why do folks want a higher watt motor?

Teresa

Member
I started with a 250 watt motor in the front wheel of my bike but the controller wasn't reliable so I purchased a Felt Bosch Performance mountain bike with a 350 watt motor and it is great. Works wonderfully well and I ride it all the time (3,000 miles in the past year). It does everything I want it to do and when commuting, it gets me up to the legal limit in just a few pedal strokes. When I'm pulling a trailer (about half of those miles), it easily maintains my speed. What benefit would a higher watt motor be? BTW, I'm only interested in legal reasons it would be helpful. I don't want to ride 30+ mph as I don't need my bike to do that. Wouldn't a higher watt motor just burn through the battery faster?
 

twoxootrs

New Member
Weight, torque, distance...read some interesting posts by George S. on how contributions by rider pedaling combined with motor output affect the overall ride. For me, I could not see anything smaller than 500W pulling me up and down hills or giving me the proportional assist I want when I am tired of pedaling after a very long ride. Sounds like you may have already found your sweet spot though if the 350 is doing all you ask of it.
 

George S.

Well-Known Member
The industry wants a 28 mph ebike. Most ebikes are more upright than race bikes and have less efficient tires. To go 28 mph takes around 750 watts. A strong rider might contribute 200 watts for a full commute, but the motor is doing most of the work. A 'normal' rider may contribute 15% of the power.

If people commute they want to maintain speed. So to fight the wind and get up hills, they need more than the 750 watts to stay near that legal speed.

If you stay a bit below 20 mph, the older legal limit, 350 watts works pretty well, especially on a mid-drive. But hills and headwinds are going to slow you down quite a bit.

You can play around with this calculator to see what the watts give you, on the flat, on hills, and into the wind. Configure generally for bar tops, MTB tires, and your weight, US units. The slider only goes to 500 watts, but you can enter any watts into the box.

http://bikecalculator.com/how.html

Basically, batteries are getting downright enormous, relative to two years ago.
 

JoePah

Well-Known Member
Those motor power ratings are very misleading. The power output is a function of the battery bms, and the controller rating.

For example, the juiced bike cross current motor is listed at 350 watts. If you look at the video I posted for that bike you'll see that the power meter is showing over 650 watts at 28 mph. Stock.

What greatly matters is torque for hill climbing and acceleration.
 

Donny

Active Member
Me personally, I think it's because people always want something bigger to go along with the "bigger is better" mentality we have in this country - that's personal opinion. People like to tinker and mod, so they are always trying to find a way to improve something - not necessarily a bad thing.

I've got a 500w 48v motor on my bike and have only been using it in pedal assist (PAS) level one (max level on my bike is three) and it's fine, even for hills. The few times I have put it in PAS 2 mode, I've just about been knocked off my bike by how fast it takes off and I'm six foot and weight about 210-215 pounds - PAS 3 is just ridiculous. Now don't get me wrong, I'm sure in an area like San Francisco or someplace like that which has more extreme hills than most places, this may be more of an issue than for people who live in generally flat areas. I think it's also important to remember that, technically speaking, these are meant to be assistance type systems to work in harmony with a *physically* powered vehicle (i.e. you're body doing the work). I see too many people trying to make these things into quasi scooters or mopeds/motorcycles when, and again this is purely my opinion, that was not their intended purpose. I think that given the cost that these bikes have and what some people are trying to make them out to be, that some of the buyers should really look into another form of transportation. You can get gas powered scooters and motorcycles that get crazy good gas mileage new/used for less than the cost of most commercially made e-bikes.
 

Teresa

Member
Thanks for the replies. I think I'm in the same camp that Donny is for the most part. At this point in my life, PAS 1 and 2 are usually more then enough to get me up hills and through the wind at decent speeds. Occasionally (like when I'm riding home trying to beat a storm), I wish I could go faster but that's pretty rare. When I take the bike out on single track with rough riding, the problem isn't usually with power but with my skills that limit my speed. Maybe as I get older, I'll want or need more power but for now, I'll trade crazy speed for distance.
 

EddieJ

Well-Known Member
Keeping it short.

