The first and BEST Qulbix Raptor mid-drive build!

[Alex07]

i always amazes me how small and yet powerful those little motors are. if you look at them the look like tiny wimpy 200w motors. if you get stopped by our law enforcement group, and they look at those motors, they let you ride on thinking: poor guy. little motors, no power

The motors maybe small but the ugly external reductions like the LR kit also looks like something home made from the 1900s and is a giveaway that this is not a stock normal power motor....But yes its still a nice build but u aint fooling anyone that its legal though lol

 

[macribs]

@izeman I agree those look tiny on this build.
@Matt good call making things more compact, damn that thing looks hot.

@Alex07 What are you talking about? Time to pack down the pipe and sober up. The reduction is a sculpture, and pure e-bike p0rn.

 

[recumpence]

Ha, I do agree that I'm not fooling anyone. It is obvious this is a powerful bike. But, at least it looks like a bike. The motoped looked like a motorcycle. that bike ran great and looked great but resembled a motorcycle. This Bike does not suffer from that problem.

Matt

 

[John in CR]

but u aint fooling anyone that its legal though lol

It's perfectly legal where I live. I feel sorry for those who live under draconian rules that make bicycles unsafe to ride on the streets if they're 100% legal.

 

[recumpence]

In my area the authorities are generally pretty good about giving lee-way on these kinds of things. If you are a responsible adult and not causing any trouble, it is fine. However, there are a few jerks that have the Napoeon complex and insist on pushing the edge of every tiny law and village ordinence. Those guys ruin things for everyone else.

I have only been pulled over on an e-bike once. That was on my 20 inch Cannondale Hooligan. I was going 22mph. The guy who pulled me over wasn't even a police officer. He was the village building inspector in a squad car. He asked me what I was riding and if I knew the legal speed limit was 20mph, not 22mph. To that question I answered "Are you serious?" --- "You are really pushing the issue of 2mph over the limit?" --- "I was going down hill. I can COAST faster than 22mph down hill." I told him I was well aware of the laws and that I was wearing a helmet and eye protection and riding in a sane manor at (for the most part) the legal speed limit and I see no reason why I should be hassled by someone, especially someone who does not have the authority to make a traffic stop.

Matt

 

[macribs]

but u aint fooling anyone that its legal though lol

It's perfectly legal where I live. I feel sorry for those who live under draconian rules that make bicycles unsafe to ride on the streets if they're 100% legal.

Even one more reason to emigrate across the sea, and you got nice weather too as a bonus. Sigh I wish I was far away from cold weather and the rule-horny regulatory biatches.

 

[ElectricGod]

In my area the authorities are generally pretty good about giving lee-way on these kinds of things. If you are a responsible adult and not causing any trouble, it is fine. However, there are a few jerks that have the Napoeon complex and insist on pushing the edge of every tiny law and village ordinence. Those guys ruin things for everyone else.

I have only been pulled over on an e-bike once. That was on my 20 inch Cannondale Hooligan. I was going 22mph. The guy who pulled me over wasn't even a police officer. He was the village building inspector in a squad car. He asked me what I was riding and if I knew the legal speed limit was 20mph, not 22mph. To that question I answered "Are you serious?" --- "You are really pushing the issue of 2mph over the limit?" --- "I was going down hill. I can COAST faster than 22mph down hill." I told him I was well aware of the laws and that I was wearing a helmet and eye protection and riding in a sane manor at (for the most part) the legal speed limit and I see no reason why I should be hassled by someone, especially someone who does not have the authority to make a traffic stop.

Matt

Cops whatever the name or branch of whatever version of law enforcement they come from can be real jerks. The electrical inspector is just a cop for electrical laws. It seems power goes to their heads and then they stop being human anymore to others they see as inferior to themselves.

This bike is brilliant. I'm sure it's worth everything you are asking for it. I looked at your motor mount. That's exactly how I thought you would mount the motors and the belt. I assume that gap between the long section of the belt and the idler roller is enough to keep the belt teeth from ever touching as the pass by each other?

 

[recumpence]

I did a bunch of work today. I Installed the battery switch, machined the axle retainers, machined sprocket spacers (required to move the peddle chainring over 3/4 inch to compensate for the wider bottom bracket), and did the final axle slot grinding to properly align the rear axle in the dropout shots.

These detail items are not 100% required to make the bike functional. But, on such a high end build, the details make a big difference.

