I have broken this post up a little as it is rather long. Hopefully it will be easier to read this way.
I seek the advise of discernable electric drive enthusiasts.
I am currently in the middle of designing a multi-terrain bike from scratch. It is a mid-drive design. The bottom bracket will drive an inverted chain which at 1:1 will drive a second shaft containing many different sprocket wheels that comprise the forward part of the derailleur gear system. The second shaft will drive a third shaft via a regular mtb chain. This third shaft is the main shaft.
The main shaft will be driven by either the rider via the pedals and the derailleur gear, or a petrol engine (the same one as used with the golden eagle kits http://www.bikeengines.com ), or an electric engine. Or all three inputs combined.
The main shaft then goes on to drive the rear wheel via another inverted tooth chain. It will also be connected to the front wheel to allow 2wd (two wheel drive), via (at the moment, as the design stands) a telescopic shaft with universal joints. The 2wd is switchable.
Basically I am stuck with choosing components for the electric drive. I guess that all I need (apart from a bit of wire + other simple miscellaneous parts including a throttle lever) is a motor, a controller and a battery. But I need some help selecting decent equipment. I am hoping that members of this group can recommend some to me. There has been a lot written in many places about this subject, and there is a lot of contradictory information out there. To a novice it can be rather confusing. So I am hoping that this post will help to reveal (from any response to it) the best electric drive products out there, at least for specification of my bike design project, which I suspect is a specification desired by many.
The bike will be a 'carapace' design. The idea is to enclose all components for their protection from dirt, water, etc. This could cause problems with over-heating, although I shall include some cooling vents in the design.
Basic requirements.
-------------------
The electric drive components should be: Light in weight, High in quality, long lasting, preferably low in maintenance, robust, efficient, and small in size.
The electric motor (further to the above).
-------------------------------------------
The electric motor will be mounted on the bike in a mid-drive position. Not as the hub in either of the wheels, although this does not rule out using a hub-type motor. At the moment the Heinzmann (900w continuous, 2000w peak) motor seems to be top of the list but I gather it is less than perfect (please correct me if I am wrong).
Should the motor be a brush type, or brushless - or would a particular motor define the answer to that (if it over comes the problems that a brush type is known for satisfactorily).
What should its voltage be ?
It should be weather-proof, and able to withstand being dropped or ridden through water (few feet deep).
It should provide instantaneous power. As soon as the throttle is turned, the motor should respond immediately at all speeds. There should be no 'lag' or delay in-between turning the throttle and the motor responding.
It should be capable of being used as a generator to recharge the bikes battery. The idea is to use the petrol engine to turn the electric motor in order to produce electricity which will then be stored in the on-board battery bank. This battery stored electricity will then be used to turn the electric motor to propel the bike when the petrol engine is not in use (in sound-sensitive locations, for example). And also when the electric motor is used at the same time as the petrol engine (power from both combined) to provide short bursts of high speed, when and if it is required.
It should have a peak power rating of about 2kw or slightly higher (before weight becomes a big problem)
It should have a continuous power rating of about 900w or thereabouts. This is similar to the Heinzmann rating.
I plan to build a switchable (external to the motor) gear box for the electric motor which will offer a choice of several ratios. I expect I shall need help in determining these ratios, especially the ratio which should be used when the electric motor is utilized as a generator. The idea is to allow the electric motor to be used for high (bike on road) speed, and for climbing steep muddy slopes with 2wd switched 'on', with a heavy trailer. And intermediate ratios. Versatility is a key design specification for this design project.
Controller.
-----------
The controller to be selected to control the electric motor, apart from that mentioned in 'basic requirements', should provide for the following:
All that is asked of with the engine. It would be pointless to have an electric motor as described above, if the controller did not allow it to be used at its optimum, ie. The controller must allow for the motor to be used as a generator, it must provide instant power. It must in general, be of a very high quality.
Bureaucratic issues are not a concern with this project. They are irrelevant. So it is not necessary to have a pedal sensor or anything else which is not needed to make the thing work, and work well. Although, after saying that, it would be a bonus if the controller had a switch which when flicked could restrict the motors power, which would (as far as I know) render the electric drive road-legal without a license, registration, etc.
Battery.
--------
This is a tough issue, or so it would seem. I know that many hold differing views on battery choice. It may be naive of me, but perhaps this is an opportunity to clarify the matter.
