Eric's Project #002

[Beagle123]

Inspired by safe's project #001 & #002...

I've been slowly buying parts in an effort to make an improved version of my moped. I'm very happy with my current bike, but it could be improved in many areas. My goals are:

1) To make a bike that's a good transportation vehicle. I'm not trying to break any land speed records. i'm more interested in range and comfort.

2) To add power by going up to 48 volts.

3) To make it lighter for better hill climbing.

4) To improve the brakes-- I now have a drum and coaster brake. I'd like disc brakes.

5) To encase the battery in the frame, so it looks like a complete bike.

Here is my first attempt at a design:

 

[Beagle123]

I purchased a cheap mountain bike from wal-mart for $160 just to take the forks and disc brakes w/ hub. I regret it a little becasue I think I could have done better by buying a good set of forks and disc brakes for about the same price.

The bike came with 26 inch wheels. I downsized them to 20 inches. I think I'll get better braking power with smaller wheels. These brakes will have to stop me (170 lbs), 4 batteries (60 lbs), the motor (10 lbs), and everything else.

 

[Beagle123]

I bought 3 inch wide wheels from my local bike shop (safe inspired again). It was quite a fiasco getting the wheels made. Many mistakes, many problems, but I finally have a really nice looking set of wheels.

I used "heavy duty spokes, and bmx rims. I think the heavier spokes are unnecessary. I've never heard of a wheel exploding.

The wide tires made it necessary to remove the brake mounts from the top of the forks for clearance:

 

[Beagle123]

I'm going to have "gears" on this bike's back wheel. I purchassed a NuVInci gear hub from ebay. If you're not familiar with these hubs you should have a look:

http://www.atcnuvinci.com/products_bicycle.php

If it works like they say, it should be amazing. I'm really looking forward to having a continuous, smooth changing of "gears."

I think these hubs are perfect for electric vehicles because electric motors have excellent efficiency at high RPMs. With this hub you can keep it in the lowest gear as the motor speeds up, then when you're in the "high efficiency zone," you can gradually change gears to speed up. Hopefully, I'll be able to maximize my bikes performance with this thing.

 

[Beagle123]

I bought all this aluminum to make the frame. I wanted to use aluminum because my ultimate goal is to make a super-light bike. This one will be practice.

The frame is basicly two pieces:

1) The battery box/seat part
2) The swing-arm to the back wheel. The lines connecting the middle of the back wheel upwards are the shocks. (see photo above)

I'm making the swing arm pieces from 1 3/4 "L" shaped angle pieces that are 3/16th of an inch thick. I'm sure there are smart people out there who could use much less metal to make a strong frame, but I'm not one of them. I'm compensating for my lack of knowledge of frambuilding by simply using thicker metal.

By the time I'm done, it may be as heavy as a steel frame.

 

[The7]

I'm going to have "gears" on this bike's back wheel. I purchassed a NuVInci gear hub from ebay. If you're not familiar with these hubs you should have a look:

http://www.atcnuvinci.com/products_bicycle.php

If it works like they say, it should be amazing. I'm really looking forward to having a continuous, smooth changing of "gears."

I think these hubs are perfect for electric vehicles because electric motors have excellent efficiency at high RPMs. With this hub you can keep it in the lowest gear as the motor speeds up, then when you're in the "high efficiency zone," you can gradually change gears to speed up. Hopefully, I'll be able to maximize my bikes performance with this thing.

Great. Seems that you are the only one using motor on NuVinci gear hub.

 

[xyster]

I'm interested to see how the NuVinci bicycle CVT handles the additional torque stress -- seems that's still an open question. Thanks, Beagle, for also being a guinea pig!

Do you know if yours' is the same model CVT that Currie uses on their high-end scooters like this one?
http://www.bernsonev.com/izip-fusion-1000-electric-scooter-with-nuvinci-drive-p-752.html

Maybe not since it says "NuVinci Automatic multi-gear drive" and "NuVinci CVP 4 speed gearing"

 

[deecanio]

yes to echo Xy - it will be interesting to see the nuvinci with electric.
loving the 3" on the 20" - i thought my 2.5" s were fat
just to check with you guys the nuvinci is not electric right? its the geared one with the big balls?


cheers

D

 

[BiGH]

welldone! already!

endless-sphere constantly amazes me - because of the sheer number of smart people who are trying new things, in the quest for better and more efficient transport! (and a bit of fun)

keep up the good work!
Take Care,
Haydon

 

[hopbot]

wow, that NuVInci hub sounds awesome! man, once i have some extra cash, that would be a nice feature to add. good luck Beagle

 

[safe]

You've been buying high quality components it seems.