Matt

 

[recumpence]

Here are the latest pictures. As you can see the power side chain system is complete. There was a bit of a delay receiving the iders sprockets due to the unique design. I decided to go with sprockets (hardened 7075 aluminum) rather than my typical skate-board wheels because of the high power on the power side of the chain, and on the slack side of the chain, I wanted side to side chain alignment to keep from throwing the chain. High power systems like this with high suspension travel can easily throw the chain because of the narrowness of a bicycle chain versus the amount of side to side deflection that can be encountered. High spring tension on the idler helps alot. But, with this much travel, it is best to suplement the chain stability in the side to side axis by using a toothed idler. This is even more important with the lengthened swingarm.

The idler wheel is mounted to a billet aluminum swing arm that pivots on ball bearings. The spring itself is mounted to the frame using a billet aluminum mount base. No expense or amount of time has been spared on the building of this bike. I have taken everything I have learned, stepped it up, and used that knowledge on this bike.

I have been asked many times what chain I use on high power builds. This is the best chain I have found. I have never broken one. It is a standard BMX freestyle chain, but thicker. It is not a 3/16 chain. It is still 1/8 inch. But, the side plates are thicker. The only down side is the master link is a special size. But, it is a phenominal chain.

I expect to have every mechanical bit finished and installed this weekend. Next week will be spent disassembling the drive unit and assembling it in a finished layout (the drive on the bike right now is a mock-up for installation purposes). After that, it is down to making the harness.

Matt

 

[macribs]

I think I just got hit with a e-bike crush. I bet I would start studdering and get sweaty pawns if I was to walk up to that beauty.
Nice work on those custom tension wheels.

 

[DanGT86]

Absolutely stunning work! I love the beefy tensioner arm. It's amazing how heavy duty a tensioner needs to be when hung from only one side. I'm curious about the effect of the top (drive) side of the chain going around a corner like that. Does that indirect path subtract efficiency any more than just the additional bearing and sprocket losses compared to a straight chain? Also do you use cad software to calculate the locations of the idlers to minimize chain growth through suspension travel or do you just trial and error that during the mock-up phase? Looking forward to seeing it run.

 

[Warren]

Matt,

I built up a single speed cyclocross/gravel roadbike with one of those chains eight years ago. I think it will outlast me.

 

[nutnspecial]

stunning work! . . . Does that indirect path subtract efficiency any more than just the additional bearing and sprocket losses compared to a straight chain?

Technically yes, and imo the more important thing IS all the added friction and esp the added maintenance and upkeep cost. What a pita- and try not to get it dirty!

I also still don't understand how these watt inputs relate to torque and control for these airplane motors and esc's. I bet a 10lb lower kV motor on a proper sensored controller would be more suitable for this application.

That said, it's badass recumpence and I bet it will scream. Your fabrication and artistic skill are there at the top 8)

 

[recumpence]

Absolutely stunning work! I love the beefy tensioner arm. It's amazing how heavy duty a tensioner needs to be when hung from only one side. I'm curious about the effect of the top (drive) side of the chain going around a corner like that. Does that indirect path subtract efficiency any more than just the additional bearing and sprocket losses compared to a straight chain? Also do you use cad software to calculate the locations of the idlers to minimize chain growth through suspension travel or do you just trial and error that during the mock-up phase? Looking forward to seeing it run.

Technically, the addition of any moving parts (anything that causes friction) decreases efficiency. However, bending a chain around a ball bearing idler is far less frictional loss than an additional reduction stage would introduce. An additional stage of reduction typically causes a 3% to 4% loss. Bending a chain around an idler is something around 1% or less. This is very difficult to calculate, though. It is not a straight forward as calculating losses through an additional reduction stage because numerous factors come into play such as amount of chain wrap around the idler, chain speed, etc. I can tell you that additional reduction stages have had a very detrimental affect on range (on my bikes), while adding idlers like this bike uses does not reduce efficiency enough to notice.

I do not use CAD for any of my builds. I layout the driveline based on lots of experience and alot of measuring and component placement experimentation.

Matt

 

[recumpence]

stunning work! . . . Does that indirect path subtract efficiency any more than just the additional bearing and sprocket losses compared to a straight chain?

Technically yes, and imo the more important thing IS all the added friction and esp the added maintenance and upkeep cost. What a pita- and try not to get it dirty!

I also still don't understand how these watt inputs relate to torque and control for these airplane motors and esc's. I bet a 10lb lower kV motor on a proper sensored controller would be more suitable for this application.

