Qulbix Q76R Frame Kits & Complete Bikes PRE-ORDER

[Rix]

i dont think an IGH internally geared hub such as rohloff etc would handle very much motor power for long..
and it would be an expensive replacement..
likely better to go single speed with higher power (less things to break
(do a search on here for "revolt" for some inspiration

So is the chain the only weak link? Can anyone confirm how much power these geared hubs will take?

I'm also fairly new with these smaller motors. Everything I deal with in the dyno lab is ~415kw. What are some good name brand motors?

Good points, I don't know what peak kw the Rolhoff hub can handle, but I am going to say not much above 2 kw. And to be successful with 2kw, probably running the smallest drive sprocket than can fit on the hub, and at least a 50T chainring up front. Rolhoff posted some data about their hubs being limited by gearing options when used on tandem bikes. Specifically restrictions on crank arm length and minimum Chainring tooth requirements. No way this hub is handling much powre over what 2 people can generate on a tandem let alone 10-14kw. Here is the link. http://www.rohloff.de/en/technology/workshop/sprocket-ratios/index.html

 

[shoebaker]

Gday Offroader,

Is that a 19" rear with 2.75 SR 241 and a 26" bicycle front? It looks well balanced. What width is the rear rim?

 

[Offroader]

Gday Offroader,

Is that a 19" rear with 2.75 SR 241 and a 26" bicycle front? It looks well balanced. What width is the rear rim?

It is a 26" front with a SR 241 17" 3.00" rear. I find this combo to work extremely well, especially if i keep the PSI low in the rear tire.

 

[Offroader]

Loving the range I have on this bike. While I never road the full 45 mile range in one bike ride, it is still nice knowing I have plenty of range. There is no reason to conserve battery power and I never worry about running low on the way back home.

charging is super easy also. I never had a charging port on my raptor 165.

Pack so far doesn't overheat in the summer temps, highest I got it to was around 37C with 32C ambient, starting battery temp was 28C.

I posted my stats in KM and Miles for a full charge from, 4.1 to 3.3 volts if anyone is interested. Remember that my 45 mile range is based on pushing some serious power, 60 watt hours a mile or 38 watt hour a kilometer.

 

[Rix]

Very nice Offroad, doesn't sound like you are having any regrets with switching from the 165.

 

[Merlin]

not Q76 related, but here is a 140km ride with same 280 GA cells
full charged 4.2 to 3.15v
looks like the CA shows me some stupid stuff ;P

 

[Quokka]

Offroader, what's your opinion on running a heavier rear motor? I am contemplating a QS273 but it's going to come in at 20kg plus.

 

[Offroader]

Merlin, yeah those stats are way off. There must be a way you can calibrate them.

The Max-E seems to get the wattage about right. I believe 4.1 to 3.3 is about 2.6 AH on the Sanyo cells. I'll have to cycle a cell to see what i get on my charger.

n running a heavier rear motor? I am contemplating a QS273 but it's going to come in at 20kg p

I'm running a Cromotor v3, and will be changing to a lighter Mxus Turbo motor to save weight in the rear.

The QS273 would be ridiculous heavy. I personally wouldn't use that unless you were going to stay on the street all the time and wanted to push serious power. The QS205 with extra copper fill is a heavy beast on its own.

However, it is hard to say how noticeable the weight is. It seems you don't really feel the weight of the hub motor too much or you get used to it. You may be able to get away with it, but why would you need such a beast of a motor.

I would be much better able to answer your question once I get my MXUS Turbo and see just how much losing 3KG of weight in the rear makes. I would say if you plan on off-roading the bike not to get it. The QS205 with extra copper fill is more than good enough.

 

[Offroader]

Finally decided to bring my bike into Manhattan for the first time. I came from Staten Island by using the Staten Island Ferry. It was no problem at all. Even another biker on the ferry was asking questions about it as he thought it was a beefy mountain bike. Was surprised when I told him it was electric.

Coming back was no problem either. The thin frame really makes the bike easy to pass off as a bicycle. I'm also using the motorcycle seat.

When driving in Manhattan with a lot of stop and go, I actually get a much higher range even though I am accelerating hard all the time after stopping.

Loving the thin frame which allows great turning with dual crown forks, great for tight city traffic you have to do a lot of turning in the city.

What is amazing is I can get from my house in Staten island to central pack in Manhattan so quickly compared to having to drive to the ferry, park,walk to the ferry, then take public transportation once inside Manhattan. With the bike I just drive it right onto the ferry, and once off drive right up to central park without having to wait for all the red lights .

That is Manhattan in the background.


Staten Island Ferry in the background.


On the Staten Island Ferry


The famous Wall Street Bull, you can't see it because of all the tourists.


Trump Tower

 

[Mammalian04]

Hey Offroader. Looks like a nice ride. It just occurred to me that it would be great to meet up and see your bike. I am in NYC every 2-3 weeks. I'll give you a shout and see if you are around next week I am up there.

