Help choosing an E bike

Electrically assisted bikes, trikes, etc. that are legal in the UK
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Lizzog
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Joined: 19 May 2022, 2:41pm

Help choosing an E bike

Post by Lizzog »

We got a Trek Verve 3 step through last year through Cycle to Work. It's a beast of a bike - 27kg without the battery- and hoiking it around a corner to get it down our passageway, then through the gate, doorway and into the dining room (where it 'lives'- can't fit it in the bike shed it's too long).
We're looking to see the bike and want to replace it something slightly lighterweight, with crank Bosch motor still. Been looking at some of the Kalkhoff Entice/Endeavour bikes, which seem to come in around 25kg. I know there are lighter bikes out there, but don't want to lose the crank motor as we live in a hilly part of the world.
Any advice?
Last edited by Lizzog on 19 May 2022, 3:00pm, edited 1 time in total.
Jdsk
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Re: E-bike advice

Post by Jdsk »

Welcome.

Do you have a target price range for the new bike?

Thanks

Jonathan
Lizzog
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Joined: 19 May 2022, 2:41pm

Re: E-bike advice

Post by Lizzog »

It's largely dependent on what we can get for the Trek when we come to sell it. It's in great condition and not done a huge amount of mileage so I'm hoping we can have a budget up to £3k
Jdsk
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Re: E-bike advice

Post by Jdsk »

Thanks

Jonathan
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Cugel
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Re: Help choosing an E bike

Post by Cugel »

Hub motor bikes tend to be heavy but if you're prepared to compromise a bit, you can buy and use a Fazua-equipped bike that has many of the characteristics of a BB motor but without the usual high-weight penalty.

https://old.fazua.com/en/drive-system/evation/

The Fazua motor is in the down tube, along with the battery, both contained in an easily removable module. The motor drives the chainset, chain and rear sprockets - as with other BB motor systems - via a gearbox housed in the bottom bracket. Fazua-equipped bikes are typically 13kg - 16kg. The least expensive seems to a Boardman sold by Halfords at less than £3000 but generally the Fazua appears in rather more upmarket bikes of £3000+ to £7000, with one or three even more than that (the carbon fibre, Dura-Ace equipped, racier items with expensive brand labels on them).

Some of these bikes are configured more for general riding, including commuting .... but most are of the "pure" road bike kind.

The Fazua system gives 57Nm of torque from it's 250 watt motor, as opposed to 40Nm from a typical hub motor and 80Nm from the beefier BB motors such as those of Bosch. The battery is just 250 watt-hours rather than the 500 watt-hours of heavier BB-motor systems. However, this still gives a good range that's likely to be well in excess of most there & back commutes. The ladywife can get around 70 kilometres over the hilly roads of West Wales before the battery says "nearly done", with her e-bike.

The ladywife has a Focus Paralane2 Fazua-equipped e-bike that comes standard with full mudguards and has a less racy road bike configuration (longer wheelbase, higher handlebars, "compliant" geometry and parts for comfort). It's currently listed at over £4000 for the Shimano 105 11-speed version with hydraulic disc brakes but she got hers in a sale with 20% off for (as I recall) £3400 .... nearly 4 years ago.

If you're feeling like it, you can remove the Fazua motor-battery module and reduce the bike weight by over 3kg. I've just bought another Fazua-equipped road bike like this one:

https://www.inspiralcycles.co.uk/bikes/ ... bike__6784

that I'm riding about without the motor and battery in. It weighs 10kg exactly like that. The motor/battery unit is currently a spare for the ladywife's bike but will get back into my bike when I become old enough and decrepit enough to justify it. :-)

Cugel
Last edited by Cugel on 21 May 2022, 5:10pm, edited 1 time in total.
“Practical men who believe themselves to be quite exempt from any intellectual influence are usually the slaves of some defunct economist”.
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peterb
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Joined: 2 Dec 2017, 10:13am

Re: Help choosing an E bike

Post by peterb »

Fazua is a crank or bottom bracket motor system isn't it? Not a 'hub' drive which has the motor as the hub of one of the wheels.
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Cugel
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Re: Help choosing an E bike

Post by Cugel »

peterb wrote: 21 May 2022, 1:33pm Fazua is a crank or bottom bracket motor system isn't it? Not a 'hub' drive which has the motor as the hub of one of the wheels.
Quite right. A slip of my typing fingers there. Post amended to read "BB motor".

