Electric bikes, why so heavy?

Electric bikes, why so heavy?

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Discussion

cb31

Original Poster:

1,239 posts

151 months

Sunday 12th December 2021
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Simple question, why are electric bikes so heavy? I'm specifically thinking of folding bikes, for example this https://velorution.com/gocycle-g4i-folding-electri...

Manufacturers claim 16.6kg but independent reviews say it actually weighs 17.7kg. The bike has magnesium wheels, is only small, carbon forks, carbon mid frame, etc. so has expensive and light materials. The battery only weighs 904g so where is all the weight from?

My cheap decathlon folding bike is less than 11kg and there is nothing exotic on it. What am I missing?

gazza285

10,513 posts

223 months

Sunday 12th December 2021
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The motor.

leyorkie

1,741 posts

191 months

Sunday 12th December 2021
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A Bosch 500w battery is 3 kilo so their 375w is less than a kilo,
Generally motor and battery adds at least 5 kilo to a bike.

Just my comments from experience

cb31

Original Poster:

1,239 posts

151 months

Sunday 12th December 2021
quotequote all
ok so looks like the motor then, do you know if they are about to get any lighter or is there nothing on the horizon? Not sure I want to pay £4k for a heavy bike.

Pilotguy

435 posts

274 months

Sunday 12th December 2021
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Mostly the battery, motor is quite a chunk too though.

gangzoom

7,371 posts

230 months

Sunday 12th December 2021
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cb31 said:
ok so looks like the motor then, do you know if they are about to get any lighter or is there nothing on the horizon? Not sure I want to pay £4k for a heavy bike.
My Boardman eBike has one of the lightest mid motor units along with a small battery which are fully detachable from the bike. I can tell you its essentially like carrying two extra D-locks around. However the extra 4-5kg gets you an extra 250watts+, that far more power than any human can mange for an extra 4-5kg of weight.

Motor and battery weights aren't reducing anytime soon.

Barchettaman

6,869 posts

147 months

Monday 13th December 2021
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Unless you have to hoik it around on a regular basis the extra weight of an e-bike is pretty insignificant IME.

You’ve got this motor thing to help you out, you see.

sjg

7,600 posts

280 months

Monday 13th December 2021
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Motor as people say. Most 250w hub motors weigh 2.5kg+ (compared to sub 200g for a reasonable conventional hub), and while they're physically smaller, a lot of mid-drive units weigh similar. Gocycle is a single sided one too while probably adds weight.

Just because it's small doesn't necessarily mean they can use less / lighter materials - still has the same forces acting on it. Gocycle use alu for the front half, and I bet the carbon rear isn't that light. The casing they cover the chain etc in will add to that too. Single sided fork won't save material compared to a double (may add to it if anything). Mag wheels are often heavier than spoked. The (big) stem/bars/seatpost will be alu and probably heavier built as they're longer than a normal bike. The Nexus 3 speed hub isn't light, although probably similar to a derailleur, cassette, hub.

The gocycle isn't bad and unless you have to drag it around folded a lot then it doesn't really matter. As said, at least the Brompton design puts the battery in the front bag so you stick that over your shoulder and carry a lighter folded lump around.

LeadFarmer

7,411 posts

146 months

Monday 13th December 2021
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Barchettaman said:
Unless you have to hoik it around on a regular basis the extra weight of an e-bike is pretty insignificant IME.

You’ve got this motor thing to help you out, you see.
When cycling off road on a mountain bike and lifting over styles etc, then the weight becomes an issue.

Also when I have to push mine up flights of stairs at the office, if it wasn't for the Bosch 'Walk' feature then that would be a pain too.

When doing maintenance on mine I like to have the bike at face height, which rules out most bike stands, and would make it heavy to lift. So I have an electric winch in my garage roof to lift it to whatever height I desire.

Edited by LeadFarmer on Monday 13th December 14:42