Opinions on the best compromise?..(lightweight small manageable folding ebike)

[woz]

hi
I'm looking for a either a lightweight folder which can be converted to an ebike or a ready made ebike. I'm reasonably technically competent and could probably tackle any maintenance and conversion myself as long as there is no major metalwork involved.

I'm not as young as I used to be (ha! universally true of everyone... ) and my physical strength isn't great. I think I would struggle going up stairs with anything much more than 20kg (although if it split into a heavy bag and the bike that might be negotiable). Of course wheeling along it won't be an issue as long as it does wheel OK when folded.
I've not been a bike owner for a long time but it's about time I started doing more exercise, I'll be doing short runs of a few miles to start with and will want to take the bike onto public transport trams (and maybe buses). I'd want a decent low gear range if I lost power as my legs could be stronger - hopefully they will improve.

I've looked at various bikes and conversion kits but I'm undecided. The Brompton has much going for it but it's expensive and I'm not sure about the 16" wheel only because the roads are in such a dire state.
I can see pros and cons for everything I look at, so it depends on where I make my compromises.
I have to be able to lift and store it (limited storage space at home unless I chain it outside with a cover on it), it has to be accepted on public transport, and spares have to be available including batteries (which is the big worry with the cheap Chinese bikes).
If money was no object I'd probably look at the electric Brompton, but I could save a considerable amount by either buying a cheap Brompton or an even cheaper 20" folder and electrifying it, but there are going to be snags whatever route I take, so the question really is where should I compromise and what could possibly go wrong...

I'm looking for opinions...
Thanks!

 

[harryS]

The simplest approach is a Swytch front motor on the bike of your choice. I've never seen a Swytch, but it looks good in pictures. I think the concept of a quick release controller hanging on the handlebars has potential connector issues.
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I'm in the USA, and currently have three DIY electric 20" folders. When selecting a bike, put frame integrity at the top of the list. See what's sold in the UK with a reputation for reliable frames.
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My bikes have rear hub motors. The first one is store bought. Others three are my DIY. All 20" rear drive bikes. I had enough experience that I just bought the motor and electrical parts separately, not as a kit, mainly because they don't sell many 20" motor kits, BAtteries can be ebike batteries, custom batteries, or even tool batteries. They go in a bag on the rear rack, although the yellow one is using a frame battery, It costs me about $300USD for the motor/electricals, Batteries range from $50-300USD. In contrast, I bought the first blue one for $389USD complete as a working ebike, but spent another $100 to make it a good ebike, It just happened to be on clearance because it wasn't a good bike.




If portability is the main goal, consider 16" wheels, and DIY allows you to use smaller batteries as needed. You can have a spare for longer trips.

 

[SC00CHB00CH]

My bike weighed 35lbs/15kg. I could probably make it a little lighter with non steel cranks , a cambium seat and a carbon handlebar. Maybe shave 2lbs? The pedals could be lighter as well. Top Speed 36mph throttle only on a pure flat road and climbs hills like a goat. I live in nothing but hills so I needed a bike with the ability to climb well. This little bike didn't meet a hill it couldn't climb.

It's a cute unassuming bike but it felt like a V6 in a honda civic. 750 watt BBS02 and 52V 8ah saddle bag battery pushing 1300 watts max. These folding carbon fiber SAVA 20 inch bikes are pretty robust. I think they're running about $1300-$1600 on sale right now. I sold the bike on ebay to a private pilot who brings the bike on board his plane in a large canvas duffel bag.

My next build I'm looking at the hummingbird folding bike (see blue bike) . Although they already make an e-bike version but it's tad underpowered for my taste. I'll probably do another BBS02 mid-drive or possibly a high end geared hub motor. Not sure yet. I like the IGH the hummingbird has and it has a standard sized bottom bracket. I sold my SAVA carbon folder with 600 miles on it with the motor and it ran great. I think without the motor and battery it weighed 22lbs.

