Help! Fiido D21 or Woosh Rambletta

Bonzo Banana · Dec 13, 2022

I'm not keen on the D21, it seems a small cramped ebike and doesn't appear to have adjustable handlebar height, its also far more proprietary with a lot more components made from unobtainium which means in the future the bike goes straight to landfill. Also the image of ebike fires in new york showed a lot of these small chinese ebikes in the mix of causes for ebike fires and I'm not sure I'd want to be sitting on a battery when it explodes into flames. The battery is ridiculously proprietary being the actual saddle post. However its very stylish and would make a great garage Queen for friends to admire but for actual riding looks horrible.

The Rambletta looks miles better to me and a lot less proprietary, not as stylish though but looks a much more practical and repairable bike. I'd personally choose one with rigid front forks.

Both feature 20" wheels though, so will wear out faster, puncture easier hitting pot holes and generally be less comfortable, well maybe not the Rambletta if you have both a suspension seat post and front suspension.

Either bike you need to carefully judge tyre pressure to get the maximum suspension effect for your weight. Not a bike to run the tyres at maximum pressure I feel. The D21 doesn't seem to mention fork material but even if steel there is no give in the design, it looks like every bump will be going through your hands, I suspect its aluminium to keep the weight down so even more harsh. Looks more like a final mile design to me, ride it to the bus stop or train station, travel on that and then ride the final mile from the station or bus stop to your place of work. So you cut out more travelling time but don't have long unpleasant sessions on the bike especially if its very cramped.

sjpt · Dec 13, 2022

For me there isn't a big benefit of suspension on roads, and it adds to weight. (but p.s., maybe more valuable on a small wheel bike)

There are big differences between different cadence sensors. Some rely on speed only; the settings control the speed cutout but give full power up to that cutout. Some control the current and thus the power. I think the Rambletta one does a combination (like the one I got with a Woosh kit), which may be better than the Volt one you tried).

Bonzo Banana · Dec 13, 2022

sjpt said:
For me there isn't a big benefit of suspension on roads, and it adds to weight.

There are big differences between different cadence sensors. Some rely on speed only; the settings control the speed cutout but give full power up to that cutout. Some control the current and thus the power. I think the Rambletta one does a combination (like the one I got with a Woosh kit), which may be better than the Volt one you tried).

I agree about suspension and make that point myself frequently. The issue I have with the Fiido is where is the flexing in its design? It has high spoke count wheels with short spokes, not much flexing there, a aluminium frame and fork both look designed not to flex at all, you then have a saddle post which is actually the battery so for certain that isn't flexing. It looks unbelievably harsh to be riding on small 20" wheels to go with the very cramped position for most riders I would say. I saw a video on youtube with a slightly over-sized rider weight wise and he said he was 85kg so clearly quite short yet looked cramped on the bike. Looks to me to be style over function. One of the main benefits of these ebikes is their small size means you can get many more in a container on a container ship so it reduces costs but really after that it starts throwing up many disadvantages for day to day use.

sjpt · Dec 13, 2022

Maybe not important for you, but rack on the Rambletta would be important for me. It doesn't look as if the Fide has fittings that would make adding one easy either.

Fido reports 35nm torque which is quite low. Not sure what it is for the Rambletta, but I suspect it will be more, so better for hills.

cyclebuddy · Dec 13, 2022

I think both bikes are worthy of consideration.

I've been riding a Fiido D11 - the cadence sensor version of the torque sensor D21 for over a year now. My initial thoughts and ongoing updates (inc a warranty claim) are here.

Whilst I respect everyone's opinion, @Bonzo Banana's critique is for the most part unfounded supposition. As an owner, the D11/21 works perfectly, and is well supported by Fiido (all spares for all models are available on Fiido's website). Other members here have bought the D21, some loved it and a couple of the owners didn't. Sizing is an issue as it is with the Rambletta (most folders do tend to be small framed), but I'm 5'10", and one D21 rider here is IIRC 6'3" and rides without issue.

Yes, the seat-post battery could be knicked, but it's not obvious it is a battery (it's not obvious it's even an e-bike); the battery is easily removed/carried with you, although I'd never leave any of my e-bikes unattended.

The one Fiido I wouldn't buy is an X (IMHO there still remain unresolved issues), but the Fiido D11/21 and Rambletta all have happy owners here.

Bonzo Banana · Dec 13, 2022

cyclebuddy said:
I think both bikes are worthy of consideration.

I've been riding a Fiido D11 - the cadence sensor version of the torque sensor D21 for over a year now. My initial thoughts and ongoing updates (inc a warranty claim) are here.

