Are 3.50-16 front motorbike tires roughly 100mm wide..?

[fireaza]

Hey guys! I'm looking for higher-end road tires to replace the knobbly 20x4.0 tires that came with my ebike. I've been looking for motorbike tires, since the only road-style bike I can find in 20x4.0 size are Supermoto X, which are a bit more on the expensive side and wouldn't be as hardy as a motorbike tire. Obviously, motorbike tires are heavier, but my bike gets a good week on a charge, so I'm not too worried about slightly reduced range.

At first, I had been looking for tires mark as "110/SOMETHING-16, since that seemed to be the figure that I saw online for what size motorbike is the equivalent of a 20x4.0 bike tire. However, I've measured the width of the tires that came with my bike, and they're actually 100mm wide, 110mm would scrape against my chain!

So instead, I've been looking at tires marked as "100/SOMETHING-16". I've been having trouble finding good choices in this size, just Dunlop K330A so far. But I've also seen tires marked in inches too, and according to THIS TIRE CONVERSION CHART, for a front, road tire (all the correctly-sized tires I've found are marked as "front" so I'm assuming I need to use the front measurement) "100/90 is 3.25/3.50".

However, not quite sure how to interpret this. By "100/90" do they mean "100mm wide, 90% ratio" or "100mm = 3.25" and "90mm = 3.50"? 100mm is 3.93 inches, but I'm assuming the difference is 'cuz motorbike tires are measured by the rim and not the tire. But either way, I'm not sure how a larger measurement in mm winds up as the smaller of the two measurements in inches, so that's clearly not right.

Does anyone know how to interpret this conversion? What 16 inch motorbike tires would be roughly 100mm wide in imperial measurements?

 

[Chalo]

By "100/90" do they mean "100mm wide, 90% ratio"

That means nominally 100mm wide, with the sidewall height being 90% of the width, or 90mm.

What 16 inch motorbike tires would be roughly 100mm wide in imperial measurements?

100/90-16, 100/80-16, 4.00-16

They'll weigh a depressing ton, and they'll be a bear to mount and dismount.

 

[Mongo]

Schwalbe's moped-ish 20x2.60 Pick-Up tire (65-406 ETRTO) is quite a bit narrower than your picks, but it's a pretty good roller and a tough tire. And it'll rim up with less fuss.

 

[neptronix]

..the huge weight and added rolling resistance will put a big strain on your ebike..
..i hope you have an excess of power available to you

 

[fireaza]

That means nominally 100mm wide, with the sidewall height being 90% of the width, or 90mm.



100/90-16, 100/80-16, 4.00-16

They'll weigh a depressing ton, and they'll be a bear to mount and dismount.

Thanks! Aren't tires measured according to the rim when measured in imperial units though? Hence why the conversion guide says "100/90 = 3.25/3.50"? I'm not finding any 16 inch tires marked as "4.00".

Schwalbe's moped-ish 20x2.60 Pick-Up tire (65-406 ETRTO) is quite a bit narrower than your picks, but it's a pretty good roller and a tough tire. And it'll rim up with less fuss.

Considering my wheels are sized for 4.00 wide tires, wouldn't 2.60 wide tires just, fall off..?

..the huge weight and added rolling resistance will put a big strain on your ebike..
..i hope you have an excess of power available to you

I've got a 1000W motor! If anything, heavier tires might make the bike less jumpy!

 

[BionicOnion]

Schwalbe's moped-ish 20x2.60 Pick-Up tire (65-406 ETRTO) is quite a bit narrower than your picks, but it's a pretty good roller and a tough tire. And it'll rim up with less fuss.

Sorry to drag this thread forward 4 pages, so I'm looking at that tire since you recommended it, is there any advantage to it over say a 3-16 moto tires outside of weight savings? I've never seen a speed rating on bike tires and have always been concerned if I can get the power I'd like to hit upwards of 45-50ish mph, can the bike tire take it? I have a background in the auto field, so I'm trying to learn

Edit: or would an emoto tire like a 3x20 work well? I have some bmx rims I'd like to use if possible, but they have i think 2.1ish tires on them so can I use the 3x20 and still fit? Do they just balloon different or?

Edit 2, just checked the rims I have have an inside width of 25mm

 

[amberwolf]

Edit: or would an emoto tire like a 3x20 work well? I have some bmx rims I'd like to use if possible,

A 20" MC tire won't fit a 20" BMX rim. See the previous posts I've made in your thread(s) about MC vs Bicycle rim and tire sizes and the very limited crossovers there are.

 

[BionicOnion]

A 20" MC tire won't fit a 20" BMX rim. See the previous posts I've made in your thread(s) about MC vs Bicycle rim and tire sizes and the very limited crossovers there are.

No i know the difference amberwolf. The diameter is the same it is a 406 rim, not a 20" moto rim. I measured the width and it's right at 24-25mm inside width, so i can run 20 inch bike tires or 16 inch moto tires. My question is, is it safe to run a 75ishmm wide tire (3 inch wide) on a rim that's 1/3 the width. From what else I've read of the forum, while not ideal for that width of a tire it will work. Ideally the rim would be 45-55mm wide from what i gather.

 

[bananu7]

Typically the tyre manufacturers will specify the acceptable rim width. With just 1000W, I wouldn't bother with a motorcycle tyre, that kind of power will be happily handled by any bicycle tyre.

 

[BionicOnion]

Typically the tyre manufacturers will specify the acceptable rim width. With just 1000W, I wouldn't bother with a motorcycle tyre, that kind of power will be happily handled by any bicycle tyre.

Yea no doubt I think I'm probably gonna limit bike tires to 2.5-3kw peak which i think should be ok for my application, my concerns were more with life of tire wear, speed safety, and puncture resistance. I do have one im looking that will potentially peak into the mid teens...but maybe just for that one position a moto tire would be a better option