 

[Offroader]

Hey Offroader. Looks like a nice ride. It just occurred to me that it would be great to meet up and see your bike. I am in NYC every 2-3 weeks. I'll give you a shout and see if you are around next week I am up there.

Sure, did you ever build your Q76R?

 

[Mammalian04]

Hey Offroader. Looks like a nice ride. It just occurred to me that it would be great to meet up and see your bike. I am in NYC every 2-3 weeks. I'll give you a shout and see if you are around next week I am up there.

Sure, did you ever build your Q76R?

Not yet. Mike (Lightning Rods) has one that he is prototyping a big block on and the other is still in the box. I am trying to encourage self to finish the FLX Alpha and Beta before opening yet another box to spread around the garage. At this point, my bikes are getting beyond my batteries so I need to revisit your battery build posts and work up a couple of those. Pretty impressive numbers (45ah) to squeeze out of the Q76.

 

[Rix]

Finally decided to bring my bike into Manhattan for the first time. I came from Staten Island by using the Staten Island Ferry. It was no problem at all. Even another biker on the ferry was asking questions about it as he thought it was a beefy mountain bike. Was surprised when I told him it was electric.

Coming back was no problem either. The thin frame really makes the bike easy to pass off as a bicycle. I'm also using the motorcycle seat.

When driving in Manhattan with a lot of stop and go, I actually get a much higher range even though I am accelerating hard all the time after stopping.

Loving the thin frame which allows great turning with dual crown forks, great for tight city traffic you have to do a lot of turning in the city.

What is amazing is I can get from my house in Staten island to central pack in Manhattan so quickly compared to having to drive to the ferry, park,walk to the ferry, then take public transportation once inside Manhattan. With the bike I just drive it right onto the ferry, and once off drive right up to central park without having to wait for all the red lights .

That is Manhattan in the background.


Staten Island Ferry in the background.


On the Staten Island Ferry


The famous Wall Street Bull, you can't see it because of all the tourists.


Trump Tower

Hey Bro, your bike looks fuqn awesome!!!! I really like your build. Its off the hook. Is that a 24 or 26MTB up front? what ever it is, it looks great with the 3.00-17 SR241 on the rear.

 

[Offroader]

Yeah, 26" up front. I am extremely happy and proud of this Q76R build. The bike is extremely reliable. I basically spent the last couple of years beating my raptor 165 and then constantly fixing things and then making them more reliable. I then used everything I learned to make my new Q76R build almost bullet proof and also extremely low maintenance.

The rear wheel build has never given me any problems since using quality 9/10 gauge spokes and using correct spoke torque.
Battery is secured very tightly and encased in closed cell foam. got rid of those awful lipo packs and used 18650 cells.
Nord lock washers used on areas where bolts constantly loosen.
Chain system completely reliable, no dropped chains very silent.
Tried to make all connectors and soldered wires as sturdy as possible. Hot glue really helps here.
Custom motor cooling is extremely reliable and has never given me any problems after I had to keep fixing and improving design for the first week.
3.4KW 18650 pack was build using mostly copper wire to give equal cell current draw. I didn't even parallel cells yet and each cell is still within ~.001 volts of each other.

All those things above took lots of fixing and improvising over the last couple of years until they became 100% reliable. The bike is now as good as you would expect if you bought a new electric bike off the show room floor.

This is all nice because I can go 20 miles away from home, and not worry about anything breaking. The last thing I want to do is push that bike all the way home from mid-town manhattan.

I can also now focus on suspension components and fine tuning the spring rates. Working on perfecting that now. I actually just did an oil change on my first fork and plan on rebuilding the rear shock. May get some better components here or upgrades for them.

A couple of things I have to see if I can figure out:
side cover bolts keep loosening, maybe I need to torque them down even more. I have to check these every other ride now.

Rear wheel suspension is very harsh, when I hit anything big and fast it really throws me out of the seat. I'm only using a 350 lbs spring but I noticed I don't use full travel unless I do a high jump. Going to try a 300lbs spring. I am not sure if this harshness is because of the heavy cromotor. I am going to upgrade to a lighter Mxus 3000 turbo soon.

DNM USD-8 fork I get absolutely no sag and seems kind of stiff. I may have broken the fork when I had to drop the bike and pushed off the handlebar twisting the fork. It was a slow controlled drop and surprised it twisted and broke so easily. I then had to untwist it to get my full travel back. I forgot how it performed when new, but I remembered it being better. I may have broken this fork and don't know if I want to use an upside down / inverted fork again because you can twist it and break them too easily. There is no lower arch support like on a normal bicycle fork.

The Marzocchi 888 fork is much more plush and smooth but bottoms out easily, I am going to try a more firm spring.

