Front hub 750d Gravel Bike
Cape Meares, Oregon
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265
Published: 2023-08-28
In 2016 I built up my first front hub 700c drop bar bike using 9c/controller/CA3 Grin components with a 48v 12ah Dolphin style battery to be able to ride the rough roads in my area. It was when they were teasing the All Axle but not quite out with it and as soon as I could get one I built up another bike with that motor. I got many miles out of each riding all over NW Oregon and other parts of the west from sea level to 10k in CO..
The bike I am presenting is my third build on the same principal of a front hub non PAS bike. Although I like torque sensing PAS on my eMTB for use on primarily road surfaces at a consistent higher cadence I prefer to utilize the cruise control available through the CA3 and use a Schlumpf High Speed Drive crankset that has up to a 160" gear for pedaling along at whatever cadence and input effort I desire or the terrain calls for. It is a much more natural experience I find.
The bike has what are little known as 750d wheels which are in development by WTB. Because they are larger in diameter than conventional 700c wheels like my other bikes had it required a new frame/fork which was supplied to me back in 2019 and is made of steel. Covid got in the way of their release but there is some amount of press going on currently about them so you may see more of them in the future. Biggest benefit over 700c I have found is that they roll very well when up and on step but are a little slower to get there. The available power and consistent momentum you get from the hub motor helps in that regard. I also have a conventional wheel built that I can swap in and leave the battery home when I want to go acoustic. To me one of the beauties of a front wheel drive, as well as the two wheel drive aspect that can come into play on certain terrain.
I really like the All Axle's ability to adapt as a 12mm for this bike as there is only one fork available and that is the standard for it. I also really like the built in torque arm and came up with a way so that a 5mm allen key is all that is needed for removal of the wheel. I use a STD version and it is sufficient to move the bike along at illegal speeds if wanted in addition to the ability to pedal effectively at those speeds. But for the most part I just power along using using up to 500w and go for distance over speed to get there.
What I really wanted out of this build was to shield the controller and battery from plain view and thus I have an L5 baserunner and a shrink wrap 52v 21700 cell 17.5ah battery residing in the top tube bag. Leaves room for a couple of King Cages and I would say mission accomplished. I also made a 1 1/8 flat mount for the CA3 that nestles it nicely away below and behind the bar yet easy access for vision and button pressing.
A Shimano 10spd, doubled via the Schlumph to a 20spd, with brifters and hydraulic brakes are sufficient I find for a drivetrain and stopping power but the first thing I go for when slowing down is the red button that activates the regen as well as shuts down the cruise control.