July 11, 20178 yr apologies if this has been covered elsewhere . So my Carrera Crossfire is reputedly able to cover 60 mile on a charge ? So how do the makers come to this figure ? I suppose if you were 7 stone and lived in a area with no hills would it be possible ? If the makers used a formula for this assumption would there be any way of inputting different weights and terrain choice to come to a guesstimate for say light medium and heavy ? also terrain easy medium hilly ? The reason I have brought this up is that I am around 16 stone and live in a hilly area , best I can achieve is 46 kilometres = 28.5 miles I was looking to do the coast to coast bike ride and would be limited to distance on 1 battery and having looked on Halfords website the cost of a back up is £400.00 Also my local dealer was telling me my battery needs servicing and I should store the battery indoors during low temperatures Are they making things up because the batteries are not achieving their figures ? Also has anyone achieved anything like the 60 mile range on a crossfire ? PS While I was in Halfords I noticed they had a new E Crossfire mountain bike for £1000.00 it proclaimed the range on that one was 40 miles ( and its the same battery according to the sales guy ?
July 11, 20178 yr I think the battery range that gets quotted is a bit the mpg figures that car manufacturers come up with and basically don't happen in the real world cause there's to many variables.
July 11, 20178 yr Good questions. The range they quote is just an estimate using pretty optimistic parameters. Never take any notice of what anybody else gets. range is always personal to you and your rides. It can be anywhere from 20 miles to 200 miles on a bike like yours - or on any other bike. The only thing that would make a difference is the capacity of the battery, though, obviously, you'd get some difference between a MTB with wide knobbly tyres and a thin light bike with a crouched riding position. No magic wand will help you. If you want to go further, you need to get a bigger (or extra) battery or pedal harder. Actually, I lied. This magic formula will work, but try not to let the secret out. Ride an average of at least 10 miles a day; stop drinking everything but tea, coffee and water; and eat only salads for the next 12 months, then you'll have no problem doing that coast to coast ride on one battery charge.
July 11, 20178 yr Is this the bike with an 11.4Ah battery? If so, 60 miles sounds optimistic to me. I have a 15.6Ah battery on one of my bikes and have managed 56 miles in a hilly area (Wales borders) with some headwinds and still had about a third of the capacity remaining using power levels 3-5 of 5. I weigh 52kg and carry about 5kg. On a 8.8Ah battery, my limit is about 30 miles along similar routes using power levels 1 & 2 of 3. The quoted 60 miles must surely be on flat roads with a lightweight rider carrying no/little load, no headwinds and on the lowest power mode eeking it out as far as possible.
July 11, 20178 yr I did 129 hilly miles on my bike with 11.6 Ah battery when I weighed 100kg. What does that tell you?
July 11, 20178 yr - either you were very very fit and those 100kg were pure muscle or your bike's 'puter wasn't working...?
July 11, 20178 yr Author I did 129 hilly miles on my bike with 11.6 Ah battery when I weighed 100kg. What does that tell you? All down hill ?
July 11, 20178 yr Author Is this the bike with an 11.4Ah battery? If so, 60 miles sounds optimistic to me. I have a 15.6Ah battery on one of my bikes and have managed 56 miles in a hilly area (Wales borders) with some headwinds and still had about a third of the capacity remaining using power levels 3-5 of 5. I weigh 52kg and carry about 5kg. On a 8.8Ah battery, my limit is about 30 miles along similar routes using power levels 1 & 2 of 3. The quoted 60 miles must surely be on flat roads with a lightweight rider carrying no/little load, no headwinds and on the lowest power mode eeking it out as far as possible. Yes 11.4 Ah .......maybe I need a different bike , are there many with 15.6 Ah batteries ? Whats yours ?
July 11, 20178 yr All down hill ? You just turn down the power. When you come to a hill, use a low gear. On an MTB, you can pedal up even the steepest hills using the third (inner) chainring and bottom gear. You don't need an electric motor. All the motor does is make you go faster in a higher gear. My pedal effort is always the same whatever I do. I've done 44 miles on my other full-suspension MTB before I even switched the motor on. You don't need to be fit. You just need time because you'll be pretty slow up the hills.
July 11, 20178 yr You just turn down the power. When you come to a hill, use a low gear. On an MTB, you can pedal up even the steepest hills using the third (inner) chainring and bottom gear. You don't need an electric motor. All the motor does is make you go faster in a higher gear. My pedal effort is always the same whatever I do. I've done 44 miles on my other full-suspension MTB before I even switched the motor on. You don't need to be fit. You just need time because you'll be pretty slow up the hills. To add to the above: when you are asthmatic you can climb just about any hill seated and MUCH faster than without a motor and in granny gear. My hub motor bike could climb pretty much anything at cut off speed (you learn to ride at 1 km/h below 25 km/h cut off) and I was using down to 5.35 W/km which lead some here to remark that I didn't really need a motor. I do need one because I couldn't do that at all without one it is just the tiny little bit of help needed to prevent stopping twice on a 3.4 km climb and gasping for air...
