My comments aren't based on experience with my own unit which has performed perfectly for well over four years now, though it's only a rarely used backup bike for a couple of months now. For further explanation, here's the reason for my concerns. I only opened my Twist site at the end of December, and as I'd found with the Torq site and Russ found with Pedelecs, it takes some weeks to educate Google into showing it. Therefore all of the feedback on these failures is in just over four months, and you'll have noticed my caution has grown only through this period.
Most of the units suffer a mainboard fault, and these are either complete failure to operate, pedelec operation faults, or more commonly, reversion to permanent eco mode only, rendering them useless on steep hills. There was a stage in the bikes history when Giant sent out a large batch of new bikes with the latter fault, accompanied by a replacement unit with instructions to dealers to swap them and scrap the old unit. This indicates to me a weakness in the electronic design may be present. None of these faults has ever been identified to my knowledge, the circuit board being embedded into place in silicone rubber and fully encapsulated so impossible to replace or fault trace, which would be difficult in any case with micro-electronics.
All those notified to me have been UK units, and apart from that majority group there have been a small number of other faults. Two bikes have suffered the small Hall sensor board coming adrift, leading to erratic behaviour. The mounting for this is rather unsatisfactory, it being located by slots in it's ends corresponding to two plastic pegs on the motor casing wall internally, and then retained by rubber washers pushed onto the peg ends. In a greasy environment, the rubber washers can slip off. The cause of one slipping off isn't known, but in the second case the bike fell over, jarring the board off it's mounts. These were repairable, but it's an extremely fiddly operation, in one case completed by the owners wife due to her smaller fingers. In one of these the plastic pegs had broken off and the board had to be glued into position. That unit isn't working perfectly, but is to be used until it finally dies. I carry out this repair using tools in a "keyhole surgery" method working through a narrow slot with a light to avoid the job of stripping the whole unit, but it is tricky and only possible because I'm so familiar with the unit.
Another bike had a motor shaft bearing fail, but as these are standard ballrace units one was obtained from a bearing supplier and fitted, still a full stripdown job with bearing pulling which many owners would not be able to do and no cycle dealer I know will do.
There have been two units with problems associated with the sealed pedelec unit, though in both cases I suspect the mainboard was the true cause.
A number of these bikes have been scrapped, with one of three current failed ones definitely going that way, and one has been donated to a Cycle Museum as justifiably a great of electric biking. One tactic David and I use where the very steepest hills aren't involved is to advise stripping out all unwanted components and motor from the alloy crankcase, leaving the unit as just a bottom bracket shell with pedal shaft. This leaves a UK Twist at around 15 kilos without battery, normal bike weight, then fitting a front hub motor. The Heinzmann fits well but is expensive, and there are many other cheaper ones, the new Nano motor being a good match performance wise, a good hill climber and cheap. These can be fed from the existing Giant battery, which can be recelled for larger capacity if wished. The end result is a neat, light and compact e-bike, albeit throttle controlled since standard pedelec discs aren't easy to adapt to the pedal shaft. It is possible though.
There are some wear issues, seemingly quality control failures. For example, David's is one of the Comforts with excessive wear on the motor output sprocket and shaft splines, the sprocket left wobbling about but hanging on so far, but thing like this are rare.
It's impossible to accurately say how many bikes are affected by total failure, but possible to estimate from educated guessing. With the youngest bikes failing being two years old, taking the period from the first two year olds through to last December, adjusting it for their being only one third of the Twist population at the two year point and qualifying that with those I've knowledge of, arrives at 1.4%.
That might seem no problem on bikes up to seven years old, but it assumes that every failure has been notified to me, and that cannot be true. Again educated guessing using the proportions of owners coming online to this site helps, since it indicates those that might have access to my site. Unfortunately that led me to a failure rate of 35 to 40% which is clearly excessive. Therefore it's impossible to be sure, but it's certainly very much over that 1.4% since owners of these utility bikes will include those least likely to be e-bike enthusiasts researching and visiting online sites. A glance at the ownerships declared on that thread in this site, bearing in mind that many Giant owners have Suedes and a couple the early Lafree models, shows how small the proportion of the 5000 UK Lafree Twist series owners are probably in here. We don't have anything like that number of total members!
In summary, a failure rate of say 5% to 10% is not too serious, but the issue is not merely one of the rate but one of the high expense involved when failure occurs. Hence my warnings.
In case anyone is still in doubt about my intentions with the Gazelle, I'd remind that I was the first to start complaining of the Torq's poor hill climbing, furiously opposed in that at the time by many new Torq owners, 50cycles and A to B. But with time the truth about it's limitations is now widely accepted, even by the suppliers it seems, and the F series are a response to that. I equally warn those interested in the Sparta Ion about it's need for electronic resetting at times, only available at two locations in the UK. And when someone mentions the BionX, I warn about it's 900 dollar battery.
Hopefully that will convince that I'm even handed in my advice. I'm not in thrall to advertisers, magazines or any suppliers and can be as independent as I like, taking full advantage of that.
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