I posted the comment below on another thread but thought I would repost as part of my response to you. I did have the issues discussed below but otherwise I'm very happy with the Shred. I am happy with the way Surface 604 helped me, particularly Sam, diagnose and fix the issue and voluntarily change out the controller on my partners bike. I purchased my bike through a dealer so can not comment on how Surface is in that regard. I still believe for the price and the components it is a well valued bike.
I thought I would give an update to the group about my ebike experience this fall. A group of us went for a ride up a logging road, about a 8% average grade, 5km into the ride my Shred pedal assist stopped working ( I was in level 2 assist). As you know, its almost impossible to ride uphill without the assist or at least for me it is. I tried several things to diagnose the issue, turning off the bike, unplugging all the accessible plugs but nothing worked. With the power on and the back tire off the ground, using the throttle I would get a short response to the hub drive but would instantly stop (no power). For some reason I got it in my head it was most likely the brake inhibitor causing the power interruption. Even with the brake applied I could get a response to the hub motor. I sent an email to Surface 604 explaining my issue as well I called the place I bought the bike to discuss my problem. The vendor (not a LBS, but really helpful tech) wondered if there was a short at the controller, I started to investigate but decided half way through removing the controller I might not ever get it back in! Surface 604 emailed me back to ask if I could bring the bike to Kelwona (2hrs from where I live) as Sam was going to be there the next day and he would fix or trouble shoot the bike. I decided to take the day and do that, I wanted to meet Sam and get it fixed ASAP. When I met the Surface team in Kelowna at a LBS, there were several of them and a fellow from China who works for Bafang. As soon as they tested my bike they said they knew exactly what the issue was, the controller was shot. They removed the controller, gave it a quick shake, a rattle could be heard, it was the blown resistor. The reason the Surface team was in Kelowna was to replace the controllers on several bikes including unsold bikes in the LBS. They showed me the new controller and pointed out the weight was considerably more because it was filled with a heat dissipating gel. What happened to my controller was it overheated and blew the resistor, there is a hot spot on the controller and the plastic covers at the male/female connections is under sized. Sam did say they are noticing this issue more in British Columbia than in the USA, perhaps due to the terrain??? Also, they had a programming firmware upgrade for the battery so the whole cutting the green wire is unnecessary if the battery is reprogrammed. My partner also has a shred and I wanted her controller changed in that bike as well. It has taken sometime but Surface sent a new controller to the vendor I bought the bikes from and they just changed the controller and reprogrammed the battery for me. I have to say that I'm happy with both Surface and my local vendor for the help they have provided. I haven't seen anything from surface regarding this issue but I would hope that if others are having a similar issue they will replace the controller regardless of kilometer on the bike. I think any bike sold after Sept 2018 would have had this issues dealt with. I have enjoyed by bike and really don't have anything bad to say about it. It is a new bike for Surface and obviously the controller wasn't the best but I think it might have been more a Bafang issue than a Surface issue. I'm curious has anyone else had this issue??