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While shopping for new tires on my bike, I saw that some dealers had a specific section for e-bike tires, where the various brands production for e-bikes was present.

Why do e-bikes need dedicated tires?

L.Dutch
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5 Answers5

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They don't need them but they are good to have. I have an e-bike that I use as a daily commuter. Here are my thoughts:

  • E-bikes are heavier than regular bikes and put considerably more power out at the rear wheel (my motor has 350 watts, I add maybe 60-80 watts at most) compared to a regular bike which only has 80 watts alone.
  • if you have an ebike with a rear hub motor, that’s a considerable amount of unsprung weight at the rear. It’s much harder to hop curbs and potholes with an ebike so it’s getting whacked much harder
  • E-bikes travel at much higher average speeds than regular commuter bikes. I average 30km/h with peaks of 40km/h which is the electronic assist speed limit. More importantly, I don't make any attempt to conserve inertia as I do with a regular bike, so I stop at all the stop signs and traffic lights. Thus, there's a lot of braking and acceleration that I do that is hard on the bike and its wheels.
  • Finally, the rear tire needs to be sturdy as it is getting more wear and also taking bigger hits on bumps at higher speeds than a standard tire.

All in all, I'm still on the original tire which is a regular tire. I'm on the tail end of its lifetime which has only been about 1/3 that of a regular tire. I will replace it either with a beefy "regular" tire or go with one from an e-bike line. I think the actual difference between the two (beefy regular or touring and a e-bike tire) will in reality be minimal.

Update 2018.7: I ended up replacing my rear tire ahead of schedule due to a sidewalk blowout. I’m not actually sure if it was natural wear or if the bike was shivved by a thief. Replaced with a tire from an ebike tire line.

TL;DR: Ebikes require a strong, hard-wearing, high speed, puncture resistant tire. These are also roughly the same requirements as touring tires so some vendors are labeling their touring tires as "ebike ready."

