D
Deleted member 4366
Guest
Crikey! You're getting worse. Crank drives require less maintenance than hub-motors? That's a new one!
Building a bike for heavy hill climbing on country roads.
- Thread starter Ash21014
- Start date
edit.. I rambled on a bit here with my own thoughts, so sorry..
If this were me, I'd go down the hub drive route. There is far too much hype about crank drives, and that is said after owning two bikes fitted with the system. I can't be sold on the opinion that crank drive is better. They somehow leave me a bit deflated and wanting more. I can't pin it down to anything specific, but they lack something, and just don't excite in the same way that a hub drive does. They are undeniably good at their job, but I certainly would never say that they are better. Just different. If you fancy a chilled ride, to me a hub drive offers a more pleasurable e-bike experience. A crank drive will in my opinion get you fitter though, but that also means that it requires greater input and effort on the part of the rider, for the same gain.
If I had both options available to me, I suspect that the crank drive bike would be used solely in respect of keeping fit, and the hub drive would be for when I wanted fun. As I'm writing this, I kind of suspect that is what is missing. The bike has become a tool for a job, and one that it excels at, but sometimes it would be nice to pop out and just chill, instead of feeling the need to stay focussed and on it.
Cols ex demo bike has just suddenly become very appealing.
I'd also say that poor quality spokes and or wheel building can affect any bike, and I certainly don't accept that hub drives require more maintenance. And crank drives certainly destroy chains etc quicker. As for wheel changing on a hub drive. Five minutes tops is all that's required for that one.
If this were me, I'd go down the hub drive route. There is far too much hype about crank drives, and that is said after owning two bikes fitted with the system. I can't be sold on the opinion that crank drive is better. They somehow leave me a bit deflated and wanting more. I can't pin it down to anything specific, but they lack something, and just don't excite in the same way that a hub drive does. They are undeniably good at their job, but I certainly would never say that they are better. Just different. If you fancy a chilled ride, to me a hub drive offers a more pleasurable e-bike experience. A crank drive will in my opinion get you fitter though, but that also means that it requires greater input and effort on the part of the rider, for the same gain.
If I had both options available to me, I suspect that the crank drive bike would be used solely in respect of keeping fit, and the hub drive would be for when I wanted fun. As I'm writing this, I kind of suspect that is what is missing. The bike has become a tool for a job, and one that it excels at, but sometimes it would be nice to pop out and just chill, instead of feeling the need to stay focussed and on it.
Cols ex demo bike has just suddenly become very appealing.
I'd also say that poor quality spokes and or wheel building can affect any bike, and I certainly don't accept that hub drives require more maintenance. And crank drives certainly destroy chains etc quicker. As for wheel changing on a hub drive. Five minutes tops is all that's required for that one.
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With regard to maintenance, that's my personal view. Punctures: in favour of CD because you can have QR on both wheels, brakes: in favour of CD because the wheels have less total inertia, shocks: also in favour of CD.
There is a situation at the moment that manufacturers tend to fit hub bikes with more powerful controllers than crank drives, but the 8-Fun BBSes have just as much brute power as the Panasonic hub and BPMs.
There is a situation at the moment that manufacturers tend to fit hub bikes with more powerful controllers than crank drives, but the 8-Fun BBSes have just as much brute power as the Panasonic hub and BPMs.
Well the 250W CD motor is fast enough on the flat at about 22mph and would be even faster for me if there was a harder gear. On steep hills I get about 11mph, but 15mph or more would be nice.
How much are these higher power motors going to affect battery life though?
I realise battery life will be disproportionately reduced because at higher speeds the bike is less aerodynamically efficient, and the higher current use will cause vdrop to occur faster, and I'm guessing more power from the motors will also be lost as heat, unless the higher power motors are more efficient?
With the 250W motor on max power for say 16 miles on the Sirocco CD there is a noticeable drop in power output, so maybe I should add a couple more cells to my battery?
On that note how does hub vs crank compare on power usage to obtain a given speed on the flat or a hill?
As to the earlier comments about me having problems with gearing, to be fair as you well know the Sirocco CD uses the cheapest components on the market, I would be using a much better group set if I went for a crank drive motor again.
I realise battery life will be disproportionately reduced because at higher speeds the bike is less aerodynamically efficient, and the higher current use will cause vdrop to occur faster, and I'm guessing more power from the motors will also be lost as heat, unless the higher power motors are more efficient?
With the 250W motor on max power for say 16 miles on the Sirocco CD there is a noticeable drop in power output, so maybe I should add a couple more cells to my battery?
On that note how does hub vs crank compare on power usage to obtain a given speed on the flat or a hill?
As to the earlier comments about me having problems with gearing, to be fair as you well know the Sirocco CD uses the cheapest components on the market, I would be using a much better group set if I went for a crank drive motor again.
The battery can take 2C without much to worry about, you can go up to 48V 24A on your battery, that's why I suggest BBS02 48V 18A 500W.
