Tire & Tube Change on UNI Bikes
Tire change on the UNI Bikes.
- Turn the bike around and place it safely on the handlebars and seat or frame end. Put a soft pad, such as a towel or blanket underneath to avoid scratches. Use a mounting stand / bicycle holder, if available.
- Loosen the axle nuts of the corresponding wheel and make sure that the spacers do not get caught on the frame or derailleur.
- Remove the wheel, if necessary disconnect the rear wheel's motor cable beforehand (if necessary, open the controller housing by loosening the 4x 3 mm Allen screws, unplug the motor cable connector and unscrew the cable clamps, in some bike versions the motor cable plug is directly underneath the rear framing, so no need to open the controller housing – the plug looks like in the picture below).
- Let all remaining air in the tire escape, e.g. by pressing an Allen key or tire lever into the valve.
- Take tire levers at hand (preferably made of plastic to avoid damage to the rim / casing) and start to lever the casing carefully over the rim edge. Always counter with a tire lever. Use tire fluid to make the tire flanks smooth in order to make the process easier. Start on the opposite side of the valve.
- Once you have lifted about one-fifth of the tire sidewall over the edge of the rim, you can use a tire lever to drive along between the rim and the casing, pushing it completely over the edge.
- Then press the tube valve through the rim and carefully remove the tube from the casing. Check it for holes / damage and mend / repair or replace it. Also, check the tire casing for foreign objects, damages and replace it if necessary.
- To completely replace the casing, pull it over the side already removed by pulling the casing completely towards the rim edge. Use a tire lever if necessary.
- Remove any foreign objects from the rim's inner bed and make sure that the rim tape lies cleanly over the spoke nipples so that they cannot damage the inner tube under pressure.
- Place the new tire casing on the rim, paying attention to the running direction of the rim and sheathing. You will find directional arrows on the brake disc and on the tire sidewall.
- Press one side of the casing completely over the edge of the rim, use tire levers as an aid if necessary.
- Then insert the new / repaired tube and push the valve through the hole in the rim. Then hold the valve firmly and press the entire tube into the casing. It helps if the tube is minimally inflated so that it retains its shape.
- Push the inner tube completely into position, centre the valve so that it looks straight out of the rim hole and start pushing the other tire sidewall over the edge of the rim. Start at the valve and work your way forward step by step on both sides, using tire levers and tire fluid if necessary – some tires are softer than others, so different tires may behave differently.
- Once the casing is fully seated on the rim, fill a little air into the tube (using a compressor or air pump), then centre the tire and make sure that all the tire flanks are equally deep in the rim bed. To do this, place the wheel with the tread on the ground, exert pressure on the side of the tread facing you and roll the wheel in one direction. Repeat this process until the tyre is evenly and cleanly seated.
- Now inflate the tire completely to the desired pressure. We recommend between 1.1 and 1.5 bar. The proper pressure is indicated on the tire flanks.
- Then mount the wheel back on the frame, make sure the spacers are positioned correctly when mounting and pay attention to the brake disc. If necessary, loosen the brake calliper to avoid damage to the brake disc.
- Tighten the axle nuts sufficiently but carefully and turn the wheel by hand to ensure that the wheel runs smoothly. Then mount and recenter the brake calliper.
- Flip your bike around again and observe the tire pressure. Make sure that no air escapes. If necessary, adjust the tire pressure to suit your riding style and the use-case of your bike.
Motor cable connector (9-pin):