Cugel
“Practical men who believe themselves to be quite exempt from any intellectual influence are usually the slaves of some defunct economist”.
John Maynard Keynes
Bonzo Banana
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Joined: 5 Feb 2017, 11:58am

Re: Help choosing an E bike

Post by Bonzo Banana »

Cugel wrote: 21 May 2022, 10:28am Hub motor bikes tend to be heavy but if you're prepared to compromise a bit, you can buy and use a Fazua-equipped bike that has many of the characteristics of a BB motor but without the usual high-weight penalty.

https://old.fazua.com/en/drive-system/evation/

The Fazua motor is in the down tube, along with the battery, both contained in an easily removable module. The motor drives the chainset, chain and rear sprockets - as with other BB motor systems - via a gearbox housed in the bottom bracket. Fazua-equipped bikes are typically 13kg - 16kg. The least expensive seems to a Boardman sold by Halfords at less than £3000 but generally the Fazua appears in rather more upmarket bikes of £3000+ to £7000, with one or three even more than that (the carbon fibre, Dura-Ace equipped, racier items with expensive brand labels on them).

Some of these bikes are configured more for general riding, including commuting .... but most are of the "pure" road bike kind.

The Fazua system gives 57Nm of torque from it's 250 watt motor, as opposed to 40Nm from a typical hub motor and 80Nm from the beefier BB motors such as those of Bosch. The battery is just 250 watt-hours rather than the 500 watt-hours of heavier BB-motor systems. However, this still gives a good range that's likely to be well in excess of most there & back commutes. The ladywife can get around 70 kilometres over the hilly roads of West Wales before the battery says "nearly done", with her e-bike.

The ladywife has a Focus Paralane2 Fazua-equipped e-bike that comes standard with full mudguards and has a less racy road bike configuration (longer wheelbase, higher handlebars, "compliant" geometry and parts for comfort). It's currently listed at over £4000 for the Shimano 105 11-speed version with hydraulic disc brakes but she got hers in a sale with 20% off for (as I recall) £3400 .... nearly 4 years ago.

If you're feeling like it, you can remove the Fazua motor-battery module and reduce the bike weight by over 3kg. I've just bought another Fazua-equipped road bike like this one:

https://www.inspiralcycles.co.uk/bikes/ ... bike__6784

that I'm riding about without the motor and battery in. It weighs 10kg exactly like that. The motor/battery unit is currently a spare for the ladywife's bike but will get back into my bike when I become old enough and decrepit enough to justify it. :-)

Cugel
I feel its important to point out that direct drive hub motors are heavy but geared hub motors can be very light and the overall weight is the lowest of all motor systems typically which is why small geared hub motors are used on a lot of e-road bikes. Also 57Nm at the crank for a mid-drive motor has maybe 2-3Nm of power losses through the chain. Their peak power readings tend to be for a shorter period of time. For example a Bosch 250W rated motor may peak at 85Nm torque but has been shown to consume almost 800W when doing that well above the 250W nominal rating of the motor. Lastly gearing is important if you have 42T at the front and 32T at the rear then that 54Nm of torque is 41Nm in reality below that of many cheap geared hub motors which provide 45Nm without any issues or power losses. Where mid-drive is climbing king is where its a high torque motor combined with low gearing those bikes are beasts getting up hills but this shouldn't be applied to mid-drive in general especially the low power mid-drive bikes which are often around the same climbing ability as hub motors and often even less. Bosch do a 40Nm mid-drive motor which is used with hub gears to stop the mid-drive motor destroying the hub gears quickly and that is less powerful than most hub motors in real world use. Lastly because mid-drives wear through drivetrain components much faster than hub motors a mid-drive bike is far more likely to have the efficiency losses of worn drive components. Typically a powerful mid-drive motor can wear through drivetrain components at 3x the normal rate where as hub motors extend the life of drivetrain components typically 3x so there is a 9x difference between. Admittedly the low power mid-drive motors do not have the excessive drivetrain wear rate of the more powerful mid-drive motors but they also don't really have any advantages over hub motors either especially if you pair the hub motor with a torque sensor rather than only a cadence sensor.
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Cugel
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Re: Help choosing an E bike

Post by Cugel »

Bonzo Banana wrote: 22 May 2022, 9:25am
I feel its important to point out that direct drive hub motors are heavy but geared hub motors can be very light and the overall weight is the lowest of all motor systems typically which is why small geared hub motors are used on a lot of e-road bikes. Also 57Nm at the crank for a mid-drive motor has maybe 2-3Nm of power losses through the chain. Their peak power readings tend to be for a shorter period of time. For example a Bosch 250W rated motor may peak at 85Nm torque but has been shown to consume almost 800W when doing that well above the 250W nominal rating of the motor. Lastly gearing is important if you have 42T at the front and 32T at the rear then that 54Nm of torque is 41Nm in reality below that of many cheap geared hub motors which provide 45Nm without any issues or power losses. Where mid-drive is climbing king is where its a high torque motor combined with low gearing those bikes are beasts getting up hills but this shouldn't be applied to mid-drive in general especially the low power mid-drive bikes which are often around the same climbing ability as hub motors and often even less. Bosch do a 40Nm mid-drive motor which is used with hub gears to stop the mid-drive motor destroying the hub gears quickly and that is less powerful than most hub motors in real world use. Lastly because mid-drives wear through drivetrain components much faster than hub motors a mid-drive bike is far more likely to have the efficiency losses of worn drive components. Typically a powerful mid-drive motor can wear through drivetrain components at 3x the normal rate where as hub motors extend the life of drivetrain components typically 3x so there is a 9x difference between. Admittedly the low power mid-drive motors do not have the excessive drivetrain wear rate of the more powerful mid-drive motors but they also don't really have any advantages over hub motors either especially if you pair the hub motor with a torque sensor rather than only a cadence sensor.
Hello BB,

Good points - although the weight difference between the lightest hub-motor bike I've seen (a Scott Addict weighing 12kg) and a light Fazua equipped bike (such as the 13kg Lapierre e-xelius I've just bought) is only 1 kg.

