The BEST and FIRST Qulbix Raptor mid-drive build!

The machine work on the hubs should be finished this week. Then off to the anodizer and they'll be done. Your drive is already on the swingarm. I also just finished your bottom bracket drive. The two systems could not be much more different. I'll be interested to hear how they compare.

I need to take some completion pictures. :D
 
Here are some photos of the completed bottom bracket drive:

219 chain primary. Stainless steel driven sprocket. This is a performance drive so a bit of chain noise is not an issue. This drive has the optional billet freewheel delete hub to make the primary drive completely bulletproof. You can't pedal without turning the motor but that's not the point of this drive. If you use a fixie rear hub you can have regen with this setup.
1.jpg


Lots of new features here. Full alloy chain guard. Chainwheel guide, fence and final drive chain tensioner, one piece 60t stainless steel secondary driven sprocket, 34t stainless steel single run chainwheel. The full chain guard would also act as a torque brace except that the upper assembly is already bolted to the Qulbix chassis and battery box. Nothing is moving.
2.jpg


Rear view of the primary and secondary chains.
3.jpg


Detail of all of the new goodies at the chainwheel. The "chainring bolts" are now grade 10.9 M8 bolts. This freewheel is a White Industries UHD. Regular W-I HD also available.
4.jpg


This drive has 15:1 overall reduction instead of the standard 30:1 to get more speed in a lower rear gear. Anyone who has ridden a multiple speed mid drive with over 3000 watts knows that the high speed gears are the ones that skip and wear quickly. This drive will get the same speed from a 22t rear sprocket that the standard drive gets from an 11t. With a chainwheel rpm of over 200 you can't pedal along with this drive at speed. Again, not the point of this particular drive.
 
Here are some photos of the swingarm mounted direct drive:

Simple. Big motor. Strong bracket. Strong chain to rear wheel. The alloy sprocket guard has a built in chain tensioner.
1.jpg


2.jpg


3.jpg


4.jpg


This drive lives in the territory in between mid drives and hub motors. Once you have this much power (3000-5000 watts) multiple speeds are not really necessary for most purposes. Like a hub motor this drive will use more power than my mid drives and it won't be as good for slow plonking on steep trails. But for flat out hauling ass on moderate grades... this should be a lot of fun.

All that remains to do on these drives is to get the billet rear hub into full production. Disc brake rotor mount, big stainless steel 219 drive sprocket bolted solidly to the hub, thick spoke flanges drilled for 36 10 gauge spokes, threaded on the right side for a freewheel track cog. Even more than the Qulbix bottom bracket drive, the pedals are just there for "limp home mode" (it beats pushing) and to be able to call the Qulbix a bicycle. Get the motorcycle pegs and seat and it's a free ride electric motorcycle.
 
looking forward to see one assembled bike :)

about the rear hub:
i wonder why you have built it similar to bicycle hubs in diameter, and not larger.
the larger the diameter, the lower the stress on the spokes, the eylets and on the rim at given torque.
 
I'm also looking forward to seeing one on a fully assembled bike! It shouldn't be long now.

Settling on a spoke flange diameter was a bit of a crap shoot. I can vary it in the future if there is a good reason to. For one thing, in order to turn down a huge cylinder of 6061 alloy to a reasonable wall thickness on the center hub, there would be a lot of expensive alloy chips on the floor and a lot of lathe time to do it. These flanges are larger in diameter than typical bike flanges, about twice as thick and they have large diameter spoke holes for 10 ga spokes. It may be that they appear smaller in diameter than they are because everything is beefed up.

The stress on the spokes is going to be really low with this swingarm drive compared to a big hub motor. Instead of 20-25 lbs on the axle there will be about 12 lbs near the swingarm pivot. We're using the same 10 ga spokes and 19" motorcycle rim that are used with the big hubbies. We should be good.
 
LightningRods said:
I'm also looking forward to seeing one on a fully assembled bike! It shouldn't be long now.

Settling on a spoke flange diameter was a bit of a crap shoot. I can vary it in the future if there is a good reason to. For one thing, in order to turn down a huge cylinder of 6061 alloy to a reasonable wall thickness on the center hub, there would be a lot of expensive alloy chips on the floor and a lot of lathe time to do it. These flanges are larger in diameter than typical bike flanges, about twice as thick and they have large diameter spoke holes for 10 ga spokes. It may be that they appear smaller in diameter than they are because everything is beefed up.

The stress on the spokes is going to be really low with this swingarm drive compared to a big hub motor. Instead of 20-25 lbs on the axle there will be about 12 lbs near the swingarm pivot. We're using the same 10 ga spokes and 19" motorcycle rim that are used with the big hubbies. We should be good.
Click to expand...
Actually, I am pulling CRAZY power (30+ hp) on my Raptor using a standard downhill rear hub and 14 gauge spokes without a problem.

Matt
 
30 horsepower! On a bike that weighs less than 100 lbs! Someone is going to have a lot of fun with your bike, Matt. :D

I don't think that transmitted power is what breaks spokes on the hub powered Qulbix. It's the pounding of all of that mass in the wheel. My hub is probably overbuilt.
 
Yes Mike, you are 100% correct. Rotational torque is not very hard on spokes. Hammering load due to a heavy Hub motor is what breaks spokes. :) very few people seem to recognize this on this forum. So I'm glad to know that you brought it up in a clear concise way. :)
 
LightningRods said:
Both drives are completed. I'm having three rear wheel hubs machined right now. Two of them have pre-sold. I made ten swingarm mount drives and have five left. I made five of the bottom bracket drives and have the parts left to build two.

I'd love to buy a Q76R and have a Qulbix of my own. I have three other projects going on at the same time that required buying bikes so I'm stretched thin. I may wait until Spring is a bit closer, clear the other projects and then get one. It's going to be a fun bike and ideal for riding in my area.

