New build. The S.U.B (Sport Utility Bike)

[Smoker]

Got my 406 & 72v20a controller kit in from ebikes canada with fairly quick shipping. The new bike is built upon a older specialized hard rock frame with an xtracycle bolt on frame conversion. The bike went together quick and no fabrication was needed with 135mm dropouts. I loaded on X6 12v12ah (54lbs) batteries to hold me off until I upgrade next year. The enclosure you see under the deck holds the 72v controller and amplifier for the mono system (music).

Wow, this thing is fast compared to my WE BD36, even with a passenger on the back I can hit 32mph. At first I was having problems with the controller over heating while carrying a passenger up long hills so I mounted X2 40mm computer fans to the heatsink on the controller and it seems to fix the problem. Handling is pretty decent with the longer wheel base while sitting on the rear deck. Sitting normal there is more weight on the front tire as the frame conversion shifts the driver weight forward.

Lots of smiles. Thank you everyone for your help.

 

[D-Man]

Nice job. Does the "xtracycle kit" use the existing wheel/axle or do they give you a heavy duty wheel/axle to support all the weight that people load on the back? How fast is the bike with just you on it?

 

[Smoker]

The xtracycle attaches via stand offs that clamp to the read dropouts and another bracket attaching to the chain stay area. The new dropouts fit a 4 series perfectly with the 7 speed cassette. The side bags are rated for 60lbs each, the rear deck is rated for 200lbs (in front of the axel 50bls behind). and side loaders rated at 60lbs.

So I smoked a few things today, not exclusive to electronics apparently. The music amp is a 12vdc computer speaker amp. I have it wired on the 4th battery (out of 6 in series) to the negative terminal and amp positive goes to the negative terminal on the 5th battery (after the fuse). I guess when the negative terminal on battery 4 came off, the 20amps of current tried to go through the amp .

Anyone have a source on 72vdc to 12vdc @ 10+ watts? Ebikesca is out of stock.

The tires I have are rated at only 40psi which gives a smooth ride but I'm scared about integrity at high speed. No speed rating on the tires. Are max speed rating usually proportional to max psi ratings?

 

[knightmb]

The tires I have are rated at only 40psi which gives a smooth ride but I'm scared about integrity at high speed. No speed rating on the tires. Are max speed rating usually proportional to max psi ratings?

For a bicycle, probably not. Tire manufactures for bicycle tires don't envision the cyclist going over 50MPH on the bike so anything less I wouldn't worry about it.

 

[fechter]

Almost a Winnebiko. Cool.

You might check Thunderstruck Motors or Electric Motorsport for dc-dc converters.

Next you'll have to mod that controller and amp. A lot of power amps convert 12v to a higher voltage for the output stage. You could bypass the converter and run the amp directly off 72v OK, that would be overkill.

 

[Beagle123]

Nice work smoker. That's amazing performance. I don't even see the batteries. Where are they?

Also, I think that thing needs hubcaps and a mini-bar. Just my opinion.

 

[Smoker]

Got a flat tire today Gave me an oppertunity to take some pics of the xtracycle kit dissassembled.


Side note: I have 2 WE 36V chargers and have to remove the batteries everytime I get home. Does anyone have a spiffy way to charge my 72v bank of 6 batteries with the two 36v chargers without removing interconnectors for charging?

Or does anyone know a good source on 72v chargers? If so what's the fastest I could charge a SLA 72v 12ah pack without degrading the life cycle?

 

[Jozzer]

if you have already 2 charge terminals on the packs, then just put a switch in between the 2 36v packs (you could use your existing switch), so each charger is isolated from the other, and leave the batteries where they are.
Or, put in a 36v/72v relay system, and charge 2 packs in parralell with both chargers in paralell, or buy a faster 36v charger to do same..
If you know if your charger are "isolated", the above is not needed, and you will be able to charge 2 36v packs whilst they are still connected as a 72v pack.
Shame about the flat Hope the repair went well!

 

[knoxie]

Nice Work

Years ago I wanted to make up an Xtracycle but you couldnt get them in the UK? so never did it, they are a great way of turning a bike in to horse! and you have added at least 1 horse in the form of the motor!

Very cool let us know how you get on with it, you will appreciate a big performance boost in time by swapping out the lead for NIMH or Lipo!

Thanks for sharing the pics

Knoxie

 

[fechter]

You can leave the packs connected at 72v and charge each half with a 36v charger as long as the chargers are isolated. To check, measure resistance between the ground pin on the AC plug and both the + and- output wires. If you see something close to zero ohms on either of these, then the chargers are not isolated and cannot be used at the same time. If they are isolated, you would see a resistance that's very high, like something over 10k.

I had some chargers that were not isolated, so I took them apart and located the trace inside that grounds the output to the AC ground pin and removed it. The ground wire was left intact on the input side of the circuit to maintain safety. The cheezy way to take care of that is to simply snip off the ground pin on the charger plug. Only one charger needs to be isolated if you're using two. I don't really recommend snipping the ground pin, since this could present a shock hazard if the charger got wet or damaged.

 

[gwsaltspring]

Great looking bike, I have looked at building one of these myself so it is good to see your results.

I'm attempting to collect some info on the differences between the C-Lyte 406 and the BD36 motors.

You seem to have some first hand experience of both.

Are you willing to answer a question or two?

 

[vanilla ice]

Anyone have a source on 72vdc to 12vdc @ 10+ watts? Ebikesca is out of stock.

I'm sure you already saw the thread on cheap ac switching power supplies, but it not, there you go. Nice beast of burden you got yourself there.

 

[oatnet]

Nice job, looks good!

Sorry to revive an old thread, but has anyone tried the xtracycle with a rear x5? I am about ready to add one to one of my bikes, but I am concerned about the dropouts handling an 88v 5305 and I'd be disappointed if I ripped them out on my first try.

-JD