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'The big problem is water': UK ebike owners plagued by failing motors

theguardian.com

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Re: 'The big problem is water': UK ebike owners plagued by failing motors

#321

Post by jjav »

dghlsakjg wrote: post #105
Etheryte wrote: post #95

Earlier quoted context omitted.

You're glossing over the fact that internal gear hub transmissions easily cost in the hundreds, whereas you can get a derailleur for a tenner or so. I've owned a number of bikes in my life and all of them have been cheaper than the transmission you suggest everyone should use.

An internal transmission hub replaces a hub, cassette, and derailleur and starts at less than $100 for the whole kit. A derailleur can cost $10, but it won’t be nearly as durable. Buying a high quality one is gonna cost in the same neighborhood as $100.

What kind of derailleur can one get for $10?

Looking at jensonusa, the cheapest rear derailleur is a Shimano Altus 7/8 speed for $22.

Re: 'The big problem is water': UK ebike owners plagued by failing motors

#322

Post by dgacmu »

mvdtnz wrote: post #120
dgacmu wrote: post #53

Earlier quoted context omitted.

The gear advantage of a mid-drive rocks but I was quite surprised that I chewed through a rear cassette in under a year / about 1k miles -- a 250W motor + heavy cargo bike + kid passenger + a large and pretty strong rider exert an awful lot of force. And with the assist, I almost never use the larger cogs, so all the wear gets concentrated. (This compares to many, many thousand miles on my road bike.) Still love the…

Why would that surprise you? A semi serious mountain biker will go through a cassette on an analog bike in 2 years. You're driving the thing with a huge motor, cargo and an entire extra human. Your expectations must have been unrealistically high.

The difference between a mid-drive (in which all of the force goes through the rear cassette) and a rear hub drive (in which only the pedal force goes through the rear cassette) is large.

Also, most people online report over 2k miles on a cassette. Pittsburgh's hills and more force are apparently good for some extra wear.

(Also, a 250W motor is fairly small by e-bike standards. They generally start at 250 and go up from there; 750W is not uncommon.)

Re: 'The big problem is water': UK ebike owners plagued by failing motors

#323

Post by hagbard_c »

fragmede wrote: post #273
hagbard_c wrote: post #91

Earlier quoted context omitted.

Seeing how as I regularly managed to break the drive cross in my 3-speed SA hub just by pushing the thing real hard under pedal power alone - this is 40 years ago - I don't think they're particularly strong. I fixed my bike by myself so all this cost me was a new drive cross but still, it shouldn't break in the first place.

I think material science minute might have advanced over 4 decades.

The cross is made of a fairly hard type of steel. They knew how to make that 40 years ago so I don't think there is any noticeable difference. If anything I suspect the older gear hubs were built stronger than the current ones.

Re: 'The big problem is water': UK ebike owners plagued by failing motors

#324

Post by lm411 »

jameshart wrote: post #117
lm411 wrote: post #106

Anecdotally, my wife's Magnum Premium 2 has held up well for 4 years of all weather use in west coast Canada. This includes pulling a cargo trailer or kids trailer year round - salty and sandy slushy snow, pouring rain, sun... For two of the years she hauled him to school everyday, in all weather, and did all of her shopping and errands with the bike. About 100km every weekday. I'll have to look at the odometer somet…

Not casting doubt on your numbers here, but to put some perspective on how much usage that implies: 100km every weekday means literally hours of use every day - we're talking about an e-bike that must average what, 20-25km/h at most? That's assuming you're not in stop-start urban traffic. So four or five hours a day? I guess if you're doing a school run that's 30 mins there and 30 mins back, morning and afternoon, pl…

The numbers might be a bit bloated, but not by a lot.

We had just moved to Canada from a country without a reciprocal drivers license exchange - no matter as she never had one. Where we had moved from, drivers licenses are largely considered optional and although I taught her to drive and she had been riding motorcycles since age 12 or so, driving in North America is way different. We moved just before covid hit. Driving lessons and license testing were difficult / near impossible to get - and with very long wait times. So it was her only form of transportation for quite a long time.

She was doing cleaning at various businesses around the area as well, so again she would take the bike to those locations every day with her little cargo trailer and cleaning supplies. She'd come home after dropping our son off at school, charge the bike, eat a snack, change trailers and head back out, then repeat when it was time to pick him up.

She quite easily spent 3-4 hours on the bike everyday. Just getting to school and back for our son was about 45 minutes one way. He wasn't in the closest school because of things the further school offered (nature school), another 30 minutes each way to the local shopping centre, and then wherever she needed to go for work.

