E-bike versus moped tires

[Altema]

I did yet another group ride with gas mopeds and motorcycles, and ran into some tire problems with the continuous high speed. Well, not really tire problems, but problems with Tannus Armour causing tube failures, and I'll discuss that specifically in another post. So as a result of TWO flats in a row on the same ride, the owner of the moped shop hosting the event suggested I try something more durable. I purchased a set of Shinko "Golden Boy" tires, which are extra thick knobby tires, and the matching tubes. Installation was difficult due to the thickness, but with a helper I got them mounted. A photo is below of the two types of tires, and I chose the one on the left.

First thing I noticed is how stable they are. Taking my hands off the handlebars, there was not a hint of wobble. Matter of fact, I had trouble changing direction with my hands off the bars. Secondly, I don't think I would ever get a flat with these, and I bet they are better in sand and snow. High speed handling is good, and they are actually rated for 93mph, which I won't be doing!

Now for the downsides. These tires are heavy at 5.9 pounds each, then add another pound for the tube. That comes to almost 14 pounds versus 7.4 pounds total for the Kenda tires and tubes. You might think this is not a big deal, but that 14 pounds of rubber and cord is on the rim of the wheel, and rotating mass is quite a bit different from just having extra static weight in your backpack. The bike accelerates more slowly and takes longer to stop. Then there's the friction. Tires "flatten out" where the rubber meets the road, and with the tread blocks being so thick, this means the blocks move closer together as soon as they meet the pavement. What do you get when rubber blocks get closer then spread back out? Friction, and that friction creates enough resistance that the bike feels like the brakes are dragging. You stop pedaling and the bike slows down immediately. It literally takes more power to get up to speed, and more power to maintain that speed. And since the drag is always there, it reduces top speed as well. Not just on a Rad bike either. A friend of mine has these tires on a dual motor 3000 watt Ariel Rider Grizzly, and he lost  several MPH off his top end.

Despite the huge positive points, the deal breaker for me is that the bike no longer feels like a bike. It feels like a heavy moped and the pleasure of pedaling is gone. This would be fine if it was used just for commuting, but I often ride for pleasure. On normal pedal assist I'd be using 250 to 275 watts. Now it's 400 watts, and the the bike feels like it's dragging the moment you stop pedaling.

So I went through the work of changing to the original Kenda tires, without the Tannus Armour which I will never use again, and the bike is light and lively again. But of course I had to verify efficiency differences, and I logged two similar rides on the different tires to verify things. A screenshot of the datasheet is included, but to summarize, the Kenda ride had a higher average AND top speed, and used 172.34 watt hours of battery. The moped tire ride had a slower average and top speed, and used 233.11 watt hours of battery. This means that riding aggressively with my smallest battery (650Wh) will get me 27.53 miles on the Kendas, but only 19.58 miles on the Shinkos. Anyway, I prefer the feel of the Kenda tires, but may switch to the Shinkos for extreme conditions.