The ported Big Block should also be done this week. It's going to be interesting to see how much more power we can push through it with some case ventilation.
Click to expand...

It's too bad the Qulbix frames cost so much...I would buy one. That and you still have to buy all the other components before you even have a complete bike. So a couple grand just to get started and you haven't even added the electrical components. All I can say is cough! That's out of my price range.
 
There are lots and lots of $2k bicycles on the market. That's just mid range. For an electric bike platform I think the Qulbix is a deal at $2k. I'm also working on a cruiser right now. $1500 for the bike and then several hundred to add an aluminum battery box. So pretty much back to $2k. I built a Foes Mutz for a customer last year. $3,500 for the bike and worth every penny.

You could always trade your fleet of scooters in. :p
 
recumpence said:
Yes Mike, you are 100% correct. Rotational torque is not very hard on spokes. Hammering load due to a heavy Hub motor is what breaks spokes. :) very few people seem to recognize this on this forum. So I'm glad to know that you brought it up in a clear concise way. :)
Click to expand...

Yes, the unsprung mass of heavy hubs together with non optimal spoke angle is the reason why they break, but this is a different problem.
What i was talking about is that you could avoid additional stress on the entire wheel when using a hub with larger spoke hole pitch circle diameter.

Matt, you have lets say 300Nm on the rearwheel during hard acceleration (at 30Hp+ and when geared for thrust you will have even more, right?)
the dia of the hub is lets assume 50mm what means the lever will be a bit less than 25mm at 3-cross lacing.
the torque is transmitted to half of the spokes, so 18 spokes.

300000Nmm / 25mm = 12000N
12000N / 18 spokes = + - 660N of tension variation in every single spoke ;)
 
madin88 said:
recumpence said:
Yes Mike, you are 100% correct. Rotational torque is not very hard on spokes. Hammering load due to a heavy Hub motor is what breaks spokes. :) very few people seem to recognize this on this forum. So I'm glad to know that you brought it up in a clear concise way. :)
Click to expand...

Yes, the unsprung mass of heavy hubs together with non optimal spoke angle is the reason why they break, but this is a different problem.
What i was talking about is that you could avoid additional stress on the entire wheel when using a hub with larger spoke hole pitch circle diameter.

Matt, you have lets say 300Nm on the rearwheel during hard acceleration (at 30Hp+ and when geared for thrust you will have even more, right?)
the dia of the hub is lets assume 50mm what means the lever will be a bit less than 25mm at 3-cross lacing.
the torque is transmitted to half of the spokes, so 18 spokes.

300000Nmm / 25mm = 12000N
12000N / 18 spokes = + - 660N of tension variation in every single spoke ;)
Click to expand...

Yea, what you said. :mrgreen:
 
LightningRods said:
Mammalian gave me the green light to mount the mid drive on the 76R frame. Here are some shots of how the new drive fits.

FullL.jpg


CropL.jpg


FullR.jpg


CropR.jpg
Click to expand...

WOW!!! Looks great! This is quite impressive. I think it might be your most compact mid drive yet. Maybe that's just because the qulbix frame is squarish and box like. I really like how the chain tensioner fits in there.
 
ElectricGod said:
WOW!!! Looks great! This is quite impressive. I think it might be your most compact mid drive yet. Maybe that's just because the qulbix frame is squarish and box like. I really like how the chain tensioner fits in there.
Click to expand...
is there any need to quote the WHOLE POST? this makes reading a pita.
 
LightningRods said:
The small primary sprocket does make the drive seem a lot smaller and tidier. And it fits the Qulbix very well. The frame is just the right shape.
Click to expand...

Quite possibly your best build yet...not that you EVER do crappy designs.
 
LightningRods said:
If you haven't seen the billet rear hub this is what it looks like:

Qulbix165Hub-Assy1.jpg
Click to expand...

How is that 90 tooth sprocket held in place? It can't be standard freewheel threads since left side only works for brake rotors which wont spin off the threads. I'm guessing you have a 6 bolt pattern over there that's the same size as brake rotors use, but offset from the brake rotor bolt pattern. I guess those black dots on the inner surface of the spoke section are the ends of the sprocket screws.
 
Here is another shot showing the detail that you're asking about.

Qulbix165Hub-Machined.jpg


Yes it's basically two sets of brake rotor 6 hole pattern. I came up with the idea of rotating them 30 degrees out of alignment with each other so that the sprocket could slide in behind the rotor. The mounting tabs for the sprocket slide through the milled gaps in the rotor flange.

The right side can either be threaded for a freewheel (as shown) or another rotor pattern could be added to move the driven sprocket from the left to the right side.
 
Quite possibly your best build yet...not that you EVER do crappy designs.[/quote]

_________________

I may be a little biased, but this is the best build I have from Mike.... :wink:

rsz_wazia_tires_mounted.jpg
 
The mid mount drive turned out really well after over a year of hard work on it. That bike is no longer available so I'm in the process of finding other bikes to install that drive on. I had fun building that one for you!
 
LightningRods said:
The mid mount drive turned out really well after over a year of hard work on it. That bike is no longer available so I'm in the process of finding other bikes to install that drive on. I had fun building that one for you!
Click to expand...


I did an 11 mile ride on it yesterday and it was awesome----

I had the tires aired up to max to help seal them --- (just set them up tubeless) and it was a little rough on the washboard gravels,...lol

But i could consistently maintain 27 mph while pedaling along in 14th gear----

I have lowered the seat which is a little more comfortable on my butt...but i am going to raise it back up a little because i am too close to the pedals---

Overall rating---OUTSTANDING :D

Is this new build the frame I saw when i was there to pick up mine????

Some great looking ideas going on with it... love that hub!
 
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