I'm still thinking of fitting a mid drive motor to my raleigh centros bicycle it's a shame yose power don't supply one as I have a rear wheel kit on my mountain bike and very pleased with it, so what sort of cost would this set me back for a complete kit anyone?

Remind me - why mid drive ?

 

Woosh have some kits here https://wooshbikes.co.uk/?tsdz

or PSWPower https://www.pswpower.com/collections/tsdz2-torque-sensor-mid-drive-motor-kits or https://www.pswpower.com/collections/bafang-8fun-mid-drive-motor-kit

 

Careful with the PSWPower kits most are not rated 250W , All Woosh kits are 250W (including the TSDZ8 - only place you can get a TSDZ8 kit that is 250W rated)

Remind me - why mid drive ?

 

Woosh have some kits here https://wooshbikes.co.uk/?tsdz

or PSWPower https://www.pswpower.com/collections/tsdz2-torque-sensor-mid-drive-motor-kits or https://www.pswpower.com/collections/bafang-8fun-mid-drive-motor-kit

 

Careful with the PSWPower kits most are not rated 250W , All Woosh kits are 250W (including the TSDZ8 - only place you can get a TSDZ8 kit that is 250W rated)

Thanks Peter for the excellent info, I would like to go hub drive but the frame is all alloy and seems fragile plus I love the stainless wheel rims so for that reason I'm thinking mid motor. Rob

For the best all around biking experience, I like the Toseven DM02. It is a torque sensing unit that delivers easy pedalling comparable to a hub motor. Mine delivers 100-140 watts of power (depends on battery 36V or 48V) in level 1. The motor will dig in and apprach 400 watts on hills.

 

For lowest cost, I like the Tongsheng TSDZ2, also a torque sense unit, but output is only available with hard pedalling, Too hard for me. I hated the stock TSDZ2. Others may disagree. A somewhat complicated third party firmware swap will fix that. With the new firmware, my wife and I really enjoyed our TSDZ2 bikes.

 

The Bafang BBS02B mid drive is fast, quiet and reliable. Highest cost. Cadence sensor, Knocks your socks off.

 

I prefer to install a mid drive over a hubmotor. There's more work to remove the BB (pedals/axle), especially on really old frames. Then again, some of those old frames couldn't handle a hub motor. My flat tire kit is certainly smaller for a hub motor. No big wrenches.

 

In truth, the riding experience depends more on the bike and its tires. Take my best bike, and it would be OK with any motor, but a good torque sense motor kit is most like riding a natural bike,

For the best all around biking experience, I like the Toseven DM02. It is a torque sensing unit that delivers easy pedalling comparable to a hub motor. Mine delivers 100-140 watts of power (depends on battery 36V or 48V) in level 1. The motor will dig in and apprach 400 watts on hills.

 

For lowest cost, I like the Tongsheng TSDZ2, also a torque sense unit, but output is only available with hard pedalling, Too hard for me. I hated the stock TSDZ2. Others may disagree. A somewhat complicated third party firmware swap will fix that. With the new firmware, my wife and I really enjoyed our TSDZ2 bikes.

 

The Bafang BBS02B mid drive is fast, quiet and reliable. Highest cost. Cadence sensor, Knocks your socks off.

 

I prefer to install a mid drive over a hubmotor. There's more work to remove the BB (pedals/axle), especially on really old frames. Then again, some of those old frames couldn't handle a hub motor. My flat tire kit is certainly smaller for a hub motor. No big wrenches.

 

In truth, the riding experience depends more on the bike and its tires. Take my best bike, and it would be OK with any motor, but a good torque sense motor kit is most like riding a natural bike,

Went for a cycle with my sister in the North York Moors today on her old 26" mountain bike, xs frame, that I converted using the Woosh Tsdz8 kit. Added hydraulic brakes, marathon 365 gt tyres (puncture resistant) and a 720Wh battery. She is planning another coast to coast trip(she did one last year), this time following Hadrian's wall

[mention=16007]harrys[/mention], I also have a TSDZ2 on my Ute cargo bike and it is superb. I don't have to pedal hard for power, I uploaded the OSF firmware and find it an easy ride as are my hubs. If I want 20mph or more then I do have to put in a lot more effort but up to 15/16mph the ride input isn't onorous.

