the black momba

[powermed]

thought that might be a catchy name...some modifications to the chargers / keeping the plug inside, dc converters under the foam for lighting. I carry a computer to work so the pelican-like case is great protection. Anyone else doing mid-engine - through the gears stuff? This is my fifth bike, I keep number two, the tidal force, for my winter commute (too much salt in Maine for the steel framed KHS). I've a 5 mile ride and charge at work - 3.5 AH at 36v is perfect. I get up to around 30 mph on flats but rarely go that fast while commuting (it's a little scary for me).

 

[Link]

Nice. I'll bet that thing's got good pickup.

And, dude, I think you're gonna want to fix that typo in the title. 'Cause I wouldn't be caught dead riding a momba, black or otherwise.

 

[retread]

Very clean design, and a cool name! I particularly like the motor-mount, as it looks very easy to remove/adjust.

 

[powermed]

Now that I know what the name means I like it more...

Great pickup, it's not hard to pop a wheely if you're not careful - combination of the 24" rear wheel and some deliberate choices using [I think] sheldon brown's gear calculator. Also the Sturmey 8 has a good ratio for my daily commute. It's held up fine now for 2 seasons of daily use (April - Nov, I switch to an aluminum bike with studded tires for the winter).

Motor mount is very easy to do, just some "weight clamps" (used in some kind of race cars), stock aluminum bar from the hardware store, and a couple of other basic hardware store items. Three point attachment of the motor seems to be critical in my experience, at least with the torque the 1000w powerpack motor and controller generate at 36v.

 

[spike]

Hi Powermed

Nice chain drive! I've been looking at doing something similar on my Dahon Matrix.
I couldn't find a chain ring to match the Currie chain size though.
I tried Scott at Evdeal but got no response (the web site is down as well).
Where did you get your #25 chain ring from and how easy was it to fix to the standard chain ring?

Cheers

Spike

 

[Link]

Now that I know what the name means I like it more...

 

[powermed]

Hi spike, not terribly challenging to mount...

TNC (ebay) has #25's chain rings for about $15 that have 5 spokes. I just laid it out on top of the front freewheel crank, marked, drilled the holes, then dremeled off each spoke removing the center ring (about a 1/2 inch or so below the holes I drilled).

One thing I'd have you keep in mind is the width of the motor and planetary gear assembly. I wouldn't want to go much "taller" than the brushless BMC motors. There's a 1000w brushed one that's about an inch taller, and that doesn't leave much room for much else between your legs (with great deference to any comment or picture Link might come up with

 

[powermed]

Found it spike;

http://cgi.ebay.com/NEW-Sprocket-72-Tooth-for-25-Chain_W0QQitemZ330246964161QQihZ014QQcategoryZ11332QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

 

[powermed]

Here's an example of a "weight clamp" - you can also use motorcycle handlebar clamps.

http://cgi.ebay.com/ebaymotors/WEIGHT-MOUNT-CLAMP-1-3-4-IN-IMCA-CIRCLE-TRACK-AFCO-RCI_W0QQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247QQcategoryZ107061QQihZ025QQitemZ380040758280QQrdZ1QQsspagenameZWD1V

 

[spike]

Excellent! I think TNC ship to Aus as well. Many thanks.

Spike