HERE is the bike in it's final build state when I sold it with both batteries it weighed in at 22kg or 49lbs. This is the heavy version I could've made it lighter. Notice the heavy spring brooks seat and the heavy suspension stem. A really fun bike. I should have painted the frame battery black. Everyone thought it was a luna bike. It's not , just the battery was from luna.

 

[BlackHand]

The simplest approach is a Swytch front motor on the bike of your choice. I've never seen a Swytch, but it looks good in pictures. I think the concept of a quick release controller hanging on the handlebars has potential connector issues.
.
I'm in the USA, and currently have three DIY electric 20" folders. When selecting a bike, put frame integrity at the top of the list. See what's sold in the UK with a reputation for reliable frames.
.
My bikes have rear hub motors. The first one is store bought. Others three are my DIY. All 20" rear drive bikes. I had enough experience that I just bought the motor and electrical parts separately, not as a kit, mainly because they don't sell many 20" motor kits, BAtteries can be ebike batteries, custom batteries, or even tool batteries. They go in a bag on the rear rack, although the yellow one is using a frame battery, It costs me about $300USD for the motor/electricals, Batteries range from $50-300USD. In contrast, I bought the first blue one for $389USD complete as a working ebike, but spent another $100 to make it a good ebike, It just happened to be on clearance because it wasn't a good bike.


View attachment 140056View attachment 140053 View attachment 140054View attachment 140055

If portability is the main goal, consider 16" wheels, and DIY allows you to use smaller batteries as needed. You can have a spare for longer trips.

That Downtube fs folder is a nice looking bike, don't think I've seen that before!

 

[mojoe]

hi
I'm looking for a either a lightweight folder which can be converted to an ebike or a ready made ebike. I'm reasonably technically competent and could probably tackle any maintenance and conversion myself as long as there is no major metalwork involved.

I love my Gocycle GX. I got it for $3000. If you can find a used GX, that might be a good choice for you. The Gocycle's have 20 inch tires. Personally, I wouldn't go with anything smaller. The bike weighs 38 lbs, and folds small. The enclosed chain drive means no mess, and no pants caught in a chain. They claim that it is maintenance free. Other than price, there are a few minor downsides to the Gocycle. As with any ebike, I always read user comments, and watch the YT videos.

I have over 1000 miles on mine. Most of that mileage was in the last six months. The only maintenance I've had to do was to spray silicone lube into the rear "lockshock", as recommended. After many miles, it squeaks.

In Eco mode, I was getting up to 40 miles per charge (slightly hilly terrain). I now use a customized setting that is between Eco and City, so get up to 30 miles per charge. If you ride in very hilly terrain, the Gocycle doesn't have enough gearing or motor for that. You can press the "boost" button to max out the motor, but on steep hills, pedaling is still an effort. My full-sized Priority Current and my new ICE trike make hilly riding easy.

It's a shame that the new G4 models are so much more expensive.

 

[harryS]

One thing about mid drives kits is they are easy to package. ALll you do is run the cable to the control display and connect a battery. Right now I could get the dreaded Tong Sheng TSDZ2B for under $300USD shipped from PSWpower, which is less than what a motor kit costs me. It has a reputation for being weak, but that's probably an attribute for a folder. Comes in 36V or 48V versions.

I always liked those GoCycles, but I don't need the portability. There are also folders with natteries in the seat posts, but they do limit the range.
.
Scooch, that was a nice build on the Sava. Must have been scary quick.