The Sirocco CD is limited by the controller, rated 36V 14A. You can extrapolate the difference. The BBS02 is just as efficient as the BBS01, about 75% to 80%, similar to the Sirocco CD. Its power consumption is similar to the CD when you ride at the same speed on the same route.
On steep hills, the more powerful motor conserves its efficiency while the smaller motor power is capped, its efficiency also drops. The bigger motor can connsume less. It's the same kind of comparison between an SWX hub against a BPM hub. D8veh can probably confirm this as he has ridden a lot of different motors.
The beauty of a CD conversion is that you can easily start from a good platform, good derailleur, good shifter, good shocks, the job is easy and the result more or less guaranteed. The pedelec sensor on the BBS02 is programmed for quick gear change, about 90 degrees on the crank for starting and stopping time against 720 degrees on the Sirocco CD. In effect, if you can instinctively stop pedalling when braking, you don't even need brake sensors. BTW, woosh sell the BBS02 36V 25A 500W, Eclipse have the 48V version.
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To give an idea of power usage on a crank drive, my trike with a BBS01 on the last two rides delivered under 8 wh per km with about 350m climbing over 22 km, flat cruising speed is 40 kph without human input and the sub 8Wh was with no rider input for the whole distance, the trick is to treat the motor like your legs the moment it starts to load up/slow down shift gears.
You can set the pas level to adjust max power with the 500w unit to a lower level.
Unlike Trex I would not ride a BBS01 without 1 brake cut out, that ~1 second cut off could kill you on the street, my trike has strong brakes and you can here and feel the motor fighting them.
Plus as d8veh has pointed out previously the cutoff will over ride a throttle failure and shut the motor down.
Oh and IMO for STEEP hills the crank drive is unbeatable.
You can set the pas level to adjust max power with the 500w unit to a lower level.
Unlike Trex I would not ride a BBS01 without 1 brake cut out, that ~1 second cut off could kill you on the street, my trike has strong brakes and you can here and feel the motor fighting them.
Plus as d8veh has pointed out previously the cutoff will over ride a throttle failure and shut the motor down.
Oh and IMO for STEEP hills the crank drive is unbeatable.
C
Cyclezee
Guest
Sorry Dave but I disagree with the longevity figues you quote for high torque front motors, e.g. my son gets several thousand miles out of a set of Schwalbe Marathon Plus tyre on an eZee Sprint GTS which has a high torque front hub motor.Ok, so that's some idea of motors then, now does anyone know a decent frame I can buy considering I'm 5'8" and 65kg, I think I'd like large diameter tyres because of the bad road surfacing etc, what do you think? And does having both rear and front suspension make a difference?
D
Deleted member 4366
Guest
Is he light? It makes a big difference.
High torque motors have a tendancy to spin on start-up and when climbing steep hills, which is why they wear fairly rapidly. Saneagle has a front BPM at 30A. He's just worn out his tyre in about 300 miles from new!
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I thought d8 was being pessimistic on front tyre wear.
I've seen no accelerated wear on my Brompton Nano, although I suppose it has a relatively weedy motor.
Tyre compound must play a big part.
Cyclezee tend to fit Marathon Pluses, which is about the toughest, longest lasting tyre available.
Trade-off is a harsh ride.
I've seen no accelerated wear on my Brompton Nano, although I suppose it has a relatively weedy motor.
Tyre compound must play a big part.
Cyclezee tend to fit Marathon Pluses, which is about the toughest, longest lasting tyre available.
Trade-off is a harsh ride.
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Cyclezee
Guest
He's a big guy and weighs about 80Kg. but not as handsome as his father
Maybe Saneagle needs to feed the power in gradually?
Nah, ride it like you stole it.
That Ansmann is a nice looking bike.
Is that a through axle on the rear?
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D
Deleted member 4366
Guest
That's a rear motor. No wonder he doesn't wear out the front tyre!He's a big guy and weighs about 80Kg. but not as handsome as his father
View attachment 10235
Maybe Saneagle needs to feed the power in gradually?
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Cyclezee
Guest
Boy you're on form today
That's not the bike he normally rides, the photo is only to illustrate the size of rider who normally rides one of these
C
Cyclezee
Guest
Hi Eddie,Nah, ride it like you stole it.
That Ansmann is a nice looking bike.
Is that a through axle on the rear?
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Yes, the Ansmann does have through axle with quick release skewer and uses a cassette.
Ansmann direct drive motor
D
Deleted member 4366
Guest
Photos never lie - except sometimes.
Remember that the golden rule is that there are no golden rules.
Remember that the golden rule is that there are no golden rules.
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strictly for what its worth - I genuinely know nothing about pedelecs, but I have a friend who has been gratuitously hammering the crap out of a Raleigh twenty he built with a madly unrestricted BPM (last time I checked he managed to coax more than 2kw out of it, and that's mainly what he gives it) for as long as I've known him (about a year) without any broken anything (including spokes)..
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