How to Fix a Flat Tire on an eBike

You’re out riding and suddenly your ride gets really sluggish, your pedaling isn’t really having a positive effect and even your motor isn’t impressed with what is going on. You may not have had a flat bicycle tire before but you can feel it, a sinking inside you as your tire sinks beneath you. Something has let the air out of your balloon of fun.

Flat tires (also known as punctures) on your eBike are not a common occurrence (thank goodness!) but you should always be prepared for the worst, and punctures are definitely one of the ride-spoiling occurrences that can happen to anyone.

In this article we’re going to cover what you need to be prepared for when a puncture comes your way, how to repair a puncture on your eBike, step-by-step, and techniques and products you can use to help prevent punctures from occurring too often.

Preparing for a puncture - what to carry in your tool kit

There are many items that should be a part of your regular eBike riding kit, and the tools needed for repairing a puncture fall into the “essentials” column. These are items you should never be without and it’s good practice to store them in a small bag that you can keep Velcroed to either your handlebars or a part of your frame. That way, you will never forget them. You don’t want to be stuck miles away from anywhere without the means to help yourself.

Here’s a list of what you need to repair a puncture when you’re out on the road or trail:

• Puncture Repair Kit - Containing: two tire levers, chalk or a marker, coarse sandpaper or a metal scrapper, and self adhesive patches or cement and patches.
• Pump - This can either be a manual hand pump or a CO2 cartridge inflator. The former may require more effort but it never runs out, while you always have to carry extra canisters for the latter. (if you carry a CO2 pump it is good practice to have a mini hand pump should you run out of cartridges.) 
• Spare Inner Tube - Some larger holes cannot be repaired. For these occasions only replacing the inner tube will fix it. On longer rides, carry two, and make sure the inner tube size matches the wheels and tires on your eBike.
• eBike Multitool - A standard eBike or bicycle multitool will fit the bill here. Make sure your chosen tool(s) include a fitting that matches the axle nuts on your wheels, or else carry a combination wrench that does.
• Knife - a small knife in case you have to cut any zip ties.
• Zip Ties - To replace the zip ties that you cut.

How to fix a flat eBike tire

There are many different shapes and sizes of eBike but, in principle, they’re all pretty much the same when it comes to fixing a flat tire. There’s only one major difference between fixing a flat on a regular bike and fixing a flat on an eBike - that is the motor and where it is located on your eBike.

In this guide we’re going to talk about eBikes that have rear hub motors, like the Denago City Model 1 and many other popular make/models. If your motor is the mid-drive type (located in the bottom bracket between your pedals) or in the other tire then the points pertaining to disconnecting or reconnecting the motor are not relevant to you; making things that little bit easier!

This guide might seem long but it should only take you 10-15 minutes to complete and once you’ve done it once or twice you’ll be able to do it in about 5 minutes.

You have two ways to proceed, the first, removing the punctured inner tube and replacing it with a new one, is easier and faster than removing the punctured tube, patching it, and re-installing it:

1. Power down your eBike and remove the battery (this makes flipping the eBike over easier and the whole process much safer).
2. You’re going to flip the eBike over onto its handlebars so, before doing so, be sure to remove or rotate the display, eBike controls, mirrors, or any other accessories that would stop the handlebars from resting squarely on the ground. As an alternative, if you have a helper you don't need to flip the bike upside down.
3. If your eBike has rim brakes then you need to open these so that you can remove the tire from the eBike. If your eBike has disc brakes there is no need to do anything.
4. Flip your eBike over so that it is sat upside down, resting on the handlebars and saddle.
5. If you’re repairing a tire without a hub motor then skip this step. If you’re working on a tire with a hub motor then you want to disconnect the cable from the motor. Make a note of the placement of the motor cable and any zip ties before you proceed. The connector could be at the point where the cable connects to the motor, where it enters the frame, or as a quick connector somewhere along the cable. Most connectors are a push-pull type, just pull them apart to disconnect. Once you’ve disconnected the motor check to see if the trailing cable is zip tied to the frame. If it is, cut these ties off to allow the wheel to be completely removed.
6. Loosen the quick release lever or the axle nuts that hold the wheel in place. The tire should be able to wiggle. Inspect the tire tread and both sidewalls to see if you can find the culprit of the puncture. If you do see it and remove it so that it doesn’t do the same thing again.
7. Pull up on the tire to remove it from the dropouts which hold the axle and, thus, the tire in place. Make a note of the position and orientation of any spacers or washers on the axle before proceeding. Keyed washers that only fit one way are common on eBikes. Place the tire on the ground.
8. Get the tire levers from your puncture repair kit and insert the flat end of one between the tire and the rim of the wheel. Rotate it outward a full 180º, pushing the tire up and over the metal rim. The other end of the lever will have a hook or groove in it. Hook this over one of the spokes of the tire to secure it in place.
9. Repeat this with the other tire lever, a few inches away from the one you just set up, but don’t hook this second one in. Instead, run it around the rim of the tire. This will pull the tire bead out and over the rim. Pull the whole bead over the side of the rim of the tire.
10. Now you can remove the inner tube. Be sure to push the valve through the hole in the rim and to take that out first. Put some air in the tube and visually inspect it to see if you can find the hole.
11. If you can’t then put some more air pressure into the inner tube and run your hand gently around it at a steady pace. You might be able to feel the air escaping somewhere. If this doesn’t work then add more air as needed and hold it near your ear. Rotate it slowly, giving it a gentle squeeze as you do so. You should be able to hear the air hissing out of a hole. You can also put the tube under water to identify the area that leaks if needed.
12. Once you’ve found the hole mark it with the chalk or marker from your puncture repair kit.
13. Take the metal scrapper or sandpaper from your repair kit and rough up the area around the puncture. This is where you’ll be placing the repair patch. Make sure to rub in at least two directions, perpendicular to each other, and that the area you rough up has the hole at the center and is larger than the patch you’re going to use.
14. Take one of the self adhesive patches, or the cement and a patch, from your repair kit and place it over the hole, with the hole at the center. Make sure the tube underneath it is flat and that you press the patch on firmly. Give it a moment or two to cure before the next step.
15. Pump up the tube so it has a good shape to it. Put your ear close to your patch to listen for escaping air. If there is escaping air then you’ll need to repeat the process detailed above.
16. If the tube is fully sealed then let out some air so that it still has shape but is floppy (put a highly inflated tube back into the tire and you run the risk of pinching it between the rim and the tire and creating a whole new problem for yourself). Start to put the tube back in the tire. Put the valve back in its hole first and work outward from there.
17. Once the tube is fully back inside the tire use your fingers to push the bead back inside the rim of the tire. It can be helpful to do this last part by running a tire lever along the inside of the rim, between the rim and the bead you’ve already replaced. Never use screwdrivers or other sharp objects that could damage the tire or inner tube.
18. Inflate the tire slowly, watching the tire to make sure the bead seats properly to the rim of the tire.
19. Fully inflate the tire and replace it onto your eBike. Fully tighten the axle nuts and reconnect the motor cable (zip tying it where necessary).
20. Flip your eBike back over, return all the components and accessories you moved back to their respective positions, and replace the battery.
21. You’re now good to go!

