DIYers: minimum width tire for safety?

[mikeschn]

DIY ebike builders,

If you were looking for a bike to convert to an ebike, and you know it will be used mostly on gravel trails, with loose gravel and twigs, what is the minimum width tire you would consider? Consider also that 20 to 22MPH would be the top speed.

Are the 2.125" wide balloon tires such as found on the old cruisers wide enough? Or maybe 2.3". Or how about 2.6"? Or maybe I shouldn't consider anything less than 4"?

I have a Giant Cypress DX with 622x45C tires, and I'm beginning to think they are not wide enough.

Your thoughts?

Mike...

 

[tomjasz]

I like my 2.25 and 2.125. however a decent 1.95 works for me as well.

 

[mikeschn]

The Cypress DX has 1.77" wide tires, so too skinny?

Mike...

 

[Roamers]

My Gazelle has 42 mm tires, but they are rated for Ebikes; got no idea what the crireria is.

 

[mikeschn]

My Gazelle has 42 mm tires, but they are rated for Ebikes; got no idea what the crireria is.

@Roamers

So is your Gazelle a pavement bike or a trail bike?

Mike...

 

[JES2020]

DIY ebike builders,

If you were looking for a bike to convert to an ebike, and you know it will be used mostly on gravel trails, with loose gravel and twigs, what is the minimum width tire you would consider? Consider also that 20 to 22MPH would be the top speed.

Are the 2.125" wide balloon tires such as found on the old cruisers wide enough? Or maybe 2.3". Or how about 2.6"? Or maybe I shouldn't consider anything less than 4"?

I have a Giant Cypress DX with 622x45C tires, and I'm beginning to think they are not wide enough.

Your thoughts?

Mike...

Most mountain bikes are in the 2 inch range, considering mountain bikes are made for.... err mountains, that should give you a clue.
More important is the tread on the tire. knobbies will be better for loose gravel, the more aggressive the knobby the better they are for looser gravel.

Classic dirt knobby CST C183 old bicycle tire 20''x 2.125'' (PAIR) Black. | eBay

Find many great new & used options and get the best deals for Classic dirt knobby CST C183 old bicycle tire 20''x 2.125'' (PAIR) Black. at the best online prices at eBay! Free shipping for many products!

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[mikeschn]

Most mountain bikes are in the 2 inch range, considering mountain bikes are made for.... err mountains, that should give you a clue.
More important is the tread on the tire. knobbies will be better for loose gravel, the more aggressive the knobby the better they are for looser gravel.

Classic dirt knobby CST C183 old bicycle tire 20''x 2.125'' (PAIR) Black. | eBay

Find many great new & used options and get the best deals for Classic dirt knobby CST C183 old bicycle tire 20''x 2.125'' (PAIR) Black. at the best online prices at eBay! Free shipping for many products!

www.ebay.com

@JES2020

That's a good comparison. How fast do MTBers go? I supposed if they are going downhill, probably quite fast. Is there a maximum size that a MTBer might consider, for example 2.6 or 3.0? Diminishing returns in the safety factor versus weight, etc...

Mike...

 

[JES2020]

@JES2020

That's a good comparison. How fast do MTBers go? I supposed if they are going downhill, probably quite fast. Is there a maximum size that a MTBer might consider, for example 2.6 or 3.0? Diminishing returns in the safety factor versus weight, etc...

Mike...

The knobbys I posted can easily do 30 mph. If you plan on any asphalt use, the knobbys will decrease your top speed as well as make more noise.
The wider the tire the more grip on loose substrate. For example fat tires, 4 inches, are recommended on sand and snow. But the extra grip and weight will slow down the top speed.
Personally, I have no problem with gravel on 26", 2.125" knobby MTB tires like the ones I posted ( at half the cost) and on asphalt I can hit 35 MPH...48v 1500wplus motor.

 

[indianajo]

Size of tire has to do with comfort. Thousands of road miles are clocked on 32 mm tires, but those people never sit down. I do okay on 1 3/8"x26" tires, but the 2.1" on my current bike are more comfortable. I've used 1.75" on it without problem. I've never owned a bike that would take bigger tires than 2.1". Tires that will not allow 55 psi (like fat tires, 20 PSI) cause unnecessary drag, IMHO. I ride knobbies not so much for traction, as to prevent flats. If the knobs are taller than 3/32" I don't get flats. Knobbies will climb a 2" tall driveway entrance (the standard now in my city) better at acute angles than a smooth tire.

 

[Roamers]

@Roamers

So is your Gazelle a pavement bike or a trail bike?

Mike...

Sorry, your criteria didn't stick when I answered. This is not a trail bike. I would not spend a lot of time in soft with these. Compacted gravel with occasional loose would not bother me. My hybrid has 38 mm and have no issue with occasional soft.

