Which RPM Q100 on 700c tires?

Omegalen

1 mW
Joined
Oct 13, 2015
Messages
17
Location
Sacramento, California
I have a bike with 700c tires that I am looking to outfit with a stealthy rear hub motor. I want to be able to sustain 20mph with very little pedal assist on flat ground.

I am looking at the Q100 series as I was told these can reliably take 800W, but I'm having trouble picking a winding. If I am running 48v through one of these, what RPM version should I get? I read somewhere that running a Q100 (260RPM) at 48v would mean 260rpm x (48/36v) = 346rpm. Does this mean I should go for the 201RPM variant if I'm looking to hold 20mph @ 48v on 700c tires? I can't seem to find any good data points on this.

Thanks for any tips!
 
Seems like you have a decent handle on the numbers side. I'm just going to add a couple thoughts: (1) some controllers can use advanced timing that artificially and with some efficiency loss increase the speed. This might be useful if you find yourself in between windings. (2) Bear in mind nominal voltage and that you may want to account so you can reach your top speed at not-full-charge. (3) Give yourself maybe 10-15% leeway for the fact you only reach the nominal speed under no-load.

That's about it, I think. Everything else is making sure you properly understand the conditions of the nominal RPM (e.g, be suspicious of "260 RPM @ 36v." is it *AT* 36V? or at a voltage that we use shorthand to suggest 36V? The best base number to work off of is something that is per-volt.
 
Hi Omegalen,
You got it right, the 201 should be better. the 201 is like the MXUS XF07 on the ebike simulator. http://www.ebikes.ca/tools/simulator.html at 48 volts and 700cc wheels you should get 21 mph :wink:
Do you know which model you want ? q100h or q100cst ? you could go with the q128 if you mean to sustain 800w continuously

leo
 
I run 17 amp controller at 44 nominal or 48 fully charge batts and that motor gets hot on hills (cute 100H). I would definitely go for the 128 which would be OK I believe at that wattage. 800 or so watts is max limit for my Q100H. I also use 20" wheels which should make less stress on the motor but on hills it gets hot. So far (2 years) it has held up.
Just sayin'

otherDoc
 
For lightest weight and strong pedalling at 20 mph, 36v 201rpm Q100C at 48v. For more relaxed pedalling at 20 mph, 201 rpm 36v Q128C at 48v.
 
Omegalen said:
I have a bike with 700c tires that I am looking to outfit with a stealthy rear hub motor. I want to be able to sustain 20mph with very little pedal assist on flat ground.

I am looking at the Q100 series as I was told these can reliably take 800W, but I'm having trouble picking a winding. If I am running 48v through one of these, what RPM version should I get? I read somewhere that running a Q100 (260RPM) at 48v would mean 260rpm x (48/36v) = 346rpm. Does this mean I should go for the 201RPM variant if I'm looking to hold 20mph @ 48v on 700c tires? I can't seem to find any good data points on this.

Thanks for any tips!
A 260 should be used in a 700 cc wheel only if the following applies;
1)The rider is fit and weighs less than 200 lb.s.
2)The hills are not overly steep or long.(steeper hills can be climbed if they are not over several blocks long and the rider can get a "run" at them.)

A 201 @ 48 volts in a 700 cc wheel will topout around 20 mph. Just a little slow for most of us.
A 260 @48 V in a 700 cc wheel will topout around 23 to 24 mph. The sweet spot I.M.O.

The fact you are considering a 260 motor means that you are dis-counting using the CST(cassette fitment)version.
Are you sure you want to do that? Many riders w/ a donor bike that has a decent gear drive system prefer a cassette over an aftermarket free wheel.
A 260 is, of course, an option for the frt., but there is a stigma around here against frt. mounts, but personally, I like them fine for low-power builds.

Does anyone have experience with this battery with integrated controller? https://bmsbattery.com/ebike-battery/701-48v116ah-bottle-09-panasonic-battery-torque-sensor-battery.html

It seems nice to have an all-in-one solution like this, but if I don't like the controller, am I stuck with it? Has anyone used one of these 20A sine controllers?
I use simple 3-speed square wave controllers, but D8veh, a well respected tester over in England has used that battery and controller and thinks highly of it. I think the controller is avail. septerately and I would be temped to buy a spare.
You will need some other stuff from BMS Battery when placing this order, do you know what else you will need?
 
The controller was once $20 but now they want to sell it you with lots of other stuff for $90 (which annoys me as I want one)

They seem okay to me. The controller that is.
 
I just placed a bmsb order. When you sign up, you will be emailed by sales staff - take advantage of it.

If you're buying a bunch of stuff, just give them your wishlist and ask them to cut you a package deal. You shouldn't have to pay more than $25 US for that sinewave controller. Ask for a quote and check the items/prices carefully. Keep your emails simple to avoid mixups.

