How important is weight of an ebike?

[zombiess]

My current bike weighs in at 66lbs and is full suspension with a 9C 8x8 and 24s2p battery. I just started thinking about the weight of the bike and was wondering how important everyone thinks it is? Primary use is just commuting and mostly paved roads, hopping curbs, etc. Top speed is just over 40mph.

I'm considering a new build on a better frame or at least upgrading what I have since I feel I'll be sticking with an ebike for a while.

 

[Solcar]

Getting off the pounds can make the riding easier not only because of accelerating and decelerating less weight, but also because the handling requires less attention and feels more natural. I had some 16" coaster bikes given to me by my neighbor that were fun to ride because they were pretty small and light, but not too small. I rode them around the neighborhood, and after a few months, I could ride a wheelie as long as I wished.

Years earlier, a friend sold me a Yamahopper, a former style of gas-powered scooter. It was much easier to ride than the motorcycles that I have ridden.

Go for less weight when you can!

 

[neptronix]

If i attach my ~15lb 20ah battery box to my bike, i feel it. The bike accelerates slower, for sure.
So weight is a detriment to acceleration as it requires more torque to move..

Where the weight is really affects the handling. Hub motors down low aren't so bad. batteries up high are real bad.

You may want to cut down on the weight of the components of your bike.
Most Dual suspension bikes aren't so light though. It isn't until you cross the $2000 barrier that they start getting fairly light..

 

[USAEBIKECO]

The lighter the better.

The weight of the bike can cause problems if your going over potholes or uneven surfaces.

Thats why I try never to use SLA batteries, or any battery packs over 15lbs.

 

[dougnutz]

While I think pretty much everyone will agree that ligher is better.... I personally think balance is more important than weight. If the center of gravity of the bike is low and between the wheels it will handle better and more naturally than a bike that is 20% lighter but has a high CG that is behind the rear wheel. From my experience with race cars any weight outside the wheels is called polar inertia and causes ever increasing problems with speed. So get as much weight inside the wheel base as you can and then the lower the better.

 

[auraslip]

OTOH, I regularly pull a 100lb trailer. Of course it accelerates a bit slower, but not as much as you'd think!

Also, with the speed limited to 20mph it pulls between 7a and 10a on the flats. Without the trailer and the speed unlimited it pulls 15a to 20a @ 30mph. So the extra weight doesn't really matter nearly as much as wind resistance.

 

[neptronix]

Depends entirely on how many amps you are running though. If you have an surplus of amps coming out of the controller, nothing is going to slow you down really.

Yep, on a straight course at a constant speed, your amp draw would only be affected by rolling resistance and aerodynamic drag so more weight at constant speeds is not a big deal.

If you live in hill & stop/go central like i do though, and you are running a limited amount of amps, then it sucks, bad.

 

[John in CR]

If you have a 40mph bike you shouldn't be on the sidewalk to be hopping curbs anyway. The biggest effect is on handling, and as stated above, placement of the battery weight is more important. Other issues can be overcome by more batteries and more power.

You're not going to do too much better than the 66lbs without giving up range, so I'd say wait for better, smaller, lighter batteries to come out.

 

[adrian_sm]

For me it all comes down to how far you need to ride, how much you like to pedal, and how likely you are to run out of juice, because riding a heavy ebike home sucks.

I have two main ebikes. I use them both for commuting to work and back on roads. One is a full suspension hub motor bike, that weighs in at 30kg. The other is a light weight build with a friction drive, that weighs in about 13kg. Both have about 2000w on tap and cruise at around 40-50kph. Both have about 30km range.

When I still have juice in the battery, both bikes are awesome. The full suspension bikes can bash over kerbs, and be the urban assault vehicle. The road bike just feels lighter, more nimble, and efficient when pedalling.

But when the juice runs out it is a whole different story. On the full suspension bike, the heavy weight, fat tires, and motor drag make me thinking about ring someone to pick me up. But for the friction drive bike, it is still an efficient road bike that is a pleasure to pedal. So I just keep riding.

So if you are unlikely to run out of batteries with your typically riding, don't stress it doesn't really mater. Until the electrons run out.

- Adrian

 

[GrayKard]

I carry my bike up stairs several times a day. The ones at work are particularly long and narrow. Both light weight and good balance really help.

My bike weighs 52 pounds.

Gary

 

[dogman dan]

Yes, where the weight is is a prime consideration. But also total weight matters. My youthfull riding days ended with graduation. With a real job, I took the money and discovered food, and never could pedal again like I did when I was 5-11 and 115 pounds.

