Finally RUNNING!! page 5 ride vids Here!! need better qualit

Whiplash

1 MW
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May 10, 2010
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Hello all, I am sure you saw Lenk's almost build, I had a similar plan before he started his thread and finally got the motor and some time to mock it up. I am going with thin but rigid chromoly plate for the brackets and will be pumping at least 2500running watts through it. The beauty of this style setup is you get all the climbing power of my old RC setup, but with a RADICALLY quieter and smoother drive!! I am very anxious to get it going but am fairly confident this is my last step in the design process I am using the 12T motor from Cell Man so I need no further reduction. I can't wait to try it out but here is a Mockup of the layout, and yes it clears the tire easily.
 

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Oh, sorry the rear hub is just for me to commute on until I get this mid drive sorted. They will not be used together. I am confident the mid motor will be plenty of power since my RC setup only had 1500 watts and was a powerhouse in my opinion. I do like the 6T motor for commuting though, it really hauls on the flat! I have seen over 40mph if I pedal with it but the cadence is crazy fast! Lol!


Hey maybe I should put a front motor too and run all three! Lol!
 
Alan B said:
So is that a mid-drive plus a rear hubmotor? How is the power transferred from the mid-drive?



The mid motor drives the freewheel cranks via a bike chain. I am not using any additionalfreewheel since these motors freewheel nicely...
 
I wanted to build something like that for ages, but I did not start my custom frame yet, I need to build a new velomobile first. Geared hubs are quite lightweight, controller-easy, and pretty much bullet-Proof under 2500w in a mid-drive IMO. well let's try it! looking forward on results :D
 
Thanks! I should have something to show by this next weekend! I basically just need to design the brackets and trim the axle down. Once I know its good, ill take it off and machine off the spoke flanges. I'm dying to get back on the trails! I really miss my drive!
 
I"m looking forward to some close up pics showing how you mounted it.
 
I have studied the picture and it sure looks like the front tire will hit the motor when the suspension compresses......

Other than that, it looks elegent.

Matt
 
Yeah its the angle, it clears by about an inch when compressed
I put a straight edge on it, and that's before removing the spoke flange. It has room to go back a bit more if necessary as well...
 
Make sure to account for the flexing of the fork upon heavy braking.
 
veloman said:
Make sure to account for the flexing of the fork upon heavy braking.

+1 !!

My RC bike had plenty of clearance until i decided to turn hard while on the brakes and nearly endo-ed myself !

I have a custom motor cover for the clyte 4 series made for me by a very clever guy from Australia ( have not seen or heard from Don in a long time .. wonder where he went ) .. i am going to do a similar setup with 100v and 40 amps in a mid-drive with a 4013 clyte !!
 
Cool that should be crazy! I will definitely keep an eye on it but I think it should be OK....
 
UGH, still plugging away at my brothers build, I should be done by the end of the week so I can get back on this! I grossly underestimated the time it would take with a baby girl sitting next to me! LOL!
 
Whiplash said:
yes it clears the tire easily.

Even on a hard hit when the forks will flex rearward as they fully compress? It looks pretty close in the pic with just straight line compression of the fork.
 
Yeah, remember I still need to machine off the spoke flanges, that will give me enough...
 
How is the progress on your trail drive coming? I like the idea of mac ran through the chain, quiet and powerful. How big is the diameter of the mac minus the spoke flange? The front tire does seem close to the motor, I don't see it hitting but other bikes out there may not have enough room to make it work.

Carl
 
Well, hopefully I will get to it this weekend, but that might not happen, I still have a few little bits to finish on my brothers build and then I can get to it. BELIEVE ME I really want to get to it! LOL!

As for the motor clearance, the diameter is about 5" if I remember correctly, so yes, some bikes may not fit it, but out of the four I have at home, they all should clear..
 
Whiplash, what are you going to use to cut the spoke flange off? I should have done that on the 9C that I shoehorned onto my trike. If I ever do another one that should be the first step. I don't have much in the way of machining tools, just a cheap drill press, saber saw, and an angle grinder.
 
Well, I am going to use my lathe most likely, but I am sure you could simply clamp the axle in a vise and plug the motor into the controller and power it up, then just grind it off till you are happy! I WOULD CLOSELY WATCH HOW HOT YOU LET IT GET and use the nastiest grit disk you can find, The flapper type will not vibrate the motor much at all compared to a hard disk... I used this trick many times with other things before I got the lathe...
 
I think frocks are big and slow enough that you don't need to be that precise. I'd probably get most of the flange off w/ a good grinder and then spin the motor up and clean it up w/ a rasp and sandpaper real quick. :)
 
Around 5 inches is all it is? From what I could gather the spoke flange holes were at about 6.7" diameter. I didn't think it could go down that far, but I have been wrong many times before. I've been trying to find detailed dimensions on the Mac but not having much luck. I can't wait to see what you come up with. I think this would be a kick in the pants on a DH Bike if you could get a quiet 3kw out.
 
I am pretty confident it will take over 2k reliably maybe 3k burst,
But I guess ill find out! As for the motor, its a little over 6" without the spoke flange..
 
Well, I finally can take a look at this again since I finished my brothers build.. I looked a little closer and with a bit of axle trimming I can get a lot more room for tire clearance! As this sits it would be fine, but after trimming the spoke flanges I will have no worries at all! Hopefully this weekend I can get some time to look into the bottom bracket mount, I am hoping that will end up the being fairly easy as I am thinking some tubing with a washer welded on either end that fits under one side of the the bottom bracket threads and then a nut that goes over the other side. Nice and clean! We will see how it goes, but I want it to fit a wide variety of frames and this is about the only way...
 

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The more I see this setup the more I'm in love with it. I was thinking that for frames this normally wouldn't fit in would be to cut the down tube out and reinforce where you cut out with steel and some good epoxy. It would get the motor back and make it look cleaner. With the right mounting this system could look really clean.

If you build your mount so that you could place your controller above the motor and somewhat attached to the downtube it would clean up the lines and make it a one piece unit with only a few groups of wires entering it. Good luck, I know I'm looking forward to how it works.

Where abouts are you located at? I could do some machine work for you if needed.

Carl
 
Im in California, and thanks! I don't suppose you have a laser cutter or CNC plasma cutter do you? I will need to get the brackets cut out in quantity once its all figured out.. I have a small lathe/mill in the garage

As for the frame cutting, if it works well I am planning on getting a TIG Welder and do just that! I may even start dabbing frames as well if it works as well as I hope!

There are a few people doing some real mice MID drive stuff, but my plan is to offer a QUALITY low cost alternative, and I think this will fit the bill nicely! If my 6t MAC can get me to 42mph with 1500 watts then once I get this baby dialed in with the right gearing I should be able to have crazy climbing power in low gear and 40+ mph on the top end! The best of the both worlds! We will see!
 
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