Fiido D21

stormfeet

Finding my (electric) wheels
Jan 24, 2022
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Hi! New to the forum. Has anyone got the new Fiido D21 folding electric bike? On paper it seems to be the Fiido D11 that's been out for a couple of years, but has an added torque sensor.
Specifically I'd be interested if the speed limit (for assist) could be tweaked similar to the D11.
It's not designed to be a fast bike, but a few more mph does help. Thanks in advance!
 

cyclebuddy

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On paper it seems to be the Fiido D11 that's been out for a couple of years, but has an added torque sensor.
That's exactly what it is (I have a D11).

The issue is the new display Fiido have just started using. On the old display, on the D11, you changed the wheel size from 20 to 12.4. That gave you a top speed of 18mph and as a bonus the display read in MPH instead of KPH. The D11/D21 motor isn't capable of giving any more than 18mph*. The D4S uses a different de-restrict method and has a different motor to achieve (at best) 21mph.

From what I read, the new display gains a USB charging port, but loses the ODO and Trip counter, and has no programming menu... some say it's a backward step, but again from what I've read so far means you're stuck to 25kph.

* You can achieve a no-load speed of 20mph with a full battery but it starts throwing controller errors.
 
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stormfeet

Finding my (electric) wheels
Jan 24, 2022
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Thanks, wasn't aware of that. Is the display something that could be straight-swapped with a D11 display spare part?
 

cyclebuddy

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Apart from the very cheapest Fiido models, all the bikes are now using the new display - including the D11, D4S and M1/Pro/M21. It can be ordered as a spare part, but it's not clear which version Fiido would supply.

You could buy a Fiido X: With torque sensor and hydraulic brakes, the 350w version does 20mph straight out of the box! It has an Aikema motor, the D11/21 a Xiongda.
 
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stormfeet

Finding my (electric) wheels
Jan 24, 2022
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2
True, i had my eye on the Fiido X.
Their FB group seems to report some faults with the first batch (could be user error, in fairness) while the D11 seems to be a tried-and-tested design. I'll have a look again.
 

cyclebuddy

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When Fiido launched the D11 it had a number of construction issues... which is reason enough not to buy an indiegogo funded project bike. In all fairness, every batch of D11's I've seen since have had those issues incrementally resolved. The D11 today is a far better bike than those early indiegogo ones and the D21 benefits from those lessons too.

IMHO, whatever issues the X may have, I'd be confident Fiido will work hard to resolve them quickly on subsequent batches.
 
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stormfeet

Finding my (electric) wheels
Jan 24, 2022
22
2
The Fiido D21 arrived yesterday! First impressions, build quality is nice, and components didn't require much tweaking out of the box. Swapped the grips and saddle. Gets moving quickly from a standstill, although the speed tops out very shortly after. Nimble on the street. Shall take it on light trails this evening.
 
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sjpt

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enjoy
 

guerney

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I have a folder, and I'm wondering if folding bikes often snap in two?
 

Nealh

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Tern folders have had big issues with the hinge weld snapping on various of their bikes, they stole some of the intellectual properties from Dahon and tried to clone the bikes and the hinge design. It seems they failed to get the hinge specs or drawings.
If you search the wider net one will find quite a few threads on Tern failures all over the world, some relate to converted bikes which likely has caused some of the issues.
 
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cyclebuddy

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The latest batches of D11 & D21 I've seen have smooth welding at the folding hinge - one of many improvements Fiido have made.
 

guerney

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Tern folders have had big issues with the hinge weld snapping on various of their bikes, they stole some of the intellectual properties from Dahon and tried to clone the bikes and the hinge design. It seems they failed to get the hinge specs or drawings.
If you search the wider net one will find quite a few threads on Tern failures all over the world, some relate to converted bikes which likely has caused some of the issues.

Personally, I'd be nervous of any sideways folding bike which doesn't have a supporting crossbar. Mine hasn't snapped yet, it's very old. The guy I buy spare Dahon parts from, says he's never had any Dahons with a rebar returned, but a few of various brands have had broken hinges (including newer Dahons), which don't have rebars. Here's an example of Dahon's "Rebar" hinge mechanism reinforcement (not a photo of my bike):


 

stormfeet

Finding my (electric) wheels
Jan 24, 2022
22
2
Week 1 of the D21, loving it! It handles heavy traffic well. Doesn't fold as tightly as a Brompton and the halves don't lock together like the Onebot S6. Carrying it on the tube is a bad idea, but less squashed situations like the overground / trains seem easily doable. It's a great bike for the price.

Might have discovered an unlock, but need a separate speedometer to verify this.

It did feel a little faster after doing the procedure, although the bike's speedometer is hard-fixed to display 25km/h as it's maximum (i.e. it could have been more, it just didn't show on screen)

"To unlock the speed on the newer displays, please try the below:
Switch the bike ON whilst holding full throttle and the right brake lever for 15 seconds."
 

cyclebuddy

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I wish they'd put magnetic frame catches on it like the Fiido X (and Onebot) to keep it folded.

That sounds like the M1 hack; do as you've done to unlock the motor speed, then unlock the (new version) display by pressing both buttons on the display until it flashes (IIRC it's either just once or else twice), then quick press the top, then lower button. The speed then also shows whatever the motor can do above 25kph. It may work on your D21.

Glad to hear you're enjoying it. Keep us updated!
 

TaffandEvan

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Feb 2, 2022
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I wish they'd put magnetic frame catches on it like the Fiido X (and Onebot) to keep it folded.

That sounds like the M1 hack; do as you've done to unlock the motor speed, then unlock the (new version) display by pressing both buttons on the display until it flashes (IIRC it's either just once or else twice), then quick press the top, then lower button. The speed then also shows whatever the motor can do above 25kph. It may work on your D21.

Glad to hear you're enjoying it. Keep us updated!
Can you bye the magnetic catches for the D21?
 

cyclebuddy

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Can you bye the magnetic catches for the D21?
Not that I've seen, and D11/21 frames don't have threaded bosses to screw them into like the X. It's only a partial solution anyway as magnets only hold the main folded frame together; the folded stem still tends to flop about a little.

As with most folded bikes, you just need one bungee cord to strap everything together tightly.
 
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TaffandEvan

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Feb 2, 2022
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Not that I've seen, and D11/21 frames don't have threaded bosses to screw them into like the X. It's only a partial solution anyway as magnets only hold the main folded frame together; the folded stem still tends to flop about a little.

As with most folded bikes, you just need one bungee cord to strap everything together tightly.
 

TaffandEvan

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Feb 2, 2022
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My mate is looking at the pure flex electric bike. He’s asked me if anyone as any thoughts on the bike.
 

cyclebuddy

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My mate is looking at the pure flex electric bike. He’s asked me if anyone as any thoughts on the bike.
There're plenty of reviews stressing the strengths and weaknesses of the Pure Flux. The main drawbacks to me would be the lack of gears making hills a buggar, and the small 7Ah battery severely limiting range. The controller programming (how power is applied) is reported as poor too.

If your mate is already a reasonably strong cyclist looking to undertake short darts over flat paved/tarmac roads and only in dry weather, it's probably an okay choice. By time you add mudguards, lights, kickstand and all the other peripheries like a rack for commuting or touring, the weight and cost adds up and the range shortens even more. As supplied it has very limited applications IMHO. A Crossfuse or Cube hybrid is far more refined and versatile, although that comes at a cost.