Whilst I respect everyone's opinion, @Bonzo Banana's critique is for the most part unfounded supposition. As an owner, the D11/21 works perfectly, and is well supported by Fiido (all spares for all models are available on Fiido's website). Other members here have bought the D21, some loved it and a couple of the owners didn't. Sizing is an issue as it is with the Rambletta (most folders do tend to be small framed), but I'm 5'10", and one D21 rider here is IIRC 6'3" and rides without issue.

Yes, the seat-post battery could be knicked, but it's not obvious it is a battery (it's not obvious it's even an e-bike); the battery is easily removed/carried with you, although I'd never leave any of my e-bikes unattended.

The one Fiido I wouldn't buy is an X (IMHO there still remain unresolved issues), but the Fiido D11/21 and Rambletta all have happy owners here.

I instantly knew the saddle post was the battery by its huge size and it looks instantly to be an ebike to me as well based on the extra width of the frame. Anyone interested in stealing it will have no issues recognising it as an ebike surely. Importantly is the stem height adjustable to get a good bike fit for long hours in the saddle? The Rambletta has an option for a longer saddle post but I can't see that as an option for the Fiido with it being the battery, how easy to recell if you use up your 500-800 charge cycles quickly or get a new battery at a reasonable price? It's not about spares today its about spares in perhaps 3 years time when the manufacturer has moved away from this design. Keeping a range of spares for all past models costs money and space it is common for Chinese companies not to offer such support. It doesn't matter when an ebike is made from non-proprietary parts and uses standard components you'll always have the option of fixing it, customising it etc. That is not to say the Rambletta is completely non-proprietary I'm sure it isn't but its starting from a much better place in that regard.

As for quality, there seems to be many issues and many people struggling to get replacement warranty parts or spares. This can only get worse with time.

Fiido is rated "Great" with 4 / 5 on Trustpilot

Do you agree with Fiido's TrustScore? Voice your opinion today and hear what 1,172 customers have already said.

uk.trustpilot.com

cyclebuddy · Dec 14, 2022

Well, @Bonzo Banana, what a great shame you didn't bother to even read my own review and ongoing commentary (which isn't entirely flattering), because that answers most of your issues. The few other issues you raise have all already been discussed in several other threads on this forum by other buyers over the past year. But to cover old ground yet again:

Bonzo Banana said:
Importantly is the stem height adjustable to get a good bike fit for long hours in the saddle?

As discussed before, the reason why it isn't adjustable is to keep bike weight down to Fiido's own target of a "light-weight" 17.5kg. It can be swapped out to an adjustable one if you want. But like Brompton do, you can add a riser bar as I did (photo showing that in my review). It uses Brompton 25.4mm fitting, so any Brompton bar fits. A lighter weight 50mm carbon riser cost me £20ish. Even so, should anyone be buying a 20" folding e-bike "for long hours in the saddle". It isn't intended to be that kind of bike.

Bonzo Banana said:
The Rambletta has an option for a longer saddle post but I can't see that as an option for the Fiido with it being the battery, how easy to recell if you use up your 500-800 charge cycles quickly or get a new battery at a reasonable price?

The Fiido seat-post battery is already ridiculously long, giving a max floor to saddle height of 1240mm (just measure that out and see how stupidly high that actually is): Fiido say up to 2m/6'5" tall riders. The battery/seat-post can be opened, but re-celling I don't know. You can buy spare batteries and chargers for all Fiido models here.

Bonzo Banana said:
It's not about spares today its about spares in perhaps 3 years time when the manufacturer has moved away from this design. Keeping a range of spares for all past models costs money and space it is common for Chinese companies not to offer such support. It doesn't matter when an ebike is made from non-proprietary parts and uses standard components you'll always have the option of fixing it, customising it etc. That is not to say the Rambletta is completely non-proprietary I'm sure it isn't but its starting from a much better place in that regard.

There's an active community on Facebook who already constantly swap out parts mostly for the sheer hell of it, so it seems: Changing the electronics to KT is a common one. Brakes to Shimano Hydraulics. Uprating the gear set. The motor is a common Xiongda. Most everything is pretty easily swapped except frame and battery - just like many other bikes. It'd even be a pretty easy task to use a rear rack battery instead of the seat-post one.

Yes, Fiido have had several teething problems when introducing new models, it seems mostly due to trying to be innovative with their designs (2980 model X bikes were recalled/refunded/replaced after a cast frame defect). From what I read, all those owners who follow Fiido's advice/process do get their issues resolved. In my own case, I only had to send a tentative email in case there might be a problem developing, and they sent me a new battery FOC (which it turns out I don't actually need - again in my review update).

