mount of the battery holder into the bottom shell of the battery. If the holder is only loosely screwed to the Duo, it should slide into the correct position. Make sure the battery/seat bench stands upright on the floor of the Duo and rests against the bulkhead with its lower rear edge. Now take the two brackets and place them under the edges of the battery base plate as shown. Mark their positions on the floor so that after removing the battery you can place them back in exactly the same spot. Masking tape works well for this.
The upper mount should sit in the lock with as little upward play as possible, as shown in the following image.
Now tighten the lower nuts of the mount to secure the position. Then tighten the two upper nuts.
Remove the battery/seat bench from the holder and place the two brackets in their previously marked positions. Mark the hole centers of the brackets and drill 2–2.5 mm holes at the marked spots, or screw the brackets directly into place. However, pre-drilling makes the process more precise and easier.
Finally, take the supplied 10 cm foam strip and stick it onto the battery under the lock opening, so that when the holder latches, the foam compresses and holds the battery/seat bench under tension. This prevents unwanted rattling while driving.
6. Throttle Cable
If you have an N1 carburetor, you can now screw the throttle cable including piston and carburetor cap onto the drive module (12). If you had a different carburetor type on the combustion engine, the carburetor cap and piston will not fit and must be replaced. Good explanatory videos can be found on the YouTube channel Simson Werkstatt.
Which notch the carburetor needle is mounted in, or whether it is missing, no longer matters for the function of the Bowden cable sensor.
To ensure the rotation of the throttle grip is correctly converted into an electrical signal via the Bowden cable, it is important to insert the carburetor piston (22) correctly into the designated cylinder (23) on the drive module. Rotate the carburetor piston as shown in the image so that the groove (29) points to the rear wheel. Inside the cylinder on the same side is a pin that you can feel with your finger. The carburetor piston must be inserted so that the groove slides over the pin. Then screw the carburetor cap (21) onto the cylinder. Make sure the cap is screwed on so far that no gap remains between the cap and the stop.
Now it’s time to adjust the throttle cable. At the top of the throttle cable is an adjustment screw. When the throttle grip is fully turned forward (no throttle), there should be just no play in the cable housing. By turning the screw out, you reduce the play. Later, when the battery is connected, you can check your adjustment:
If you turn on the ignition and nothing happens when twisting the throttle, the screw is turned out too far. If throttle works and there is no play in the housing, the adjustment is correct. You don’t need to worry that the upper stop is wrong and reduces max power, because at full throttle the stop is always the cap, which is in the same place regardless of adjustment.
Attention
Be sure to reinstall the rubber cover (20) on the carburetor cap. Otherwise, the sensor may be damaged by rain.
Ensure that your throttle cable and grip have minimal friction. The grip should snap back to closed from fully open using only spring force. If not, disassemble, clean, and re-grease the grip and/or replace the Bowden cable. Sometimes the rubber of the throttle grip rubs against the clamp. To fix this, shift the rubber outward on the disassembled throttle tube. A video tutorial on throttle grip maintenance can be found on the YouTube channel 2Radgeber.