July 11, 20178 yr Author You just turn down the power. When you come to a hill, use a low gear. On an MTB, you can pedal up even the steepest hills using the third (inner) chainring and bottom gear. You don't need an electric motor. All the motor does is make you go faster in a higher gear. My pedal effort is always the same whatever I do. I've done 44 miles on my other full-suspension MTB before I even switched the motor on. You don't need to be fit. You just need time because you'll be pretty slow up the hills. I always turn down the power and try to use the gears until i find it to hard to pedal , the other day I turned off completely for ages because my battery was on its last legs but that was on the flat as soon as i come to a hill i do need assistance because the weight of myself and the bike , anyway thanks for making me feel inferior to your prowess .
July 11, 20178 yr I always turn down the power and try to use the gears until i find it to hard to pedal , the other day I turned off completely for ages because my battery was on its last legs but that was on the flat as soon as i come to a hill i do need assistance because the weight of myself and the bike , anyway thanks for making me feel inferior to your prowess . What gears do you have?
July 16, 20178 yr Shimano Acera 8 gears . You need a double or triple chainring to climb hills without power from the motor or with low power.
July 16, 20178 yr To add to the above: when you are asthmatic you can climb just about any hill seated and MUCH faster than without a motor and in granny gear. My hub motor bike could climb pretty much anything at cut off speed (you learn to ride at 1 km/h below 25 km/h cut off) and I was using down to 5.35 W/km which lead some here to remark that I didn't really need a motor. I do need one because I couldn't do that at all without one it is just the tiny little bit of help needed to prevent stopping twice on a 3.4 km climb and gasping for air... .. will we get into the no man's land of using crank drive and the gears... Going real slow in a very low gear with a crank motor allows the motor develop its full mechanical power. Going real slow on a hub motor is wasteful as the majority of the electrical energy is converted to heat...
July 16, 20178 yr Good questions. The range they quote is just an estimate using pretty optimistic parameters. Never take any notice of what anybody else gets. range is always personal to you and your rides. It can be anywhere from 20 miles to 200 miles on a bike like yours - or on any other bike. The only thing that would make a difference is the capacity of the battery, though, obviously, you'd get some difference between a MTB with wide knobbly tyres and a thin light bike with a crouched riding position. No magic wand will help you. If you want to go further, you need to get a bigger (or extra) battery or pedal harder. Actually, I lied. This magic formula will work, but try not to let the secret out. Ride an average of at least 10 miles a day; stop drinking everything but tea, coffee and water; and eat only salads for the next 12 months, then you'll have no problem doing that coast to coast ride on one battery charge. .. except if you were eating only salads for a year , you wouldn't have the energy to lift the cup of tea.... You need a few spuds.
July 16, 20178 yr .. except if you were eating only salads for a year , you wouldn't have the energy to lift the cup of tea.... You need a few spuds. Potato salad?
July 16, 20178 yr apologies if this has been covered elsewhere . So my Carrera Crossfire is reputedly able to cover 60 mile on a charge ? So how do the makers come to this figure ? I suppose if you were 7 stone and lived in a area with no hills would it be possible ? If the makers used a formula for this assumption would there be any way of inputting different weights and terrain choice to come to a guesstimate for say light medium and heavy ? also terrain easy medium hilly ? The reason I have brought this up is that I am around 16 stone and live in a hilly area , best I can achieve is 46 kilometres = 28.5 miles I was looking to do the coast to coast bike ride and would be limited to distance on 1 battery and having looked on Halfords website the cost of a back up is £400.00 Also my local dealer was telling me my battery needs servicing and I should store the battery indoors during low temperatures Are they making things up because the batteries are not achieving their figures ? Also has anyone achieved anything like the 60 mile range on a crossfire ? PS While I was in Halfords I noticed they had a new E Crossfire mountain bike for £1000.00 it proclaimed the range on that one was 40 miles ( and its the same battery according to the sales guy ? .. they are not really making it up as regards battery maintenance. But that's no problem, just charge it up every three months even if the bikes not used, and keep it at moderate temperature. The other question, as d8veh, has referenced is much more complex. To answer it you have to add together all the energy loss mechanisms on riding a bike and compare it to the energy stored in the battery. Bosch have a calculator on their website and you can play with the variables. Schwab have a nice graphic showing power losses as a function of speed etc. The most important variables are. 1. Speed and wind resistance. Power loss increases by the cube of the speed. That means whatever power was lost at 10 kmhr it is 8 times more at 20kmhr. The riders stance and clothing affect thus 2. Weight of bike and rider.. the rider being the most significant this affects in two ways. Rolling resistance of the flexible tyres is dependent on weight. That's why railways use steel wheels. And work done going up and down hills. You never get back going downhill what you put in going uphill, as wind resistance matters. 3. Numbers of stops and starts. 4. How much energy you the rider are prepared to contribute.