Now I'm about 185, and worring about 5 pounds more or less bike weight is a joke to me. My commuter has generally weighed between 85-95 pounds depending on the size of the tool kit, and 100 pounds if carrying 70 mile range. It's set up to carry cargo, with front hub helping the balance. At about 95 pounds that particular bike starts to handle worse. Other bikes handled worse at much lighter weights. Back to where it's carried.

 

[zombiess]

If you have a 40mph bike you shouldn't be on the sidewalk to be hopping curbs anyway.

Not quite sure what my top speed has to do with hopping curbs, but I often drop off and climb up curbs and cross medians. I also ride on a paved bike path (at bicycle speeds because people are extremely rude/stupid and going faster would be dangerous for all the dolts and unleashed dogs) a lot, but just because it goes 40+ doesn't mean the throttle is on/off only LOL. Sidewalk use is kept to a minimum.

If my fabricator would ever finish modifying my seat post mount I'd be able to change the handling of the bike by putting the batteries on the top tube. Should be much nicer and less prone to power wheelies. I think I'm just experiencing the bug of wanting to build something because I have a 2806 motor and 12 FET controller I can't seem to get rid of and hate to see it laying around not being used.

I re weighed the bike since I made some changes, it's 72lbs now and was 36 stock.

 

[CrazyJerry]

OTOH, I regularly pull a 100lb trailer. Of course it accelerates a bit slower, but not as much as you'd think!

Also, with the speed limited to 20mph it pulls between 7a and 10a on the flats. Without the trailer and the speed unlimited it pulls 15a to 20a @ 30mph. So the extra weight doesn't really matter nearly as much as wind resistance.

Yes! The trike weighs in at 120lbs but only needs 8-10 amps to cruise at 30 mph..
18-20 amps to cruise at 44 mph... Aero pays back big time.
CrazyJerry

 

[auraslip]

[youtube]FJsMDsT8siU[/youtube]

Speaking of light bikes....

 

[AussieJester]

Thats why I try never to use SLA batteries, or any battery packs over 15lbs.

Oh really! well at the risk of actually promoting your company--> SLA equipped Chicago Electric e-bike I think its important readers (also potential buyers) know what you actually think, in comparison to what you actually sell...just to be fair you understand, seeing you knock every retail e-bike posted on ES

Weight is always important as has been said, but also where that weight is distributed.
Having weight high up and to the rear of the bicycle, on a rear rack in a cheap plastic box (as the cheapo
e-bike i linked to above has) for example is very bad for the bikes handling.
Weight is better centralized within the frames triangle hence those that have been at
this hobby for awhile always try to mount packs within the bicycle frames 'triangle'
so the handling of the bike isn't as badly compromised. The bicycle was not designed for this
extra weight, so IMO it is extremely important where batteries and motors are
put on the bike. jm2c

KiM

 

[MadRhino]

The ratio weight-power is what matters. IE: a 15 HP 100 pound bike will handle lighter than a 50 pound with 4 HP. Then, how is that weight reparted is making for the acceleration stability and cornering ability. Weight should be placed low for precise manoeuvers at low speed (trial), but higher for precise cornering at high speed (road racer).

 

[gtadmin]

... but higher for precise cornering at high speed (road racer).

If this was the case, all motorbikes would be built with the motors placed as high as possible in the frame I can't think of one high performance road bike that does this.

Weight itself has minimal affect on top speed on the flat, but does affect the rate of acceleration (+ve and -ve) and especially changes in elevation (going up a hill)

 

[dogman dan]

Well, here I go posing in the rifle scopes view. Blast away AJ.

The bike AJ linked to will not handle all that bad. It's got a huge advantage with the front hub weight where it is. It would handle a lot better with only 15 pounds back there, vs some slas of course, and better still if either battery was located in the frame center. Again, a lot depends on the particualr frame used. Many many many cheap bikes would handle very crappy in that configuration, front hub and 30 pounds on the rack. But the typical classic beach cruiser frame is stiff enough to get away with it much better than most wallmart specials. The cheap bikes will sway like crazy with the frame flex.

What handles really bad, is the rear hub, with rear mount battery. Even a light battery is pretty bad.

When it comes to hubmotor bikes, I have ridden nearly everything, and not just around the block either. A minimum test is at least 500 miles.

Also Rhino is correct about weight placement. I could name plenty of examples, IE every single crotch rocket.

