In the interests of full disclosure, I thought I'd update this thread as I've owned this Fiido D11 e-bike for a year now.
Mileage isn't particularly high given lockdowns and now rail strikes, but here's what I've found good and bad about the Fiido D11 in that first year. It's used for an 8-mile commute each way using trains, but only once or twice every week, and less so with Covid and now strikes, so I drive instead.
I changed:
Handlebars: The reach on what is a small frame is a bit short for me at 5'10", so I added 2" riser bars (£23) which (with rotation) can increase/shorten reach and/or add height.
Grips: Everyone says the rubber is as hard as nails. I changed mine for soft leatherette (£10)
Brakes: The no-brand mechanical disc-brakes squealed a bit; sintered pads on cheap rotors. In truth, they work very well as they are. I changed these to Zoom semi-hydraulic (£24) which improved things a fair bit, but ideally I'd change the rotors too.
Pedals: Just a personal choice - all my bikes now have the same Wellgo platform pedals.
Tyres: Changed to Marathon Green (£15 each) - no-one needs a puncture mid-commute
De-restriction: I did - to 18mph, which is all the tiny Xiongda motor can give. A bit naughty, but on a commute you're not riding for pleasure, you're riding to get there.
I added:
An aluminium rack (£15) and trunk bag (£15).
A stem/handlebar mounted Bluetooth speaker (£15) so I can listen to Radio 4 (how sad am I?).
What's gone wrong?
The headset bearings became a very little loose. Some commented about "no grease" and shouted loudly on Media about how "disgusting", "poor" and "unfit for purpose" this was. In my view it's routine maintenance. On disassembly, the bearings were in fact very well greased, and the issue was the locking hex bolt had loosened off very, very slightly. I packed in some more grease and added a drop of lock-nut to the bolt, and that cured that.
Wheel spokes: Again, lots of whinging on social media about how crap the wheels/spokes are with spokes constantly loosening/braking. To my mind this is again routine maintenance. If you're on the heavy side (as I am) and ride rougher ground (as I do), regular checking is sensible. Three loose spokes after the first month. Two more in month 3. All rear wheel. Nothing since. It's a cheap bike with cheap wheels. IMHO these things are likely to happen.
Battery: Fiido had a problem with a batch of seat-post batteries where the end-cap (onto which the saddle is mounted), would open up. That happened to me in Week 51 of the 52 week warranty where a very small opening became visible. Not knowing if this was or would become serious, and given the warranty was about to expire, I emailed Fiido in case such a fault became catastrophic. They sent me a new seat-post battery. The existing battery to me still seems fine, and I still ride with it. Fiido CS I found impressively good.
This isn't a bike for everyone. Price has risen from slightly over £700 pre-Brexit, to £800 post-Brexit, and now £900 in this post-covid world of high inflation.
It's a relatively cheap bike, but I think fair value. With very minor TLC, it's been a solid, reliable and dependable performer, at least thus far. And Fiido service has been exemplary.
So much for the "it's inferior Chinese rubbish" and "there's no back-up or support if you buy on-line" and "you'll never get spare parts for it" theorists. That hasn't been my own personal experience at all. Fiido's CS response is very good, warranty claims handled well, and all the spares you'll ever need are openly available to buy on their own web-site.
The only caveats I see in buying a Fiido of any description is that there are very few places in the UK you can see or try them before purchase, and I'd guess that's because there isn't any dealer profit to be made in selling them. So it does require a leap of faith. And there won't be a dealer around every corner who knows the brand or will willingly help you if you're not able to manage the maintenance yourself.
Otherwise I'd say the Fiido D11 is a solid buy: One year in and I have no regrets whatsoever.