I got my controller separately because it could overheat if integrated in the battery housing. Also, it's a pain to replace/repair a malfunctioning controller if it's in a battery case.

Shipping will be expensive regardless of order size, so piggyback extra tidbits on your order. The suggestion to get an extra controller is a good one.

Check out the other Q100/Q128 builds on the forum and ask lots of questions before committing.
 
motomech said:
Omegalen said:
I have a bike with 700c tires that I am looking to outfit with a stealthy rear hub motor. I want to be able to sustain 20mph with very little pedal assist on flat ground.

I am looking at the Q100 series as I was told these can reliably take 800W, but I'm having trouble picking a winding. If I am running 48v through one of these, what RPM version should I get? I read somewhere that running a Q100 (260RPM) at 48v would mean 260rpm x (48/36v) = 346rpm. Does this mean I should go for the 201RPM variant if I'm looking to hold 20mph @ 48v on 700c tires? I can't seem to find any good data points on this.

Thanks for any tips!
A 260 should be used in a 700 cc wheel only if the following applies;
1)The rider is fit and weighs less than 200 lb.s.
2)The hills are not overly steep or long.(steeper hills can be climbed if they are not over several blocks long and the rider can get a "run" at them.)

A 201 @ 48 volts in a 700 cc wheel will topout around 20 mph. Just a little slow for most of us.
A 260 @48 V in a 700 cc wheel will topout around 23 to 24 mph. The sweet spot I.M.O.

The fact you are considering a 260 motor means that you are dis-counting using the CST(cassette fitment)version.
Are you sure you want to do that? Many riders w/ a donor bike that has a decent gear drive system prefer a cassette over an aftermarket free wheel.
A 260 is, of course, an option for the frt., but there is a stigma around here against frt. mounts, but personally, I like them fine for low-power builds.

I have not thought about how considering a 260 motor means I am discounting cst can you explain more what you mean by this? Are you saying that people prefer the original cassette over the one that an while vendor will give?

When you say 201@ 48 volts and 260 @ 48 volts, are you speaking in the context of a 36 volt battery?

Will these 135mm q100 and q128 hubs fit my 130mm steel dropouts?

Thanks!
 
The Q100cst comes in 201 and 328 @36v it works with a cassette and is slightly smaller motor.
The Q100h comes in 201 and 260 @ 36v it works with a freewheel.
Regular bike have a cassette and not a freewheel. Freewheel are much less reliable. If you want to pedal a lot a cassette is better.
When he says the 201 @48v he means the 201 model running at 48v at the place of 36v.

The Q100 série and Q128 série are 135mm but since you have steel dropouts you shouldn't have any problem stretching the dropouts

Could you tell us more about what bike you plan on using? Pic?

Leo
 
Hey Omegalen

Multiply the speed of the motor by the increase in voltage to get the new speed. You got that down.

Most of these are sold with a nominal voltage of 36v. if you over volt them to 48V (33%), then the no load speed goes up by 33%. Whether you or the bike can maintain that speed is the question. The Q100 is targeted at about 16mph. Higher than that and you increase the risk of overheating if you can't maintain the speed the motor wants to turn at (ideally about 80% of its no load speed). In other words, it will overheat faster on a hill.

YOu can change the spacing of a Q100 if you want. I have one on a 120mm dropout. In your case, 5mm on steel frame shouldn't be a problem, but you can add spacers if you need to (I just used a nylon bearing from a hardware store).

There is nothing particularly wrong with a freewheel, other than it limiting the options of what you can buy if you like expensive light weight stuff.

I'm running a 328rpm motor at 25-26mph. Running a 260 rpm at 346rpm is doable, just puts you more a little more at risk for heat related issues (i.e. would work best for a light rider on flat terrain). My 300 rpm Q100 runs at the same road speed as motomec quoted for the 346 version (36v nominal at 48v).

If you really want to go into a lot of detail on this, read the thread in my signature. I built and tested a 200rpm, 300rpm and 328rpm version.
 
The size of the wheel doesn't matter comparing 26" to 700c.

The circumference of a typical road tire and mountain bike tire is about the same. Actually, the 700c requires a lot less power in my case, just because it is lighter and much more efficient. I get about an addtional 25% range on my 700c bike vs my 26" bike, even though I ride the 700c at higher speeds. Contrary to popular belief, the 700c requires less energy.

I wouldn't get to worried about 26" vs 700c.
 
leo99 said:
The Q100cst comes in 201 and 328 @36v it works with a cassette and is slightly smaller motor.
The Q100h comes in 201 and 260 @ 36v it works with a freewheel.
Regular bike have a cassette and not a freewheel. Freewheel are much less reliable. If you want to pedal a lot a cassette is better.
When he says the 201 @48v he means the 201 model running at 48v at the place of 36v.

