Finally bought a smaller folder for conversion...

[morphix]

Fighting talk

Brompton Ti with 1.6kg Goldant front hub motor, 13.5kg "bike carry weight" and about 2kg bag weight including battery and controller in the other hand

I fear you may be searching for the Holy Grail in that you want light and quite a bit of power. I think Tongxin use to do Nano rear motors though it seems no longer do. You would need to email them.

Gearless_Motor-OutRider Eshop - EBike Kit Supplier-Complete Electric Bike Conversion System

You might want to check the rear fork spacing too.

Regards

Jerry

Thanks Jerry I've been reading your first Brompton conversion thread with interest over the last few days and taking notes..all the related questions and answers has been very helpful as I have the same questions and face the same decisions..

I guess with small wheel bikes it's always a compromise if you want to maintain the fold and low carry weight.. the trick is finding the right balance. You seem to be happy with lower power and putting in more effort (at times) than you would on a larger bike.. I'm coming round to your way of thinking, and thinking that maybe, that's the whole point of a 16" bike..i.e. not to create an electric bike that moves like a full size bike, but rather to provide subtle assistance without compromising the bikes purpose. If you need more power, keep a second (larger/heavier) bike. I will keep my first bike I think or maybe build a 20" with a bigger motor to replace it next.

I want the Mezzo to be light enough to carry up and down stairs without straining my knee daily, and small enough to take on trains/planes should the need arise...

Sooo....can I get my build to < 17kg.. I think so! My 26" was only just over 20kg.

The Mezzo is 11kg add to that 1.9kg for the motor (assuming I can get Q85R)..2.3kg for my 36v 10Ah battery and another kg for the controller and other bits...16.2kg! If I remove the gears and keep it single or dual gear..that will shave maybe a kg off bringing it down to 15.2kg... that doesn't include the weight of the bag of course..I'm planning to buy the Mezzo Commuter bag which is purpose designed to slide on the rack and keep all the kit in there..it's weather proof has carry handles and a shoulder strap so that is ideal (although expensive at £60, but then you only buy it once!). I will take a similar approach to yours with a umbilical cord and waterproof socket on the rear.

I want to keep the handlebar free of any kit and keep it minimal..no speedo/LCD console or LED indicator, no switches.. I will use the Speedict Android app with my HTC mounted to control the speed.

Well this is still all theory! Since nobody has ever converted one of these yet we don't even know if it's even possible. I'm a bit worried about the aluminium rear drop outs..but after reading a post on this subject on Endless Sphere I'm feeling a bit more confident it won't cause any problems.. do you think it would be wise consider some reinforcement for the torque still?

 

[Deleted member 4366]

Having decided on rear hub I've been looking at motor options on GBK and BMS...

Does anyone have any experience or knowledge of GBK-100R (Q100) or GBK-85 (Q85) motors supplied by GBK and BMS? These weigh 1.9kg and 2.1kg and look more powerful than the smaller tongxin motors, they are rated at 250-350W with 328 RPM option for 16" rim. ..

I use one in my Dahon and it's a perfect match. Mines actually a 24v 201 rpm one, which equates to 301 rpm at 36v. It's smooth, quiet and free-running. Top speed is about 18 to 20mph at 36v, so in 16" wheels speed would be 15 to 16mph, but climbing would be good. The 328rpm 36v should have 10% higher speed. I measured the no-load speed of a 328rpm one in a 26" wheel at about 30mph with 36v, which would be 18mph in a 16" wheel, so it looks like 15-16mph would be real world speed.

With 12S lipos and 30% of the shunt soldered, my Dahon flies - able to sustain over 20mph even up slight hills with my 100kg on board. With your weight, you'll be maxing out everywhere and flying up the hills. Lipos are lighter than other batteries, which is also an advantage. I've never used a Tongxin, but from what I've heard, they can't give the power of the Q100 because the rollers slip.

As Jerry said, you need to check the rear drop-out width. I think my Dahon was 120mm, so it took fair amount of levering to get the motor in. You can reduce the width of the Q100 a bit by using a 6 speed free-wheel and reducing the length of the spacer.

 

[morphix]

Thanks d8veh, that's been really helpful! I think I'm decided on the Q100 then assuming the Q85 isn't available in rear version.. it's strange that, have you ever seen one? It's only 200g weight difference anyway and the Q100 is presumably more powerful yet no more expensive so it's a worthwhile trade-off. If the Q85 is available in rear version I'd like to compare to Q100 in terms of energy efficiency and performance.

