11-50T Cassette on Cute Q100CST Setup

zukster

zukster

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This setup worked out for me to get a Garbaruk 11-50 cassette on my Q100CST Hub motor.

http://garbaruk.com/11-speed.html

Other current 11-50T cassette options are OneUp and SunRace. I picked up the Garbaruk because it was the lightest at 300 grams.

Setup:

11-50T 11 cog Garbaruk cassette
X01 Eagle Rear Derailleur 12 gear
XX1 X-ACTUATION Trigger Shifter 11 gear

The reason it works is that the SRAM and Shimano 11 speed cassettes have almost identical cog spacing.

The SRAM 12 speed X01 derailleur has the same cable pull ratio as the SRAM 11 speed XX1 derailleur. This means you can interchange the X01 and XX1 derailleurs between the 11 and 12 gear drivetrains.

The X01 Eagle derailleur is necessary to make it up to the 50T cog, and it is designed to do so. One could also do the Garbaruk or OneUp Shimano 11 speed derailleur cage modifications. I decided to go with the SRAM Eagle X01 because it is originally designed to handle 10-50T without modification needed.

Then the XX1 shifter cable pull matches the cog spacing for the 11-50T 11 cog cassette when used with the SRAM X01 or XX1 Eagle derailleurs.

If you were modifying an XT or XTR derailleur with the Garbaruk or OneUp conversions, you would use a Shimano 11 speed shifter to match the Shimano derailleur.

I decided to buy the X01 Eagle derailleur because I did not yet have an 11 speed XT or XTR derailleur to work with. The SRAM XX1 shifter gives nicer shifting than my previous OneUped 10 gear drivetrain with RADed XTR derailleur.

I went with the SRAM XX1 11 speed chain. From what I read it is the closest locally available that is a bit thinner like the YBN 11 speed chain OneUp sells. The slightly thinner than 11 speed Shimano chains like SRAM or YBN work better to avoid backpedal downshifts on an 11-50T setup.

My guess on this setup proved right and I get excellent shifting with no backpedal chain drops.
 
Ok, so you make your pedal drive work efficiently over a 4.5:1 wheel speed ratio. But why? Your motor doesn't tolerate that. It will either be useless in the top gears, or in the bottom gears, or possibly both.
 
A motor can be run at almost any speed.
Efficiency will be lower at 5 MPH, but if torque is kept low, it won't overheat.
It's always nice to get a little kick at steep climbs.
 
When using a 1x setup, and a 42T front chainring, you get pedal road speed and also climbing gears.

1xgear-ratios.jpg


Cable-pull-Derailleur-shift-ratio-Cog-pitch.jpg
 
Chalo said:
Ok, so you make your pedal drive work efficiently over a 4.5:1 wheel speed ratio. But why? Your motor doesn't tolerate that. It will either be useless in the top gears, or in the bottom gears, or possibly both.
Click to expand...

The other thing is I use the Grin Phaserunner controller which is pretty torquey in the low gears and to keep the motor up to speed in the high gear, it can be operated at 72v to spin the motor faster, or its field weakening feature at 36v also works fine, up to about 40km/h - fast enough for me.
 
zukster said:
Chalo said:
Ok, so you make your pedal drive work efficiently over a 4.5:1 wheel speed ratio. But why? Your motor doesn't tolerate that. It will either be useless in the top gears, or in the bottom gears, or possibly both.
Click to expand...
The other thing is I use the Grin Phaserunner controller which is pretty torquey in the low gears and to keep the motor up to speed in the high gear, it can be operated at 72v to spin the motor faster, or its field weakening feature at 36v also works fine, up to about 40km/h - fast enough for me.
Click to expand...

That's good to know. My own experience with electric motors is that when you cut the speed by half or more, you can still get the same torque, but the motor overheats quickly. The implication is that hub motors have a sweet spot of practically usable speed range that's much narrower than that of even a narrowly geared pedal derailleur system.

I built custom 12-38 7-speed freewheel stacks for myself back in the early '90s, so I could get satisfactory gear range from a single ring. This latest trend towards wide range cassettes​ and single rings is very much to my liking, especially with new developments like 11-40 8-speed cassettes that allow much lower cost and maintenance than 10- and 11-speed systems.

That said, the e-bike applications for these things seem to center around mid drives, not hub motors.
 
Where did you find a 38 cog back in the 90's, and what derailleur could shift that big? That is a pretty impressive feat. I used to build 7 speed 12-32 dura ace freewheels with newer HG cogs for the big ones before the cassette motor hubs came out. I know its a lot of work to match everything up.

That will be nice to see more economical 8-9 speed wide range cassettes. I think 10-12 speeds is getting to be a bit much. I spent the cash just to get the wide range, but I'd prefer an 11-50 in a 9 speed. Finding used XT and XTR shifters is much easier for 9 speed than 8 speed. That is my only preference for 9 over 8. The nicest shifters I ever owned were 8 speed XT pod quick shifters ; they're just hard to find now.

I have not really stressed out the motor going slow up a long steep hill yet. I'm generally pretty careful after having burnt out some of the small Bafang hubs. I'll post back here after I have tested this setup better. This thread was primarily meant to give folks and idea of a nice way to do 11-50T on a Shimano freehub.
 
At the time I was making 12-38 freewheels, cassettes and index shifting were the new hotness and nobody wanted anything to do with dumb old freewheels. So the sprocket boards at the shop I worked at were basically mine for the pillaging. The shop manager wouldn't even accept my offer to pay for the loose sprockets.