It will be interesting to see how well the aluminum frame turns out. I know in my own history the first few frames had problems that later I learned how to correct or do better. It's a learning process that's for sure. Don't expect perfection right off the bat... you have to adapt if things don't go according to plan. (assume your plan will change along the way)

I think everyone now can see what I mean about trying to fit a 3" wheel into the standard front fork. The clearances are really tight and if the tire is even slightly irregular (which for my tires they are) you have troubles with the tire rubbing.

You will LOVE the traction you get. Even though they are 20" tires you're going to get traction like you've never even imagined... 8)

Are you going to try "motor current limiting"?

If you can build the circuit you could essentially eliminate any heat related problems you might otherwise have. Just a thought.

 

[safe]

Beagle123: My 1200watt Uniter motor a weird shaft. It is threaded on the top, then dual D bore, then two flat spots. I guess you could attach a #35 to the flat spats on the axle. I actually have a working solution, but it used #25 chain. Aparently its rated at 140 lbs. I have a 80 tooth #25 sprocket for the back that fits the freewheel adapter, and my motor will accept a 11 tooth #25 sprocket.

Safe: I do own that motor. Yes, you could get away with the #25... it will wear faster. I've gone through one chain after 2000 miles but I've been running less power for most of it. The #35 is a better quality option, but if you can do it already I'd say go ahead and think about an upgrade later. You might also decide to change the gearing anyway, so you could make all the changes at once. When in doubt use what you have until it breaks. The shaft on the 1200 watt motor is where you would use the twin set screws on a sprocket to bolt it onto the motor. If the "double d" flat spots are in the right place as far as alignment then you can use them, otherwise you might need modifications. It should just bolt on though if you ever plan to go with the #35.

 

[Beagle123]

Thank you everyone for the encouragement and advice.

The7: Fetcher showed pictures riding a bike with one of these hubs. He went to Thunderstruck Motors and they had one.

Xter: They list in the hub’s manual that the maximum torque is 135 Nm (Newtons * meters) or 100 ft lbs (foot* pounds) Also they say its suitable for cruiser or commuter bicycles. (?) I’m thinking that if you took 100 lbs and hung it on the end of a 1 foot ruler that would be a lot of torque. I don’t know anything for sure. But I think it looks good.

Also, it can’t be the same hub as on the scooter. This one is big and weighs about 10lbs.

Decianno : Yes, big balls.

BigH, HopBot: Thanks a lot!

Safe: I can’t tackle motor-current limiting until I have a bike to use it on. I plan to develop an electronic device that controls everything (i.e. current, and gear) .

I’m still very unclear on how to attach those 114 tooth sprockets to the back wheel’s 1 3/8 inch threaded connection. I plan to post an extensive question on my motor/sprocket/chain dilemma very soon, so I’ll leave it to later.

 

[Beagle123]

Started Frame Today

After posting yesterday, I got inspired to do more work on the bike. So, I ran out to the garage, and cut the wrong hunk of metal off my swing arm, and ruined it.

However, I made another trip to the metal yard and bought more aluminum.

I made the beginnings of a battery box. It's important to have a good jig to hold everything in place to weld. In this case, I just had to cut two wood blocks that were the width of my batteries, then clamp the angle pieces to them.

I like how the cross-piece fits. I had to grind a bunch of little spots to get it to fit.

I did the swing arm in a similar fashion.

Later I'll make the top of the box the same way.

 

[xyster]

Far more advanced than my battery boxes. But what's the whiffle ball for?

 

[Toorbough ULL-Zeveigh]

But what's the whiffle ball for?

For whiffling dixie.

 

[xyster]

But what's the whiffle ball for?

For whiffling dixie.

Maybe it dropped out of that CVT....

 

[fechter]

Are you going to weld that yourself?


The NuVinci I rode was powered by something almost as big as an Etek. I think it will have no problem with the motor in the picture.

On the rear sprocket, as I recall, he had a "normal" threaded freewheel bicycle sprocket on the hub, then a much larger sprocket with a large center hole was bolted to the smaller sprocket. The bolts passed between the teeth on the smaller sprocket.