That said, it's badass recumpence and I bet it will scream. Your fabrication and artistic skill are there at the top 8)

The issue with a lower KV, bigger motor is just that, it is bigger and heavier. I would rather extract all I can out of a small motor than carry around extra weight that does not benefit me. Also, the controller size is an issue. I do not understand why controllers for typical e-bike applications are so friggin HUGE. I have gotten spoiled by these tiny RC controllers. In fact, I have been experimenting with even higher RPM and smaller motor size. The motors on this bike will run at over 10,000 RPM at full throttle. I am working on a single motor drive for one of my other bikes that will spin a 3210 at over 13,000 RPM instead of a 3220 at 10,000. Super high RPM with a deep reduction gives crazy power. I am not 100% sure how the crazy high 13,000 rpm will do for longevity. But, all of my current bikes are running at 10K rpm for years without any problems. Hopefully the higher RPM will be OK. This bike will run 3 turn Wye motors. That will give around 10,500 rpm. These are the same motors I have in two of my other bikes. They are super reliable.

I will say this, complexity is not a problem for the end user as much as the one designing and building the system. I have a large amount of time invested in this drive system. That being said, I have this down to a science. The reliability of my bikes is nearly 100% at this point. I just do not have any problems with my bikes what-so-ever. So, maintenance is a non-issue. Now, keeping everything clean is another thing. My secret to keeping my bikes clean? I do not ride in mud or rain. That means all I have to worry about is dust. This bike will be ridden in the snow. But, that is just clean water. No problem.

Matt

 

[John in CR]

Damn good question about the controller size, especially since ours are mostly air inside, which just acts like an insulator to keep much of the heat in.

BTW, what's your no-load current, with and without the drive chain if you have it?

 

[recumpence]

Damn good question about the controller size, especially since ours are mostly air inside, which just acts like an insulator to keep much of the heat in.

BTW, what's your no-load current, with and without the drive chain if you have it?

The bike is not running yet.

I can tell you the no load efficiency is actually poor on my bikes. They shine under load.

Matt

 

[Daim11]

Bike looks really good Matt, I want to take it for a ride so bad I can't stand it! Great power and 80ah for hours of fun, the rider will get tired before the bike runs out of juice... I can't wait to see of video of her rolling on the power!

 

[ElectricGod]

RC controllers are quite small for their advertised amp ratings, but then how often do RC controllers really hold up to the current load they say they are rated for? If an EV manufacturer says their controller can handle 100 phase amps, I'm inclined to believe them. When an RC company says their controller is good for 100 amps, I get really skeptical and believe that its more like 50% of that rating. Anyway, compact size still requires heat sinks to pull off heat. I have a Turnigy monster 2000 ESC. It's supposedly rated for 200 amps at 48 volts or 9600 watts. When I consider the extraordinarily small heat sinks on it compared to an actual EV grade motor controller that is also good for 10,000 watts, I have to conclude there's no way the Monster ESC can possibly realistically handle 9600 watts. People that use RC controllers for EV stuff probably should upgrade to larger heat sinks. So much for that diminutive size.

This bike does look brilliant. I'd love to give it a ride.

 

[recumpence]

RC controllers are quite small for their advertised amp ratings, but then how often do RC controllers really hold up to the current load they say they are rated for? If an EV manufacturer says their controller can handle 100 phase amps, I'm inclined to believe them. When an RC company says their controller is good for 100 amps, I get really skeptical and believe that its more like 50% of that rating. Anyway, compact size still requires heat sinks to pull off heat. I have a Turnigy monster 2000 ESC. It's supposedly rated for 200 amps at 48 volts or 9600 watts. When I consider the extraordinarily small heat sinks on it compared to an actual EV grade motor controller that is also good for 10,000 watts, I have to conclude there's no way the Monster ESC can possibly realistically handle 9600 watts. People that use RC controllers for EV stuff probably should upgrade to larger heat sinks. So much for that diminutive size.

This bike does look brilliant. I'd love to give it a ride.

Not true with high quality ESCs. I Have pulled 210 amps for 7 minutes straight on Edge160 controllers without a problem. That was in a wakeboard that continuously pulled 210 amps. That was with a small fan to cool them. But, that proves they can, indeed, take alot of abuse. The issue with all controllers is high load at partial throttle. That is very hard on any controller. Therefore, I setup my systems based on the use they will see. That is, not only for the mechanical reliability, but electric reliability as well.