I think in today's world we are seeing a lot more users wanting moped power without much effort hence these higher rated mid drives at so called 250w continuous rating that don't require much effort.

I'm a TSDZ2 rider - I have them on two of my bikes and whilst I have put OSF (Open Source Firmware) on them, I only did this to allow some bespoke tweeking of various settings - prior to OSF I personally found the original firmware sufficient.

 

As for rider input - I'm still a capable pusher of pedals and even on my rather heavy 'old school' Ridgeback flat handlebar machine, I rarely have to use more than the 2nd level of assist and I'm a rather hefty 94Kg fella!

 

I'm really rather fond of the Torque Sensing system despite it's bulky (ugly to some) mid drive appearance, although my front hub converted bike is also nice to ride but I do notice its 'non torque sensing' power delivery system despite the excellent KT controller I use.

My DM02 and TSDZ2 are installed on 45 year old steel Raleigh "racers" switched from drop bars to higher ones. Skinny 27 tires. It's like riding in the 1970's again, while in your 70's (age), These little mid motors still like the rider spinning the pedals.

I have Shengyi DWG22C rear hub motors on a tandem and a solo. They have worked very well for many thousands of miles now. I also fitted a Tongshen TSDZ2B mid-drive motor to another tandem which has a Rohloff 14 speed hub. I bought my conversion kits from Woosh and they were pretty much ‘plug and play’.

 

The riding characteristics of each system are very different but suit my requirements admirably. The cadence sensing hub motors give plenty of power and are well suited to bowling along at a reasonable pace on the roads. The torque sensing TSDZ2B works very well with the Rohloff hub as a single chainring is not really a handicap when you have the 14 speed hub. The Tongshen is noticeably less powerful than the rear hub motor, but it does exactly what I want in terms of providing some assistance on hills / headwinds.

 

There are pros and cons for each solution, so I don’t believe there is a simple ‘one-size-fits-all’ answer as so much depends on the intended use of the bike.

 

The addition of electric assist is a real game changer for someone of my advancing years and it has allowed me to continue cycling futher and faster than would otherwise be possible.

For the best all around biking experience, I like the Toseven DM02. It is a torque sensing unit that delivers easy pedalling comparable to a hub motor. Mine delivers 100-140 watts of power (depends on battery 36V or 48V) in level 1. The motor will dig in and apprach 400 watts on hills.

That's not easy pedalling. The power is very low for hill climbing. Most of us would find that inadequate. My 250w hub-motor takes up to 1100w from the battery at maximum setting, which is around 650w of real output power. I set it at around 120w for normal riding, and when I need a boost for the hills, I just press the button. I can pedal as hard or easy as I choose not constrained by any stupid torque algorithms.

 

I have two identical bikes. One has 48v TSDZ02, the other has 48v hub-motor with 22A KT controller. The hub-motor one is better all round. It's more pleasant to ride, it's much faster up hills and I can always pedal as hard or easy as I want. Also, it's going to be a lot more reliable and less demanding on replacement drive parts. I have the crank-drive bike for towing. I used it a lot for general riding around when I first built it, while I rebuilt my other one with a legal motor. For general use, the hub-motor one wins by quite a lot for sheer convenience and control of power.

Edited January 18Jan 18 by saneagle

That's not easy pedalling. The power is very low for hill climbing. Most of us would find that inadequate. My 250w hub-motor takes up to 1100w from the battery at maximum setting, which is around 650w of real output power.