 

[EMGX]

I have bikes with tires ranging from 103psi 700x32 (Gatorskin) to 65psi 26x2.2 (Maxxis Holy Rollers). Like everything in life it is a compromise. The 32c at 100+psi makes for an easy pedaling faster but much more jarring ride. The 26x2.2 Holy Rollers are super stable, almost motorcycle like at speeds up to low 40mph, have a much more supple ride and have been great on pavement as well as gravel and slick mud - they definitely have a weight and rolling friction penalty - but still nice tires. My more in between tires like Schwalbe 700x40c G One gravel tires and Continental 26x1.75 (and Schwalbe Marathons) are more in between, as expected. None of them seem unsafe to me, depending on road conditions (the Gatorskins are skittish on loose gravel and I wouldn't ride them places where I can easily ride the Holy Rollers).

 

[mikeschn]

@EMGX

That's a real good starting point for me. Thanks...

 

[mikeschn]

I found a cute little video yesterday... and I can certainly see lots of benefit to the mid-fat size!

If anyone wants to see the video I watched of JohnnyNerdOut, it's here:

But so far I've only made it to 2.3". Ha!

Mike...

 

[AHicks]

"Loose gravel" can be a pretty unpredictable surface, especially if you are spending the majority of your time on it. If loose like you say, it sounds like you might have it right using a target of 2.25"-2.8". I certainly wouldn't be looking forward to riding on anything narrower. From there, it's about tread pattern that will work best.

 

[tomjasz]

Gravel bikes are popular here with hundreds of miles of gravel country roads. Tires range most commonly from 38mm 1.5” to 50mm 2”. 40mm tires are very commonly found on gravel bikes.

 

[JES2020]

I found a cute little video yesterday... and I can certainly see lots of benefit to the mid-fat size!
View attachment 122314

If anyone wants to see the video I watched of JohnnyNerdOut, it's here:

But so far I've only made it to 2.3". Ha!

Mike...

It's really simple, If you are planning on snow or sand riding , get a fat tire. Or if you just have to have the look.
Otherwise a standard 2.125"(consider what tread you want), for trails, gravel and grass, and street, will work fine.
If you're ONLY on street, then you want thinner, smooth tires, for less resistance.

 

[AHicks]

It's really simple, If you are planning on snow or sand riding , get a fat tire. Or if you just have to have the look.
Otherwise a standard 2.125"(consider what tread you want), for trails, gravel and grass, and street, will work fine.
If you're ONLY on street, then you want thinner, smooth tires, for less resistance.

From a rolling resistance standpoint, and possibly from a best ride possible on less than perfect surfaces, I believe you need to look at the tire ratings supplied by the tire manf.

I stumbled into the 2.4" Schwalbe Super Moto-X tires for instance. They are clearly a balloon type at 2.4" (for outstanding ride), but are also very highly rated when it comes to rolling resistance, or better said, the lack of it! Unusual as well, these tires work really well with lower pressures, like down in the range of 30psi!

Point being, you don't necessarily NEED a thinner tire for acceptable rolling resistance.

Bonus on the Schwalbe tires is the built in flat resistance. Considered by many as the best available for this type tire.

Point being, our bikes are all running the Moto-X for mostly pavement with occasional hard packed trail use. I would highly recommend them to anyone riding similar surfaces.

Super Moto-X | GreenGuard | Black | 27.5x2.40 | Addix | 11100726.01

WIDE, COMFORTABLE, SAFE! Whether travelling on asphalt or trail, the beefy Super Moto-X offers the best riding characteristics and plenty of comfort. The extra-resilient DoubleDefense construction lets you reach your destination safely, even in the tough…

www.schwalbetires.com

 

[mikeschn]

I've not been able to find a "good" rolling resistance website that covers all the tires I would like to know about... I found this, but many tires are missing...

The Best Road Bike Tires | Bicycle Rolling Resistance

Best road bike tires in these categories: all-round, all-round tubeless, fastest, fastest tubeless, puncture resistance, puncture resistance tubeless, low-cost.

www.bicyclerollingresistance.com

I do have the super moto X, which are nice... and am also considering the Big apple, which look similar, but how does the rolling resistance compare to K-Rad and Holly Mollers?

 

[Gionnirocket]

.. as for safety I would consider tread design as much as tire size. Tires such as Continental eRuban, Kenda Kwick Drumlin and Schwable Johnny Watts are good for pavement as well as gravel with much less noise and rolling resistance then full_on knobbies... all with an ebike rating.

 

[JES2020]

I've not been able to find a "good" rolling resistance website that covers all the tires I would like to know about... I found this, but many tires are missing...

The Best Road Bike Tires | Bicycle Rolling Resistance

Best road bike tires in these categories: all-round, all-round tubeless, fastest, fastest tubeless, puncture resistance, puncture resistance tubeless, low-cost.

www.bicyclerollingresistance.com

I do have the super moto X, which are nice... and am also considering the Big apple, which look similar, but how does the rolling resistance compare to K-Rad and Holly Mollers?

Your moto X is going to have less rolling resistance than something like the K- Rad, but the moto X is not a knobby.
You have to figure out what type of riding you are going to do first, street or dirt.