I'm tempted by the Tongxin/nano for it's ultra-low weight (1.6kg?) and the aesthetic value of a tiny motor..but I think with this build I have the capacity to take the Q100 and still have a sub-17kg bike...so for the extra performance it's worth it.

12S lipos sounds intriguing..but aren't those the batteries that require a fair bit of safety know-how and special handling? I'm wondering if it's worth moving to 48V? But that would mean extra battery weight so perhaps 36V is the best of all worlds..

 

[morphix]

Someone else raised the question about electrifying Mezzo D9 and Cwah says the rear dropout width on Mezzo D9 is 135mm...so looks good for Q100? It means dropping to 6 or 7 gears though, no problem. Cwah recommended the Cute 100 motor..I wonder if that is the same motor as the Q100?

 

[morphix]

The Mezzo is 11kg add to that 1.9kg for the motor (assuming I can get Q85R)..2.3kg for my 36v 10Ah battery and another kg for the controller and other bits...16.2kg! If I remove the gears and keep it single or dual gear..that will shave maybe a kg off bringing it down to 15.2kg...

Hmm.. i didn't factor in switching to big apple tyres and putting a more comfortable saddle on ;-) Maybe losing the gears and adding another 2kg for the bike mods would take me to around 17.5kg total weight with Q100... and 15.1kg carry weight..minus the bag...bit heavier than I would like, but this bike at 11kg is not the lightest folder by a long shot... I could have got the Dahon Uno at 9kg but it's considerably more £££ than what I got the Mezzo for...and the Mezzo has the rack and smaller folding size...always trade-offs..unless you love Brompton ;-)

If I don't like the Mezzo I think I will just get a Dahon Uno and be done with it. I could always fit a light rack on it. I'm still on the lookout for a Dahon JetStream that's within my price range, as a faster bike for more comfortable longer journeys to replace my 26".

 

[Deleted member 4366]

Most guys on ES use lipos, and when you look at their arrangements with them strapped all over the bike with wires everywhere, if there were problems, we'd here about it. The only problems I've heard of are when people try to get too clever with BMSs etc. If you keep it simple, there's very little risk. They give huge power, so you have to make sure that there's no chance of a short, by wires rubbing/pulling etc, They vapourise connectors instantly when you get it wrong, which helps prevent fires. Cwah manages OK with them and he started with quite a low knowledge base-point. The modern chargers are all intelligent with built in safety features. I think lipos got their bad reputation when charging was much more DIY.

Having said all thay, you still need to be careful and sensible with their application, and it's worth reading about the risks so that ou can avoid them. There's some good threads on ES.

 

[morphix]

Most guys on ES use lipos, and when you look at their arrangements with them strapped all over the bike with wires everywhere, if there were problems, we'd here about it. The only problems I've heard of are when people try to get too clever with BMSs etc. If you keep it simple, there's very little risk. They give huge power, so you have to make sure that there's no chance of a short, by wires rubbing/pulling etc, They vapourise connectors instantly when you get it wrong, which helps prevent fires. Cwah manages OK with them and he started with quite a low knowledge base-point. The modern chargers are all intelligent with built in safety features. I think lipos got their bad reputation when charging was much more DIY.

Having said all thay, you still need to be careful and sensible with their application, and it's worth reading about the risks so that ou can avoid them. There's some good threads on ES.

Thanks I will certainly do some research and give this some serious consideration. If they're cheaper and lighter than buying 36v "bricks" from China so much the better ;-)

 

[jerrysimon]

One of the beauties of the Brompton and the Dahons (not all have them fitted) is they have a frame mount front carrier block which allows you to use quick clip on luggage on the front of the frame, which is not effected by steering. With a front hub this makes any bag controller/battery arrangement simple.

Re Lithium Polymer batteries I used them for years in my RC hobby days and never had problem. I would not be happy about leaving them charging unattended though in my office/house so have tended to avoid them in the ebike application. They clearly offer big advantages though.