 

[tomjasz]

I did a ZIZZO Forte, 300lb capacity with a BBS01B 250W 36V 250lb load at 20mph.
Forte $430
BBS01B $350
10Ah battery $300
light kit front led rear running and brake lights integrated with motor, $30

 

[woz]

Thanks for all the replies, perhaps I should have mentioned that my understanding of the UK regulations** to which it must comply is:
Motor power no greater than 250W (motor plate must show (manufacturer or power) and (voltage* or speed)
A top speed of no more than 15.5mph
Pre 2016 manufactured throttle allowed, post 2016 twist throttle still allowed but only up to 3.7mph from a standing start, to go any faster a pedal movement sensor must be used in conjunction with the throttle. If the throttle alone is capable of taking it to a higher speed than 3.7 (to a max of 15.5) the manufacturer must apply for type approval.
@harryS What did you need to do the the bought bike to make it useable/better
**That's how I understand the regulations which are not easy to understand
*I'm not sure what the relevance of voltage is as long as it's below 50V(for electrical safety reasons) , it doesn't tell you anything about the power output.

 

[EMGX]

QIROLL isn't mentioned much on this forum but there is a thread with information from users who seempleased with it. 250w, 1.2 to 1.6kg (including battery) depending on the battery chosen. I'd be interested in trying one but I don't have a need and it seems expensive for what it is.
Image from ebay listing


Tongsheng tsdz2 torque sensing mid drive is very easy to install/remove and lacks the wiring rat's nest that often accompanies hub motor kits (excepting the Swytch). My experience on a few folding bikes that I installed on (20", 24" and 26") is that they provide excellent assist but mine are 36v 500w and 48v 750w. I have no idea how the 36v 250w version performs.

Here is a $200 Walmart folder when I had it on that bike. That bike went from 26# to just over 40# with the tsdz2 and a 36v 10ah battery (in seat bag)


A QIROLL on that bike would weigh less than 30# if the weights on the ebay listing are accurate.

 

[SC00CHB00CH]

Thanks for all the replies, perhaps I should have mentioned that my understanding of the UK regulations** to which it must comply is:
Motor power no greater than 250W (motor plate must show (manufacturer or power) and (voltage* or speed)
A top speed of no more than 15.5mph
Pre 2016 manufactured throttle allowed, post 2016 twist throttle still allowed but only up to 3.7mph from a standing start, to go any faster a pedal movement sensor must be used in conjunction with the throttle. If the throttle alone is capable of taking it to a higher speed than 3.7 (to a max of 15.5) the manufacturer must apply for type approval.
@harryS What did you need to do the the bought bike to make it useable/better
**That's how I understand the regulations which are not easy to understand
*I'm not sure what the relevance of voltage is as long as it's below 50V(for electrical safety reasons) , it doesn't tell you anything about the power output.

Then look nowhere else ,this is lightest ebike folding bike on the market @ 250watt , It's pricey but probably one of the lightest best built folding ebikes on the planet. You can upgrade the tires at checkout if needed.

Electric Folding Bike Gen 2.0

The new Electric Gen 2.0 is the lightest folding e-bike in the world. Simple, powerful, portable and a joy to ride. Shop Prodrive Folding Bikes here.

hummingbirdbike.com

 

[woz]

@SC00CHB00CH
Sadly at nearly £5000 (or nearly $6000) it's just a few £ over my budget but thanks for the suggestion.
On the other hand if it will fit into the boot of my Bugatti....

 

[mojoe]

Then look nowhere else ,this is lightest ebike folding bike on the market @ 250watt , It's pricey but probably one of the lightest best built folding ebikes on the planet.

Electric Folding Bike Gen 2.0

The new Electric Gen 2.0 is the lightest folding e-bike in the world. Simple, powerful, portable and a joy to ride. Shop Prodrive Folding Bikes here.

hummingbirdbike.com

That's more expensive than a Gocycle, which is made in England. When you first setup the ebike with the app, you are asked whether to set it to EU or US regulations.

I just looked at the specs. It is quite a bit lighter than a Gocycle, but the battery capacity is half. I doesn't look like a good value, to me.

 

[SC00CHB00CH]

That's more expensive than a Gocycle, which is made in England. When you first setup the ebike with the app, you are asked whether to set it to EU or US regulations.

I just looked at the specs. It is quite a bit lighter than a Gocycle, but the battery capacity is half. I doesn't look like a good value, to me.