July 16, 20178 yr Going real slow on a hub motor is wasteful as the majority of the electrical energy is converted to heat... No it doesn't. It depends which hub-motor you have. What you can't have with a hub-motor is high speed and efficiency at low speed, but many hub-motors are efficient at low speed. maybe your old 24v Urban mover was crap, but don't judge all hub-motors from that. a lot has changed since you bought it all those years ago. have you tried one of those old Powabyke Euros with the lead batteries? They climb like a goat. You don't even have to pedal. They were rated at 200W. What's more, they have/had considerable more climbing torque and probably efficiency too than the 24v Panasonic crank-drives of the time. Should we therefore say that crank drives are no good at climbing?
July 16, 20178 yr No it doesn't. It depends which hub-motor you have. What you can't have with a hub-motor is high speed and efficiency at low speed, but many hub-motors are efficient at low speed. maybe your old 24v Urban mover was crap, but don't judge all hub-motors from that. a lot has changed since you bought it all those years ago. have you tried one of those old Powabyke Euros with the lead batteries? They climb like a goat. You don't even have to pedal. They were rated at 200W. What's more, they have/had considerable more climbing torque and probably efficiency too than the 24v Panasonic crank-drives of the time. Should we therefore say that crank drives are no good at climbing? What you mean UrbanMover "was",? it still is and it's ears would be burning with embarrassment, if it could hear me singing it's praises. It has small wheels and is pretty nifty on the local steep slope up from the road. It only wants a fresher battery and it will be good for another decade. I think, that it has only the 200w motor cannot confirm as the websites refer to a different product now..It came with the NimH 8amp26v pack, typical of the era, but since replaced. Little amount of rust, so good stainless steel in parts. It's a dinky little bike, limited range but good fun. Unfortunately as a folder, it's a bit cramped. Can we agree that a hub motor, irrespective of power rating has a specific speed at which it is most efficient and at lower speeds will be somewhat lower efficiency. ?Can we agree that because the hub is directly coupled to the wheel and tyre that that translates to an optimal road speed for that motor on that wheel.? Similarly a crank motor has a speed at which it's efficiency is peaked. But and this the crucial difference, because the crank is connected by a chain, and the possibility of gears, there is no such limitation on road speed. This means that massively low ratio gears can be fitted so that they can go up walls (exaggeration)., Slowly.!!!
July 16, 20178 yr ... Similarly a crank motor has a speed at which it's efficiency is peaked. But and this the crucial difference, because the crank is connected by a chain, and the possibility of gears, there is no such limitation on road speed. This means that massively low ratio gears can be fitted so that they can go up walls (exaggeration)., Slowly.!!! My experience with 32:34 is coherent with http://www.bikecalc.com/speed_at_cadence and gives between 9 and 10 km/h at cadence, seated, on a hill with +10% gradients the motor drawing less than 200 W most of the way! Air resistance: 2.9 W/km for the Quest(!) @ 40 km/h I am guessing that more than compensates for the extra weight of the vélomobile but it does only weigh as much as many e-bikes on the market. The new 1.4 kg xiongda coupled with a pinion C1.9xr correctly geared would take care of the weight on the hills, a 3 speed derailleur/freewheel combination with 18, 22 and 26 teeth would expand the already good 569% range quite handily! Imagine a motor + gearbox weighing about 3.8 kg (including freewheel)...
July 16, 20178 yr What you mean UrbanMover "was",? it still is and it's ears would be burning with embarrassment, if it could hear me singing it's praises. It has small wheels and is pretty nifty on the local steep slope up from the road. It only wants a fresher battery and it will be good for another decade. I think, that it has only the 200w motor cannot confirm as the websites refer to a different product now..It came with the NimH 8amp26v pack, typical of the era, but since replaced. Little amount of rust, so good stainless steel in parts. It's a dinky little bike, limited range but good fun. Unfortunately as a folder, it's a bit cramped. Can we agree that a hub motor, irrespective of power rating has a specific speed at which it is most efficient and at lower speeds will be somewhat lower efficiency. ?Can we agree that because the hub is directly coupled to the wheel and tyre that that translates to an optimal road speed for that motor on that wheel.? Similarly a crank motor has a speed at which it's efficiency is peaked. But and this the crucial difference, because the crank is connected by a chain, and the possibility of gears, there is no such limitation on road speed. This means that massively low ratio gears can be fitted so that they can go up walls (exaggeration)., Slowly.!!! That's all correct, though the words you used could be a bit misleading to some. All motors have a speed at which they're most efficient, but the efficiency curve is broad, so you can deviate a lot from the optimum efficiency speed without it making much difference. Here's a graph of an Ezee motor running with 15 amps. Look at the efficiency curve. efficiency is above 60% all the way from 5mph to 32 mph and above 70% from 9 mph to 31 mph.
Join the conversation
You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.