Suntour AG (Alpine Gear) freewheels and derailleurs​ had been a thing in the early to mid '80s, so that's where the 36t and 38t sprockets came from. I would get 12-28 7-speed Suntour Winner Pro freewheels, disassemble them and widen the range. I didn't use an AG Tech derailleur; the more common Suntour V-GT Luxe worked fine for me.

There was a drawback to my system. Those Winner Pro freewheels used the crappy Suntour remover spline, and between my size and the size of the 38t sprocket, the tool was incapable of removing the freewheel once it had been ridden hard. So every time I had to remove the freewheel, I had to remove the sprockets first, crush the body in a vise or otherwise disassemble it, and wrench off what remained. Then I'd put my sprockets on a new or salvaged freewheel body. It only worked for me at the time because nobody really wanted freewheels at all unless they were index shiftable.

As long as your motor stays cool, then I guess everything is, well... cool. I'm wary of these things because I'm so much heavier than the designs intended (even though I don't ride on very steep terrain). I have a nice Q128 in my hoard, but I think I'm going to have to use it as a jackshaft or mid drive, lest I overcook it.
 
I was thinking the same as Chalo. To use that 50T sprocket, you must be down to about 3 mph, which would soon kill a 201 rpm Q100cst if you kept the power on. What size wheel is it in?
 
26 inch wheel. 42T on the front chainring, so road gearing is like a standard mountain bike with a normal 22/32/42 front triple, when on the 11T and 42T - just fast enough. Not quite road bike speeds, but its a mountain bike. For the trails and steep hills, it could be a little lower when in 50T, when not using the motor, but its close enough.
 
IMHO, that gearing would be OK as far as pedalling is concerned and it would be OK for a crank-drive bike, but it doesn't help the motor in any way, so it'll overheat and/or possibly damage the gears. The Q100needs to be kept spinning fast to get its power.
 
d8veh said:
The Q100needs to be kept spinning fast to get its power.
Click to expand...

That's pretty much my experience as well. I have trained myself to go easy on the throttle when not moving fast. I learned this lesson after burning out a couple of small Bafang 8FUN motors. Getting the 201RPM motor rather that the 328RPM helps move the motor range to the lower speeds. Also, when using the Phaserunner controller, the Field Weakening feature adds a few MPH to the top speed when road riding. I think its a pretty balance setup.
 
zukster said:
This setup worked out for me to get a Garbaruk 11-50 cassette on my Q100CST Hub motor.

http://garbaruk.com/11-speed.html

Other current 11-50T cassette options are OneUp and SunRace. I picked up the Garbaruk because it was the lightest at 300 grams.

Setup:

11-50T 11 cog Garbaruk cassette
X01 Eagle Rear Derailleur 12 gear
XX1 X-ACTUATION Trigger Shifter 11 gear

The reason it works is that the SRAM and Shimano 11 speed cassettes have almost identical cog spacing.

The SRAM 12 speed X01 derailleur has the same cable pull ratio as the SRAM 11 speed XX1 derailleur. This means you can interchange the X01 and XX1 derailleurs between the 11 and 12 gear drivetrains.

The X01 Eagle derailleur is necessary to make it up to the 50T cog, and it is designed to do so. One could also do the Garbaruk or OneUp Shimano 11 speed derailleur cage modifications. I decided to go with the SRAM Eagle X01 because it is originally designed to handle 10-50T without modification needed.

Then the XX1 shifter cable pull matches the cog spacing for the 11-50T 11 cog cassette when used with the SRAM X01 or XX1 Eagle derailleurs.

If you were modifying an XT or XTR derailleur with the Garbaruk or OneUp conversions, you would use a Shimano 11 speed shifter to match the Shimano derailleur.

I decided to buy the X01 Eagle derailleur because I did not yet have an 11 speed XT or XTR derailleur to work with. The SRAM XX1 shifter gives nicer shifting than my previous OneUped 10 gear drivetrain with RADed XTR derailleur.

I went with the SRAM XX1 11 speed chain. From what I read it is the closest locally available that is a bit thinner like the YBN 11 speed chain OneUp sells. The slightly thinner than 11 speed Shimano chains like SRAM or YBN work better to avoid backpedal downshifts on an 11-50T setup.

My guess on this setup proved right and I get excellent shifting with no backpedal chain drops.
Click to expand...

Do you think X01 Eagle Rear Derailleur 12 speed will work with a 10 speed XX EXACT ACTUATION™ Trigger Shifters and a 10 speed 11-50 cassette ?

Thanks
 
The 10 speed sram shifter has a cable pull of 3.1. The 12 speed derailleur has a cable pull ratio of 1.12. So that would equal a cassette cog pitch of 3.47. A real 10 speed cassette has a cog pitch of 3.95, so that combo is way to far off to work :cry:
 
zukster said:
The 10 speed sram shifter has a cable pull of 3.1. The 12 speed derailleur has a cable pull ratio of 1.12. So that would equal a cassette cog pitch of 3.47. A real 10 speed cassette has a cog pitch of 3.95, so that combo is way to far off to work :cry:
Click to expand...

thanks
 
Anyone know how many pole pairs the Q100CST has?
I have an old touring bike I'm building up with a Q100CST 201rmp and a Phaserunner. I've heard conflicting reports on motor pole pairs and I'm trying to get to the bottom of this.
-Cheers y'all
 
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