Note that if you want you can skip the repair (steps 11-15) you can simply replace the inner tube with your new, spare one. This is useful in a time crunch but is a wasteful solution as a properly repaired inner tube will last just as long as an inner tube that hasn’t been repaired. Many riders put a brand new tube in on the road for the fastest repair, but bring the punctured one home to repair at a more convenient time.

Park Tool has a great video showing these steps in order:

What's the difference between changing an eBike tire and a regular bike tire?

The only difference between changing a regular bike tire is the motor component. Other than that everything is almost the same. Some eBikes have eBike specific tires that are more heavy duty than regular bike tires. They are thicker, making them more durable for the high force they experience during stopping and starting, as well as to carry the extra weight of the “e”. The extra thickness of ebike tires means that they’re less prone to punctures than their regular tire counterparts. However this doesn’t make them immune to them (hence this blog post).

Are liquid sealants a viable alternative to removing the wheel?

For many riders, removing and installing the wheel (especially the rear wheel) can be confusing or challenging. Liquid tire sealants can be an alternative prevention and repair technique in some cases.

They are a viable alternative, however they need to be applied before you get the puncture. Liquid sealants work using centrifugal force, meaning that the spinning of the tire keeps the liquid sealant on the outside surface of the inner tube and this quickly fills any small punctures before you can notice them. Trying to add liquid sealant after the fact, when the tire is already flat, is less effective. 

Liquid sealants fill holes up to 3-4mm (around 1/8 inch) in size. Liquid sealants can be put into all Schrader valve inner tubes (the most common factory valve on eBike tires and tubes) and Presta valves that have removable cores. There are multiple brands of these liquid sealants on the market and there are even inner tubes, like the Slime brand, that come preloaded with sealant for convenience.

Sealants do not, however, protect from cuts or gouges to your tire’s sidewall. If you have sealant in your inner tube and it deflates because of a puncture you’re going to be dealing with quite a large puncture or a hole in the sidewall of your tire. These can still be repaired using the methods above, but, because of the presence of the sealant, it can be a messy job to do so. When using inner tubes with sealant, you should still carry a spare inner tube with you so that you can replace your tube should you get an irreparable puncture.

An alternative to purchasing inner tubes with liquid sealant are tire liners. These fit between the tire and the inner tube and provide an extra physical barrier between the inner tube and the outside world, stopping nails or glass from reaching the inner tube.

Alternatives to fixing a flat tire on the road or trail

If you haven't mastered the technique of changing a flat, don't despair. There are alternatives to DIY repairs:

• Always carry your repair kit - even if you don't know how to use it, another friendly cyclist might be able to help you, IF you have the right tools, pump, and tube on hand. 
• Use AAA. Check your auto policy to see if emergency road service covers your bicycle (it does in many states)
• Use a local bike shop - many local independent brick and mortar bike shops are now offering mobile repairs and some are available in emergencies. Put the number of your favorite shop in your phone.
• Call an Uber or Lyft as a last resort. Both services allow riders to specify larger than normal vehicles.

Before attempting a repair, make sure you actually have a puncture

All bicycle tires bleed air slowly over time, even when there isn't a puncture. If your eBike has been sitting unridden for a while, you might find the tires are low. Try inflating the tires to their proper pressure and see if it holds before you start a repair.

Because all bike tires will go soft as time passes, you should regularly inflate your tires to the proper pressure as indicated on the tire sidewall. Check at least weekly and use a floor pump to easily inflate. They inflate much faster than the small pumps designed for portability.

Once you know what the proper pressure feels like, it's much easier to quickly identify a puncture.

A flat tire on your eBike isn't the end of the world

Your first flat tire might seem a bit daunting, but you can see that it’s not too hard to fix. Fixing a flat requires the right tools, a little time, and a dusting of patience. Once it’s complete you’ll feel like a champion and every time you do it it’ll get easier and easier. But hopefully you don’t have to do it too often!