We went through a lot of tires and brake pads, but other than general maintenance the bike held up great and is still going strong.

She has a good job and nice little car now, so the bike is seeing a lot less use this year.

She is as tough as nails. :)

Re: 'The big problem is water': UK ebike owners plagued by failing motors

#325

Post by fulafel »

EnigmaFlare wrote: post #301
fulafel wrote: post #154

Earlier quoted context omitted.

Power is power, there is no combined "power + torque" that measures how much wind you have in the sails. Torque just characterises how much power you can get along different RPMs. But the EU/UK 250 W cap is so low that it seems unlikely torque characteristics would enter the picture significantly unless you're going very slowly. I think most of the mainstream EU ebike motors are capped this way (vs designed to have a…

Torque (at the wheel) does matter as well as power. With a hub motor, the gear ratio is typically fixed so you're at the mercy of the motor characteristics, but driven through the chain, you can change it. I used to have a low powered hub motor e-bike and it was fast but pretty useless at accelerating from stopped or climbing hills. At these very low speeds, an optional low gear would have put the motor in a higher p…

>> Power is power, there is no combined "power + torque" that measures how much wind you have in the sails. Torque just characterises how much power you can get along different RPMs.

> Torque (at the wheel) does matter as well as power.

If you are getting 250 W of power at the wheel (in other units, 250 Joules per second, or 250 Newton-meters), that's what you are getting, no torque about it.

>> the EU/UK 250 W cap is so low that it seems unlikely torque characteristics would enter the picture significantly unless you're going very slowly

> Though perhaps you're saying these motors are so over-rated that even close to stall torque, their reduced power output is still 250W?

Yes, I was saying something close to that ("very slowly").

IOW the overprovisioning of the motor combined with the power cap makes the motor work much more like a "always 250 W" power source than a "250 W peak output modified by torque" power source.

Re: 'The big problem is water': UK ebike owners plagued by failing motors

#326

Post by timonoko »

ode wrote: post #182
heresie-dabord wrote: post #103

Earlier quoted context omitted.

If in a dry climate, a derailleur transmission can last a long time and will be cheap to maintain. But once a person starts replacing quality components with like quality, especially in a wet climate, a derailleur transmission can be expensive over 10 years. The set of my experience is { Shimano: [ $various_derailleurs, Nexus 3, Nexus 7, Alfine 11 ] , Rohloff: [14 speed], Other: [rear-hub e-bike] } $various_derailleu…

Why is the Nexus 3 rubbish?

They are always sold with wrong sprockets. The high gear is never usable. Number 2 gear is connected directly, and so it should be the default on no-wind flat road. Then it lasts forever on flat country like holland.

Re: 'The big problem is water': UK ebike owners plagued by failing motors

#327

Post by timonoko »

timonoko wrote: post #326
ode wrote: post #182

Earlier quoted context omitted.

Why is the Nexus 3 rubbish?

They are always sold with wrong sprockets. The high gear is never usable. Number 2 gear is connected directly, and so it should be the default on no-wind flat road. Then it lasts forever on flat country like holland.

I have 420 mm folding bike with Nexus-3. The correct ratio is less than 2:1, which meant changing both sprockets to smallest and largest available. I do not even know what to do with 622 mm wheels.

Re: 'The big problem is water': UK ebike owners plagued by failing motors

#328

Post by DANmode »

bowsamic wrote: post #306
DANmode wrote: post #304

Earlier quoted context omitted.

> ITV News investigations have found there is a "growing problem with severe mould and damp" throughout the UK, with councils often not dealing with residents' complaints. > Damp problems affect around six per cent of homes in London with serious condensation being the most common form. > Damp and mould were responsible for almost a third (28 per cent) of category one hazards in London councils, more than twice the p…

The UK is not particularly humid. This is just poor house construction

The climate in the United Kingdom is defined as a humid temperate oceanic climate.

London will barely momentarily touch below 50% humidity in the next 10 days.

Re: 'The big problem is water': UK ebike owners plagued by failing motors

#329

Post by HeatrayEnjoyer »

isbvhodnvemrwvn wrote: post #200
HeatrayEnjoyer wrote: post #197

Earlier quoted context omitted.

There's no combustion, why is there cooling at all?

There is no combustion in a kettle either, why does it boil water? Axles and brakes don't combust either.

> There is no combustion in a kettle either, why does it boil water? Axles and brakes don't combust either.

A kettle sits on top of a flame... which is combustion.

Axles should not be getting hot. You want to get your car checked.

Brakes are intentionally designed to cause as much friction as possible, the opposite of an electric rotor.

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