Juiced Hyperfat 1100 - Peanut Butter Gears in Mac Motor, or Something Else? ( Periodic Acceleration Loss, Halting Acceleration )


New Member
Hi all,

I bought a Juiced Hyperfat 1100 used about six months ago. My goal was to use it to replace (or almost replace) my car, since I live 1/4 mile from my office, and never travel more than 5 miles to stores, etc.. I got this rather than a more traditional 250w bike because I live in an area with some brutal elevation changes, and I didn't want to have to fight the hills alone. I suspect that the bike was mostly used for off-roading by the previous owner (judging by the amount of mud I found in various nooks and crannies when I cleaned it up), but after some basic TLC (new discs and pads, brake bleed, derailleur adjustment, lube, it seemed to be working great.

I'm posting here for help because, related to an earlier inquiry, Juiced customer service completely ghosted me when they found out I was not the original owner, even after I had volunteered to pay full price for any parts I needed without argument.

So, the problem:

The Hyperfat is rated for 275lbs. I'm not overweight at all, but when I take my toddler to preschool we're not too terribly below that number between me being 6'3", my toddler, her bike seat, locks, water, helmets, etc. etc. and we're going up substantial hills (1,100 elevation change). I think this might have caused a problem with the motor.

Anyway, the bike has started doing this thing where it feels like the motor is losing power for about a second every couple of seconds, almost like the feeling you'd get if you tapped the brake levers just enough to shut down the motors. The bike isn't dying completely, and the wheel is still turning freely forward and back (as freely as a hub motor ever turns, anyway). Tried disconnecting brake cutoff wires, restarting bike, cleaned contacts, etc. No change. Motor is a tiny bit whiny, but that might be what it always sounded like from the factory, since I never experienced it new. No obvious noise changes when the power loss happens. Previously I had managed a solid 32MPH on flat ground with moderate effort. With this problem, I'm lucky to get past 25.

The weird thing is that it doesn't seem as pronounced when I use the throttle. The bike seems to get linear power delivery then, although still below what it could manage when it wasn't having issues.

I've also noticed, since I bought it, that the speedometer on the handle bars gives inaccurate readings sometimes. Like, when I start pedaling hard, it'll say I'm going 39 just seconds after leaving a light, then settle back down to like 24-25 after a minute. Sometimes on downhills it reads speeds that are, just, no way am I doing anywhere near that. I've been on a traditional bike going 45 downhill, I'd know if I was going 50. I'm not going 50. The power delivery is all smooth and normal when this happens, however.

I'm wondering if I might have smoked the internal planetary gears, or if it could be something with the controller. If it is the gears, anybody know where you could get replacement gears or a gear/clutch set for the mac motor on the bike?

Could it be something else?



Active Member
Its known as cogging to any Hyperfat owners, and its been an issue for a while for the ebike. The issue appears to be the controller drops out of sync with the hall sensor and it starts to limit the power delivery every few seconds. And Juiced had already promised the people inquiring about the Hyperfat 1100 that this issue was addressed, but it appears it was not. See this thread for some more info on it - Hyperfat 1100 pre-order thread


Active Member
I wish I could find more info on it for you, and I REALLY wanted a Hyperfat when I started shopping for an ebike, but I moved on to something a lot more practical for my riding trails. I still love what Juiced as been able to bring to the consumer, but across their model lines they have had some issues with their choices of components, namely those HF controllers or the cheap subbed out forks on the RCS.

I seem to recall a thread on Endlesssphere where a guy pulled the stock controller and added a Cycle Analyst that cleared up all of his issues, but I can't seem to find it now.


New Member
It's just weird because it didn't happen initially. This also explains why when I reset the bike and pull the battery off the issue often goes away for a while.


Well-Known Member
Regarding pulling the battery off to get a good reset, have you had a good look at that connection?