The Q100 série and Q128 série are 135mm but since you have steel dropouts you shouldn't have any problem stretching the dropouts

Could you tell us more about what bike you plan on using? Pic?

Leo

So, to confirm, I would have to buy a freewheel if I went with the Q100/128H? Would this https://bmsbattery.com/ebike-parts/...o-parts.html?search_query=freewheel&results=4 fit on a Q128?

One more thought: there are parts of my commute that would involve long instances of not stopping; I'm thinking a cruise control function might be nice. I can't seem to find a solution for this on bmsb- any ideas?
 
That is correct the Q100h and Q128h need a freewheel. The one you chose works but is a 14-28 which can be not very practical at top speed depending on what is your chainring. There is a model from dnp with 11-32 teeth that you can find at a lot of places.

People are usually very happy with PAS from bms controllers for long-distances.
Do you know what controller you want? Be careful with your choice because a lot of 48v controller give 20 amps and more. That would be too much for the Q100h.

Leo
 
Omegalen said:
leo99 said:
The Q100cst comes in 201 and 328 @36v it works with a cassette and is slightly smaller motor.
The Q100h comes in 201 and 260 @ 36v it works with a freewheel.
Regular bike have a cassette and not a freewheel. Freewheel are much less reliable. If you want to pedal a lot a cassette is better.
When he says the 201 @48v he means the 201 model running at 48v at the place of 36v.

The Q100 série and Q128 série are 135mm but since you have steel dropouts you shouldn't have any problem stretching the dropouts

Could you tell us more about what bike you plan on using? Pic?

Leo

So, to confirm, I would have to buy a freewheel if I went with the Q100/128H? Would this https://bmsbattery.com/ebike-parts/...o-parts.html?search_query=freewheel&results=4 fit on a Q128?

One more thought: there are parts of my commute that would involve long instances of not stopping; I'm thinking a cruise control function might be nice. I can't seem to find a solution for this on bmsb- any ideas?

There is a cassette version of the Q100.
Personally, I like the shimano 32-13t freewheel. I change the chain ring to get the gearing I want. Personally at 20mph, I like 42t by 16t. But I pedal faster than most of the people here.

Not going below 13t on the freewheel does a lot to improve chain wear and minimize skipping if you pedal hard (again, not a top worry about people here). Going below 13 is just kind of iffy. The DNS freewheels are just kinda iffy. You put them together, and you get people who think freewheels aren't any good. Get a basic shimano freewheel (min 13t) and a chain ring that matches your speed and you won't have any problems.

(FYI, 42t x 13t at 20mph is 75rpm. not too bad).
 
So now I'm wrestling if I want to go with the 100cst or 100h. I'd like to go with the 100h because I don't want to sacrifice power, but I have a 6 speed and cannot seem to find a good freewheel for it (I could only find a 7spd 11-32). Should I just learn how to rebuild the drivetrain and go with the 100h? I'm technically-minded, so I cannot imagine this is too hard to do?

Looks like BMSB is all out of Q128's aside from their 328rpm variant, so I'm going to just go with the Q100h. With very mild peddling, will a 36vQ100h 201 RPM motor @ 48v get me to 20+ mph? What kind of speed sacrifices are there with the q100cst?

Thanks
 
Omegalen said:
So now I'm wrestling if I want to go with the 100cst or 100h. I'd like to go with the 100h because I don't want to sacrifice power, but I have a 6 speed and cannot seem to find a good freewheel for it (I could only find a 7spd 11-32). Should I just learn how to rebuild the drivetrain and go with the 100h? I'm technically-minded, so I cannot imagine this is too hard to do?

Looks like BMSB is all out of Q128's aside from their 328rpm variant, so I'm going to just go with the Q100h. With very mild peddling, will a 36vQ100h 201 RPM motor @ 48v get me to 20+ mph? What kind of speed sacrifices are there with the q100cst?

Thanks

Good questions.

you can use a 7 speed freewheel on a 6 speed bike, if it fits the dropout. The chain and indexing for a 6, 7,8 speed is the same. you will just have to choose one gear you will never use (or convert to 7 speed).

I don't think there is much of a power difference between the H and CST, but the body of the CST motor is narrower to allow room for the wider larger cassette.

36vQ100h at 201rpm over volted to 48v is almost the gold standard for these motors if you want to go 20+mph. Above 20mph the motors are going to appreciate some extra power to maintain a faster speed. I.E either pedal harder, or be aware of the increased likelihood of heat related problems if you increase the electrical power.
 