As we know, there are plenty of twats who like to publicly shout about poor product/poor service on Social Media thinking that's a constructive way to have issues resolved. 45 reviews on Trustpilot out of 300,000 bikes sold since (IIRC) 2016? Most of those reviews don't even stack up, and a few there appear to have bought bikes through unauthorised selling channels, which Fiido have always strongly advised against (because they're not supported). There are many happy customer reviews on Fiido's own website, the few negative ones there are often from those who don't know one end of a bike from the other.

I'm certainly not blindly defending Fiido. They're not perfect and neither are their bikes, but you wouldn't expect them to be "Cube-like quality" for the money. The Fiido D11 is today £726, shipped from within the UK. The D21 is £877 shipped: That's a 17.5kg, true torque sensor folding e-bike with a branded Xiongda motor, 7sp Tourney gears, (mechanical) disc brakes, 417Wh battery, kickstand, lights and mudguards. Tell me that isn't a good deal in this climate?

Bonzo Banana · Dec 14, 2022

cyclebuddy said:
Well, @Bonzo Banana, what a great shame you didn't bother to even read my own review and ongoing commentary (which isn't entirely flattering), because that answers most of your issues. The few other issues you raise have all already been discussed in several other threads on this forum by other buyers over the past year. But to cover old ground yet again:

As discussed before, the reason why it isn't adjustable is to keep bike weight down to Fiido's own target of a "light-weight" 17.5kg. It can be swapped out to an adjustable one if you want. But like Brompton do, you can add a riser bar as I did (photo showing that in my review). It uses Brompton 25.4mm fitting, so any Brompton bar fits. A lighter weight 50mm carbon riser cost me £20ish. Even so, should anyone be buying a 20" folding e-bike "for long hours in the saddle". It isn't intended to be that kind of bike.

The Fiido seat-post battery is already ridiculously long, giving a max floor to saddle height of 1240mm (just measure that out and see how stupidly high that actually is): Fiido say up to 2m/6'5" tall riders. The battery/seat-post can be opened, but re-celling I don't know. You can buy spare batteries and chargers for all Fiido models here.

There's an active community on Facebook who already constantly swap out parts mostly for the sheer hell of it, so it seems: Changing the electronics to KT is a common one. Brakes to Shimano Hydraulics. Uprating the gear set. The motor is a common Xiongda. Most everything is pretty easily swapped except frame and battery - just like many other bikes. It'd even be a pretty easy task to use a rear rack battery instead of the seat-post one.

Yes, Fiido have had several teething problems when introducing new models, it seems mostly due to trying to be innovative with their designs (2980 model X bikes were recalled/refunded/replaced after a cast frame defect). From what I read, all those owners who follow Fiido's advice/process do get their issues resolved. In my own case, I only had to send a tentative email in case there might be a problem developing, and they sent me a new battery FOC (which it turns out I don't actually need - again in my review update).

As we know, there are plenty of twats who like to publicly shout about poor product/poor service on Social Media thinking that's a constructive way to have issues resolved. 45 reviews on Trustpilot out of 300,000 bikes sold since (IIRC) 2016? Most of those reviews don't even stack up, and a few there appear to have bought bikes through unauthorised selling channels, which Fiido have always strongly advised against (because they're not supported). There are many happy customer reviews on Fiido's own website, the few negative ones there are often from those who don't know one end of a bike from the other.

I'm certainly not blindly defending Fiido. They're not perfect and neither are their bikes, but you wouldn't expect them to be "Cube-like quality" for the money. The Fiido D11 is today £726, shipped from within the UK. The D21 is £877 shipped: That's a 17.5kg, true torque sensor folding e-bike with a branded Xiongda motor, 7sp Tourney gears, (mechanical) disc brakes, 417Wh battery, kickstand, lights and mudguards. Tell me that isn't a good deal in this climate?

Cube is just an importer brand that buys from different factories their bikes have been shown to be both poor quality and very good quality which I guess is dependent on which factory they have used. A lot of the Bangladesh Cube bikes are a bit poor. Just yesterday there was a video from kevcentral about fiido frames failing and the recall for those.

I'm not a fan of these small proprietary ebikes but its good to know people are learning how to improve them and fit better components. I just look at the Fiido and Rambletta and know that for long term use, comfort and practicality the Rambletta looks miles better to me. Call me crazy but I like a bike that performs well straight from the box and will continue doing so without the need for modifications or new parts. If you are considering spending another £300 lets say in a short space of time why not just put that towards a better more suitable ebike in the first place?

cyclebuddy · Dec 14, 2022

Bonzo Banana said:
I just look at the Fiido and Rambletta and know that for long term use, comfort and practicality the Rambletta looks miles better to me. Call me crazy but I like a bike that performs well straight from the box and will continue doing so without the need for modifications or new parts.