 

You're right about the power. A 48V hubmotor with a 20-25A KT controller is pretty strong, I've seen my LCD3 displays show 800-1000 watts on a hill.

 

But my TSDZ2 has OSF firmware, and mne is adjusted so I ', pedalling with the same effort as my other ebikes at 10-12 mph. Easy pedalling for me. On a hill, I shift down a gear or two, and it's OK. The bike maxes out at 12A, so I'll nver get the same max power. but it's still enough for me.

Edited January 19Jan 19 by harrys

You're right about the power. A 48V hubmotor with a 20-25A KT controller is pretty strong, I've seen my LCD3 displays show 800-1000 watts on a hill.

 

Presumably that's the easily metered electrical input power, rather than mechanical output, that the motor will have no way of measuring. The difference of course, goes into warming up the windings of the motor and can be very considerable. The motor may be able to stand the heat, but the wasted energy will nevertheless reduce how much range one can get from a given size of battery.

 

That's the main reason I choose mid-drive: by keeping the motor spinning at it's most efficient rpm, even up the awfully steep hills we have here in the Peak District, I don't need such a big and heavy battery to go the distance without range anxiety. And since I ride with a mixed group of e-bikers and muscle bikers, it's more sociable to go slowly up hills, which I can do by selecting a lower gear rather than a higher level of assistance.

Presumably that's the easily metered electrical input power, rather than mechanical output, that the motor will have no way of measuring. The difference of course, goes into warming up the windings of the motor and can be very considerable. The motor may be able to stand the heat, but the wasted energy will nevertheless reduce how much range one can get from a given size of battery.

 

That's the main reason I choose mid-drive: by keeping the motor spinning at it's most efficient rpm, even up the awfully steep hills we have here in the Peak District, I don't need such a big and heavy battery to go the distance without range anxiety. And since I ride with a mixed group of e-bikers and muscle bikers, it's more sociable to go slowly up hills, which I can do by selecting a lower gear rather than a higher level of assistance.

Both types of motor suffer from the same issue, but in different ways. With a hub-motor, it's the bike speed that effects the efficiency. With a crank-drive, it's the pedal speed. On a crank-drive, if your gearing is too high, your pedal speed will be low causing low efficiency and overheating. If it's too low, you can't get enough power at a comfortable pedal cadence and lose overall efficiency. Crank-drives have the additional problem that some riders like to spin and some grind. The motor can't deal with both efficiently, but a hub-motor can. Everything has advantages and disadvantages. You can't just pick one thing as justification.

 

Personally, I see the balance of advantages and disadvantages leans in favour of hub-motor for general all-round cycling, and crank motor for complicated and steep off-road riding.

 

I tested two bikes with exactly the same motor, battery and controller. One was installed in the hub, the other drove the crank with a chain, so the power went through the gears. I recorded the amps, power and charge consumption at every stage during the same 20 mile ride. There were differences during the ride depending on hills mainly. At the end of the ride both had consumed approximately the same number of watt-hours, so I conclude that there is no overall difference in efficiency between the two arrangements.

 

If you have a lot of power, you can always turn it down if you don't need it, but if you don't have enough, you can't turn it up. The point about the 48v 22A AKM128 motor is that it has all the power you need and it can give very good efficiency. Over a few days of hilly rides, I achieved a range of 129 miles from a single charge. A couple of days later, I was in a hurry, and I managed to empty the same battery in 25 miles. The only differences were the speed I went and how hard I pedalled. You can achieve any range or efficiency with any bike. It's just a question of how you use it. You can't claim super efficiency from any bike or system without being able to test between them and replicating every pedal stroke in terms of speed and torque, which is impossible.

My experience of the two different motors pretty much aligns with the observations made by saneagle & harrys above.

 

My Lishui controller on the 48 volt hub motor peaks at 17amps whilst the TSDZ2B is set for a peak of 12amps. The hub motor is much quicker up hills, the mid-drive is perfectly capable but you just drop down through the gears to keep the little motor spinning away. I'm a pedal spinner rather than a stomper.