 

[Mammalian04]

I am working up a battery that can be swapped between the Q76R and the Raptor 140. I have drawn up a 20s11P and mocked the layout.
Photos are in the thread linked below but this drawing gives the general idea.:
https://endless-sphere.com/forums/viewtopic.php?f=3&t=81050

 

[Offroader]

mammalian04, I'd like to see how you are going to connect those cells in series.

 

[Mammalian04]

mammalian04, I'd like to see how you are going to connect those cells in series.

This is obviously just one side of the battery. Orange lines are additional strips of the same width but I just used another color as it was getting hard to see.

Also, all the cells have a "+" on them but of course they will alternate positive and negative.

 

[Quokka]

I am with offroader. The cells on the top right only seem to be 3 deep which by math book will give you around 60mm in cross section for amps to pass through if using nickel sheet. Depending on what material you plan use for the battery connection, i think you will be forced to use greater than .2mm nickel, in sheet form to stop the series connectors from getting hot.when making my battery, i worked out the max amps from my p's- which was around 120 amps, then worked backwards with the amount of nickel required to transfer the amps through the cell and hence the number of cells that need to be next neighbouring p group. this is where offraders design is clever. The copper wire in his pack is basically acting as a sort of bus bar for current flow.
The 18650 ultimate repository by nobu has a great table with material vs current flow that helps a lot for working out what material you should use. Also temember that .3mm nickel is hard to weld, and pure copper has a poor mechanical bond to the battery after welding.

I would try to go for a minimum of 4 cells deep preferably 5 to be adjacent to each other. Hope this helps

Edit- just saw your jpg. Much clearer and better design than originally thought. Still worth a check with series connections current flow though

 

[Mammalian04]

Ok, here is a revised version to try and spread the connections. (The attachment is a higher resolution).

I just had a thought though, I have seen somewhere that some folks just use an entire sheet of nickel. Instead of strips. Maybe that is a better option than all the layers welded on on top of another...

 

[Quokka]

Here is my pack.. Took quite a lot longer than anticipated as i had to build my own spot welder. Really happy with it though. 20s 12 p pack of ga sanyos using .2mm nickel sheet and adaptto bms. Should be good for 120 amps, i hope!

 

[Offroader]

Here is my pack.. Took quite a lot longer than anticipated as i had to build my own spot welder. Really happy with it though. 20s 12 p pack of ga sanyos using .2mm nickel sheet and adaptto bms. Should be good for 120 amps, i hope!

Quokka very nice pack and because it is so similar to mine in size if you are using the Max-E you can tell me your resistance number. Mine gets around 50. This is basically a 5 volt voltage sag which is what I notice when looking at my volts when going full throttle at Max-e set at 82 battery amps, which shows around 95 amps on the display.

How much higher than 50 you get when using your max-e set at around 82 batter amps will be mostly extra loss you have in your connections vs mine. Actually since you have a 12p pack you would need to set your amps at 70 battery amps to get a better comparison.

To be honest, that is the best way it should be done because mine was really difficult to build. However, you will not get perfect current draw through the cells like I do, how much this matters is questionable and debatable.

I guess a way to determine this is how well your cells stay in balance and if you need to bulk charge. My cells are not yet paralleled and they stay within .001 volts of each other for the whole pack, I believe this shows my cells have close to perfect current draw though them as they would drift a little. Will pull my pack again after a l lot of cycles to see just how close they are staying.

 

[Offroader]

Ok, here is a revised version to try and spread the connections. (The attachment is a higher resolution).

I just had a thought though, I have seen somewhere that some folks just use an entire sheet of nickel. Instead of strips. Maybe that is a better option than all the layers welded on on top of another...

View attachment 1

What I recommend you guys can do is where the cells are hard to connect with enough nickel, use copper wires for that whole series connection. Like mammalian, you can do this at the top when your series connections need to go from right to left. Have to keep all the copper wires the same length.

Using wires is a real pain in the butt like I have used, but if you have to use it once or twice in the pack not a big deal if it makes lining up all the other cells much better.

 

[Mammalian04]

Like mammalian, you can do this at the top when your series connections need to go from right to left. Have to keep all the copper wires the same length./quote]

Yep! That's what I was thinking at the top using your pack as inspiration.

Also, I might look into the nickel sheet for the rest. That stuff is expensive though!!!

 

[Rix]

not Q76 related, but here is a 140km ride with same 280 GA cells
full charged 4.2 to 3.15v
looks like the CA shows me some stupid stuff ;P

Missed this earlier, thats impressive.

 

[Rix]

Here is my pack.. Took quite a lot longer than anticipated as i had to build my own spot welder. Really happy with it though. 20s 12 p pack of ga sanyos using .2mm nickel sheet and adaptto bms. Should be good for 120 amps, i hope!

That is a really sweet pack! looks sano as hell also.