RoboKaren
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    Not sure your argument stacks up. An ebike adds around 10kg to the bike, doubling its weight, but with a 90kg rider, the ebike+rider is only 10% more weight. An elite rider can put out 1500W peak and sustain around 450W for an hour, so the power of an ebike is typically less than the power tires put on pro racing bikes have to handle. – mattnz Sep 06 '17 at 08:34
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    Yes, I'm not a pro rider nor am I riding in a race. When at the gym and working at the same effort level as when I commute, I only put out around 100 watts max, more than that and I start sweating too much. – RoboKaren Sep 06 '17 at 08:37
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    And as for weight, my ebike is roughly 15kg more heavy than an equivalent bike but it's all unsprung weight with a huge mass centered on the rear hub. This has consequences especially when hitting potholes and curbs. Remember that riders are normally considered sprung weight as we use our arms and legs to absorb some of the shock. – RoboKaren Sep 06 '17 at 08:38
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    @mattnz The relevant comparison is tyres for regular Joe street bikes (and I mean "street", not "road") versus e-bikes, not pro racers versus e-bikes. Your regular Joe isn't putting out 250W, let alone 450. Also, the pros use tyres optimized for speed at significant expense to durability. – David Richerby Sep 06 '17 at 09:32
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    An elite rider capable of sustained output of over 400W is going to have his or her tires changed regularly, probably by the team mechanics – Argenti Apparatus Sep 06 '17 at 12:24
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    @mattnz - Elite riders will also know how to avoid road obstacles so that the tires do not get damaged. Doubling the speed of a regular rider can be problematic. My understanding is there is a general concern about regular riders hitting obstacles at speed and losing control. Most regular riders do not have practice on how to handle a bike at speed, so most ebikes are designed to be extra robust. The only reason there are thin delicate tires on road bikes is to eeek out every last drop of speed - and we are willing to accept the consequences that come with that choice. – Rider_X Sep 06 '17 at 15:49
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    You don't need to be an elite rider to outperform the motor. Most regular commuters will put out similar or more power than the motor. – Qwerky Sep 06 '17 at 16:16
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    @Qwerky the legal motor power limit where I live is 250W. That's a decent bit of effort. I know because I regularly do it on my bike. The motor can keep that up until the battery runs out, but most commuters couldn't. Remember most commuters are on any old bike in ordinary clothes and don't want to sweat too much. In other countries, much higher powers are legal. – Chris H Sep 06 '17 at 16:41
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    @mattnz I'd say more like 20kg,nearly all on the back wheel. That starts getting significant – Chris H Sep 06 '17 at 16:42
  • @Chris - Given the entire weight of the Bosch system is under 15 pounds (7 kg) , which is probably less than the weight difference between the lightest and cheapest MTB's or Hybrids, I sense we need might be in need of a new term E-BSO :) – mattnz Sep 07 '17 at 01:02
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    Bosch is a bottom bracket motor so its weight is divided between wheels. You don't have to be riding a BSO to use a rear wheel hub motor. – RoboKaren Sep 07 '17 at 02:44
  • Well, I used to be a decent rider, capable of a sustained 20mph on the flat. Then got a very serious illness; nowadays I use an e-bike a lot. Interestingly, over a 12.5 mile commute the 'best time' is almost identical between the two. The e-Bike is a round 20kg heavier than my road bike at full load, but the speed of the e-bike is more even - it's very hard to get it past 18-19mph even on a slight downhill where a road bike would be over 20mph. So any extra wear would be entirely down to extra weight on the e-bike – Andrew Jon Dodds Sep 07 '17 at 07:00
  • @mattnz you may be right. A decent lithium battery made out of standard cells weighs about that much, so Bosch must be saving quite a bit of weight there. Possible if they don't use steel-cased cells. Then the mirrors are highly variable. Most e-bikes also have a pretty sturdy frame. So you could build one at around 20kg, but it would be expensive. Most are cheaper and heavier. – Chris H Sep 07 '17 at 07:33
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    I think the point about unsprung weight deserves more emphasis, I suspect this is the dominant factor for requiring sturdier tires. The motor is completely unsprung, stiff mass, unlike not only the rider but also the stuff stored in e.g. a pannier, which isn't completely rigid. – leftaroundabout Sep 07 '17 at 12:58
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    The Bosch weight is just the motor and not the battery weight. – RoboKaren Sep 07 '17 at 14:05
  • By the way, lots of cyclists stop at red lights and stop or slow to around walking pace for stop signs. So I don't think you get to claim that as a special stress on e-bikes. – David Richerby Sep 08 '17 at 10:08
  • Even if a motor is capable of 350W to be legal (at least in many countries) it may only deliver the amount of power that equals the rider's input. 80W-rider + 80W-motor is less than a well trained cyclist can give on average on even skinnier tyres. It's just marketing, IMHO. – Carel Sep 10 '17 at 20:36
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    Errr... Carmel... do you own or ride an ebike? None of the models, even pedelecs work that way. Rather, they either have a throttle that can give 100% or if they are in pedelec mode they adjust the throttle based ether on effort (torque) or cadence but none of the algorithms expect a 1:1 contribution. It's perfectly normal to get full motor output even at a modest contribution level by adjusting the assist level on your ebike control panel. – RoboKaren Sep 10 '17 at 20:39
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According to Schwalbe at https://www.schwalbe.com/gb/e-bike.html

For standard pedelecs with pedal assistance up to 25 km/h no specific tyres are stipulated by the legislators. But the loads and average speeds of these bicycles are also higher than in the case of normal bicycles. We therefore recommend only certain tyres as “E-Bike Ready 25”. Primarily, these are the tyres of the Marathon and Energizer series as well as the comfort tyres Big Apple and Big Ben.

I call BS on this. 25km/h is not a high speed, nor is the extra weight significant compared to the weight of the rider. Compare this to touring bikes. A touring bike will generally be expected to ride at this speed (less than 16mph) and the luggage will exceed the weight of a motor and battery - but nobody makes touring bike tyres that are made due to the expected "high speed".

