Electrifying roadbike - q75

Jonca

10 mW
Joined
Dec 5, 2015
Messages
22
Location
Finland / Central Europe
For few months I have been reading ES and other sources to learn about different options for e-assistance. I have a road bike with aluminium frame and fork and 25mm & 28mm 700c tyres on it. I want to point out that my goal is not to build a bike which climp hills or goes 40 km/h without pedaling. But a bike which would be as good (as possible) to ride as it is now, but just with a little help from the motor to keep the speed and save my energy when I have headwind, slight uphill etc. On that way I hope I could increase the range I can comfortably ride during a day.

For sometime already I have been thinking to purchase a q75 hub motor(BMSBattery seems to be the place since elifebikes doesnt have it anymore in stock). I dont know why but I find very little info/people s experiences about this motor. For example q100 seems to be quite common here, many nice builds with it.
LSW-675 sine wave controller with LCD is my most likely the choice as controller. There are not many controllers that are working with cencorless q75 and I have the idea in my head that sine wave should be quiet, good. So, since I want to keep the bike light as possible, I prefer front hub motors, want to keep my budget low. Is there any reason why I should concider something else than q75? As a battery the plan is to build one from 18650 cells. Mayby 11s or 12s(I believe the controller should handle at least 11s) for 201rpm motor to get around/close to 30km/h no load speed.

Also why I prefer some "powerless" motor is that I want a relatively long range from the battery + want to keep the weight down = motor should not consume much power to get long range from light battery. When I am riding in the city. Or am riding, for whatever reason, slower than 10-15 km/h (10mph) I should have now reason to use the motor. Also I am quite light weight, round 65kg, and there are no long steep hills where I m living. I really just want to increase my avarage speed on longer rides and to allow myself sometimes taking it bit easier and let the motor help. The goal is to have system which would be efficient and give its max power around 15-25 km/h and also to assist a bit after that till 30km/h.

So my fellow cyclists. Does somebody have bad experiences about q75 or LSW-675 controller. Or any other comments why I shouldnt do it in this way?
 
It's late here and I can't go into much detail now, but I'm pretty sure there are no Q series mini's that will run sensorless. The 16 poles and compound gears result in a motor that spins so fast that sensorless motors can't get "sync'ed up" w/ the controller. I know my Q100's won't. I have no idea why BMS Battery lists them as compatible.
You will want to run the SO6S and SLCD-3 display.
Are you totally sure you will be happy with a 30 Kph top speed?
If you want to read more tonight, you can read back thru my posts using the search words, Q100, 100H and SO6S.
 
I'm running sensorless using a Phaserunner. Its a pretty pricey controller though. Worth every cent in my opinion, but I don't mind paying for quality.
 
Thanks for the replies,
According to BMSBattery that is exactly the difference between Q75 and the other Cute motors. Q75 is sensorless and other quties with sensor. If Q75 would have sensor then I would have more options for controller. (also I remember reading, maybe from Pedelecs, that guys have had issues trying to run q75 with controller meant for sensor)

motomech said:
Are you totally sure you will be happy with a 30 Kph top speed?
Lets say that I prefer an e-assist that would run efficiently 15-20 kph on headwind or slight uphill. Over a one that would have 40 kph top speed. Here we have 25 kph legal limit for ebikes, and I would not like to go too far from that. When there is strong tailwind or downhill one can easily go close to 40 kph with a road bike, and thats fast enough for me. What I mean is that the idea is to use the motor mainly when headwind, uphill etc. And to only pedal(motor off) when the bike goes easily 30 kph or faster. (And I guess I can always overvolt if I want more speed.)


I checked the Phaserunner from Grin tech. It seems bit "heavy" for my purpose, 80A and pricey also for this Project. You mean you run it with Q75 or with Q100 ?
 
My Grandfather gave me some advice once. he said to always take just a little more than you think you need. A little waste is forgivable, but not having enough is often as bad as not having any.

You seem resistant to the bigger Q100, but you should at least consider the Q85, 250w motor. There is a point where a motor is so weak that it doesn't make up for the added weight, expense, and hassle of installing it. I think the Q75 is very close to that point.
 
If Q85 would be wider I would consider it. Q100 weights already more than 2kg and I feel that adding more than 2kg to the front wheel of a bike that weights less than 10kg is already quite much. You might be right that Q75 gives so little that its not worth all the hassle(I have been also thinking bout it). Thats why I would like to hear someones experiences about it. I have seen guys here twice my weight with bikes twice hevier than mine are happy with Q100, so why I wouldnt be happy with slightly smaller motor.
 
I think I have very similar design goals as you Jonca. I am also starting to look into the Q75.

Have you made an decisions or progress with your project?
 
Jonca said:
I checked the Phaserunner from Grin tech. It seems bit "heavy" for my purpose, 80A and pricey also for this Project. You mean you run it with Q75 or with Q100 ?