Thanks for the great information. I looked at the schematic for the q100h to see if I could find the allotted space for a freewheel; they don't have measurements for it. Does anyone know if the DNP 11-32 freewheel (http://www.amazon.com/DNP-Epoch-Freewheel-Nickel-Plated/dp/B005QCK9QW fits flush on the q100h or will this freewheel overflow a bit and require that my dropouts be wider than 135mm? Boy, the q100cst or front wheel hubs seem pretty nice about now...
 
As I recall, the Q100H w/ a 9-speed DNP is about 136 or 137 mm. Just a slight spread of the chain stays, really minor, it can be done with bare hands. A sm. flat washer(avail. in any hardware store)needs to be placed inside the drop-out so the 11T gear doesn't rub on the inside of the chain stay.
I ride every day w/ a 260H frt. and a CST rear(both on 12S Lipo and 17 A controller) and the power difference is noticable. Around a 20 to 30% more power from the H.
The H is much louder(gear whine), while the CST is almost silent.
As stated above, a 7-speed DNP will work with a 6-speed shifter set-up. You will end up only using to highest 3 gears, or so w/ the H and maybe 4 w/the CST.
You deffinately will want the 11T sm. sprocket.
If I were you, I would just use the 260 H on the frt. w/ a 20 A controller. It's the easiest to install, with no wheel dishing. Done right, a frt. mini is very stealthy.
20 Amps is a little much for the CST, 17 is about the max.
I use BMS battery torque arms on all my motors, but it's important to have one a frt. mount, it's easy to install.
Here is a simple MXUS 260 frt. mount;
https://endless-sphere.com/forums/viewtopic.php?t=235&p=651777#p651777
 
motomech said:
As I recall, the Q100H w/ a 9-speed DNP is about 136 or 137 mm. Just a slight spread of the chain stays, really minor, it can be done with bare hands. A sm. flat washer(avail. in any hardware store)needs to be placed inside the drop-out so the 11T gear doesn't rub on the inside of the chain stay.
I ride every day w/ a 260H frt. and a CST rear(both on 12S Lipo and 17 A controller) and the power difference is noticable. Around a 20 to 30% more power from the H.
The H is much louder(gear whine), while the CST is almost silent.
As stated above, a 7-speed DNP will work with a 6-speed shifter set-up. You will end up only using to highest 3 gears, or so w/ the H and maybe 4 w/the CST.
You deffinately will want the 11T sm. sprocket.
If I were you, I would just use the 260 H on the frt. w/ a 20 A controller. It's the easiest to install, with no wheel dishing. Done right, a frt. mini is very stealthy.
20 Amps is a little much for the CST, 17 is about the max.
I use BMS battery torque arms on all my motors, but it's important to have one a frt. mount, it's easy to install.
Here is a simple MXUS 260 frt. mount;
https://endless-sphere.com/forums/viewtopic.php?t=235&p=651777#p651777

Thank you for the great information about the size, noise and power implications between the different motors.

What is the dropout width required for the frt 260H?

Do these motors have an internal speed sensor that the BMSBattery S-LCD can read from? I can't find any info about that on their website.
 
Front motors are 100mm wide.

The speed sensor is a bit hit and miss. BMSB say that theirs have the sensor, but there's always a small chance that it doesn't. With or without speed sensor, it's no problem. It's very easy to use an external sensor if the motor doesn't have one, even for the controller's where BMSB says it's not compatible. In those, you just have to solder a a couple of wires.
 
I have the 201rpm q100H laced to 700c and 13s (48v) getting about 22 mph unassisted using the bottle battery integrated 09 controller for a clean install. It's decent and good for commuting with short hill climb but nothing to get too excited about.
What I would do is just use the existing 6 speed freewheel you have on the bike because you don't need that many gears on an electric bike. If you want to upgrade, then find a mega range 7 speed freewheel (old Shimano ones) and get 7 speed shifters which are cheap. Save the cassette and 10 speed system for a nicer bike build.

Lastly, speedmotor only works if electricity is going to the motor. It's not a big deal, just that your trip meter will be off, so if you really need that information, either solder or install a cyclocomputer.
 
puregsr said:
Lastly, speedmotor only works if electricity is going to the motor. It's not a big deal, just that your trip meter will be off, so if you really need that information, either solder or install a cyclocomputer.

That can happen when you didn't set the parameters in the LCD correctly. All Q100 motors should have the internal speed sensor now.

If you have an old Q100 without a speed sensor, you can use an external speed sensor from a cycle computer or buy one from BMSB or wherever.
You then have to solder the speed signal wire to the white wire from the motor in the controller compartment.

The bottom white wire in this photo is the speed sensor from the motor:



I used a three wire external speed sensor. I drilled a hole to bring it through (top thick black wire) and joined the red 5v to the red at the top (could have spliced the wires) where it solders to the board and spliced the black a black. I cut the white speed sensor wire from the motor and joined the white from the new speed sensor:

 
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