Not all of us want more power. For eMTB use, the Bosch CX motor rated at 250w and peaking at 612w is plenty. I also have no problem with the UK cut off point of 15.6mph.

For me, a pedelec is a bicycle that just happens to have an electric motor available to help assist at a sensible and reasonable level, and nothing more. If I wanted to ride a motorcycle I would.
 
Last edited:

Bike_On

Well-Known Member
Those motor power ratings are very misleading. The power output is a function of the battery bms, and the controller rating.

For example, the juiced bike cross current motor is listed at 350 watts. If you look at the video I posted for that bike you'll see that the power meter is showing over 650 watts at 28 mph. Stock.

What greatly matters is torque for hill climbing and acceleration.
Power rating in watts is typically the expected average power the motor can handle (ie Heat) at 100% of the time.

Then you have peak power during acceleration and up hills, which is likely 2x the normal rating, depending on controller/bms/ battery limits.

For comparison, I like to use the power metric of Whrs/mile. The bigger the motor, the higher the speeds, the more hills, the more accelerations, the less pedaling, the higher the #.

Over many years and several bike topologies, I have found that 750W-1000W motors will use 20-30 whr/mi. The lower powered motors, 250-350W, will use 5-15 whrs/mi, depending on all the conditions. The 750-1000W will allow you to cruise 25-30mph, and average 22-28mph range. The 250-350W will allow you to cruise 15-25mph (speed pedelecs) and average around 17-21mph.

I hope that helps making decisions.

Per Teresa's comments, I would add ride time/distance as a factor. Folks riding/commuting over 10miles will get tired of the 20mph limit and want a bit more speed. Otherwise, if sub20 is fine for you, a solid 350W system will be quick and fun.
 
for me it is about choice. i can choose what type of bike that i want for the type of riding i do. hopefully the ebikes will not be overly regulated. i like the freedom to choose and not be told what i can have.
 

Bike_On

Well-Known Member
Keeping it short.

Not all of us want more power. For eMTB use, the Bosch CX motor rated at 250w and peaking at 612w is plenty. I also have no problem with the UK cut off point of 15.6mph.

For me, a pedelec is a bicycle that just happens to have an electric motor available to help assist at a sensible and reasonable level, and nothing more. If I wanted to ride a motorcycle I would.
Not all want more power because not all needs more power. A 250W MD can smash the hills. So can a 350-500-700W MD and do it faster. They are still much, much less powerful and lighter than even a 100cc motorcycle. Everything greater than 15mph and 250W is not a motorcycle.

Not mentioned here is weight. Higher power, bigger motors, bigger batteries and weight is up. Some designs are very minimal, light weight, small batteries. What is best, better, preferred? Just like normal bikes, weight matters. A good power/wt ratio will make a bike more fun and responsive. There is also the human power/wt effect which decreases with bigger powered bikes. I think Eddie is saying that he wants his human/wt effect to be sizeable and 'feel' it when riding.
 

vincent

Well-Known Member
i think that like everything else there is a time and place for it

at my heavy weight and pedaling hard my 300watt motor even using throttle overrride and going up a medium size hill it is barely making it

san francisco hills etc, forget it

sure it depends on where you live, how far you need to travel etc

and agree that even though there is risk that some people might abuse speed etc and cause some trouble, i would rather not be told we cannot have them either

if i am on the bike path here doing 24mph i think that is too fast even on a legal bike that goes to that speed

but think on the road with cars that speed might be safer

there is also a big difference in maintaining a gas motor anything and running an electric bike with a larger motor
2 completely different animals to me
 

Donny

Active Member
I also see the concept of speed continuously being mentioned as a factor and not just in this thread. I've never had a conversation with anyone on a traditional bicycle who was concerned about speed per se (outside of people who race) - this is something I'm seeing in the e-bike world. Sure, someone might passively say "I can keep up with traffic" or something along those lines, but that is different than we are talking about here. Again, the intent of these bicycles is not to move you along at 40mph (or however fast you think is enough) to keep up with traffic, but rather to provide you some *assistance* with your existing pedaling of a bicycle. Most people usually figure out commuting routes that keep them out of traffic as much as possible anyway in my experience (which may not be everyone's and I accept that). People know that riding a bicycle is going to take longer than driving a car (in most cases) and that's usually factored into their daily time tables.

