Check out my new electric fatbike

[jcovaltine]

This is my first electric bike build. So far I couldn't be happier. The mid drive setup is made by Tangent Motors. Dave is a great guy to work with. He made some modifications to his kit so it would clear my chain stays (Didn't want to modify my frame). This thing is a beast, wheelies no problem, rips up the hills like nothing. Couldn't be happier. The battery box is home made. Shaped it with balsa and hardwood then covered both the interior and exterior with 3 layers of fiberglass. So far everything it holding up great. I went with the Luna Cycle 52 volt battery pack.

 

[tahustvedt]

Epic bike!

 

[jcovaltine]

Epic bike!

Thanks man

 

[E-geezer]

Nice clean build, well done.

 

[StinkyGoalieGuy]

Beautiful!

Any details on how you made the clamps that hold the battery box to the frame? Can we also have some close up pictures of those clamps?

 

[liveforphysics]

Nice build!

 

[Ykick]

Very well done!

'gonna need to look into that Tangent drive...

 

[jcovaltine]

Beautiful!

Any details on how you made the clamps that hold the battery box to the frame? Can we also have some close up pictures of those clamps?

I purchased 8" hose clamps from Home Depot. Cut off the ribbed portion, was able to bend it easily to conform to the frame. Found some rubber which had an adhesive side to it and there you go. Cost me about $10 to make all 4. I will post pictures when I get home.

 

[WoodlandHills]

Did you make a mold? And if so what did you use for release agent. Also boat resin or epoxy? I LOVE the battery box!

 

[cal3thousand]

Very nice!!

Can you share some performance spec for those looking into these kits?

 

[litespeed]

Super clean, very nice.

Tom

 

[jcovaltine]

Did you make a mold? And if so what did you use for release agent. Also boat resin or epoxy? I LOVE the battery box!

Thanks it took longer than I thought to make but totally worth it.
I just first made the shape out of Balsa wood and then layered both the in side and out side of it with glass.

 

[tangentdave]

This bike is so clean, it almost makes me want to put the batteries on the bike. This is the first setup with the new 104/74mm BCD spider I made up for fatbike chainstays:




This just barely clears the chainstays on this bike. I have to modify the freewheel flange since the 5x74mm BCD is within the diameter of the flange. Aside from that, it was just several tries until I found the right combination of chainring bolts and countersinking holes until thing fit right.

jcovaltine is setup with a 3210+TalonHV120, running a redesigned, quieter 40:1 internal ratio and a 16->24t secondary (60:1 motor->crankset). We also have temperature protection provided via Cycle Analyst with the temp sensor directly measuring the motor windings. The 3210 can handle 120A burst, this is really the ultimate ebike killer- about 2kW continuous and 7kW peak in 7lbs? Hell yes.


-dave

 

[jcovaltine]

Very nice!!

Can you share some performance spec for those looking into these kits?

Check out Tangentmotors.com for the technical specs on the kit. But let me tell you this setup really rocks. It will wheelie no problem. Top speed not sure yet I'm guessing 35-40 but with my tubeless tire setup I get a little nervous about the tires blowing out. I was more interested in hill climbing. Dave is a great guy to deal with. There were two other bigger motor options I could have gone with. In must cases I would usually go with the biggest but Dave said this setup would be more than enough and I'm glad I went with it.

 

[ColinB]

Looks super!

Have you worked with fiberglass before? I'm very jealous. I need to do something similar for my bicycle. Currently my battery box is a plastic bin, and it doesn't look quite as nice as yours.

Can you suggest where a fiberglass newbie might start?

Thanks,
Colin

 

[jcovaltine]

Looks super!

Have you worked with fiberglass before? I'm very jealous. I need to do something similar for my bicycle. Currently my battery box is a plastic bin, and it doesn't look quite as nice as yours.

Can you suggest where a fiberglass newbie might start?

Thanks,
Colin

I grew up flying Gas powered RC airplanes. Before all the almost ready to fly models I was building my planes out of balsa wood. You usually glass the center section of the wings. So yes I have some experience, and I know what technics works for me. Are they the right way probably not but I was able to achieve the outcome I was looking for. I will post more photos haven't figured out how with out up loading my photos to photo bucket then sharing from there. PITA

Basically I made the box out of balsa first. Think I used 1/8" sheets for the sides with curves and 1/4 hard wood ply for the areas that had the blind nuts. After that I just started my first layer of cloth on the outside of the box. I just used whatever Home Depot had. However the weave wasn't very tight. I found a fiber glass supply shop where I was able to get 8oz cloth which had a very tight weave. For the resin I used what Home Depot had in stock. Is there better stuff, yes I'm sure but this was all a test on how long this will hold up. The battery is pretty heavy think around 12 pounds. This box I made has a total of 6 layers of fiber glass. If I see that it's starting to crack I will probably build another one with more layers. I also lined the inside of the box with rubber to give the battery a little cushion. I think it will all hold up fine for normal trail riding and a few jumps here and there but in an event of a crash I'm not sure.

https://www.instagram.com/p/BEnLkwLt1Sf/

 

[WoodlandHills]

Very nice workmanship! I've done similar using pieces of doorskin (very thin plywood) hot glued together and covered with resin. I made a paste from resin and sawdust and squirted it out of the corner of a Baggie, like icing, along the seams to glue it together......... Yours came out a lot better!

 

[StinkyGoalieGuy]

How did you get your finish to look so smooth? Just a lot of sanding? I had assumed you smeared Bondo on it and sanded it down.

 

[WoodlandHills]

How did you get your finish to look so smooth? Just a lot of sanding? I had assumed you smeared Bondo on it and sanded it down.

Maybe not: a second coat of resin after the first has cured somewhat will fill the weave and give a smooth surface. Too much resin at first will cause the cloth to float on the resin and defeat the purpose. Adding a second coat before the first has fully cured will give a chemical bond as well as a mechanical one and avoids having to deal with "blush", if using epoxy.

 

[jcovaltine]

How did you get your finish to look so smooth? Just a lot of sanding? I had assumed you smeared Bondo on it and sanded it down.

I made sure each layer was very smooth. I used a old credit card to spread the resin and squeegee of the excess on every layer. For the last layer I put the resin on thick and didn't squeegee off as much. That way I had a thicker layer to sand. What you don't want to do is sand into the cloth. So yes a lot of sanding was involved and three coats of primer. But I'm happy with the finish there are some imperfections but nothing to noticeable.

 

[ColinB]

Thanks for the extra information? How did you do the access hatch?

I'm lucky - there are several sources for epoxy and fiberglass cloth in my area. (I don't know which to use, but I'm able to buy them! lol.)

Colin

 

[WoodlandHills]

If you are working with wood or ply then epoxy is best as far as penetration and absorption, if you are working with foam then either will work although polyester is a lot cheaper and can be bought at Home Depot. For this sort of thing where the wood is a core for the glass cloth, poly resin is just fine, it's only when you start talking about structural bonds and Stitch-and-Glue construction that epoxy becomes mandatory.

 

[beast775]

What a great build 8) .

 

[waynebergman]

Great fat bike there. Way to go. That is pretty cool to have the motor and the battery pack all in the main triangle. I also like the fact that the reduction is a 40 to 1. Sounds like you could be able to have a nice pedal cadence for assisting the motor with this kind of reduction. Awesome!