BB motors do act through the bike's full transmission so will contribute to sprocket & chain wear. However, in practice the power going through such a transmission when pedalled by a typical e-bike rider, even with the motor on, is likely to be broadly equivalent to the power going through the transmission of a non e-bike pedalled by a very fit cyclist. Those transmissions are made to take quite high wattages, often much higher than the output from a 250 watt e-bike motor, especially a Fazua.

For example, I will be typically putting out between 150 - 350 watts during a ride (usually towards the lower amount but the higher when overcoming various steep Welsh rises that come with alarming regularity around here). The ladywife on her e-bike, and 25 kilos lighter than me, is, together with her Fazua motor, outputting about the same amount of watts as we ride together. (She can drop me on the long steep hills but not on the short ones).

So, her transmission on the e-bike is not likely to wear any faster than mine. Indeed, maintaining her bike over nearly 4 years tells me that this is so, as her chain and sprocket wear rates are even less than on my non e-bike, for broadly the same mileages.

I'm sure that more powerful BB motors than that of the Fazua system will have a greater wear effect on transmissions, especially as the weight of such bikes tend to approach 30 kg rather than the 12 - 16kg of lighter hub and Fazua-equipped bikes.

**************
The OP seemed to be asking for an alternative to the BB motored e-bike currently owned because it is too heavy to easy manage when not being ridden. I suggest the Fazua bike as an alternative because they tend to be much lighter yet retain the same feeling as the heavier BB motored bikes. Fazua bikes can also be turned into an ordinary bike by removing the battery/motor module, which is not generally the case with hub-motored bikes or beefier BB motored bikes.

There are a number of Fazua-equipped bikes that are configured as commuters and tourers, although they tend to be more like 18kg than 13-15kg. That's still a lot lighter than the OP's current e-bike. though. I haven't seen many hub motor bikes that are configured as commuters or tourers, although they must exist. Is their typically lower motor torque an issue if the total weight goes up? I wouldn't have thought so since they can cope with heavy as well as light riders ..... ?

Cugel
“Practical men who believe themselves to be quite exempt from any intellectual influence are usually the slaves of some defunct economist”.
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freeflow
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Re: Help choosing an E bike

Post by freeflow »

I cannot understand why people think that e- bikes cause excessive wear on components. Riders who routinely exceed 250 watts don't experience such wear.
Bonzo Banana
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Re: Help choosing an E bike

Post by Bonzo Banana »

freeflow wrote: 22 May 2022, 6:06pm I cannot understand why people think that e- bikes cause excessive wear on components. Riders who routinely exceed 250 watts don't experience such wear.
Firstly this 250W rating is all nonsense, so called nominal rating or whatever its called is massively exceeded by many mid-drive motors. As I wrote previously Bosch motors have been shown to peak at close to 800W. What they don't do is exceed the 15.5mph limit in restricted mode. You are also combining human power with the motor power all through the same drivetrain. It is a very common issue but there are lots of ways to reduce it. Clearly low power mid-drive motors don't have the same issues, other riders may keep to low power modes and they may be more careful how they use the motor. There are now gear change sensors that cut power when you change gears on some ebikes and others may tweak/lightly press brake levers to cut motors when they gear change. There are so many variables. Ultimately though if you are putting through 3-5x the power through the drivetrain of a normal rider you must expect faster wear rates. Legal hub motors are not as powerful typically you may be getting 2-3x the power but its independent of the drivetrain so it massively reduces the wear rate. In fact some cheap hub based ebikes have pretty awful components from brands you've never heard of on low end freewheel drivetrains. It doesn't matter because the drivetrain gets a much easier life so such awful components actually can hold up quite well. Take away the hub motor and those components don't perform as well. There are many advantages and disadvantages of all motor types but reduced drivetrain wear is one of the big positives of hub motors. It makes them the ideal choice for commuting and long distances. Even if you snap a chain on a hub motor which really never happens because the drivetrain gets a much easier time, but if you did you just have to spin your legs and the motor will work even without a chain. Unless you have a torque based sensor rather than cadence. The point is the drivetrain doesn't even have to exist for a hub motor ebike to work although you will definitely need it for the steeper hills.
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