Qwerky
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    Basically what they're saying is that their tougher ordinary tyres (e.g. the marathon series of touring tyres) are good for e-bikes. And an e-bike can maintain 25km/h in circumstances where the same rider couldn't on a normal bike, and accelerate to that speed more quickly. Also the consequences of a sudden failure on a 35kg bike doing 25km/h are significant, so you don't want a tyre that spends much of its life worn – Chris H Sep 06 '17 at 16:53
  • Thank you - This has to be THE correct answer as you have provided a reference from a manufacturer. – mattnz Sep 06 '17 at 20:20
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    All of Schwalbe's touring targeted tires are also rated as "E-Bike Ready" either 25 or 50. So it seems correct that the needs of touring bikes and e-bikes are similar. Yes, it's marketing, but the people buying e-bikes aren't necessarily the tire-nerds that touring cyclists can be, so genuinely not know that a walmart tire is a bad idea. – Jamie A Sep 06 '17 at 21:28
  • AFAIK there is no legislation anywhere in the world that controls speed ratings for bicycle tyres. So the manufacturer is "technically" correct with "For standard pedelecs with pedal assistance up to 25 km/h no specific tyres are stipulated by the legislators" but its disingenuous and unethical. – Criggie Sep 06 '17 at 22:28
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    @Criggie In Swiss law there are minimum braking accelerations per wheel (among myriad other regulations). For example a tire on the front wheel of an electric assist bike which has the assist function enabled at speeds over 25km/h (but below 45km/h) needs to be good for 3,4m/ss measured as the average starting at the time when the braking lever is first pulled until full stop, with an initial speed of 40km/h, without any skidding or blocking, with an initially cold tire on a horizontal surface, without using the hind brake. I don't know if every tire automatically passes this and other tests. – Nobody Sep 07 '17 at 20:00
  • @Nobody thank you for that - I was unaware. Nice spotting! – Criggie Sep 07 '17 at 20:10
  • @ChrisH Why does it matter whether the same rider could maintain 25km/h on a normal bike? No manufacturer warned me that I should buy special tyres for my non-motorized bike because I can maintain 25km/h on the flat for an hour. Would I not need special tyres for an e-bike because I can do that speed unassisted? Would an unfit friend need special tyres on their e-bike if they wanted to come for a ride with me? – David Richerby Sep 08 '17 at 09:53
  • @ChrisH , Qwerky: Re "25km/h is not a high speed": Not as peak, but it surely is high as an average. Of course the average speed will be higher with an E-bike, all else being equal, and using sturdier tyres is a reasonable idea. No, it is not mandatory, and no, nothing will immediately fail; but having what would otherwise be peak speeds (downhill, back wind, speeding; situations which make you alert) as standard mode of operation makes it seem reasonable to use sturdier equipment. The same reasoning applies to other components like frame and brakes, which are usually more robust, too. – Peter - Reinstate Monica Sep 08 '17 at 09:53
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    Another aspect is that the usual "safety/robustness vs. weight" balance which is heavily in favor of weight for good bikes shifts towards safety and robustness for e-bikes because the weight gain is compensated for by the motor. – Peter - Reinstate Monica Sep 08 '17 at 10:00
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    @PeterA.Schneider 25km/h isn't unusual as an average. I'm just a guy who commutes on a hybrid and sometimes goes out for a ride at weekends. Cycling is the only exercise I get so I'm not unfit but I'm not any kind of competitive/sportsman/keep-fit enthusiast or whatever. One loop I like to do is 24km with 170m of climing and it takes me a shade over an hour. Anyone who owns a proper road bike and wears lycra is going to be riding faster than me. – David Richerby Sep 08 '17 at 10:02
  • @PeterA.Schneider my average moving speed on my hybrid is 24km/h. That's my slower bike. On the tourer it's over 30 – Chris H Sep 08 '17 at 16:16
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    @ChrisH Google "e-bike riders", images, and try to guess what their average sustained speed on a conventional bike could be. You are not representative. – Peter - Reinstate Monica Sep 08 '17 at 21:46
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    @PeterA.Schneider neither am I a regular e-bike rider. I'm a fairly typical commuter/weekend cyclist and I'm about as fast as someone on a (European) e-bike. Comparing the same individual with and without a motor isn't useful. Instead on an e-bike you've got a (potentially heavier and inexperienced) rider who can do 25km/h on a heavy bike even when the road surface is poor – Chris H Sep 09 '17 at 06:02
  • @Nobody I like your "full front braking" test, have you tried it? –  Dec 06 '19 at 14:47
  • @HansJanssen No. I read part of the relevant law book and happened to remember this tidbit. I don't know how difficult this is, for example whether I could do this on a heavily loaded bike with non-ebike tires. It wouldn't be that hard to test though, you can calculate the breaking distance corresponding to that deceleration, mark it out on a flat road, do a sprint to the start marker going as exactly at 40km/h as possible and then see if you can brake within that distance. – Nobody Dec 06 '19 at 16:36
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    @DavidRicherby you wrote that comment about two scores of KOM ago! – gschenk Dec 09 '19 at 21:03
  • @gschenk Gosh. I feel old, now. :) – David Richerby Dec 10 '19 at 09:07
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In brief - "sales and marketing"

Changing tubes/tyres on an ebike can be more awkward, especially on the powered wheel, plus ebikes tend to attract less "mechanical" riders than regular bikes, being a gateway ride.

So an ebike tyre will be a marketing term for higher puncture resistance and lower rolling resistance, and probably in the wider sizes to cope with the extra weight.