There are some differences between motorized gasoline vehicles versus electric, sure. The point is what are people's intended purpose behind using an e-bike. If a person is more concerned with speed and high power output because you want to keep up with traffic, my suggestion is that they might want to consider an alternate form of transportation. People opt for using a bicycle because it's practical, it's cheap (generally speaking), it's economical, it makes them feel better about the environment, exercise, and bicycles are generally more nimble for navigating congested areas and therefore allow you to avoid gridlock. An electric bike is an extension of those ideas and I don't think increasing the power output of the average bicycle is going to change any of that.

I've said it in other threads and I'll say it here too - this trend is going to continue and we are going to end up seeing regulations limiting what is allowed on these bicycles. I'm already reading of some states starting to crack down on them for these reasons. Again, this all purely in my own opinion ;)
 
Last edited:

Teresa

Member
Great conversation. I guess it all comes back to your goals and expectations. I wanted a bike with help and am still a fairly strong rider so I can still supply some of the work (except when exhausted at the end of a long day of work) and just enough kick to make off rode riding fun and not exhausting. I get all that plus terrific range from the 350 watt and 32 volt battery. I don't want to ride 30 miles per hour and I use it for commuting every day because I think that is to fast for our bike trails. If I had to ride on the road with traffic, I probably wouldn't commute to be honest and still wouldn't want to go a whole lot faster then that. Hit one pot hole at 30 mph and you could be flattened.

Whether we like it or not, regulations will be coming. Once people catch on to the idea, it opens up biking to a lot of folks that just couldn't do it now. I'm kind of excited where this could go......
 

wren

Member
30 mph is terrifyingly fast to some, and slow to others. We're all different.

As @EddieJ points out, more power isn't so important on a mountain bike (although I prefer plenty of torque) but power can actually be a safety plus on the street.

Please don't worry about what will happen if I crash at higher speed. Regular bikes can go 35-40 or more on descents. Wear safety gear. Also, as @EasyMotion Rider points out, we are adults and should be able to make our own choices, as long as we're respectful of the safety of others.

As for shared use paths, every bicyclist, electric or not, needs to be cautious and sane around pedestrians and slower riders. But, there's no point in limiting e-bikes to speeds slower than the lycra-clad masses can achieve.

To answer the original poster's question, I want more power (and corresponding controller) to accelerate faster and to hit a higher top-end. If I could ride a Kawasaki on a shared path, there'd be no need for an e-bike!
 

Donny

Active Member
I know around here (which may not be representative of everyone), all of the trails/paths have a speed limit of 10mph-15mph and that applies to everyone/anything. Granted, that's not to say that people don't exceed that and obviously there is nobody actively enforcing that anyway on the trail systems (here anyway). As I've said before, what I see happening is that e-bikes are going to end up being limited by regulation because a certain segment of its population cannot act responsibly with the technology. These things already walk a fine line between being a bicycle and being classified as a scooter/moped anyway. Want to look at a recent (and maybe bad) example of this? Look at drones. They got popular, people started doing incredibly stupid, illegal, and dangerous things with them, and now drones of a certain class have to be registered with the government, etc. all because people couldn't control themselves with their new toys. The end result is a minority of the population ruined it for everyone else and I see this same thing happening down the road with e-bikes. Personal opinion ;)
 

EddieJ

Well-Known Member
Donny, sadly it isn't just your opinion.

Some of those regulations are already impedeing on the use of eMTB's, Moab are I believe banning eMTB's from National parks etc, and here in the UK we could be seeing the same, and all because of a minority of irresponsible pedelec owners fitting and using dongles. A situation that is far from being helped by one particular UK Haibike dealer who actively promotes them. The irresponsible selling, and illegal use of dongles, is more than likely going to eventually result in eMTB's being banned from pretty much everywhere.
(Link Removed - No Longer Exists)

I am already starting to witness the beginning of this happening, with the mtb events that I take part in. Conversations with event organisers, and questions that I have been asked, definitely lead me to believe that my days of riding at these events, are definitely numbered. Something that I am not all happy about, and I have zero tolerance of anyone using dongles, S pedelecs, or other illegal ebikes in public places.
 

wren

Member
all because of a minority of irresponsible pedelec owners fitting and using dongles
I tend to think the majority of the mountain bike community is opposed to every ebike, high speed or not. On their websites they refer to ebike as "motorcycles" and say that's how they need to be categorized. No one is looking at whether it's a speed pedelec or has a throttle, if it has a battery and a motor it's evil in their eyes.