Regards

Jerry

 

[Deleted member 4366]

Not much cheaper, and they still come from China. A pair of 8aH 6S Zippy packs is about £150 or there's these that'll give 10AH for about the same:
22.2v 5200mAh 25C 6S Li-Po RC Battery R/C Trex 500 600 | eBay
You still need connectors to wire them for 44v (£5 to £10), a voltmeter/wattmeter on your handlebars (£5 to £100) and a charger with power supply (£20 to £70), but after that, you have a lot of flexibility.

 

[morphix]

I've just been looking at the keyde website at their motors... I don't know if these are tongxin, but they look more advanced and lighter compared to the usual offerings on GBK/BMS etc. I noticed one has the controller and speed sensor built inside and still weighs just 1.6kg and there's another unusual looking roller motor whatever that means? I noticed their external controller is super tiny only 60g. They also have a fancy LCD computer which allows you to control the speed of the motor. Some nice stuff and prices look not too bad either.

I just contacted them to find out some prices and details as they have no rear motors listed..they just told me they're only supplying front motors at present as rear motors are still being tested.

 

[morphix]

Following on from my last post, just had another reply from keyde for those interested in their products..

I asked when the rear motors will be available to buy and they reckon about a month or so.

I also asked them if the motor with the built-in controller and speed sensor works with their LCD computer controller, and they said yes.

I asked if it also works with the Speedict widget and Android app, and they said no.

I don't know whether their tiny external controller works with Speedict either, I suspect not.

 

[Deleted member 4366]

If you only want the cycle computer and battery functions, it will work. you wire it in series with the battery leads.

To get the governor functions, you need an independent throttle input to the controller. The speedict can take its own PAS and throttle signals, which it then processes into a throttle signal that's sent to the controller. IIRC from Jerrysimon, the PAS takes precedence on the Keyde controllers, so the governor and other signal processing would only work on the throttle when you're pedalling. As soon as you let go the throttle, the PAS would take over, unlimited.

 

[morphix]

If you only want the cycle computer and battery functions, it will work. you wire it in series with the battery leads.

To get the governor functions, you need an independent throttle input to the controller. The speedict can take its own PAS and throttle signals, which it then processes into a throttle signal that's sent to the controller. IIRC from Jerrysimon, the PAS takes precedence on the Keyde controllers, so the governor and other signal processing would only work on the throttle when you're pedalling. As soon as you let go the throttle, the PAS would take over, unlimited.

Thanks for explaining d8veh much clearer now was very confused how the Speedict actually works! It sounds like a good alternative with more flexibility than the LCD controller.. I have one of these LCD controllers (different type) with my existing kit on my 26" and it's a lot better than the basic LED things that come with most kits, I can control the PAS to 6-levels and it does distance/speed and journey time but only has very rudimentary battery power usage and current draw info, just some bars..so the Speedict takes it to a whole new level and I like the ability to map journeys and upload to PC etc.

 

[jerrysimon]

Morphix I assume you have seen the Goldant (Keyde) motor thread ?

The problem with their controller is it is pedelec only. They did do an update and provided a throttle for us but the pedelec takes priority (the throttle kicks in once the pedelec has started the motor) and if you stop pedaling the throttle has no effect.

The good news is that the Lyen/ecrazyman controllers work perfectly (the throttle is nice and smooth) with it providing you lower the current to around 10-12A.

The Goldant motors are made by Tongxin and are for sale through the Outrider outlet as well. I have been told that in a year or so the slightly heavier Nanos will probably be phased out.

The roller brake one is a big NO NO. I got a couple of them in error a few years ago when I purchased my first Tongxin Nanos. Fortunately I was able to take them apart and cut off the large splined boss on the casing which is used for the roller brake fitment.

The Goldants with the controllers in them have a large mark up. Its better to get the stock one and then use a Lyen/Ecrazyman controller.

Regards

Jerry

 

[morphix]

Morphix I assume you have seen the Goldant (Keyde) motor thread ?

The problem with their controller is it is pedelec only. They did do an update and provided a throttle for us but the pedelec takes priority (the throttle kicks in one the pedelec has started the motor) and if you stop pedaling the throttle has no effect.

The good news is that the Lyen/ecrazyman controllers work perfectly (the throttle is nice and smooth) with it providing you lower the current to around 10-12A.

The Goldant motors are made by Tongxin and are for sale through the Outrider outlet as well. I have been told that in a year or so the slightly heavier Nanos will probably be phased out.

