GT Zaskar - second build

[scfoster]

So I've decided one bike is not enough.....

Build #1 has a rack, mirrors, fenders and all the stuff for the daily commute. Looking for a second build which I can use for commutes but want to take on light trails as well. Definitely want it to be somewhat stealthy. No big batteries (commute is only 5.5 miles each way & can charge at work) required.

Here's the donor bike, a GT Zaskar 29er Elite in bone stock form at 28.6 lbs (13kg).

UPDATE:

Here's the bike with the BBS02 installed and the Samsung battery pack. Weight with the battery pack is 45.4 lbs (20.6 kg).

I prefer this configuration of the battery installation... too bad it doesn't actually fit on the bike, There is about 5mm of interference between the battery pack and the frame. I'm loath to start shaving the battery pack to make it work.

So the first question is whether I should go with the 750W BBS02 like my other bike or a MAC 6 Turn Hub motor? The BBS02 has the built in controller with the weight centered. Would also be able to swap out rims/tires for different uses. The Mac Hub would more than likely be faster on the road but the weight will be on the rear and require a separate controller box. The upside of the hub motor would be a real torque sensor in the BB with V3 Cycle analyst integration.

My commute is relatively flat with some hills but nothing outrageous (300 ft - 90 meter elevation change) or long in duration. 2/3 of trip is city streets with stoplights each block. I do end up on the sidewalk for part of it which is accepted by local police as some of the streets are narrow. Lots of potholes and deep ruts (tax dollars at work). Then there is one short section of smooth road with no breakdown lane, shoulder or sidewalk where traffic is moving at 40-50mph. That's the section where it would be safer if I was moving over 30mph (speed limit is 35).

Looking for input on pros & cons of each choice.

 

[Avitt]

Do you prefer PAS-only, without a throttle? If so, then the rear motor with a torque sensor is probably the better choice, as it will help you to take off from stoplights without downshifting.

If you don't mind have a throttle, then this concern is not a factor, since you can just give it a little throttle input to get going.

 

[melodious]

I'd base builds off power level. Your commute bike is 30mph capable? I'd take it up to either 40-50mph for your next build. But that bike pictured isn't one I'd put to that task.

Reason, ever since I put the BBS on my folder, I'm finding it's rather the same ride as they both go 30mph. One is more nimble and the other just rolls over most things. In fact, when my folder is all decked out, I have more carrying potential vs. my racked Surly. They both IMHO, are still underpowered to compete with on road traffic (that's where 40+mph builds shine).

 

[scfoster]

Points taken. I'm happy with the BBS02 and I do like that a separate controller box is not required. The Samsung battery is more than enough to get to work and back without a recharge, so something half it's size would be useable. It just barely didn't fit vertically on the seat post. I'm thinking of a custom battery pack mounted vertically in the frame triangle against the seat post. Would be smaller and a lot less visible. It would have to be removable as I would have to charge it at the office.

Here is another thread discussing the BBS02 vs the Mac10.

 

[scfoster]

Added the Wattmeter purchased on Amazon for $21. Really not happy with my wiring job and the mounting (as you can see it's not straight). Got the Sugru package today so I'm going to fix the mounting.

For the bike wiring in general, I really don't like all the wires, so I ordered a crimper for $9 that comes highly recommended and plan on using these powerpole connectors to standardize the connections. They're rated at 30 amps and can be purchased for lower or higher amperage ratings.

Here's a picture of the battery I originally purchased from em3ev.com with the Anderson Powerpole 30 amp connectors. Six are linked together for the motor connection (3 for positive side and 3 for negative). Two are used for the battery charging cable. Not sure why three are used for the positive and three for the negative side. I would assume one 45amp connector would work but Paul must have a good reason.

So the plan is once I get all the of the ordered connectors, I'm going to clean up (shorten) all the wiring to give everything a more OEM look to it.