 

Interestingly, in mixed terrain riding I have found little or no difference in power consumption. I usually check the battery voltage after a ride and over the same distance / route, there is virtually no difference between the hub motor and the mid-drive. I don't have a watt meter to show real-time power input, but both motors are run at relatively low power settings.

 

On steeper hills, I tend to ramp up the power on the hub motor to keep my speed up and keep the motor spinning at a decent rpm and then drop it back down to a lower setting after a climb. I do the same with the mid-drive, but it has noticeably less 'oomph' than the hub drive.

 

I would agree with Crankwinder that a mid-drive is a better choice for lower speed riding at modest power settings. Our mid-drive is fitted to a tandem with MTB size tyres which we use for (very mild) off-road routes and it works really well in that role.

even up the awfully steep hills we have here in the Peak District,

some good ones near me too !

 

https://clevelandwheelers.com/root/climbs/killer-climbs-map/

Both types of motor suffer from the same issue, but in different ways. With a hub-motor, it's the bike speed that effects the efficiency. With a crank-drive, it's the pedal speed. On a crank-drive, if your gearing is too high, your pedal speed will be low causing low efficiency and overheating. If it's too low, you can't get enough power at a comfortable pedal cadence and lose overall efficiency. Crank-drives have the additional problem that some riders like to spin and some grind. The motor can't deal with both efficiently, but a hub-motor can. Everything has advantages and disadvantages. You can't just pick one thing as justification.

 

I don't though, pick just one thing. I also mentioned the facility to ride socially with muscle bikers. They are demoralised by e-bikers zooming up the hills, which unfortunately is the only way to keep a hub-motor spinning at something like its most efficient rpm! But before I get onto hub motors, what of those supposed crank drive problems? Sure, cadence can vary, but any cyclist with some experience of riding on muscle power alone, plus an ounce of intelligence, knows very well how to keep their cadence reasonably constant. It's simply a matter of equipping one's bike with a sufficiently wide range of gears - especially low gears - and shifting as appropriate. With today's highly reliable, wide-range '1×' derailleur systems, it's easy to keep a crank-drive spinning nicely and is second nature to anyone who already has a few decades of muscle-biking experience. I'm so accustomed to pedalling at 80-90rpm that it just feels wrong to let my legs drift round at 60!

 

Gears too low, is that even possible? Given that you can't fit a chainwheel much smaller than 40T on most crank-drives and the ubiquity of 11T top sprockets, it would be a very strange e-bike that lacked a high enough gear to work efficiently at 25kmph. As for those poor souls who never learned and cannot now be bothered to move their legs more than once per second, I guess that for them, a hub motor may be the best thing.

 

But what size of hub motor? You write of your 48v 22A AKM128, that "it has all the power you need and it can give very good efficiency". I'm sure it does and can: that's a whole kilowatt! What you have there is an electric moped - not anything like a bicycle as we know it. Because that's how electric motorbikes and cars work: just bung a big enough electric motor in it and there is no need for gears. Your typical driver, after all, expects to go near enough the same speed uphill as on the flat. Bicyclists however, don't.

 

A human pedalling a bicycle is by its very nature, a seriously under-powered vehicle for its weight. And the only way such a vehicle gets up a steep hill is slowly, in a low gear. E-bikes are supposed to perform much the same as a typical bicycle. (And that's yer typical bike in the street, NOT in the Tour de France!) That's why their motors aren't supposed to be capable of delivering more than 250W continuously. And provided it's delivered to crank, so one has the option of taking longer to climb a hill, 250W should be enough. Because energy = power × time, so take your time and a limited amount of power will nevertheless suffice.

 

To sum up, if you want an e-bike that's something like a pure pedal cycle, but easier, choose crank-drive. And if you want something more like a motorbike, but would trade some speed for the freedoms of cycling, get a hub-drive. But unless you can avoid really steep hills, it'll have to be an illegal hub-drive!