They (Hummingbird) claim 60km/37mi range with the battery and it's 16lbs/7kg lighter than the GoCycle. That's quite a weight difference.
*23lbs/11kg hummingbird vs *39lbs/18kg gocycle.

GoCycle looks nice too though and that's within the weight requested by the OP.


*note , I rounded up weights of both bicycle types in kg/lbs

 

[SC00CHB00CH]

@SC00CHB00CH
Sadly at nearly £5000 (or nearly $6000) it's just a few £ over my budget but thanks for the suggestion.
On the other hand if it will fit into the boot of my Bugatti....

Bugatti !!
Oh man you got me.

There was one (Hummingbird) on EBAY US without a motor for $3500 us/ $3000 gbp , I was gonna snag it but the owner went out of town and pulled the ad. I contacted him and when he gets back he's gonna contact me. It's the belt drive version with the IGH hub. I planned on installing a BBSHD on it.
The gocyle looks nice too.

 

[tomjasz]

@SC00CHB00CH You are ignoring content by this member.
Sadly at nearly £5000 (or nearly $6000) it's just a few £ over my budget but thanks for the suggestion.
On the other hand if it will fit into the boot of my Bugatti....

36MPH or 58KPH on a 20" Bike isn't the brightest move. There are NO eBike braking systems capable of safe and sane stopping distances at 58KPH. Some 4-piston systems might be capable but who puts $600 hydraulic systems on $300 bikes? Anyone claiming reliable and safe and sane stopping distances hasn't done any MSF-style track day testing. Am I criticizing someone's choice? No. Been there done that. I'm just not willing to die on an eBike. The Luna(tics) encourage this behavior, so be it. IMO this behavior will bring more and more oversight and rules. I can drive a cage capable of unsafe speeds safe and sane and believe I can also ride a powerful eBike at safe and sane speeds.

I HATE the eBike class system, but systems like OSHA exist because of poor choices and dangerous practices. IMO WE create oppressive rules. We sold scores of BBSHD motors to goofs throwing them on $300 Walfart frames incapable of decent stopping distances under pedal power. It ALWAYS bothered me. But I always felt that if these loose screws killed themselves without harming others, well Darwin at work...

I bought 3 BBS01B 250W motors from an American eBike builder that discovered Americans wouldn't buy what they perceived to be underpowered bikes. I apid $100 apiece for them and all three got mounted on Zizzo Forte folders and could carry a 250lb load at 20MPH all day long. AND had a decent scurry across an intersection speed, better than an acoustic bike. I road my 36V 350W original BBS01(A) again today and had no issue crossing a bust 30MPH speed limit city street. Some guys just seem to need Viagra....

 

[SC00CHB00CH]

36MPH or 58KPH on a 20" Bike isn't the brightest move. There are NO eBike braking systems capable of safe and sane stopping distances at 58KPH. Some 4-piston systems might be capable but who puts $600 hydraulic systems on $300 bikes? Anyone claiming reliable and safe and sane stopping distances hasn't done any MSF-style track day testing. Am I criticizing someone's choice? No. Been there done that. I'm just not willing to die on an eBike. The Luna(tics) encourage this behavior, so be it. IMO this behavior will bring more and more oversight and rules. I can drive a cage capable of unsafe speeds safe and sane and believe I can also ride a powerful eBike at safe and sane speeds.

I HATE the eBike class system, but systems like OSHA exist because of poor choices and dangerous practices. IMO WE create oppressive rules. We sold scores of BBSHD motors to goofs throwing them on $300 Walfart frames incapable of decent stopping distances under pedal power. It ALWAYS bothered me. But I always felt that if these loose screws killed themselves without harming others, well Darwin at work...