The roller brake one is a big NO NO. I got a couple of them in error a few years ago when I purchased my first Tongxin Nanos. Fortunately I was able to take them apart and cut off the large splined boss on the casing which is used for the roller brake fitment.

The Goldants with the controllers in them have a large mark up. Its better to get the stock one and then use a Lyen/Ecrazyman controller.

Regards

Jerry

Thanks Jerry for the warnings! It's a minefield Shame they don't have the tongxin in rears. I think I found the Outrider website but it doesn't look like they have the rears either, unless I'm looking at the wrong site.

Well it would be nice to save some weight and get one of these 1.4-1.6kg tongxin motors but I noticed they only seem to go up to 260 RPM for 16" as opposed to the Q100's 328 RPM... would it make a huge difference for speed and torque?

 

[jerrysimon]

You can still get the Tongxin Nano slightly heavier rear motors I think. You would have to email Diana Lin.

The Goldant motors even though speced at 260RPM run a 16" wheel at 16.5mph with their pedelec only controller. I have one on my Brompton Ti and it is way quicker than my Tongxin Nano fitted to my other Brompton. Not as much torque on hills as you say though.

With the lyen/ecrazyman controller using throttle they seem to run slower. However using the Speedict you can set the throttle end points to overcome this, though I have not tried it yet as I am waiting for a replacement Speedict.

Regards

Jerry

 

[jerrysimon]

The Tongxin Nano rear motors are on this page


Jerry

 

[morphix]

You can still get the Tongxin Nano slightly heavier rear motors I think. You would have to email Dianne Lin.

The Goldant motors even though speced at 260RPM run a 16" wheel at 16.5mph with theit pedelec only controller. I have one on my Brompton Ti and it is way quicker than my Tongxin Nano fitted to my other Brompton. Not as much torque on hills as you say.

With the lyen/ecrazyman controller using throttle they seem to run slower. However using the Speedict you can set the throttle end points to overcome this, though I have not tried it yet as I am waiting for a replacement Speedict.

Regards

Jerry

Interesting! One wonders how fast the 328RPM Q100's will be then! But those weigh 2.1kg. It's a tough decision to make whether the extra weight is worth the extra performance. If I stick to the original aim a super light bike, then I should go for the Tongxin I guess.. I'm tempted to just buy both and test them out and sell whatever I don't use on, I'm sure someone here will buy it ;-)

The other thing is, noise..the tongxin are very quiet aren't they can hardly hear it running (I saw your video earlier on youtube!) I expect the Q100's are a fair bit more noisy running that much faster.

 

[jerrysimon]

Yep the Tongxin Nanos are pretty much silent and are reported to run better in freewheel mode.

The Tongxin Goldants are a little noisier but not much.

These motors use flat steel rollers gears rather than the nylon cog/gears.

Earlier versions of the Nanos did prove less reliable in larger wheels. The new lighter Goldant motors are as yet untested, though neither of mine have failed in the first few months of use yet.

I think if you are going for a rear motor I would just initially go with one of the GBK/BMS ones. If you don't like it you can always then try one of the Tongxin rear ones (if you can source them) and then sell the other one as you say.

For any super light bike, a front hub using the Goldant is probably the only way to go.

Regards

Jerry

 

[morphix]

Yep the Tongxin Nanos are pretty much silent and are reported to run better in freewheel mode.

The Tongxin Goldants are a little noisier but not much.

These motors use flat steel rollers gears rather than the nylon cog/gears.

Earlier versions of the Nanos did prove less reliable in larger wheels. The new lighter Goldant motors are as yet untested, though neither of mine have failed in the first few months of use yet.

I think if you are going for a rear motor I would just initially go with one of the GBK/BMS ones. If you don't like it you can always then try one of the Tongxin rear ones (if you can source them) and then sell the other one as you say.

For any super light bike, a front hub using the Goldant is probably the only way to go.

Regards

Jerry

Q100 it is then. I can order right away with the Q100 so no month delay. I'm really eager to get this conversion started so I get a few rides in before the frost and ice starts ;-) It's been quiet mild for the time of year so hopefully we will get a few more sunny dry days yet before the winter sets in.

I'm expecting the Mezzo to arrive today or tomorrow as it was shipped yesterday by Parcel Force...once I know it's ok and suitable I will do an express delivery order for the kit. I haven't ridden my 26" for months due to my bad knee but I've kept the battery charged every month so it should be good.