EU and UK law does not stipulate how much power is supplied to the motor or how much power the motor develops. It just stipulates the manufacturer maximum continuous rating of the motor must be maximum of 250w. There is nothing illegal about a 48v 22a controller. In fact, at slow enough speeds, just about any hub motor would overheat outputting 250w of power.

I don't though, pick just one thing. I also mentioned the facility to ride socially with muscle bikers. They are demoralised by e-bikers zooming up the hills, which unfortunately is the only way to keep a hub-motor spinning at something like its most efficient rpm! But before I get onto hub motors, what of those supposed crank drive problems? Sure, cadence can vary, but any cyclist with some experience of riding on muscle power alone, plus an ounce of intelligence, knows very well how to keep their cadence reasonably constant. It's simply a matter of equipping one's bike with a sufficiently wide range of gears - especially low gears - and shifting as appropriate. With today's highly reliable, wide-range '1×' derailleur systems, it's easy to keep a crank-drive spinning nicely and is second nature to anyone who already has a few decades of muscle-biking experience. I'm so accustomed to pedalling at 80-90rpm that it just feels wrong to let my legs drift round at 60!

 

Gears too low, is that even possible? Given that you can't fit a chainwheel much smaller than 40T on most crank-drives and the ubiquity of 11T top sprockets, it would be a very strange e-bike that lacked a high enough gear to work efficiently at 25kmph. As for those poor souls who never learned and cannot now be bothered to move their legs more than once per second, I guess that for them, a hub motor may be the best thing.

 

But what size of hub motor? You write of your 48v 22A AKM128, that "it has all the power you need and it can give very good efficiency". I'm sure it does and can: that's a whole kilowatt! What you have there is an electric moped - not anything like a bicycle as we know it. Because that's how electric motorbikes and cars work: just bung a big enough electric motor in it and there is no need for gears. Your typical driver, after all, expects to go near enough the same speed uphill as on the flat. Bicyclists however, don't.

 

A human pedalling a bicycle is by its very nature, a seriously under-powered vehicle for its weight. And the only way such a vehicle gets up a steep hill is slowly, in a low gear. E-bikes are supposed to perform much the same as a typical bicycle. (And that's yer typical bike in the street, NOT in the Tour de France!) That's why their motors aren't supposed to be capable of delivering more than 250W continuously. And provided it's delivered to crank, so one has the option of taking longer to climb a hill, 250W should be enough. Because energy = power × time, so take your time and a limited amount of power will nevertheless suffice.

 

To sum up, if you want an e-bike that's something like a pure pedal cycle, but easier, choose crank-drive. And if you want something more like a motorbike, but would trade some speed for the freedoms of cycling, get a hub-drive. But unless you can avoid really steep hills, it'll have to be an illegal hub-drive!

That's not correct. I think you're getting confused between speed control and current control, which is independent of motor type. With current control, you can set the power to the level of assistance you want, then pedal as hard or easy as you want at whatever speed you want.

 

Regarding your other points, I'm talking about OP's Raleigh Centros, not some high tech expensive MTB.

 

You clearly have no idea what an AKM128 is like with a KT controller. Several of us on this forum had/have them, and we all were/are very happy with them. I exchanged mine for legal MXUS XF08, which runs more or less the same because I still have the same controller. I think you're still missing the point about choice of power.

EU and UK law does not stipulate how much power is supplied to the motor or how much power the motor develops. It just stipulates the manufacturer maximum continuous rating of the motor must be maximum of 250w. There is nothing illegal about a 48v 22a controller. In fact, at slow enough speeds, just about any hub motor would overheat outputting 250w of power.

Woe betide those manufacturers whose motors are capable of far more than 250W continuously, should our lazy regulators ever seek to accurately assess them.

