Ebike 2 Folding the 2,21kWh battery rack !!

[Doctorbass]

I began today to desing and draw what will be my batery rack on my ebike 2.

I began with measuring space between the front wheel tire and frameand the width where the pedals are.

I will built it in alluminium 1/8 thick and will make some hole to remove weight.

Here are the pics:

I will share all subpack like:

2 x pack 6s18p onder the main frame

12 x subpack 1s 18p on top of the first 6s18p pack on each side of the main frame, the rest will be placed where empty space of the rack.

The wheel will never touch them if my measurements are good :wink:

 

[TylerDurden]

We better add cardboard to the "most usefull inventions" topic.

 

[lawsonuw]

heh, High end "CAD" at it's best

(that's Cardboard Aided Design, best tool I know for fitting stuff in an existing machine)

Marty

 

[Miles]

......that's Cardboard Aided Design....

 

[steveo]

Hey doc..

You are experiencing the fun time i had!.. I'd suggest how i did mine ... but you are using different cells... Just keep at it you will find something that will work for you... I suggest using vinyl metal coated straps to hold you cells in place .. its worked well for me ... heres a pic to give you an idea

i had it like this before .. I've changed it to fit 2 33v 11.5ah on each side of the bike .. it is now nice & balance .. i must take pics & video!


P.s. Doc i highly recommend mud flaps!


-steveo

 

[safe]

Don't forget that under heavy braking the front forks will tend to bend inwards a little. In the worst case scenario the forks will bend under heavy braking and then touch the battery which will cause the tire to brake even more, more flex, more brake... etc... etc... tire locks up and either you skid or go over the front.

Two broken collarbones... (his was a water bottle malfunction)

(see the "Scary Accidents or Near Accidents " thread in General Discussion)

 

[Doctorbass]

Thanks for the safety advices guys, I dont want to someday the need to post in the scarry accident!

I think that the free space i left between the tire and the battery would be suffisent. I may consider to add some spacer on the fork tobe to limit the movement, or to change from a 2.1"tire to a 1.75".. i'll see, but the shock was pressed at the max with quickgrip when i checked the free space.. and i still have free space.. but i may need to watch closely to the forst 6s18p pack inther the frame, cause the space is closer...

i'll work on that today. it's 11:36am here.. great cofee, sunshine, no wind... another great day for diy !

Doc

 

[safe]

I should explain more...

With long travel suspension the amount of flex will be more at longer distances. So when you are bouncing up and down while braking the maximum clearance needs to be a little more with the tire fully extended than all the way in. Just leave a little extra there. (maybe 20% more room)

This sort of thing is a pretty common problem on motorcycle road racers when they try to get the fairings as close to the tire as possible. The last thing you need is for the front tire to touch when you hit the front brakes going into a turn.

Just be sure to allow more space in the extended position than the compressed condition that's all... people don't think about that. There is more flex the longer the distance from frame to front wheel because the leverage is greater.

There are times when if you are going over a bump with the front brakes on heavily that you will have the suspension rebound on the back side of the bump... it's this rebound situation that is the time that the tire will rub and not the compressed state.

You know how over the top of a bump you get a "chirp" sound from the tires on heavy braking? That's because on the back side of the bump the tire is unloaded and has less traction. When that tire lands again it's more fully extended and the braking force is momentarily higher. That's the "spot" where the problem shows up... nowhere else... front forks tend to flex back and forth as you go over the bumps and the braking force varies. (this is all assuming heavy braking of course)

 

[Drunkskunk]

Looks good Doc!
Had you considered using carbon fiber at all?

 

[Doctorbass]

Looks good Doc!
Had you considered using carbon fiber at all?

No, i dont, i want cheap material that are easy to work with.

I estimate the total weight of the bike to around 90lbs and i dont border with that. i may replace the original disk brake for 8 inch diameter and make some holes in the alluminium rack, but no more.

My first treck ebike was 82lbs and the center of gravity was near perfect and it was easy to drive with.

Doc

 

[Doctorbass]

continued UPDATE here: http://endless-sphere.com/forums/viewtopic.php?f=14&t=4540

Doc