Looking to build my own bike to replace Woosh Sirocco CD.

[Ash21014]

I've had no end of problems with my Woosh Sirocco CD and bad service from the company.

So I'm considering converting my own e-bike, and I feel like I've certainly got enough experience based on the number of repairs I've already had to make to my existing e-bike!

My dad has given me one of his lightweight road bikes ~8kg, and I've already built my own 12Ah 36v battery which I've actually tested to be 12Ah and not some vastly over stated capacity rubbish off ebay as so many are. Unlike the Woosh battery which takes forever to charge with it's pathetic 84W charger, it will fully charge in only 30mins too!

So I'm just wondering what the best resources are when it comes to converting an exising road bike into an e-bike?

Any help would be appreciate here, thanks.

 

[Deleted member 4366]

What sort of problems did you have with the Woosh?

To charge a 12aH battery in 30 mins will take at least 24 amps. What sort of cells are you using that can take that?

Converting a road bike is as easy as any, especially if it has a steel frame. The biggest problem is deciding what stuff to get because you're balancing weight against power/torque. A road bike can go relatively fast. If you get a motor that can give meaningful torque at those speeds, it won't be light, so you waste everything you gained by getting a lightweight bike in the first place. If you're lightweight yourself (less than 75kg), you could use a 328 rpm Q100 motor with the power turned down until you reach cruising speed. A crank-drive might work, but is relatively heavy, and it'll mess up your gearing.

 

[Geebee]

These threads should give you a good start.

Re charging a 36v 12ah battery 30 minutes, how and how safe? I like to charge my LiPos's slow enough to cause zero temperature increase.

http://www.pedelecs.co.uk/forum/threads/stealth-electric-bike.17923/#post-221228
http://www.pedelecs.co.uk/forum/threads/very-lightweight-e-bikes.16923/

 

[hoppy]

I've had no end of problems with my Woosh Sirocco CD and bad service from the company.

So I'm considering converting my own e-bike, and I feel like I've certainly got enough experience based on the number of repairs I've already had to make to my existing e-bike!

My dad has given me one of his lightweight road bikes ~8kg, and I've already built my own 12Ah 36v battery which I've actually tested to be 12Ah and not some vastly over stated capacity rubbish off ebay as so many are. Unlike the Woosh battery which takes forever to charge with it's pathetic 84W charger, it will fully charge in only 30mins too!

So I'm just wondering what the best resources are when it comes to converting an exising road bike into an e-bike?

Any help would be appreciate here, thanks.

Please give details of problems.It's not fair on Woosh or potential buyers to be so vague.

 

[Ash21014]

Details:

Within less than a year after buying the bike, the battery completely failed apparently due to moisture getting into the BMS. The pedal sensor broke. The front brake completely stopped working. The computer got ruined by internal condensation. And I had to remove the front light which was held in place by one screw which it freely pivoted about no matter how many times I tightened it, which just seemed like shoddy design. Now I am having problems with power suddenly cutting out despite the computer showing a full charge.

When my bike got back from repair the battery was still totally dead, despite "being repaired by a very good technician" it seemed as though they hadn't tested the bike at all, and they had to send a replacement. Also the bike had clearly been dropped from a height because the battery holder on the back was majorly bent and paintwork damaged (which could only have happened after the battery had been put back in place) and had to be forced back into shape. Considering the packaging it was sent in there was no way it could have been caused by the courier and I actually unloaded the bike myself from the van.

Also it's just not very nice to ride, assistance power seems to be a flat increase with assistance level so level 1 or may be fine for riding on the flat, but does not produce anywhere near enough torque to climb a hill which means I have to keep changing the assistance level every time I come across a hill, a target torque or speed would have been a much more appropriate assistance setting.

As far as power delivery goes, it stops and starts very suddenly upon hitting 15mph, so it's a jolt of on-off like a yo-yo with the bike being easy and then very hard to pedal alternately, certainly not a smooth ride, on the flat I actually prefer to ride a normal road bike!

As for charging the battery, I am using multiple 5Ah cells with a 10A charging current, which they are rated for, I use these for other electronic projects and have not experienced problems with them being damaged by this.

Similar to this.

Converting a road bike is as easy as any, especially if it has a steel frame. The biggest problem is deciding what stuff to get because you're balancing weight against power/torque. A road bike can go relatively fast. If you get a motor that can give meaningful torque at those speeds, it won't be light, so you waste everything you gained by getting a lightweight bike in the first place. If you're lightweight yourself (less than 75kg), you could use a 328 rpm Q100 motor with the power turned down until you reach cruising speed. A crank-drive might work, but is relatively heavy, and it'll mess up your gearing.

I weigh 60kg, I need to climb steep hills in my area, up to 25% incline so ideally I'd like to use a crank drive motor.

 

[JohnCade]

I've recently taken delivery of a Sport CD model, which is identical to yours other than a smaller battery, no mudguards and slightly different forks.