They won't be cheap either, because ebikes aren't.

Adam Rice
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Criggie
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    I understand your cynicism, but your answer is a bit confusing as it first claims it is essentially smoke and mirrors, and then you make valid points why a more robust tire may be more appropriate. So which is it? I would also suggest that e-bike tires with sturdier construction will have higher, rather than lower, rolling resistance. Rolling resistance is less of an issue in this use case, given that an electric motor provides assistance. – Rider_X Sep 06 '17 at 15:41
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    @Rider_X the term "ebike specific" is a marketting term, that represents certain features that have been available for a long time pre-dating ebikes. Its nothing new in the underlying tech, just retargetted. – Criggie Sep 06 '17 at 19:45
  • The answer by @Qwerky nails it. Criggie is right - its a marketing gimmick. – mattnz Sep 06 '17 at 20:24
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    I agree it's a marketing term, but it's a useful one, and I take issue with the idea that it's necessarily a gateway ride, as if one should "progress" from an e-bike to a regular ride. I commuted for years on a regular bike, 7 miles each way, before moving farther to the suburbs, where a e-bike conversion makes a regular 17-mile each way commute possible. I'm going faster, harder, and with a heavier load, and tires labeled "e-bike ready" have proven better able to handle it than my former tires. – Tim D Nov 03 '20 at 17:15
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    @TimD Let me expand that . Ebikes are a gateway into cycling, from non-cycling. So are scooters, e-scooters, and rental bikes/scooters. Being able to ride one of those "lowers the barriers to entry" in accessibility, and helps new riders get moving without the costs of buying a bike. In terms of ebikes, the barrier is "its too hard / I'm too out-of-shape" and the ebike takes the edge off the physical component of the barrier. What you ride is less important than That you ride. I think ebikes are good gateways, to be clear. – Criggie Nov 03 '20 at 18:56
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A regular bicycle tire can be just as sturdy and last just as long under more stress by a regular rider. The joke I have heard among cyclists involve a newcomer to a bike race such as RAGBRAI with an electric bike who inevitably falls behind (and is surprised by this) because regular cyclists (not even pros, just people who ride daily and are serious about cycling) can frequently output more watts on a consistent bike than the legal limits of an electric bike, or at least outperform on stretches where the electric has trouble and falls behind.

So, an e-bike may or may not need "dedicated" tires. But... eBikes are not marketed towards people who are interested in putting in a lot of exertion in their ride. Those people don't need electric assist.

While the question does not say what "dedicated" means, there are a couple of possibilities. One is that, being marketed towards people who are more interested in getting from point A to point B economically which a bit of fitness thrown in on the side, it can make sense to sell "niche" or "proprietary" tires which are optimized towards that goal. These tires can be cheaper to make, at the expense of the second point, weight. But the rider can easily tolerate this since the bicycle is motor assisted. Because of this trade-off a heavier tire can also be made tougher to last longer to match the target market of people who don't want to be on the side of the road changing a tire.

Michael
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I ride a regular bike (Trek Fx7.2) and an eBike (Giant Quick E+) in casual fashion (ie not superfit or above average). The Giant weighs about 10kg more than the Trek, but since riders vary over 20kg it can't be a weight issue. The Giant is limited to 25km/h assistance which means I very rarely get over 30km/h (Weight/motor/big tyres makes it difficult), whereas I can cruise at 30km/h+ on the Trek (for limited amounts of time on the flats). So it can't be a speed thing either. Based on this I think it's just a marketing gimmick. Tyres are either built for durability (slower, heavier, more puncture resistant, long lasting) or performance (fast, light, easily punctured, limited life). I can't see how an electric motor changes any of that.

Happy Harry
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  • Why can't it be a weight thing? For any given rider (e.g., you!) rider+Giant will be 10kg heavier than rider+Trek. Sure, a rider who weighs 20kg more than you will put more weight on the Trek's tyres than you would on the Giant's, but that's not a like-for-like comparison. – David Richerby Oct 26 '18 at 11:29
  • It can't be a weight thing because the tyre doesn't know who's going to be riding the bike. Remember these so-called 'e-bike rated' tyres are supposed to have special thing that makes them work better on an eBike. If that is true, what is the special thing? – Happy Harry Nov 04 '18 at 21:18
  • You mention already that tyres may be optimised for different aspects. In an E-Bike tyre most people do not care very much about rolling resistance. But they care very much about puncture resistance, since replacing a rear tyre on an ebike is considerably more work. – gschenk Dec 09 '19 at 20:59