 

[wineboyrider]

Don't feel bad Dogman my bike now has your old cheap tool box in the back of my whale of a bike! The women's bike with the pings mounted in the center of the bike sure did handle way better at the Death Race Glad I did that for handling purposes. It is nice to move your battery from bike to bike though without all the fuss. 8)

 

[Dingo2024]

although I think weight of the bike IS important.......I think strength of materials / components should not be over looked......carbon road bikes may be great but mounting an electric motor to one might not be the best idea. How many have had problems with torque arms etc. on alloy frames. I dont think the weight weenie has a place in ebikes (at least not the current crop (not crap :wink: ) of retail stuff .

hell.....even tyres make a big difference.......try riding a bike with Hookworms and then change to 2" slicks @ 70psi

Ian

 

[nuevomexicano]

Thats why I try never to use SLA batteries, or any battery packs over 15lbs.

Oh really! well at the risk of actually promoting your company--> SLA equipped Chicago Electric e-bike I think its important readers (also potential buyers) know what you actually think, in comparison to what you actually sell...just to be fair you understand, seeing you knock every retail e-bike posted on ES

Weight is always important as has been said, but also where that weight is distributed.
Having weight high up and to the rear of the bicycle, on a rear rack in a cheap plastic box (as the cheapo
e-bike i linked to above has) for example is very bad for the bikes handling.
Weight is better centralized within the frames triangle hence those that have been at
this hobby for awhile always try to mount packs within the bicycle frames 'triangle'
so the handling of the bike isn't as badly compromised. The bicycle was not designed for this
extra weight, so IMO it is extremely important where batteries and motors are
put on the bike. jm2c

KiM

I haven't been here long, but you seem to make a mini-career of following up lester12483's posts with snark. Did he kick your dog or something?

To be fair I have one of his 48V12AH batteries and it weighs 2 pounds less than the 48V10AH Ping battery everyone raves about. His 36V battery weighs a full 2 pounds less as well. I'm fine with the handling having it mounted on a rear rack and combined with a relatively light weight rear geared motor. The battery in frame is ideal, but the battery on my rear rack is basically the same as the book bag with books and laptop I had been regularly carrying there before electricfying. Its not like I was crashing because of carrying my bag and books to work. The battery is maybe even better since its smaller in size. Even a relatively crappy rear rack can take 6 or 8 pounds without killing handling for my around town commuting.

 

[deardancer3]

at the engineering brainstorming meetings, (local pub after work) it was often said:

"You can change anything you want in a product, but you can seldom change only one thing"

Soooo, if you lower the weight, what else changed? just cost? or did your loose or gain some functionality?
So, you lightened the bike by 5 pounds by getting a fancier battery, and it cost you an extry $300 say.
Did the reliability/lifetime of the pack change? did the range increase? Is it easier for smaller people to ride?

I know some small riders that weight is very important; they have 30 pound ebikes, it does what they want, and they can load it in their car and on a bus rack un assisted. Personally, I find it easier and cheaper to add 50w of power than to drop 5 pounds of an ebike.

Me? Get me and 40lbs of groceries up an 8% grade on a day I can hardly pedal. ebike weight is a consideration, but not so much when you consider me and the "snacks" weigh 250lbs.

( also heard at the watering hole; for every pound you cut off of the weight of your commuter bike, you eed to carry a 2lb heavier lock and chain)
d

 

[MadRhino]

It is important, but not the same importance for everyone. If one is after performance, and like riding rough mountain trails at high speed shaving the bark of big trees in every corner... Then weight and balance are damn important, for they are a life saver. On the other hand, the girlie carrying school books on the city bike path might not have the same consideration for weight distribution and frameset quality.

Every bike should suit someone, just know what kind of rider that you are and build accordingly.

 

[Ykick]

Batteries mid-frame will always provide a huge improvement in handling.

I believe 60lbs is a very nice eBike target weight for 20-30 MPH specs. 85-100lbs not much fun to schlep around and just feels heavy, harsh and flexing under way. 'probably need much stronger frame and wheels for rough surface duty too.

 

[mr.electric]

I am still trying to find a good way to mount my batteries in the frame. Dual suspension bikes have such a small usable area in the big triangle due to the shock/ swing arm position. I did a temporary mount of my heaviest battery under the down tube and it rode much better for a few rides but needed a more secure mounting system. I'm at 70 lbs with one battery. Now that I'm playing with rc packs I see that the small triangular Jand brand frame bag will hold two 6s 8ah bricks enough for local rides. I always try to minimize weight as long as it doesn't cost too much money.