I am running it on the Q100H.

It is definitely a pricey controller. It's extremely small and light compared with many comparable power controllers though. It is quite pricey, but given the features and programmability, it's certainly worth it if there's nothing else out there that suits your need.
 
Hello and thanks for the interest of this "project" :)

I ordered the Q75 with LSW675 controller and LCD + some other stuff from BMSBattery already some days,, weeks ago. I will definitely post here how it works for me once I have the motor running, if bmsbattery manage to deliver my order someday. Will take some time since I also need to get a battery, build wheel around the motor etc.
 
I love my Q75 front wheel build. I've had it for over 2 years - run errands for groceries, commuting constantly with never a problem. I originally thought it might not be powerful enough - but my concerns have been offset with flawless, stealthy performance. I weigh about 145 lbs and the weather here in Tucson is hot - so I'm impressed with the motor/battery set up from bmsbattery for the money spent.
 
chevino101 said:
I love my Q75 front wheel build. I've had it for over 2 years - run errands for groceries, commuting constantly with never a problem. I originally thought it might not be powerful enough - but my concerns have been offset with flawless, stealthy performance. I weigh about 145 lbs and the weather here in Tucson is hot - so I'm impressed with the motor/battery set up from bmsbattery for the money spent.


Need pictures!!!

(3 posts in 4 years?)
 
Where in Tucson are you?
Let's meet up for a cold drink sometime.
The only other Ebikes I know use my used parts and they are kind of junky.
 
Good to hear good things bout Q75. I have been reading German pedelecsforum.de with googletranslator and there are few guys with Q75 + LSW-675 setup and they seem to be happy with it.

Finally my project also has seen progress. I have build 11s3p battery pack from LG 18650 cells and laced the wheel for my motor.

I have rolled the motor at home. Not drove the bike with electricity on yet. Today I had a ride with the newly build rim and motor on(without battery, controller..) Motor is so light and rolls so well that it rides exactly like before without the motor. Light rim and double butted, only 1,5mm diameter in the mid., spokes also helps to keep the weight down. Today or tomorrow I should have first test drive with motor running.

The LSW-675 controller I have is programmable controller. You can program it either with computer(some adapter and software needed) or via display. I have Kingmeter kms5 display. With computer its possible the change if the PAS levels are limiting current or speed. To my disappointment mine seems to be speed limiting and I cannot change current/ speed via the display. Levels etc. I can change. Anyway I want to have some small switch placed on handlebar, so was thinking if I could use, for example, three position switch as a throttle and make that work together with PAS as a kind of current limiter. Or just use only throttle since just as chas58 the plan is not to use the e-assist on really low speeds.

Next step is to make proper mountings for battery and controller, to find a solution for throttle/on-off switch. The best would be some small switch(I have drop bar) with hall censor(display gives error if I just connect +5v to signal on throttle connector). I ll keep you updated.
 
I tried the Q75 in a roadbike, using the BMSB bottle battery with the included sensor less controller. It was very rough at first, but after I changed the P1 (?) parameter, which is magnets x reduction ratio, it was a lot better. Unfortunately, I couldn't find the information about the magnets and reduction ratio, so I estimated and tried different settings until it wasn'the too bad, though it didn't seem very happy at low speed. I think what, with the right settings, it might be OK. I gave up with it because the power was quite low.
The Q100 has the same clutch and bearings, so the drag would be the same, but you get more power for very little extra weight..
 
I have now been driving with my new e-assist for few times. I was surprised how quiet it is. Only on steeper hills I hear quiet whirling otherwise nothing. Even more surprised that I didnt manage to get the motor warm at all. Rode some bit steeper hill up and touched the motor and it was cool as any other part of the bike.

Overall I am very happy with it. Definitely enough power for my purposes(I like to pedal), battery seem to last forever. Only thing I dont like is the stupid speed limiting PAS levels. I really need to get some throttle/button.


d8veh said:
I tried the Q75 in a roadbike, using the BMSB bottle battery with the included sensor less controller. It was very rough at first, but after I changed the P1 (?) parameter, which is magnets x reduction ratio, it was a lot better. Unfortunately, I couldn't find the information about the magnets and reduction ratio, so I estimated and tried different settings until it wasn'the too bad, though it didn't seem very happy at low speed. I think what, with the right settings, it might be OK.

On that German forum someone wrote he had tried many different controllers with Q75 and the LSW-675 is the only one which with it runs smoothly.

d8veh said:
The Q100 has the same clutch and bearings, so the drag would be the same, but you get more power for very little extra weight..

