First Build Questions / Advice

[timctx]

Getting ready for my first build. Been checking craigslist daily for a suitable bike and wanted to tap into the experience on this site.

Been looking at electric bikes and picked up a Ezee Sprint on craigslist a few weeks ago for $400. Fun bike but a little girlish and top speed is really lacking. Only get about 15mph on flats without pedaling. But needless to say I am hooked and now want to up the power.

Info:

6' 0" 270lbs

I definitely want to pedal and freewheel so probably geared.

Commute about 5 miles round-trip with one decent hill. I live in Austin and coming home up the congress hill from the river sucks when it's 95 F.

Joy rides on hike-bike trail on weekends.

Would like to sustain 20mph on flats, 25 with pedaling.

Range is not a big deal. Would like to get something around 10 miles per charge.

Want to be able to detach battery and charge. I live on second floor and carrying these things up stairs sucks. Even the little Ezee is a handful. I have a storage closet at ground level in my condo but no power.

Comfort bike with front shocks is most likely candidate though I have an old chromoly Stumpjumper that I use as a bar bike and might be good for a front hub. Otherwise a Trek Navigator or Specialized Crossroads.

Motor / Battery possibilities:

Emissions-Free MAC 500W 10T is my top candidate. Probably matched with 52V 9.2ah battery pack. Think this would get me about 10-12 miles at 20-25mph. Read on a few posts about how long it sometimes takes Cell_Man to get things out. Am I looking at 2 weeks or 12 based on experience?

Also considering the Magic Pie with built in controller for simplicity and getting a Ping battery. Will this combo be plug and play? I am ok with crimping some new connectors but not up to soldering a board.

Also toying with the idea of a small Lipo pack from HobbyKing but the charging and assembling seems a bit daunting.

Recommendations for a different donor bike or power combo are welcome. Money is not really an issue but getting up an running with some power in fairly short time frame is.

Thanks!

[dogman]

If you want the bit more power, and the freewheeling ability, then The Mac 10t makes sense. So does the battery.

It won't arrive Ebay fast, but I couldn't say what his shipping time is. It's summer, bike season and all. He could have a backlog of batteries to build.

But if you settle on something else, all you'd likely have to do is install the same kind of connector onto the battery and controller to connect those wires.
If you go with the ping, get a 15 ah. Cellmans battery can be smaller because of the better discharge rate. But the ping needs to be 15 ah to have enough power for a typical 20-25 amp controller.

[Drunkskunk]

+1 for the MAC 10turn and battery combo.

The Specialized Crossroads XC from the middle of last decade would be good. The modern ones are not worth the effort in my oppinion.

The Trek navigator isn't a bad bike, but I much prefer the Trek 820. Its a more solid bike.

[timctx]

Thank you both. There are a few 820's listed in my local craigslist for around $250-300.

Given the Suntour M2025 is steele would you recommend front or rear motor? Front seems a lot easier and would make for nice balance if I put the battery and controller in a frame bag like this http://www.amazon.com/Bicycle-Triangle- ... B006JA8WEG.

Sent cellman an e-mail and waiting on response.

If there is a big wait I will try to grab a decent kit on ebay, Lipos from Hobby King and a basic Linen controller. I have been reading up on Lipo and still don't fully get the BMS setup.

[dogman]

I like front motors fine for street riding. But for dirt it really has to be rear motor. You can ride easy trails with front hub, but when the wheel starts spinning in the dirt, most people really hate that with a front wheel.

Maybe I misunderstand, and you mean paved bike paths? Steep single track bike trails need the rear motor.

[timctx]

Only offroad will be well maintained hike and bike trail around the river downtown. Using the bike paths is one reason for ebike over scooter. Primary use is short trips and commute downtown without getting sweaty and not worrying about parking.

I like the simplicity of front motor and since the Trek 820 has steel shocks think that is feasible. Also should work for weight distribution... motor in front, battery/controller midframe, my fat behind in the rear.

Given your experience with LIPO is there a basic setup you would recommend for a short haul pack good for about 5-6 miles? Need cells, charger, power supply, not sure about BMS.