 

[Beagle123]

First Welds Today.

I'm not going to weld it myself, but I will PERSOANLLY drive the parts down to the welding shop.

I dropped-off the parts today. I can't wait to see them welded together. In the meantime I made a bracket for the disc brake. It shold hold it almost directly over the center of the disc. It's necessary to place it over/behind the disc so the wheel can slide in from the dropouts. (Pictures later (welded!))


Thanks for the tips fetcher.

 

[Beagle123]

Got Welds Back

I picked-up the parts from the welder. He was a great guy, and he only charged me $35 to do a bunch of welds. They look great. He used a huge machine. It was a tig welder. It was about 4 feet tall and 2 feet wide.

He welded the swing arm part, and the bottom of the box that holds the batteries (the body). Its starting to look like something.

Results below.



I bought these shocks for my project. I don't like how heavy they are. I'd like some lightweight bicycle type shocks, but I can't find that type. The shocks that came with my moped weere much lighter, but these are the replacement shocks for them.

Does anyone know where there are 10-12 inch shocks that are lightweight?

Also, they're supposed to be adjustable. Does that mean you can adjust their length? or their stifness? I'm guessing that you adjust them by twisting. Does anyone know how that works?

Since I couldn't work too much while my parts were at the welder, I started making a workbench. It's great. I"ll include pics when done tomorrow.

With this great new welding technique, I hope to be done before safe

 

[xyster]

Will your Beagle buddies ride your ebike with you? Might be a great way to attract the attention of the wee-mun (especially for Safe, who could use one).

 

[Beagle123]

Hi Xter. Don't worry about safe, he won't have balls soon, so he has no need for women anyway.

Weight Analysis

I was worried that I may be creating a bike that's as heavy as my old one (no improvement) so I bought a postal scale to add-up the weights:

Weights in kg:

Back Wheel w/ Disc 6.58 14lb 8 oz
Front Wheel 2.7 5lb 15 oz
Seat+Post 1kg
Front Fork + Caliper + Stem 2.8 6lbs 3 oz
Handlebars 0.82 1lb 13oz
2 Side Shocks 1.6
Horizontal Swing Arm + Caliper 1.64 3lb 10oz
BatteryBox Frame 2.1
Battery Box Walls 1.51
Neck 1.5
Lithium Batteries 8kg
Unite Motor 6.35kg
Chain 0.45kg
Back triangle that connects to the shocks 2kg
Total 39.05kg = 86lbs

So it looks like it will weigh a little over 90lbs when I'm done. THis is a compramise number for me. I'd like to have light tires and spokes. and a less heavy duyty frame, but Its a good compramise.

 

[Beagle123]

Bits of Progress

Today, I cut off the sidews of the L metal pieces that make my back fork. Its just extra metal sticking off the side.

I put the back wheel into the fork, and located where the disc brake caliper shoug go. Once I positioned it correctly, I clamped it down with Vice Grips, so the welder can weld it to that exact spot.

I'll be welding the top and bottom of the battery box tomorrow

Its nice having a workbench.

.

 

[Beagle123]

Good Progress Today

I had the top and bottom of the battery box welded today. It went very well. You can see in the pic that I'm starting to build the sides now. I've put two wood blocks that are 7 3/4 inches lond inbetween the top and bottom piece to serve as a jig. Then I put a piece of plywood on top and on the bottom of it and sandwiched the pieces onto the blocks using drywall screws to hold them in place for the welder.

The force of the screws going down holds the metal pieces exactly in place.

The key to getting good results is building a jig so everything is fixed in the right place.

I made the top of the box 1 inch longer than the bottom because one of the side pieces of the box will be a wall that supports my seatpost. I'm making it at a 10 degree angle.

 

[Beagle123]

The motor Arrived Today




I'm going to try the Unite 600 watt gearmotor first, but its replaceable. The pic will give you an idea where it goes. I chose this motor just for the simplicity of the install. I'm going to use #420 chain that fits the sprocket of the motor, and will also fit the bicycle sprocket on the back wheel. I won't have to make any alterations (last time I had to make a custom sprocket.)

The other pic shows where the motor will go relative to the battery box. It looks like it will fit perfectly. Notice that I left all the pieces on the battery box and back forks long, so I can just cut them to length later.

Note: the battery box is on its side.