MB-1-E Part Sixteen: The continuing saga

MB-1-E's picture

Since we last met, I've been riding my MB-1-E all over.
The controller works great now.

I swapped out the hub sprocket.
I did have a 60 tooth sprocket and changed that to a 72 tooth ... What a difference!
I can climb hills now, even the steep ones.
On the steepest of hills, I do pedal to help keep the RPMs up, but it's a dramatic change from the smaller sprocket.

I had one malfunction, that was the adjustment bolt for one of the struts that support my Motor/ Jackshaft assembly. It bent as the weight of the motor pounded down on it. The bracket rolled toward the back of the bike and therefor bent the bolt.
I straightened that out today with a little heat from my MAP gas torch. I protected the braze with a damp cloth and it bent back to nearly perfect.
I'll be beefing those adjustment bolts up in the future but wanted to ride the bike.

I went up a steep, long hill today and the bike did very well. I did encounter another problem however (I'm finding all the weak links in the system) ... the DPDT switch that I use to switch from Parallel/ Series to just Parallel gave out.
The hill must have been too much for it.
I had to pedal home ... thank goodness for Pedal Assist!

So a better DPDT switch is on the list.
I'm open to any suggestions.
It's a 24V system. Batteries have 36Ah@24v. I've got a 200A controller. Motor is a Scott 650W (3/4hp) with 30A continuous draw. (pulls much more than that on hills, I'd guess 125A)

Well back to the drawing board (as us draftsmen often say).

Happy EV'ing!

before comments


echuckj5's picture

Hey Dave,

Whats up with with this, I think you're riding to much and are forgetting to share some final pictures with us.
Just kidding,

Anyhow, I was thinking, if you have 2 banks of 12 volt batteries, could'nt that watts up meter be put on just one of the banks if batteries? Will it read at 12 volts?

If you notice I rarely comment on any electrical questions unless I feel I have rock solid information. My abilities are on the mechanical and mathematical end. Electronics, zero ability. I read up on dpdt etc. sounds like one more thing to go wrong. I have worked around electrical relays for years and they always seem to wear quick. Most stuff that I own that have switches use low current relays to engage solenoids that handle the higher currents. A large manual contactor should be enough to separate the two battery banks for charging.

Looks like you hooked yourself to this e bike thing. I find it unpleasant to have to drive nowadays, always like taking the e bike if possible.



MB-1-E's picture

Hi Chuck,

The DPDT switch is pretty handy in my setup.
I could do it manually, but I'd have to rethink my connections between banks a bit.
Right now I have my connections made with the lugs machine screwed to my terminals. That could be tiresome and might put extra strain on my small battery terminals.

Now if I had push on connectors there it wouldn't be too hard to swap out for charging.
Maybe I could just make an insulated copper bar that clips on for running and two that clip on for charging in parallel.

The switch seems to work fine for a while but if it ever arcs at all then it's shot.
I don't ever need to switch it when there is an amp draw so theoretically it should work.
In practice, however, I must have turned my key (an allegator clip for now) on first, thus making a small draw. When I flipped the switch it must have arc'd some.

I like the manual connection if I can figure a way to do it without damaging my terminals.

I just need one of those DPDT Frankenstein switches (the ol' knife switch) ... bzzzzzzzzzzzzzT

And ... Yes, I do need to take some more pics.
I'll do my best ... but it cut's into my riding time

Have you done anything with your ratio yet? :P
Also kidding, of course ...
BTW - Thanks for the info. ;)


Electric - Bridgestone MB-1 Mountain Bike
Icon Photo of lighning striking Eiffel Tower Jun 3, 1902, taken by MG Loppe'

Dave B

<a href="http://visforvoltage.org/book-page/996-mountain-bike-conversion-24v-3-4h... - Bridgestone MB-1 Mountain Bike</a>

echuckj5's picture


No, hav'nt ordered that 48 tooth, will soon, on my current bike should put me at 11 to one though.

About that watts up, could that be hooked up to one bank of batteries?

Fechter posted on another forum a better way to wire our battery packs called "buddy pairing". I use a 24 volt charger so it seems like I should rewire my battery pack. Hope he posts the diagram over here.

My current version of turbocad does not allow me to save in a format that infraview, which I downloaded, will convert. Looks like I'll have to buy something more up to date in the cad area so I can post some drawings to share here.

Need to get the cad problem resolved, then I will post a build on my current bike.



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