My initial impression was that it didn't have quite the power going uphill I thought it might have. But I got the hang of it quite quickly and in fact I was pedaling harder than I really needed to, and when I took it easier and let the motor do most of the work it went up 15% hills without that much help from me. I'm late sixties and 84k so I would have thought with your weight and age, I assume you are quite young from the reference to your father, it should be a doddle to climb hills.

in my case I do want to do some work and get bike fit again though, but I'm not sure why you are changing the power mode all the time. You could just leave it in say 3 and use the throttle to help on steep hills. As to the cut out, it is noticeable but it's not very sudden like hitting the brakes, and it is a legal requirement. You can change the settings to have assistance up to a bit faster if you want.

I didn't think my bike was packed very well it must be said. The forks were not braced together at the drops and were just resting in the bottom of the box. There was some packing which looked like it was shaped to hold them in place but it was just chucked in on top of the bike along with some other packing which looked as if it should be holding things in place.

But no damage done and I think the bike will do me for what I want very well. I'm already going up some very steep hills which I struggled up the last time I had a normal bike here five years ago a lot faster and easier, and I'm not bike fit at all right now.

 

[trex]

On flat roads, you don't need much assistance to reach 15mph so the 15mph speed limit programmed into the King Meter is a big annoyance. Woosh and other companies can't do anything about this legal limit. I myself dislike it so I derestrict my bike, I can cycle as fast as my legs can without this on/off annoyance. Once you derestrict the bike, problem with assist levels goes away too, you can leave the bike at level 5 for example, the bike simply slows down when climbing hills then goes faster after.
It is very difficult to make a bike that is light and can climb 15% + hillls without using crank drives. Even powerful motors like the 8-Fun BPM will overheat on 15% hills in just 7 minutes with a 20A controller, and achieves maximum speed of only 4mph. Compare the BPM with 20A controller against the CD with 14A controller on the same 15% hill, you will see how efficient the CD is.

 

[JohnCade]

Trex, I'm not really sure what this assist problem is? If it was left at 5 all the time wouldn't it perform in exactly the same way until it hit the legal cut off? Or are you saying that if it was derestricted it would go faster but have less climbing torque?

 

[Ash21014]

Yes I am young, but going up 25% hills is not "a doddle" regardless of how fit you are, at level 3 assistance mode it is difficult considering it's a 25kg bike, and it still has the sudden cut out at 15mph on the flat.

The only way to get a comfortable ride from this particular bike is to disable the limit entirely, which they say invalidates the warranty, (though I highly doubt their bikes really meet the EN15194 certification like they claim anyway).

Trex, I'm not really sure what this assist problem is? If it was left at 5 all the time wouldn't it perform in exactly the same way until it hit the legal cut off? Or are you saying that if it was derestricted it would go faster but have less climbing torque?

The problem is, at setting number 5 which is good for climbing hills, the bike is very easy to ride on the flat, then the motor cuts out suddenly like you've just gone into a 50mph headwind, this is not a comfortable way to ride! The power loss is supposed to be gradual!

 

[JohnCade]

You could use the throttle on hills and keep it in a lower mode. Or just change the settings on the King Meter which is very easy to do apparently and which I will probably do myself. I find the cut off is pretty noticeable but not that bad, and the bike is quite easy to pedal without assist when it's up and rolling on the flat.

Can't see how it would invalidate the warranty because no one would know you did it, and you can just put it back to normal in seconds if you need to.

 

[Deleted member 4366]

You only have to reset the LCD to a higher speed to get rid of the cutting out at 15mph, which makes it much more pleasant to ride, Like that, the motor will assist to 24mph. If you remove the magnet from the wheel (just twist it to face the other way), it'll go even faster, but you lose the speed display. The different PAS levels give different powers, so you can't do anything about that.

Your light needs a spring washer. That's basic engineering. If a bolt comes loose on its own, no point in just tightening it because it'll do it again until you use an anti-loosening system like a spring washer, crinkle washer, loctite, wire, pin, etc.

The charging system is slow, but you can leave it unattended overnight so that it's ready in the morning. Why do you need to fast-charge. You still didn't say which cells you have.

 

[Ash21014]

Using the throttle or disabling the limit makes the bike illegal though, which somewhat defeats the point for me when cycling on the road.

I've removed the front light and replaced it with a 1000 lumen torch, it was simply not bright enough to act as a headlight on country roads anyway.

The reason I need to fast charge is because the battery capacity is not high enough to do an entire days riding sometimes, after 20 miles up a hilly area it is clearly pretty drained.

The cells I use are Lithium Polymer Turnigy 3.7v 5000mAh cells designed for RC planes, they are rated at 20C.

 

[JohnCade]

Not sure using the throttle makes it illegal. As I understand it the UK allows it even if it's a slightly grey area.

 

[trex]

Yes I am young, but going up 25% hills is not "a doddle" regardless of how fit you are, at level 3 assistance mode it is difficult considering it's a 25kg bike, and it still has the sudden cut out at 15mph on the flat.

The only way to get a comfortable ride from this particular bike is to disable the limit entirely, which they say invalidates the warranty, (though I highly doubt their bikes really meet the EN15194 certification like they claim anyway).



