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TQ-Systems mid-drive, the German off-road hot rod

TQ stands for “Technology and Quality”, and it was started in Bavaria (Germany) by Detlef Schneider and Rüdiger Stahl in 1994They are an engineering and design firm that works in aerospace and medical equipment (among other things). At one point, they formed the Clean Mobile company to handle the mid drive ebike system they had designed.

The 3rd element eSpire, using a Cleanmobile mid drive

TQ decided that the Cleanmobile division would file for insolvency (after the majority of European bicycle retailers had signed exclusive agreements for the German 250W Bosch drive, found here). They had filed in February of 2012, and it was granted in August of 2012. TQ then changed the ebike drive-systems division name to TQ-Systems.

The Audi Ebike, seen below , draws a constant stream of attention, but the prototype never went into production. It is beautiful, and it also used the first-gen Cleanmobile drive.

The Audi electric bike prototype, made from carbon fiber, and using the first-gen Cleanmobile mid drive.

Although you can legally use a high-powered system on off-road trails in Europe, the 1400W / 180-Nm Cleanmobile drive had not found any bicycle partners, since the retailers only wanted to experiment with adding an ebike to their lineup that would ALSO apply to the large EU 250W street ebike market. Regardless of their failed first attempt, TQ tried a second time with the bicycle accessories company “Additive”, to make a mild trail bike with a large cargo bag in the central triangle of the frame.

The 2014 Additive ebike with the 2nd-gen Cleanmobile drive

The second-gen Cleanmobile drive used a dual planetary reduction for a significant 180-Nm of torque. This is the level of power where some riders become concerned about how fast the chains and sprockets wear out. That being said, weaker mid drives cannot accomplish the jobs that a 180-Nm mid drive can do, so any extra wear that occurs is because the rider is applying heavy loads to this drive.

What I mean is that…if you ride easy trails, you don’t need this much torque, but if you ride on trails that need this much torque, then you don’t don’t care about replacing the chain and sprockets more often, because no other drive can survive what you do.

The Third Generation TQ Drive

This new 3rd-gen TQ drive swapped the dual planetary reduction for a single Cycloidal reduction (see below). And due to the significant 180-Nm of torque on the previous version, I suspect the 2nd-gen motor would eat through batteries pretty fast.

TQ-Systems chose a single Cycloidal reduction for the third-gen system. We reported on cycloidal drives when we first saw the Tangent Ascent mid drive  Dave at Tangent chose the cycloidal reduction because it is currently the most compact and light reduction possible. It allows an unusually high reduction within the allowable space.

The TQ-Systems 3rd generation drive motor

60-Nm, Panasonic 36V 250W

70-Nm, Shimano STEPS, 36V 250W (for more info, click here)

75-Nm, Bosch Turbo (click here)

80-Nm, Yamaha 36V 250W

90-Nm, Brose 36V 250W (for more info, click here)

120-Nm, TQ HPR 120S

160-Nm, Bafang Ultra Max

An exploded graphic of the drive system from the TQ website

The arrangement of the major components inside the TQ drive

The controller is bonded to the left-side aluminum case cover, and that makes the entire drive-case a heat-sink. If it is mounted in an aluminum frame, then the entire frame of the bike draws heat away from the motor and controller.

The TQ motor display from Eurobike 2018.

The Haibike battery pack can be replaced through an access plate at the bottom of the frame.

The Cycloidal RPM Reduction

We have previously reported on the cycloidal reduction found on the Tangent Ascent mid drive (for pics and details, click here). Notice that the inner ring has ONE LESS TOOTH than the outer ring? The motor drives an eccentric in the center, and one revolution of the motor shaft (and it’s eccentric) causes the outer ring to advance a distance of one tooth. The outer ring shown below has 40T.

The 40:1 cycloidal reduction from a Tangent Ascent

I’ve circled the cycloidal reduction teeth in the TQ drive. It appears they use a stack of laser-cut discs.

“…The electric motor drives an elliptical roller bearing. The oval contour moves 150 pins in a wave pattern between the inner gear (148 teeth) and the stationary external gear (152 teeth). The pins act as transmitters. Transmission takes place between the rotary motion of the bearing (input: motor) and the internal gear (output to the chain ring). All the pins are engaged around the entire circumference achieving power transmission that occurs in a minimum of installation space. The transmission gears down in only one stage with a ratio of 37:1. That is, at a pedaling frequency of 80 rpm, the electric machine is running at about 3000 rpm…

They have toned-down their design from 180-Nm to the current 120-Nm, which would extend their battery range, and help the internal parts last many more years than the previous model. Even so, it is almost twice the wheel-torque compared to the common 75-Nm Bosch unit.

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