 

All the motors and setups described in your post are exploiting unpoliced loopholes at best, and in those cases where a specially labelled "250W" version of a motor whose own manufacturer rates at 800W are made specifically for the UK market, they are downright dishonest in my view.

 

It is nonsense to keep pushing the idea that the regulations are not intended to restrict power: of course they are.

I don't though, pick just one thing. I also mentioned the facility to ride socially with muscle bikers. They are demoralised by e-bikers zooming up the hills, which unfortunately is the only way to keep a hub-motor spinning at something like its most efficient rpm! But before I get onto hub motors, what of those supposed crank drive problems? Sure, cadence can vary, but any cyclist with some experience of riding on muscle power alone, plus an ounce of intelligence, knows very well how to keep their cadence reasonably constant. It's simply a matter of equipping one's bike with a sufficiently wide range of gears - especially low gears - and shifting as appropriate. With today's highly reliable, wide-range '1×' derailleur systems, it's easy to keep a crank-drive spinning nicely and is second nature to anyone who already has a few decades of muscle-biking experience. I'm so accustomed to pedalling at 80-90rpm that it just feels wrong to let my legs drift round at 60!

 

Gears too low, is that even possible? Given that you can't fit a chainwheel much smaller than 40T on most crank-drives and the ubiquity of 11T top sprockets, it would be a very strange e-bike that lacked a high enough gear to work efficiently at 25kmph. As for those poor souls who never learned and cannot now be bothered to move their legs more than once per second, I guess that for them, a hub motor may be the best thing.

 

But what size of hub motor? You write of your 48v 22A AKM128, that "it has all the power you need and it can give very good efficiency". I'm sure it does and can: that's a whole kilowatt! What you have there is an electric moped - not anything like a bicycle as we know it. Because that's how electric motorbikes and cars work: just bung a big enough electric motor in it and there is no need for gears. Your typical driver, after all, expects to go near enough the same speed uphill as on the flat. Bicyclists however, don't.

 

A human pedalling a bicycle is by its very nature, a seriously under-powered vehicle for its weight. And the only way such a vehicle gets up a steep hill is slowly, in a low gear. E-bikes are supposed to perform much the same as a typical bicycle. (And that's yer typical bike in the street, NOT in the Tour de France!) That's why their motors aren't supposed to be capable of delivering more than 250W continuously. And provided it's delivered to crank, so one has the option of taking longer to climb a hill, 250W should be enough. Because energy = power × time, so take your time and a limited amount of power will nevertheless suffice.

 

To sum up, if you want an e-bike that's something like a pure pedal cycle, but easier, choose crank-drive. And if you want something more like a motorbike, but would trade some speed for the freedoms of cycling, get a hub-drive. But unless you can avoid really steep hills, it'll have to be an illegal hub-drive!

Welcome to the lion's den!

Welcome to the lion's den!

Woe betide those manufacturers whose motors are capable of far more than 250W continuously, should our lazy regulators ever seek to accurately assess them.

 

All the motors and setups described in your post are exploiting unpoliced loopholes at best, and in those cases where a specially labelled "250W" version of a motor whose own manufacturer rates at 800W are made specifically for the UK market, they are downright dishonest in my view.

 

It is nonsense to keep pushing the idea that the regulations are not intended to restrict power: of course they are.

You realise that includes your motor? What do you have the maximum current set to?

A bike with a controller limited to 6.944445A X 36V = 250W would be crap ride regardless of motor type. I'd demand a refund instantly.

Edited January 22Jan 22 by guerney

Anyone that every looked at the original 1947 'Miracle on 34th Street' should know that if the post office believes that something is the case, then it must be the case (i.e Santa Claus exists). Anyhow a local postman has the bike below, 250W rated, 70nm torque that can pull a 300Kg payload. The front hub motor I believe is an ezee (that I think) is often sold as a 1000w in other jurisdictions.

 

Edited January 23Jan 23 by Sturmey