The problem is, at setting number 5 which is good for climbing hills, the bike is very easy to ride on the flat, then the motor cuts out suddenly like you've just gone into a 50mph headwind, this is not a comfortable way to ride! The power loss is supposed to be gradual!

The CD is good on tarmac roads, steady ride.

what you like doing is a bit of extreme e-biking. The CD is not made for off-roading, its heavy rear rack battery will fly off the bike. Its 14A controller is no good for this.
you need the main mass low and in the middle of the bike, that means lipo, bottle style battery strapped to the downtube and a more powerful crank motor, 350W BBS01 25A or 500W BBS02(48V 25A) CD kit on a strong and light bike.
Without spending much money, you can replace the CD controller with a 20A version (Woosh sell it for £25 as spare for their Big Bear kit), replace the rear rack battery with your Lipo and replace the front fork with something better.

 

[Deleted member 4366]

As you know how to handle lipos, you can use a 201 rpm Q100H kit from BMSBattery. Solder the shunt in the controller to get it up to about 18 amps for better hill-climbing. It sounds like you don't want assistance past 15mph, otherwise I'd have recommended the 260 rpm version with 12S instead of 10S.

Throttles are not illegal in the UK. We've got a sort of concession from the Department for Transport.

 

[halfer]

Or just change the settings on the King Meter which is very easy to do apparently and which I will probably do myself.

(...)

Can't see how it would invalidate the warranty because no one would know you did it, and you can just put it back to normal in seconds if you need to.

I believe the Bosch system records settings changes, so even if you return it back to the default, a technician can tell. I don't know about the King Meter, but it's worth being aware that some electronic kit can report on you!

 

[Ash21014]

I'm not off-roading, I live in Cumbria and commute in the countryside which is a hilly area where the roads are often up to 25%. The bike climbs hills absolutely fine, and has plenty of power, but it's components are failing and the weight is a right pain, so I want to start from scratch with this road bike with a legal 250W crank motor and electronic systems that don't cause the bike to stop and start so suddenly.

If needed I can increase the batteries voltage to 48v if that helps.

Does having the battery on the back of the bike not make for a more favorable centre of gravity for braking? The extra weight on the rear wheel must surely allow the wheel to exert a greater breaking force if needed?

When I do off road I do de-restrict the bike and get about 25mph on the flat, and as you guys say the issue is gone. But on the road I don't need that kind of speed, it just ends up reducing the range of the bike which isn't great as it is.

 

[Deleted member 4366]

I believe the Bosch system records settings changes, so even if you return it back to the default, a technician can tell. I don't know about the King Meter, but it's worth being aware that some electronic kit can report on you!

The King Meter has no storage, so it can't tell anybody what you've done, not that Woosh would care.

 

[trex]

I'm not off-roading, I live in Cumbria and commute in the countryside which is a hilly area where the roads are often up to 25%. The bike climbs hills absolutely fine, and has plenty of power, but it's components are failing and the weight is a right pain, so I want to start from scratch with this road bike with a legal 250W crank motor and electronic systems that don't cause the bike to stop and start so suddenly.

If needed I can increase the batteries voltage to 48v if that helps.

Does having the battery on the back of the bike not make for a more favorable centre of gravity for braking? The extra weight on the rear wheel must surely allow the wheel to exert a greater breaking force if needed?

When I do off road I do de-restrict the bike and get about 25mph on the flat, and as you guys say the issue is gone. But on the road I don't need that kind of speed, it just ends up reducing the range of the bike which isn't great as it is.

The weight of the battery should really be split 40% to the front, 60% to the rear, same ratio as your weight on the bike.
the battery on the back is a rubbish solution, it's like carrying a loaded panier all the time, OK on tarmac roads but useless off roads. The best position for the battery is on the downtube, next best, behind the seatpost, although you have its weight more or less over the centre of gravity, it lengthens the wheelbase for about 12cm, damaging the handling of the bike.
48V system is always better than 36V if you need extra power.
regarding legal bikes, you can't have a legal bike that can pump out enough power for what you want to do. you already ask too much from the CD.
The 500W MMT crank drive with built in torque sensor from XOFO may be the best for your project but they are not ready for a few months yet. The motor runs at 48V 25A, weighs about 4.5kgs, your battery weighs 2.5kgs, your bike will weigh 8.5kgs + 4.5kgs + 2.5kgs = 15.5kgs and will pump out about 1200W peak. There is no throttle, the torque sensor in the motor replaces it. Hub motors overheat on 15%+ gradients and will ruin your frame in minutes - not much use for your project.

 

[JohnCade]

I'm not off-roading,

When I do off road I do de-restrict the bike and get about 25mph on the flat, and as you guys say the issue is gone. But on the road I don't need that kind of speed, it just ends up reducing the range of the bike which isn't great as it is.

Worth bearing in mind as you seem reluctant to bend the law regarding derestricting at all, is that it is just as illegal to derestrict an ebike for use off road as it is on the road. Many people seem not to be aware of that but the law is clear.

As long as the public has access to an area the bike must be restricted, and it's only legal on private land where the public has no right of access.

I'm sorry that you have had these problems with your bike but I wonder if perhaps you are pushing it a bit further than it was designed for?