When I bought my 750 watt mid drive Stunner in late 2018 Biktrix claimed that the Sturmey Archer 5 speed IGH would be strong enough. I naively accepted that. The hub began clunking loudly, even at low assist levels, right away. They replaced it for me, and said that it was a rare infant failure. The new one clunked less - as opposed to the required not at all - initially, but the clunks increased after ~3000 miles. Last summer it began skipping and clunking all of the time. I was out of warranty with Biktrix, so I found a youtuber who pulled the core on his identical IGH, soaked it in synthetic ATF and reinstalled. His problems were solved. I did this twice, to no avail.
I read that I.T.M.T. Sturmey Archer explicitly warned that their IGH was not e bike compatible. I wrote Biktrix about this. No response, and the same bike is still being sold.
So, thru my local bike shop, I ordered a shimano sg-c7000-5d 5 speed hub, laced to a new wheel, a shifter, and associated trim. Over $600 all told (the bike shop took their markup, so sharp shopping might bring this down). This hub is explicitly e rated, and I did the arithmetic for max rated torque with my sprockets. I'm coming in under. I installed the wheel and shifter last week and rode it 14 miles yesterday. Silent, with similar high gearing, low gearing a little slower than Sturmey Archer's, and IMO, less IGH friction. It is my main city driver, and I can dress for St. Louis weather from now on, unless it's wet and/or icy. My wife (2018 750 watt Evelo Aurora, with Enviolo auto trans and big battery) and I also share a Bob trailer. Either of us can load it with 60+# of groceries or Total Wine and More items and ride it home.
So, be waved off this bike, and for it's misrepresentation, Biktrix. Instead, there must be a similar product out there (750 watt mid drive, 5 speed hub, good weight rating), with an e rated IGH. Look for that, maybe with a torque sensing motor, hydraulic brakes, and an adjustable chain tensioner.
I read that I.T.M.T. Sturmey Archer explicitly warned that their IGH was not e bike compatible. I wrote Biktrix about this. No response, and the same bike is still being sold.
So, thru my local bike shop, I ordered a shimano sg-c7000-5d 5 speed hub, laced to a new wheel, a shifter, and associated trim. Over $600 all told (the bike shop took their markup, so sharp shopping might bring this down). This hub is explicitly e rated, and I did the arithmetic for max rated torque with my sprockets. I'm coming in under. I installed the wheel and shifter last week and rode it 14 miles yesterday. Silent, with similar high gearing, low gearing a little slower than Sturmey Archer's, and IMO, less IGH friction. It is my main city driver, and I can dress for St. Louis weather from now on, unless it's wet and/or icy. My wife (2018 750 watt Evelo Aurora, with Enviolo auto trans and big battery) and I also share a Bob trailer. Either of us can load it with 60+# of groceries or Total Wine and More items and ride it home.
So, be waved off this bike, and for it's misrepresentation, Biktrix. Instead, there must be a similar product out there (750 watt mid drive, 5 speed hub, good weight rating), with an e rated IGH. Look for that, maybe with a torque sensing motor, hydraulic brakes, and an adjustable chain tensioner.