Besides, that is one major reason I am running twin motors on this build. Two controllers is more capable than one.

Years ago this was a big debate (rc controllers versus big ebike controllers). The general consensus was if a good quality (Castle Creations is the #1 for this) Controllers were used and the system was setup properly, they survived wonderfully and will run very efficiently. That still holds true. The main issue is quality components and proper setup.

Matt

 

[nutnspecial]

Thanks for the reply Matt. The latest setup looks really good btw, and would lend itself to a smaller cover when one is desired. I definitely think it's worth the number mentioned.

_____on esc's
Correct me if I'm wrong, but what I've witnessed from rc builds is the esc's just don't compare to torque and efficiency of similar rated sensored motor controllers? So they're smaller and lighter cuz they're not designed with that in mind, and also lack some of the other functions like ebrakes, speed switch, regen etc. In otherwords, you have to feed them more power to get a similar torque curve, and deal with higher reductions, but they are the smallest and lightest drive systems capable of the most power.

I'm curious what the bracketry, motors, and all but the final reduction weigh Matt? Guessing 6lbs or a little more? That's just so light for how much power it can handle!!

 

[recumpence]

Thanks for the reply Matt. The latest setup looks really good btw, and would lend itself to a smaller cover when one is desired. I definitely think it's worth the number mentioned.

_____on esc's
Correct me if I'm wrong, but what I've witnessed from rc builds is the esc's just don't compare to torque and efficiency of similar rated sensored motor controllers? So they're smaller and lighter cuz they're not designed with that in mind, and also lack some of the other functions like ebrakes, speed switch, regen etc. In otherwords, you have to feed them more power to get a similar torque curve, and deal with higher reductions, but they are the smallest and lightest drive systems capable of the most power.

I'm curious what the bracketry, motors, and all but the final reduction weigh Matt? Guessing 6lbs or a little more? That's just so light for how much power it can handle!!

Good question. Here is something to consider regarding efficiency; a small controller has much less thermal mass. However, if setup properly, they run very cool. I rarely see temps higher than I can touch with my finger (130f). At full throttle the Edge 160 is 99% efficient. My single motor bikes average 23wh per mile at 22mph. So, efficiency is not a problem.

Also, the small size of these controllers works well partly because RC applications typically run at our near 100% throttle all the time. So, proper setup is needed for applications where partial throttle is used often such as in our bike applications.

Now, the big issue is the other factors you mentioned. There is no regen. There are zero ebike specific features. That requires creativity to work around.

As for component weight, your guess is pretty much spot on. 6 pounds for all mechanical drive components. Ironically the heaviest part in the system is the long chain.

Matt

 

[atarijedi]

I'd like to know more about that plate you have on top, with what I assume is the battery switch?

I'm wishing that Qulbix didn't pre-cut/drill the holes in the chassis, so I could do it myself. But they did. Didn't occur to me to put a plate over top and do my own thing though. I also like the switch, which one did you use? Is it removable, or just a push-pull switch?

 

[McKitterick]

Matt, that is such crazy-gorgeous-wild engineering and design - kudos to you! Looks great and like it'll be a blast to ride.

I have a question for a problem I just had with mine that maybe you've already figured out. Seems like you're running power from the motors through your reduction setup directly to the left-rear gear, while retaining a derailleur setup on the right side for pedaling under your own power. I've just installed the 6000-watt kit from Tangent on a traditional downhill bike. On its maiden voyage, when I reached half-throttle, the motor ripped the chain right off the gears, nearly taking my leg off: https://endless-sphere.com/forums/viewtopic.php?t=84683

I'm thinking of swapping over to a belt drive, but your comment that you've never dropped a chain makes me reconsider. With a single-side drivetrain like mine, do you recommend sticking with a chain (but going with the thicker one you use and maybe special gears?)? Have you tried belt drives and compared for high-power applications like this?

Thanks!
Chris

 

[recumpence]

I'd like to know more about that plate you have on top, with what I assume is the battery switch?

I'm wishing that Qulbix didn't pre-cut/drill the holes in the chassis, so I could do it myself. But they did. Didn't occur to me to put a plate over top and do my own thing though. I also like the switch, which one did you use? Is it removable, or just a push-pull switch?

It is the battery cutoff switch. It is a rotary marine battery cutoff switch with a 1,400 amp limit. I will have to find the brand and get back to you. I found it on eBay.

Matt