Tire Choice - Where the rubber meets the road

[Onidaren]

I currently have generic cheap chinese 26" wheels. The front wheel weighs 5lbs = 2.27 kg with tire and tube, inflated (assume the rear weighs more due to cassette, chainring, derailleur, chain, etc - but how much more? dunno).

I am installing a 3000w Cyclone kit on this bike, but I will be running it at 52v and 25A (1300W) using a lyen controller and lunacycle dolphin pack (controller is programmed to limit current). The primary intent of this motor is to safely (and briefly) navigate roads with no bike lines, where left turns are unavoidable, speed limit is 45mph, and cars show no mercy.

One additional consideration is that I actually intend to pedal this monster at times when I do not need the motor. Therefore I want my bicycle to have decent speed and handling for my 100W human output.

I would like to upgrade to:
gatorskin tires: http://amzn.com/B002SR3O88
continental tubes: http://amzn.com/B0068FAWJ0
650c rims: http://amzn.com/B00C1C7I0K

Which will bring mass down to around 2lbs. rpm will also decrease because we are using a larger 27.5" outer diameter (My understanding is that this includes the tire, correct me if I'm wrong).
The diameter of the tire cross section will shrink from around 2" to 1"." The density of tire rubber is roughly 74lb/ft^3. I have calculated that the wheel upgrade will reduce the needed power by around 75W whenever I want to change the speed of the wheel. This means better acceleration, which means more stress on the spokes, hub, tube, and tire because the bike will still weigh about 200lb including rider and cargo.

The $200 question is, can these tires and wheels realistically handle 1300W on a typical electric bike? The $1500 question is, will I still be able to maintain traction? Ultimately the answer has to come from experience and real life tests. Here's where I defer to the experts on ES.

Has anyone else had this crazy idea before, or is it just me? Who has tried it, and how did it work out? Did you need any modifications? Is there an objective chart somewhere that can tell me how many watts of power is appropriate for a given tire, bike weight, and motor power?

I am open to better ideas. safety and performance are coequal priorities because in my case, they are interdependent.

 

[Chalo]

Continental Gatorskin tires have superb marketing. That's the only superb thing about them, in fact. Otherwise, they're just ordinary training-grade sport tires with a cosmetic grating on the outside that shreds up and motivates people to buy a new pair before the old ones are used up. They're still made in Germany, which is nice. Those folks have to earn their high wages somehow.

I don't know where you got your notions about rolling resistance and tire size, but all else equal, fatter tires are measurably faster in terms of rolling resistance. They have slightly higher aero resistance, which starts to matter at speeds faster than you can go with pedals alone.

Try a pair of 26x2.0, or if you like, 26x1.5 or 1.25" Panaracer RiBMo tires. Those are actually long-wearing and puncture resistant (unlike Gatorskins), fast like Gatorskins, and they have nicer ride quality. They cost less, too.

650c rims only measure 12mm larger in diameter than MTB rims. They offer nothing, except terribly poor tire selection with 28mm as the largest option. 26x1.25 slick tires on normal MTB rims do everything better than 650x23c. And they're the same diameter overall.

650b is a wheel size for suckers, only 4% larger than MTB wheels with the same size tires. Rims and tires cost a lot more, though-- approximately double compared to normal 26".

 

[Chalo]

Also worth noting is that lighter wheels have less steering inertia and accelerate very slightly faster, but they have less stability at speed. Skinny tires offer less traction than fatter ones, which exaggerates any handling shortcomings. If you're going to go faster than humanly possible, the advantages of sturdy wheels and wider tires strongly outweigh the few advantages of light wheels and skinny tires.

 

[Kevin Crawford]

I've used Gatorskins on a road bike, and while they are nice, supple tires, the flat protection leaved more than a little to be desired. If you're commuting, you probably want something dependable.

I wouldn't even consider buying anything other than Schwalbe Marathon Plus. I've used these - and I swear this is not an exaggeration - for over 10,000 miles, with not one flat. Are there faster tires available? Sure. How fast are you when you're stopped for a flat repair? And, they look nowhere close to being worn out. I wouldn't be at all surprised to get 20,000 miles out of them. How's that for value? I'm not even sure I need to carry anything for flat repairs anymore. They can be difficult to mount, but once they're on, they'll be rock solid.

 

[Chalo]

I have used lots of both Schwalbe Marathon Plus and Panaracer RiBMo for uncounted thousands of miles, and I've had the same record of punctures in both: one each. Both from nasty sharp long metal objects. They're both pretty unimpeachable in terms of puncture protection.

However, the Marathon Plus rides harsh and slow, with poor traction, compared to RiBMo. And it costs more. And it wears faster. I've bought a bunch of them, but I don't expect to buy any more of them. If I can get the same demonstrated protection, with much better efficiency and ride quality and traction and endurance, for less money, I don't have to think to long about it.

 

[Onidaren]

Also worth noting is that lighter wheels have less steering inertia and accelerate very slightly faster, but they have less stability at speed. Skinny tires offer less traction than fatter ones, which exaggerates any handling shortcomings. If you're going to go faster than humanly possible, the advantages of sturdy wheels and wider tires strongly outweigh the few advantages of light wheels and skinny tires.

Thank you for pointing me towards the ribmos, they look awesome. I have been researching this for months and still would never have known about them.

I will take your advice for this build, because I am planning to carry cargo and I need the traction/handling to be good. I am still curious if anyone has tried putting a medium wattage mid drive on a bike with quality 650c or 700c tires, and how did it work out.

 

[Chalo]

700c mid drive conversions are common; I've even done them in my shop. 700c is sometimes referred to as 29 inch when it's fitted with a fat tire. The width range for 700c tires runs from 18 to 75mm, with a limitless variety of options.

650b is an ascendant marketing-driven size that offers nothing new, and when fitted with fat tires, it's referred to as 27.5 inch. It works just like regular 26", because the rim size difference is less than an inch, but it costs double. Since the industry is very hot to get you riding a new, more expensive bike, they're pushing this fashion trend pretty hard and you're likely to find recent conversions that use it.

650c is an obscure size used almost exclusively on triathlon aero bikes and ancient Schwinn cruisers. You can get tires for it in 20-23mm widths, plus a single option in 28mm from Terry, or you can get thick nasty 26 x 1-3/4" cruiser tires made for old Schwinns. There are no good all purpose tires made in that size. I doubt you'll find a single e-bike conversion that uses it.