I bought 3 BBS01B 250W motors from an American eBike builder that discovered Americans wouldn't buy what they perceived to be underpowered bikes. I apid $100 apiece for them and all three got mounted on Zizzo Forte folders and could carry a 250lb load at 20MPH all day long. AND had a decent scurry across an intersection speed, better than an acoustic bike. I road my 36V 350W original BBS01(A) again today and had no issue crossing a bust 30MPH speed limit city street. Some guys just seem to need Viagra....

It ran fine for me and braked quite well. In fact 600+ miles on the equipped brakes. I actually ran the bike on a small race track here in Asheville that looks like a small version of Daytona speedway with high banks. It was a closed track. I ran the bike at full speed with no issues. Was it scary , yes it was but I was in full gear, helmet , gloves ,pad , etc. I also only ran my bike on off road trails or long stretches of highway. I'm a respectable e-bike rider.

The bike in question cost $1600 new it's not a cheapo $300 bike. It's built by SAVA whom trained in Germany on how to build one-piece carbon frames. The new owner of the bike whom is a pilot and engineer installed an IGH hub. I'm awaiting his updates as we speak. I wasn't sure if he went rohloff or shimano 3-4 speed.

Furthermore you keep mentioning "Luna-tics" in reference to the e bike seller LUNA for which I have no affiliation with. ONLY the battery on the bike was from LUNA , not the controller , not the motor , only the battery and charger was purchased from Luna.
I hated the LUNA logo on the battery as I didn't want people to assume the bike was built by Luna. ONLY the battery on the frame was from Luna.
The steep hills that bike has gone down using heavy breaks and 220lb body actually surprised me , the brakes held up quite nicely.

This is the donor bike for my build as equipped from the factory. Nothing but the batteries , motor ,seat and headset were added by me.

SAVA Z1 Carbon Folding Bike 20" inch Disc Brake Folable Bike Shimano 20/22 Speed

The foldable Carbon fiber frame provides the folding bikes with a structure that is uniquely strong and lightweight. it was made for even the smallest of storage spaces without tools. The cricket quickly and easily folds for storage and transport. Easy to adjust and assemble. 14-day easy returns.

savadeck-bike.com

I had no plans on going 36mph on the hummingbird , in fact with 18inch tires I'd expect something closer to 28mph tops.

In fact I've often thought of going to back to a pure bicycle for exercise no motor , most ebikes these days don't excite me. I want a lightweight powerful ebike that doesn't have tires the width of an elephant's trunk and frames mass produced in China.

 

[SC00CHB00CH]

This carbon fiber ebike has 250watt ,weighs 17kg and cost about $3500-3700 US
rear hub version

SAVA E6 Electric Bike - Sava Bikes

What This Product Is About: The carbon fibre foldable frame gives this portable folding bike by SAVA a structure that is both sturdy yet light. the

savabicycles.com

mid-drive version 15kg

Folding smart electric bike (Mini 20 inch carbon Folding bicycle) - Sava Bikes

What This Product Is About: The carbon fiber foldable frame gives this portable folding bike by SAVA a structure that is both sturdy yet light. the

savabicycles.com

 

[woz]

It ran fine for me and braked quite well. In fact 600+ miles on the equipped brakes. I actually ran the bike on a small race track here in Asheville that looks like a small version of Daytona speedway with high banks. It was a closed track. I ran the bike at full speed with no issues. Was it scary , yes it was but I was in full gear, helmet , gloves ,pad , etc. I also only ran my bike on off road trails or long stretches of highway. I'm a respectable e-bike rider.

The bike in question cost $1600 new it's not a cheapo $300 bike. It's built by SAVA whom trained in Germany on how to build one-piece carbon frames. The new owner of the bike whom is a pilot and engineer installed an IGH hub. I'm awaiting his updates as we speak. I wasn't sure if he went rohloff or shimano 3-4 speed.

Furthermore you keep mentioning "Luna-tics" in reference to the e bike seller LUNA for which I have no affiliation with. ONLY the battery on the bike was from LUNA , not the controller , not the motor , only the battery and charger was purchased from Luna.
I hated the LUNA logo on the battery as I didn't want people to assume the bike was built by Luna. ONLY the battery on the frame was from Luna.
The steep hills that bike has gone down using heavy breaks and 220lb body actually surprised me , the brakes held up quite nicely.