I looked at many folders before buying my own Fiido and dismissed the Rambletta because the Fiido:
1) Is lighter to carry
2) Trolleys better (can be pushed easily along a station platform)
3) Has a bigger battery
4) Is cheaper

What the Rambletta has is:
1) It's a low step if that matters
2) It has 8 gears instead of 7.

It depends what you intend to do with the bike and which factors are more important to you. The D11/21 is IMHO a better mixed-mode commuter.

You do seem to have an automatic downer on all things blatantly Far-Eastern when most mainstream European bikes are in any case made there too. Your pseudo-British Rambletta may get screwed together by a bloke called Bob in Southend, but who is to say that our man Yìchén in Shenzhen (or any of Fiido's 200 staff) can't screw a bike together properly too?

No disrespect at all to Woosh or their staff. I like the Rambletta too. I'm just making a point.

cyclebuddy · Dec 14, 2022

Bonzo Banana said:
Just yesterday there was a video from kevcentral about fiido frames failing and the recall for those.

Yes, I've seen it. That regurgitated "news" is only about 4 months old, and long since corrected. Again much crap spouted about derated motors: No it isn't. It's marked as 250w for EU compliance. It's the same with their M1P/M21 model. But actually finding that out would be far too difficult, and that doesn't get views does it?

The trouble with Fiido bikes is they're cheap enough for people to deliberately destroy for the sake of gaining YouTube cred, views and subscribers (and advertising revenue). Here's a typical example with the Fiido X:

Deno · Dec 15, 2022

My dad has the D21 because he needed decent range and relatively low weight with a torque sensor. Its the only folding ebike that delivers that at its price point.

I would describe the ride as 'sporty' but its certainly not uncomfortable. It handles tidily and seems very rigid for a folder. The fit and finish is comparable/favorable to my cube - the welds and paint finish are really very smart. I am the 6'3" and I didn't feel cramped but you know its a compact frame. The bike is very able to reach its limiter and then suffers from quite a drop off beyond that, its not so much power but it runs out of gearing for me, suspect a larger chainring would be required. In saying that I am reasonably fit and this would not be an issue for everyone. Also I suspect most folders have the same issue due to wheel size.

No experience of the rambletta but Woosh have a good rep. on here.

Jaxter · Dec 15, 2022

i have had a fiido d4s for two and a half years only problem i have had was rear spokes breaking, i got the rear wheel rebuilt with stronger sapim spokes.
I also replaced the tyres with some thicker marathon big apple tyres as i was feeling every bump riding some real crappy city streets.
I have had the bike serviced once which was just the mechanical bits they didnt touch the electrics, and the bike hasnt missed a beat i caveat this by saying it is kept indoors so this helps, but i bloody love that bike perfect for my use case short jaunts to and from family and a great for doing the shopping.

Woosh · Dec 17, 2022

Bannerblade said:
Can anyone expand on differences between cadence sensors?
When I rode the volt the motor seemed to turn on like a switch a second after pushing the pedal

there are things to consider when you talk about pedalling sensors: cadence, torque, speed and current.
the bike's electronics offers usually 5 levels of assistance to suit the road's gradient and riders' fitness, it is important to understand how programmatically the controller ramps up the assistance at the start and computes the effective current for the motor after that initial push off. More current equals more power. In the old days, before the pedal sensors, the controller uses the throttle's signal. The pedal sensors replace simply the throttle. If your bike has both pedal sensor and throttle, the latter takes precedence when active.

torque sensor: consists of a sleeve fitted around the bottom bracket axle and a strain gauge. When you push on the pedal, the sleeve rotates a tiny little bit around the bottom bracket axle. The displacement is proportional to the force you exerce. The strain gauge measures the displacement of the sleeve.
On bikes fitted with torque sensors, the controller multiplies the sensor's signal by the assist level and that's pretty much equal to the throttle level. Good point: the signal helps the controller's electronic to guess very well how much power you would want from the motor.