The battery to be used with the bike I am designing, again further to that listed in 'basic requirements', should:
Be capable of being constantly 'topped up' from the generator on the bike (motor used in reverse). It should not have a memory effect problem and should be good for many, many cycles.
Be capable of powering the electric motor (the one described above), to propel the bike for 40 or 50 miles at a speed of around 10 to 15 mph without any pedaling input from the rider.
To repeat myself, it should be very light, robust and capable of a long life (preferably with little or no maintenance).
The battery will be required to provide power to the bikes lights as well as to the electric motor at the same time. This will include the type of 'high-end' lights which utilize Solarc ( http://www.solarc.net ) lamps and similar H.I.D. type lights and the like which are known for requiring special batteries. The same battery will need to be capable of providing power also to various accessories via a 12 volt socket to be located on the bike. Accessories will include a pda for a moving map display, electric horn, indicators, etc. I guess all that would be required is just another wire from the battery to a transformer en route to the accessory socket, thus bypassing the electric motor and specific drive components altogether.
The battery will need to be in several parts so it can be kept in several locations about the bike. Also, when the electric drive is not required for a trip, the battery should be capable of being separated so that enough of the battery will be left on the bike to power the accessories and the lights etc. without causing weight problems. ie. It is (obviously) inefficient to carry around on a pedal bike a battery powerful enough to turn a 1kw motor for many miles, when all that is needed is enough electricity to power a small set of lights for an hour or so. The entire weight of the bike complete with both motors and the battery in-place, should be low enough to allow the rider to lift it up and onto their back. I plan on including within the design some back-pack like straps (and a steering lock) to make this easier. Lifting the bike up will be necessary to carry it over gates and fences etc.
------------------------------------------------
Other equipment I may need could include various voltage regulators, a device to protect the battery from over charging, a device to regulate the battery. I do plan on having instrumentation to keep me informed of power being used, power remaining, system status, and so on. If, from reading the above, you have any suggestions. I would be very grateful to learn of them.
Thanks for reading this. Your input would be much appreciated.
P.S Manufacturers and retailers are very welcome to also respond. I would be pleased to hear from all on this subject. I am located in the U.K, but I could purchase equipment via mail-order if I have to. That is not a problem.
(I have posted this information request in a few places, so you may have seen it before, but good advise is hard to come by)
I seek the advise of discernable electric drive enthusiasts.
I am currently in the middle of designing a multi-terrain bike from scratch. It is a mid-drive design. The bottom bracket will drive an inverted chain which at 1:1 will drive a second shaft containing many different sprocket wheels that comprise the forward part of the derailleur gear system. The second shaft will drive a third shaft via a regular mtb chain. This third shaft is the main shaft.
The main shaft will be driven by either the rider via the pedals and the derailleur gear, or a petrol engine (the same one as used with the golden eagle kits http://www.bikeengines.com ), or an electric engine. Or all three inputs combined.
The main shaft then goes on to drive the rear wheel via another inverted tooth chain. It will also be connected to the front wheel to allow 2wd (two wheel drive), via (at the moment, as the design stands) a telescopic shaft with universal joints. The 2wd is switchable.
Basically I am stuck with choosing components for the electric drive. I guess that all I need (apart from a bit of wire + other simple miscellaneous parts including a throttle lever) is a motor, a controller and a battery. But I need some help selecting decent equipment. I am hoping that members of this group can recommend some to me. There has been a lot written in many places about this subject, and there is a lot of contradictory information out there. To a novice it can be rather confusing. So I am hoping that this post will help to reveal (from any response to it) the best electric drive products out there, at least for specification of my bike design project, which I suspect is a specification desired by many.
The bike will be a 'carapace' design. The idea is to enclose all components for their protection from dirt, water, etc. This could cause problems with over-heating, although I shall include some cooling vents in the design.
Basic requirements.
-------------------
The electric drive components should be: Light in weight, High in quality, long lasting, preferably low in maintenance, robust, efficient, and small in size.
The electric motor (further to the above).
-------------------------------------------
The electric motor will be mounted on the bike in a mid-drive position. Not as the hub in either of the wheels, although this does not rule out using a hub-type motor. At the moment the Heinzmann (900w continuous, 2000w peak) motor seems to be top of the list but I gather it is less than perfect (please correct me if I am wrong).
Should the motor be a brush type, or brushless - or would a particular motor define the answer to that (if it over comes the problems that a brush type is known for satisfactorily).
What should its voltage be ?