This is the donor bike for my build as equipped from the factory. Nothing but the batteries , motor ,seat and headset were added by me.

SAVA Z1 Carbon Folding Bike 20" inch Disc Brake Folable Bike Shimano 20/22 Speed

The foldable Carbon fiber frame provides the folding bikes with a structure that is uniquely strong and lightweight. it was made for even the smallest of storage spaces without tools. The cricket quickly and easily folds for storage and transport. Easy to adjust and assemble. 14-day easy returns.

savadeck-bike.com

I had no plans on going 36mph on the hummingbird , in fact with 18inch tires I'd expect something closer to 28mph tops.

In fact I've often thought of going to back to a pure bicycle for exercise no motor , most ebikes these days don't excite me. I want a lightweight powerful ebike that doesn't have tires the width of an elephant's trunk and frames mass produced in China.

Is that a thin elephant's trunk or a thick elephant's trunk, and which end of the trunk?
I only ask that because I genuinely wasn't sure which you meant, but looked at from an engineering perspective a small wheel (16" for example which the Brompton is) will ride into indentations more easily, I assume wider tyres would cushion the ride better but of course they come with a weight overhead, on the other hand it may not be as important on a 20" wheel.
I should add I like the Sava although not much difference in price to a Brompton, but whats the situation when you apply all that torque to the front forks, do you have to put torque spreader or some sort of strengthening?

 

[SC00CHB00CH]

Is that a thin elephant's trunk or a thick elephant's trunk, and which end of the trunk?
I only ask that because I genuinely wasn't sure which you meant, but looked at from an engineering perspective a small wheel (16" for example which the Brompton is) will ride into indentations more easily, I assume wider tyres would cushion the ride better but of course they come with a weight overhead, on the other hand it may not be as important on a 20" wheel.
I should add I like the Sava although not much difference in price to a Brompton, but whats the situation when you apply all that torque to the front forks, do you have to put torque spreader or some sort of strengthening?

"thick" was referring to the almost hilariously thick and wide tires they put on mass produced Chinese rebranded e bikes. You often see many ebikes that have suspiciously similar frames with different vendor names on them. anyways I think I getting a bit off-topic there ,I apologize.

It appears SAVA has 4 e-bike versions , a rear hub drive , 2 front hub motor drives and a mid-drive version. Personally I would stick with the rear-hub version. I don't have experience with their front hub bike , that may be the one you're questioning about front fork torque?

The SAVA I had was custom built it was a normal version of their bike with an added 750watt BBS02 mid-drive motor. The rear square shape of the carbon frame held up nicely to the torque , no flex under load and fulling climbing wattage. They make very robust carbon frames.

On my bike even thin 1.65 tires handled all the terrain I used it on , but I added thicker 1.95 bmx tires when I sold it. Whatever use case scenario you think you'll need get the appropriate tire size but don't think you need overly thick tires. I'd say if you're planning on riding on the beach , snow , or possibly mud then think about thicker tires. I'm leaning towards the rear-hub version if you buy the pre-built. It's got the bafang version. I've never heard of the yuebo t400 mid-drive they use , maybe someone else can chime in. Their rear hub version is a good solid motor from Bafang.

 

[SC00CHB00CH]

Here are the two front hub styles , with smaller 14in tires/rim

Pedelec Intelligent Electric bicycle (250w Brushless motor) - Sava Bikes

What This Product Is About: The carbon fiber foldable frame gives this portable folding bike by SAVA a structure that is both sturdy yet light. the

savabicycles.com

SAVA Electric Folding Bike - Sava Bikes

What This Product Is About: The carbon fibre foldable frame gives this portable folding bike by SAVA a structure that is both sturdy yet light. the

savabicycles.com