cadence sensor: consists of a magnet ring which is attached to the bottom bracket axle and a Hall IC which produces a pulse each time a magnet passes in front of it in the forward direction. When you pedal backward, the sensor does not produce a pulse, otherwise the motor would start if you pedal backward. Good point: the number of pulses per second is proportional to how fast you rotate the cranks, not how much force you push on the pedal. Weak pedallers are not disadvantaged.
On bikes fitted with cadence sensors, the controller's electronics has only two input variables: the cadence (pulses/second) and the bike's speed, it uses two methods to compute the ramp up and ramp down of assistance: speed control and current control.
speed control:
the controller is programmed to ramp up the speed until it reaches a preset speed then ramp down the assistance. Higher assist level equals higher preset ramp down speed. Level 1's preset is usually about 9-10mph, level 2 about 11-12mph, level 3 about 13mph, level 4 about 14mph and level 5 about 15mph. If the maximum speed limit is raised, those presets will spread a bit.
current control:
here, speed presets are replaced with current. Level 1's preset is about 50% of the controller's maximum, level 2 65%, level 3 80% level 4 90% level 5 100%. All those current presets operate all the way from standstill to 15mph, maximum legal speed, thus does not produce the initial jolt. Those presets can usually be reprogrammed using the buttons on the bike's LCD.

Nealh · Dec 17, 2022

It's not cadence sensor' s that the issue , it is down to the controller programmimg and system used. A lot of controllers use speed control which is crappy, no matter which pas level you are in they give max current all the time until you hit the cut off speed. It means you get a hard push in the back all the time
Better systems use current control, the rider decides the current level to use and how much power is supplied. KT use current control as default but one can opt to use speed control in the settings, Lishui use a mix of both though the power % on some can be user set.

The cadence sensors I use need a 1/10 rotation to activate as they use 10 magnets.

RHB123 · Dec 18, 2022

I'd add this, if it was just down to looks, I'd take the D21 any-day. But I know nothing about the mechanics, and you have to love a bike if you're going to use it everyday, don't you?

sjpt · Dec 18, 2022

A couple of clarifications.

I thought that cadence sensors that actually used the cadence as more than an on/off pedalling/not pedalling were pretty rare.

I thought that most current control systems also included speed control, so that at half setting not only is the current halved below cutoff speed, but the speeds at which the current ramps down and cuts off are alos lowered.

Is that right?

cyclebuddy · Dec 18, 2022

RHB123 said:
I'd add this, if it was just down to looks, I'd take the D21 any-day. But I know nothing about the mechanics, and you have to love a bike if you're going to use it everyday, don't you?

The Fiido D21 uses a true Torque Sensor so relies on how much pressure you put into the pedals to determine how much assistance is given from the motor - as Woosh described above.

The cheaper Fiido D11 is exactly the same bike, but uses a Cadence Sensor to provide a combination of Current Control and Speed Control, again as Woosh describes above.

This graphic is from a different bike so not exactly the same, but is very similar, and helps illustrate how the D11 applies power:

Woosh · Dec 18, 2022

sjpt said:
A couple of clarifications.

I thought that cadence sensors that actually used the cadence as more than an on/off pedalling/not pedalling were pretty rare.

I thought that most current control systems also included speed control, so that at half setting not only is the current halved below cutoff speed, but the speeds at which the current ramps down and cuts off are alos lowered.

Is that right?

that's correct.
I am usually rubbish at explaining things, I found this brilliant explanation on the famous Grintech's ebikes.ca:

https://ebikes.ca/learn/pedal-assist.htm

Which is Better?
This is one of those questions with an "it depends" kind of answer. Many people will assume that a torque sensor is ideal and represents the gold standard for PAS control, and that the basic PAS sensors represent a poor but inexpensive alternative. We don't think it's that simple, as people who prefer to regulate motor power independently from their pedal effort will be better served with a basic PAS setup.

A torque based control directly couples the motor power to the rider's power output. That means that going uphill you need to pedal hard to get sufficient power to climb, while on the flats or downhill’s if you pedal hard you will end up getting motor power when you don't actually need or want it. The overall experience is similar to riding a non electric bike, where your riding efforts vary significantly with the terrain; sweat going up, take it easy going down. If that is the behavior that you want then it works extremely well.

On the other hand, one of the benefits of an ebike is that you can use the motor to decouple the terrain from how hard you need to pedal. The motor can make up the difference between what your legs are putting out and what is required for the given hill and headwind. If you want to be able to ride comfortably with a given effort that doesn't change much whether going up or down, then you'll need the motor to put out lots of power when climbing, and then minimal to no power on the downhills, even while leg power remains the same. A basic PAS sensor with an easily handlebar adjustment for the PAS power level allows you to achieve this behavior quite nicely. It provides independent control of motor power and your pedal effort like a throttle, but without needing to constantly hold a throttle position.

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