Ebike for short steep commute

CountingCrows

Hello,

There seems to be a bewildering number of e bikes available. I need something my wife can use for a short 10km cycle which includes a very steep hill. The bike will be locked at the dart station so something that doesn't scream rob me, I'm expensive! Budget 2K sticker price and needs to be a Bike2Work supplier.

Would this be a good fit?

https://garyscycles.com/product/giant-prime-e-3-w-2017/

homer911

All ebikes would cope with a steep climb. As an ebike owner, if you are leaving it at a Dart station, you should be removing the battery to make it less nickable so choose one where the battery does not weigh a ton and has a carrying handle. Personally I would only spend this money where I know the bike will be stored securely - the ebikes in Halfords tend to be a fair bit cheaper, while they may not have the same quality its less of an issue if the thing is stolen or damaged

There are also folding ebikes available which your OH could then bring on the Dart - again, I have seen these in Halfords for around the €800 mark (sorry, I don't have any association with them, they just happen to be my closest "bike" shop)

Duckjob

Would advise you to go for a mid-drive system rather than a rear hub motor. They tend to be better climbers since a mid drive can leverage the gears for a steep climb whereas a hub motor can't.

peasant

+1 for the mid-drive motor, 250W hub motors (max legal limit) do not cope well with steep hills.

But even with a mid drive, on a very steep hill you might want to check (test drive?) that the gearing on your bike is suitable.

On my bike for example, with a 42 tooth front sprocket and nine gears (dunno about no of teeth) the lowest gear would still be too high for a really steep hill.
At a reasonable cadence it gives me a speed of 13 km/h...which is way too much for a really steep hill...and even with the motor normal hills present quite a workout...not sure if I could even make a really steep hill.

So something with more mountain bike like gearing might be a better bet.

cdaly_

CountingCrows wrote: »

Hello,

There seems to be a bewildering number of e bikes available. I need something my wife can use for a short 10km cycle which includes a very steep hill. The bike will be locked at the dart station so something that doesn't scream rob me, I'm expensive! Budget 2K sticker price and needs to be a Bike2Work supplier.

Rent a bike locker at the dart station.

CountingCrows

cdaly_ wrote: »

Rent a bike locker at the dart station.

None at her station i’m afraid.

CountingCrows

Any specific mid drive model recommendations?

homer911

CountingCrows wrote: »

Any specific mid drive model recommendations?

Pretty much any ebike using either the Bosch or Yamaha drive systems. Bosch claim over 50 bike manufacturers using their system.

peasant

...and depending how steep that steep hill really is ...

Yamaha and Brose systems can be had with dual front sprockets, giving you the option to really gear down into mountain goat territory.
(I've only ever seen those on fairly expensive MTB's though, Haibike and the like)

But ..if it's only a short commute, high speed isn't the main objective but the steep hill is...maybe talk to your dealer to modify the bike with a smaller front sprocket. They come in different sizes on most systems. Can't really see any reason why a nice city bike couldn't be fitted with a MTB sprocket, if that's what it takes.

In that case...almost any bike with any (mid) motor could be made suitable.

EDIT
That bike in your opening post looks fine to me and seems very good value.
The motor should be a Yamaha motor (labelled Giant) and therefore it shouldn't really be a problem to change sprockets to something from their MTB range should the original setup turn out to be too high for your steep hill.

Alternatively, chain reaction have this ladies MTB on sale:
http://www.chainreactioncycles.com/mobile/ie/en/lapierre-overvolt-cross-800-ladies-e-bike-2017/rp-prod148750

Another thing for the parking at the station...a removable display would be nice. A stolen or badly damaged display basically renders your e-bike useless as the display on these things doesn't just display but actually switch on/off and control assist levels.

rubadub

That bike claims to have a 60Nm torque. Which is surprisingly high for a bike like that.

Here are the bosch ones ranging from 40, 50, 63, 75Nm

https://www.bosch-ebike.com/en/products/drive-unit/

I have the 63Nm and it does have a decent kick off it. I can get up steep hills around Killiney, Vico road etc not a bother, passing lads on road bikes up out of the saddle while still seated always gets looks of amazement! a lot of people would just get off their bike and walk on some really steep bits. Most mountain bikes I saw were lower torque, so 60Nm seems very high for a bike like that.

but giants idea of 60Nm might not be the same as Bosch's -if peasant is right saying its a Yamaha then it likely is a legit comparison.

I would not dare leave my bike at a dart station, just screams "the owner is gone to work, so fire ahead". If I absolutely had to do something, I would find somewhere else to lock it nearby, and use high end locks of course. If the battery is gone and the speedometer is gone then a pro theif will likely know it will cost a fortune to replace them and so its not as worthwhile robbing.

I used to have a cassette with a real high number tooth ring on it.