What gets me is what hypocrites these guys are as they shout out "on your left" as they whiz by the hikers. I understand their desperation as they get pushed off hiking paths ... what we need to do is be together with them not opposing each other.
 

EddieJ

Well-Known Member
I can't argue with the comments made about the mountain bike community. I get treated pretty well at the organised events that I take part in. I've had some negative comments, but just ignore these, but when I read some of the negative comments on social media by a minority of pedal mtb users, it is quite shocking. I've read all kinds of threats in respect physically harming ebike riders, and a local journalist out testing a KTM around here was spat at.

We know that ebikes ease congestion when ridden on the road by potentially not holding up traffic so much, and even free up a space on the road that might otherwise have been filled with an additional car. Off road, my experience is that eMTB's are actually frequently kinder to trails than pedal mtb's as the additional forward momentum, offers are more linear and smooth ride. Just a shame that many can't see that.

In respect of organised events, one of the key elements is public liability insurance. Ebikes need to be legal, as the events are held in public spaces, and from the conversation that I had last year with an event organiser, they cannot police the bikes and check them, so banning all ebikes might be the only available option.

I also know what you mean about the shouting and whizzing past hikers. I see it quite frequently, and just as bad or rather worse, is not slowing down or stopping for people riding horses. I must admit that I have had some very aggressive hikers block my passage a few times this year, each trying to say that I shouldn't be riding where I was, and each of them completely wrong. The most comical of which was one particularly aggressive hiker who tried to tell me off, whilst he was actually standing right in front of a cycle path sign. A bit of an oversite on his part, but one that I was quick to politely point out. My path was still blocked though, and I ended up falling from the bike because of it. It was at this point that a female walker from the group stepped forward, and said that they should not have blocked my passage, and that I had every right to be there. Up until that point, I was prepared to give them the benefit of doubt of not knowing. That was the third incident in the same day, and I suspect that it very much been orchestrated to cause all mtb riders grief.
It was beautiful calm sunny day, I just couldn't understand why anyone would want to prevent someone else from being out in the countryside enjoying themselves. Luckily I had already stopped and had a couple of lovely long and pleasant chats to other walkers, and just reminded myself of this, and didn't let it spoil my day or provoke things. Clearly I was out having a far more productive and enjoyable day than they were. :)

Sorry to have gone so far off topic.
 
Last edited:

George S.

Well-Known Member
here in the UK we could be seeing the same, and all because of a minority of irresponsible pedelec owners fitting and using dongles.
I assume these giant corporate ebike companies could lock down the bikes so dongles wouldn't work.

California is supposed to be forcing ebike manufacturers to label their wattage and top speed, next year, and then lock the bikes down. There is no evidence, none, that anyone is taking the new California rules seriously. The US industry seems to be a little out of control, actually.

It's going to be really hard to get e-mtb access to US trails without some limit on the power, but street riders don't want any limits. The line between a commuter and an e-mtb just isn't that clear.

I try to keep my bikes legal. I try to experiment with bikes and motors to find combinations that work, within the rules. It's just sort of a challenge. It's too easy to say "Gosh, lets get a 60v battery and run it at 40 amps".

I assume really refined mid-drives will make 750 watt motors pretty acceptable to most people. But right now you pay a premium for motors that are just not that final and really refined product. I'm not going to buy a premium drivetrain I know will be obsolete in 2 years. I can buy a $350 Magic Pie and do anything I want, more if I boost the watts.

I don't go fast but I do ride into stiff winds and I do climb long grades. The industry doesn't know what it wants, so all it wants is everything.