Hi Mike,
Well as you know I have a real nice Santa Cruz Frame, I always have to sell one thing to get another, and sometime in the future I would sell the Frame to help pay for a more E-Bike Specific Frame, I am not going to Bevel the Frame, so that makes the Speed Drive not usable on my bike.
In regards to new designs in the Bike Industry, well I have recently found out that Specialized is going away from the BB30 Bottom Bracket Shells,
They are going back to threaded BSA on many/most of their bikes,
However, and this is important, much to my " initial " disappointment of using more and more ... Direct Mount Cranks,
( because I can buy the few years old but still new Shimano Hollowtec II Cranks and BB's at Great / Low prices )
The more Research I do on Direct Mount Cranks , the More I like them.
I have just a couple of days bought a couple of Well Used , Race Face Direct Mount Cranksets.
And I can tell you this is a welcome change to the 2 piece and the old Square Taper Bottom Bracket Cartridges and Crankarms.
This is one " Improvement " that you Will come to welcome.
Now that I have taken one apart it is very clear to me how we in the E-Bike world can use Direct Mount Cranksets to our advantage.
The very obvious one to anyone wanting a Mid-Drive and having a freewheel on the crank ( and yes I want a freewheel in on the Crankset more than a planetary gear crankset )
some good advantages are adjustable chainlines , very easy chainring changes, but most importantly interchangeable Spindles, with interchangeable Spindles custom made Spindles for E-Bikes are now a improvement because we can use the rest of the Direct Mount Crankset and Chainrings , but have spindles that have the groves to hold a Freewheel and perhaps two chainrings as well, by just making the Spindle a few mm's longer and the splines that hold the chainrings/and for us a Freewheel , a little deeper into the Spindle .
By just making custom Spindles and using two chainrings , you/we have a much more simple system than that Speed Drive .
And
Much Lighter in weight as well, and probably much more durable too.
>
LightningRods said:
Hey ScooterMan,
1- Most mid drives run through the chainwheel. They must have a freewheel in the chainwheel or else you would get beaten to death by the pedals if the motor speed overran your pedaling speed. I wanted to run a low tooth count 219 driver sprocket to get decent reduction in one stage. That eliminates a freewheel sprocket on the motor. Also by eliminating the freewheel from the final drive it has one less fragile part to break and we get regenerative braking. I decided it was a good trade off.
2- There are BSA threads on the left side of the Speed Drive. There are also beveled "cones" at each end of the BB. Part of the install of the design of BB is that you have to chamfer a bevel into the ends of the BB shell on the frame. When you tighten the BB cup on the left it sucks the two cones into the chamfers and it keeps the BB from counter rotating. I haven't played with this enough to understand why they did it this way. The unit was designed by German engineers so I figure that they may have a clue.
3- The bike industry is doing a lot of things to bikes that are not good from our perspective. Press fit BBs are a major problem for chainwheel mid drives. I'm not sure how the direct mount chainwheels will affect things. Like the press fits some people seem to love them, others seem to hate them. Bicycle manufacturers are changing things just to change them, trying to distance themselves from the Walmart bikes. A lot of it is unnecessary.