[dogman]

My misunderstanding then. You might want to look at some measurements closely though, since some suspension forks have room for some motors, some have room for any front hub, and others are too close together for use of any front hub motor. It just depends on the exact space between the tubes, in general if the fork dropouts are mounted towards the inner edges of the shock tube, you have room. Center mounted, some motors may not fit between the tubes.

As long as the road is dry, front hub is no problem. When wet, you just need to get on the throttle more gently.

You want a torque arm, and two C washers. The c washer fits into the cup in the forks, typical with a quick release hub, or modern bikes "lawyer lips" the place to get that is Grin Cyclery. For an alloy fork, two torque arms.

[timctx]

Update: Have not heard back from cellman and I want to be up and running fairly soon.

Rented a Stromer from a local bike shop. Not bad, they gave me 2 days for $30 and put about 25 miles on it. General impressions are pretty good but man is that thing heavy!! Carried it upstairs last night and don't want to do that every day and would never shell out $3k+, maybe $15K.

The DD is definitely a negative when not under power. The drag was noticeable and just felt strand. Same with the pedelec, it worked but did not feel natural. I did not like the half throttle, much prefer my Ezee Sprint full throttle but have not tried the thumb yet.

The Stromer had more power but less initial juice than the Ezee, about what I expected from DD vs. geared. Top end was much better though not exceptional. I think they cut power at 20mph on the Stromer and my Ezee can barely get me to 16mph. I think with 20 Amp / 1000 watts the Stromer would be pretty awesome.

Will probably go ahead and order a magic pie 3 if I don't hear from cellman by tomorrow which is a week. And doing research getting comfortable with the Lipo stuff so will probably go that route for the weight to power benefits.

[dogman]

Easy enough to just ride under power at all times with a DD and throttle. Late in the riding season now to wait on Cellman.

[winkinatcha]

hey mate,

i have only just completed my first front wheel build and have prolly clocked about 100 miles on it so far. I have put well over a 1000 miles on a variety of rear wheel builds.

My experiences (similar to others based on the comments/responses to your thread) are that the front wheel is fine for the kinda surfaces/work you are looking at, firm, relatively smooth, unlikely to have either the bike airborne, or trying to get up a 50% hill with dubious traction

I am now a front wheel convert after using the current front wheel build purely as a shared cycle way/road/ foot-trail commuter. Main reason... I can keep or upgrade the rear wheel and human powered gearset, so can work on maximum efficiency on the pedal powered front without having to compromise due to restrictions on freewheels, space, brakes, and wheel size.

BUT I would not be even vaguely inclined to Jump a front wheel build or do the dubious surface sharp incline thing unless under duress, whereas with my variety of rear wheel builds, I takes off road and does stupid things with them all the time.

Here are some details of the Front wheel build I am currently working with.
http://frankencycle.wordpress.com/builds/pocket-rocket/

The motor is rated as 500w at 24 volt, the battery is 24 volt 15ah, the frame is steel, ex "hybrid" with a 700c road rear wheel and freewheel fitted.

Joe

[dogman]

I always did like front hub for street, and have it on my commuter to this day. If you have a tall FS bike, it's possible to pedal through corners without pedal striking on the pavement. Then you get to corner with power on both wheels for great traction.

And you get to keep 9 speed rear wheels with nice cassetes, which you might prefer to 7 speed screw on freewheels. 48 tooth front and 11 tooth rear is a good cruising gear for a 48v bike. No need to hunt down a 52 tooth crank that fits an MTB frame.

Front hubs on alloy shock forks is not ideal though, you can try many different forks before you find one that actually works with the motor installed. They tend to bind with the motor powered up. And of course, you have to install it right, or you get to go buy new teeth and collarbones.

[hjns]

... And of course, you have to install it right, or you get to go buy new teeth and collarbones.

Where do you buy your new collarbones?? Can you grow them on trees?

[dogman]

No, they make em from titanium or something. Mine cost $15,000. I'm a little miffed, now I have screw heads that stick out right where a pack strap goes. You'd think for 15 thou they could learn to countersink screw heads.

Along with never install a front hub wrong, don't fumble your water bottle into the front forks like I did. Fortunately, a cheap helmet saved me from having to buy a new skull.