It should be weather-proof, and able to withstand being dropped or ridden through water (few feet deep).
It should provide instantaneous power. As soon as the throttle is turned, the motor should respond immediately at all speeds. There should be no 'lag' or delay in-between turning the throttle and the motor responding.
It should be capable of being used as a generator to recharge the bikes battery. The idea is to use the petrol engine to turn the electric motor in order to produce electricity which will then be stored in the on-board battery bank. This battery stored electricity will then be used to turn the electric motor to propel the bike when the petrol engine is not in use (in sound-sensitive locations, for example). And also when the electric motor is used at the same time as the petrol engine (power from both combined) to provide short bursts of high speed, when and if it is required.
It should have a peak power rating of about 2kw or slightly higher (before weight becomes a big problem)
It should have a continuous power rating of about 900w or thereabouts. This is similar to the Heinzmann rating.
I plan to build a switchable (external to the motor) gear box for the electric motor which will offer a choice of several ratios. I expect I shall need help in determining these ratios, especially the ratio which should be used when the electric motor is utilized as a generator. The idea is to allow the electric motor to be used for high (bike on road) speed, and for climbing steep muddy slopes with 2wd switched 'on', with a heavy trailer. And intermediate ratios. Versatility is a key design specification for this design project.
Controller.
-----------
The controller to be selected to control the electric motor, apart from that mentioned in 'basic requirements', should provide for the following:
All that is asked of with the engine. It would be pointless to have an electric motor as described above, if the controller did not allow it to be used at its optimum, ie. The controller must allow for the motor to be used as a generator, it must provide instant power. It must in general, be of a very high quality.
Bureaucratic issues are not a concern with this project. They are irrelevant. So it is not necessary to have a pedal sensor or anything else which is not needed to make the thing work, and work well. Although, after saying that, it would be a bonus if the controller had a switch which when flicked could restrict the motors power, which would (as far as I know) render the electric drive road-legal without a license, registration, etc.
Battery.
--------
This is a tough issue, or so it would seem. I know that many hold differing views on battery choice. It may be naive of me, but perhaps this is an opportunity to clarify the matter.
The battery to be used with the bike I am designing, again further to that listed in 'basic requirements', should:
Be capable of being constantly 'topped up' from the generator on the bike (motor used in reverse). It should not have a memory effect problem and should be good for many, many cycles.
Be capable of powering the electric motor (the one described above), to propel the bike for 40 or 50 miles at a speed of around 10 to 15 mph without any pedaling input from the rider.
To repeat myself, it should be very light, robust and capable of a long life (preferably with little or no maintenance).
The battery will be required to provide power to the bikes lights as well as to the electric motor at the same time. This will include the type of 'high-end' lights which utilize Solarc ( http://www.solarc.net ) lamps and similar H.I.D. type lights and the like which are known for requiring special batteries. The same battery will need to be capable of providing power also to various accessories via a 12 volt socket to be located on the bike. Accessories will include a pda for a moving map display, electric horn, indicators, etc. I guess all that would be required is just another wire from the battery to a transformer en route to the accessory socket, thus bypassing the electric motor and specific drive components altogether.
The battery will need to be in several parts so it can be kept in several locations about the bike. Also, when the electric drive is not required for a trip, the battery should be capable of being separated so that enough of the battery will be left on the bike to power the accessories and the lights etc. without causing weight problems. ie. It is (obviously) inefficient to carry around on a pedal bike a battery powerful enough to turn a 1kw motor for many miles, when all that is needed is enough electricity to power a small set of lights for an hour or so. The entire weight of the bike complete with both motors and the battery in-place, should be low enough to allow the rider to lift it up and onto their back. I plan on including within the design some back-pack like straps (and a steering lock) to make this easier. Lifting the bike up will be necessary to carry it over gates and fences etc.
------------------------------------------------
Other equipment I may need could include various voltage regulators, a device to protect the battery from over charging, a device to regulate the battery. I do plan on having instrumentation to keep me informed of power being used, power remaining, system status, and so on. If, from reading the above, you have any suggestions. I would be very grateful to learn of them.
Thanks for reading this. Your input would be much appreciated.
P.S Manufacturers and retailers are very welcome to also respond. I would be pleased to hear from all on this subject. I am located in the U.K, but I could purchase equipment via mail-order if I have to. That is not a problem.
(I have posted this information request in a few places, so you may have seen it before, but good advise is hard to come by)
