Talking about bicycle/e-bike wheels, tires and tubes might not sound so interesting in the scheme of things, especially since I have yet to talk about brakes (equally as important as tires, and the topic of my next post). But I think tires, and their supporting cast, wheels and tubes, are extremely important! And here’s why…
Electric bicycles are heavier than regular bicycles, tend to go a bit faster than a bicycle under pedal power only, and in some cases (to be explained), the rear tire might be considerably harder to change ‘in the field’ than a standard bicycle tire. But we’re getting ahead of ourselves.
Let’s start with wheels. Wheels come in many sizes. My current e-bikes all have spoked 26″ wheels with a 1.5″ width rims. This wheel size has been around a while, so it’s likely you’ll find 26″ wheels if you’re hunting for an older frame to build out an e-bike with. More modern mountain bike wheel sizes include 27.5″ and 29″.
As far as wheel widths are concerned, for mountain bikes and for my DIY e-bikes, 1.95″ to 2.5″ wide tires are the norm. I tend to stick with 1.95″ tires since most of my riding is on paved trails and roads. This tire provides less weight and rolling resistance, but is wide enough to provide a good contact patch on the road surface. I also tend to go with a Slick Wire Bead tire like this one, rather than a traditional knobby mountain bike tire.
Slicks make less road noise and stay planted on a paved road surface better than knobbies. I’m also not a fan of fat-tire e-bikes which can have tire widths up to 4″. For better handling and control, there’s a category called ‘plus-size’ tires which fall into the 2.4″ to 3.25″ range. The popular Rad City 4 Commuter runs the Kenda K-Rad 26″ x 2.3″ which I would consider a plus-size tire on the lower end of the scale, and is an excellent choice for this type of e-bike!
Getting back to wheels for a moment, it should be obvious that your wheel size is going to dictate your tire size and choices available to you. Fitting the wrong size tire to your wheel will have unfortunate consequences!
Once you have settled on a tire size, you’ll need to find tubes that work for your given wheel and tire. Here’s where things can get interesting. First, some wheels are designed for Presta valve stems and some for Shrader value stems. Presta (on the left) is slightly less common on mountain bikes these days than Shrader (on the right, and what you’ll find on your car as well). But still, you have to know which valve type your bike requires before ordering new tubes.
Second, when talking about Shrader valve stems, you’ll need to know if your wheels are single or double-wall (very common on the rear wheel of a rear hub e-bike). As it turns out, rear-hub e-bikes can create a lot of torque, so e-bike manufacturers will use double-wall rims for added strength and durability. But why does this matter you might ask when shopping for tubes? Because you’ll need to buy a tube that has a longer valve stem for a double-wall rim than you would for a single wall rim, resulting in a valve stem that’s too short to connect your air pump to. Here’s a typical tube that works with a single wall rim:
The description doesn’t say how long the valve stem is so it’s likely about 34mm long and won’t work with your double-wall rim – too short. So with a little more searching, you’ll find something like this:
This tube has 48mm Shrader valve stem and will work great with your double-wall wheel(s).
On my DIY bikes, I’m running single-wall wheels on the front so a 34mm stem works fine. However, if you’re in the habit of carrying a spare tube with you on your rides, be sure to carry a tube that will work for either wheel.
As a parting thought, I’m not sure I would actually be able to change the tube on the rear tire of my rear hub e-bikes when I’m out and about. This is because the axle bolts are torqued down and require a wrench (that I don’t carry with me) to remove, AND disconnecting the wires necessary to remove the rear wheel is very cumbersome. I learned all this because I actually got a flat on the rear tire on DIY Build #1, just not while I was riding, thankfully. So what to do?
- I’m now installing Slime tube protectors in each of my tires – which might help,
- I carry a bottle of Slime Tube Puncture Repair Sealant, a Shrader valve tool, and a tire pump in my Camelbak pack as a get-home strategy for my rear hub bikes, and
- I carry a charged cell phone to call home for a lift if necessary (or for other emergencies).
PS – When riding the mid-drive e-bike, I carry a standard tire repair kit since the front and rear wheels are easily removed so tires and tubes can be repaired. The essential ingredients of this repair kit include:
- 3 tire levers
- 1 tube (Presta in this case)
- air pump
** Update **
A couple good videos concerning tires and tubes (specifically about how to prevent flats):