But it might not be compatible with the bikes deraileur.

peasant

rubadub wrote: »

I used to have a cassette with a real high number tooth ring on it.

But it might not be compatible with the bikes deraileur.

The chain line might be another thing that is not compatible. With so much torque going through the whole drivetrain it is important that the chain line doesn't get too much out of true, otherwise your chain, cassette and crankset won't last very long

Joe1919

Just some physics (I think) and rough figures.....

Potential energy (joules or watts per second) = Mass(kg) X G (9.81) X height (meters).

So lets assume that the ebike motor is 250w and the efficiency at 80%, the rider is 75kg and the bike is 25kg.

PE = mgh,
h = PE/mg = (250 X 80%)/ (9.81 X (25+75) = approx .2 meters/sec or 1 meter every 5 seconds is the maximum height that can be gained.

On a very steep hill (e.g a 1 in 10 climb), the maximum theoretical speed would be 2 meters/second or 7.2 kilometers/hour.

PS I have not allowed for the pedaling effort, but one could add ones own (muscle) power and redo the figures.

philstar

so what happens when you come to a steep hill..do you press a button and away you go...or does the bike automatically know its on an incline ?

Greentree_uk

have to ask, where is she getting the dart from and to? if you are getting an ebike, its faster to cycle than take a dart!

Lumen

Joe1919 wrote: »

Just some physics (I think) and rough figures.....

Potential energy (joules or watts per second) = Mass(kg) X G (9.81) X height (meters).

So lets assume that the ebike motor is 250w and the efficiency at 80%, the rider is 75kg and the bike is 25kg.

PE = mgh,
h = PE/mg = (250 X 80%)/ (9.81 X (25+75) = approx .2 meters/sec or 1 meter every 5 seconds is the maximum height that can be gained.

On a very steep hill (e.g a 1 in 10 climb), the maximum theoretical speed would be 2 meters/second or 7.2 kilometers/hour.

PS I have not allowed for the pedaling effort, but one could add ones own (muscle) power and redo the figures.

.2 vertical metres a second = 720 "VAM" (vertical meters per hour) from 200W.

A regular person can put in 100W without breaking sweat, so that'll give 1080 VAM before drag, so lets say a little under 1000 VAM.

That's a decent rate of ascent for a recreational cyclist on a proper road bike going flat out on an extended climb, never mind someone pootling along fully clothed on an ebike.

fryup

^^^^^^^^^^^

i say you guys are great craic down the pub

CountingCrows

Greentree_uk wrote: »

have to ask, where is she getting the dart from and to? if you are getting an ebike, its faster to cycle than take a dart!

Glenageary to Merrion Square

rubadub

philstar wrote: »

so what happens when you come to a steep hill..do you press a button and away you go...or does the bike automatically know its on an incline ?

Mine has some sort of indicator on the side suggesting what power level you should be at, I am not sure as I never use it.

You can adjust the power on my bosch to be off, eco, touring, sport or turbo. So you can use it sort of like gears, you switch it up or down with your thumb, readily accessible like it was gears. So if you are in the same gear and come to a hill you can ramp it up to turbo, or if going down a slight incline you can put it on eco. If your battery is running out you can lower the power down, and if you are nearly home and see there is plenty left you can ramp it up again, you get to know how much you have left. If you are in the highest assitance mode and struggling you just drop your gears down.

I think of it more like being on a tandem bike, the "person" on the back will stop pedalling once you get over a certain speed or stop pedalling yourself. If you are going up a hill you will likely have to put some effort in yourself, while the motor is going as hard as it can, if you do not want to break a sweat you do not have to, just lower the gears accordingly. You can still get exercise if you want, either by lower your assistance or just cycling harder yourself.

CountingCrows wrote: »

Glenageary to Merrion Square

I would prefer to cycle that, my mates bike was nicked at glenageary and was not even particularly good.

You have to account for walking time from merrion square to work, and time waiting for the dart, and cycling to the dart. I can get to work in 17-20mins now, people were telling me it must be great having the luas near me, but its a 20min walk to the luas, and 11min walk from the luas to work, 20-25mins on the luas, and possible 10mins wait if I just miss one. So if I absolutely have to get to work on time I need to leave about 1hr before.

Greentree_uk

CountingCrows wrote: »

Glenageary to Merrion Square

You would manage that in 30 mins on a spedelec. Bike, Talk to joe @ dlbcycles I do leopardstown to Clare hall in 38 mins (20km). Oh and I wasn’t that fit when I started

Bigus

Try and get one with the battery mounted on the frame down tube , much better centre of gravity, and definitely the mid drive Bosch motor.
Lapierre overvolt cross 400 is a good alrounder

fryup

anyone have the carrera vulcan or coyote edge ??

Lumen

fryup wrote: »

^^^^^^^^^^^

i say you guys are great craic down the pub

...says the twitcher