I have Exploere +GTS 2021 US spec'd. I had this happen 1 time albeiet my bike is fairly new just over 400 miles so far. I was in top gear about 26mph when the chain came off front sporket.
Stopped put the chain back on the ring and continued on.
this isnt a design flaw. this is a bicycle.
stuff happens
This *never* happened with my old bike which is a cheap MTB /w 21 speed. I say this is a design defect because it happened very easily. I can easily ride this bike on most surfaces because of the electric assistance, so I had the gear set to 8 or 9 most of the time. When this occurred for the first time, I told myself that it can happen. But the very next day it happened again, at around 10mph. This is when I contacted Giant Canada who asked me to contact local dealer for a look. After several days of failed attempt to get through my local dealer, I finally got through their service department and explained what happened. I was told that it is NOT normal, something is off with the bike and they will take care of it.
So I dropped off my bike happily expecting they would resolve the issue for me. Next day I got a call saying the bike is ready and the issue is taken care of. They did not explain what exactly they did but I did not care much as long as it's fixed. Upon picking up the bike, I was asked to check it out before I leave so I took it for a ride in the parking lot in front of the Giant dealer. The parking lot had speed bumps to force cars to slow down. I hit the speed bump at low speed (<20Km/h, any faster it would become dangerous). After hitting the speed bump 3-4 times the chain promptly came off. I had to take it right back to the dealer.
Later I got a call saying that I'm riding the bicycle at the manner it's NOT designed for. I should not be using the tall gears on this bike, which was the explanation. Riding the bicycle at low speed at tall gear is a wrong thing to do. At this point, I was convinced that the issue is real, and they want me to believe what they are saying. The fix they suggested is to downshift on bumps on flats. WTF.
Anyway, by this time I was completely exhausted. I just wanted my bike back. Since then I carry pair of gloves just so that I can get the chain back on without getting my hands covered with sticky oily residue when this happens.
Yes, stuff happens on bicycles. However, chain coming off 3 times on a 4 day span under normal riding condition is definitely NOT normal, and can only be explained by design defect/limitation. 9 speed cassette paired with single speed sprocket isn't a good match to begin with, in my opinion. The derailleur does not have a clutch and appears to have relatively weak return spring, which I believe is part of the issue.
Luckily, I've not had the chain come off lately and it is mainly because I consciously try to avoid the situation where this can occur, like forcing the assistance level down to ECO+ or normal at the highest. This way I'm forced to ride at lower gear below 8 and avoid the situation altogether. Roam E+ is one of the cheapest options available from Giant for an E-bike, but the overall features fit my needs and still fairly expensive for a bike. At this price, I feel like I have a right to ask for a robust design that will minimize issues like this.