Yes, Q100 weight only 80% / < kg more than Q75. But if one is going to use that "extra" power, bigger battery is needed, bigger controller, maybe torque arm etc. When I was planning this thing. I was thinking I would rather carry one more kg of battery than motor.
I know that for many people few kilos more or less doesnt matter. But even with light touring gear on it I want that I can easily carry the bike into the train, few floors up etc.
If I would need/could choose, I would rather take slightly higher rpm than more power. Bike accelerates quite quickly to its top speed on a flat ground(around 31-33 km/h at full battery, me pedaling with, display showing between 0 to 100 watts consumption).
 
Good to hear your conversion was succesful. Last year i did test ride with this:

http://www.greencycle.fi/product/162/sahkopolkupyora-specialized-race-c2-e

It was pretty impressive. Light and fast.
 
IMG_20160607_052815511_9.jpgIMG_20160607_052907216_9.jpg
motomech said:
Where in Tucson are you?
Let's meet up for a cold drink sometime.
The only other Ebikes I know use my used parts and they are kind of junky.

We should meet up for some drinks sometime. I live near Glenn/Campbell and ride to the hop shop for beers near Fort Lowell/Dodge quite a bit - but really never see other ebikes around town much. I ride around on the loop quite a bit also.

I'm embarrassed that my current bike might be considered junky :oops: - but I feel it's almost perfect for what I use it for.
 
chevino101 said:
View attachment 1
motomech said:
Where in Tucson are you?
Let's meet up for a cold drink sometime.
The only other Ebikes I know use my used parts and they are kind of junky.

We should meet up for some drinks sometime. I live near Glenn/Campbell and ride to the hop shop for beers near Fort Lowell/Dodge quite a bit - but really never see other ebikes around town much. I ride around on the loop quite a bit also.

I'm embarrassed that my current bike might be considered junky :oops: - but I feel it's almost perfect for what I use it for.
PM sent.
 
chevino101 said:
View attachment 1
motomech said:
Where in Tucson are you?
Let's meet up for a cold drink sometime.
The only other Ebikes I know use my used parts and they are kind of junky.

We should meet up for some drinks sometime. I live near Glenn/Campbell and ride to the hop shop for beers near Fort Lowell/Dodge quite a bit - but really never see other ebikes around town much. I ride around on the loop quite a bit also.

I'm embarrassed that my current bike might be considered junky :oops: - but I feel it's almost perfect for what I use it for.
PM sent.
 
Here is a picture of my bike. On the floor you can see the "battery rack" which is normally attached to the mountings of water bottle cage on seat tube. Then I just slip the battery in it and secure it with rubber band and reusable zip tie.

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In the summer I did trip to Czech republic(have friends there) and back from Helsinki Finland with this bike. Partially by trains and buses, partially by bike. Since I haven´t done similar trip without the e-assist its difficult to compare.. but I think it helped quite much to keep the average speed up and was a big help on uphills and legs with strong headwind.
 
chas58: I have only PAS and small display where I can choose the pas level. On a long open road PAS+speed limiting controller is actually quite good(on my previous posts I was complaining about speedlimtng controller). For more urban riding I would like to have current limiting throttle or button. I have read your topic and seen you have nice door bell button. I might try to build some small switch during the winter. Often I am using the buttons on display bit like throttle, but its not very handy.

I have self made 11s3p battery from 18650 2850mAh LG cells. No BMS, bulk charging, have balance wires thou for checking the voltage and to balance when needed. After this summer cells are still within 0.01 V. Never needed to balance!

Now the weather is winterish here already and lately I have been riding mostly my other, non e-bike, or this bike without the battery.



Eskimo said:
Good to hear your conversion was succesful. Last year i did test ride with this:
http://www.greencycle.fi/product/162/sahkopolkupyora-specialized-race-c2-e
It was pretty impressive. Light and fast.

Thanks, I have never tried mid drive. Would be interesting to try.

abecrizer said:
I think I have very similar design goals as you Jonca. I am also starting to look into the Q75.
Yes, we have similar setups, good work. Hope you ll get your gears fixed. I am also curious to hear if you can find spare gears anywhere.
 
Hello again,

What are the chances LSW-675 controller https://bmsbattery.com/ebike-kit/543-36v250w-lsw-675-sine-wave-controller-with-lcd-ebike-kit.html will handle 12s Li-Ion battery? Currently I have been running it with 11s3p charged to 45.4V without any issues.

Capasitors are marked to be 50V, then there are some other components I dont know what they are(see photo), marked with 50V. I didnt find anything when I googled with the exact codes on transistors but I found many transistors with "70NF80". They are usually 68 max V. But on these transistors there is "CHN 51,3" is thsi perhaps the max. voltage?
11.JPG
View attachment 1 P1040518.JPG


I have just been thinking that for next summer I could try my bike with higher voltage. Maybe I'll do like that, that I'll make one 1s3 or 2p battery pack which I'll connect to my main pack when it's not full anymore. To get more speed when the voltage has dropped already.
 
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