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How to get a big heavy bike up the hill

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  • ama3655@aol.com
    Morgan - The data I gleaned from your video seems to support the fact that more current at a higher voltage gets the bike up the hill better. No big surprise.
    Message 1 of 8 , Jan 2, 2009
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      Morgan -
       
      The data I gleaned from your video seems to support the fact that more current at a higher voltage gets the bike up the hill better. No big surprise.
       
      Have you checked into A123 systems nano phosphate/lithium cells? They will support some very high discharge and charge rates, abuse doesn't cause them to vent hydrogen fueled flames. We've been using them for some model airplanes that suck up the juice and they are pretty bullet proof compared to everything else.
       
      Also, your power leads looked kind of wimpy. Short fat wires are a good thing for DC current demands. Find a good welding supply, they will have some fat high strand count copper cables that will let the current flow and are also flexible. I'd like to see you smoke some tires going up that hill.
       
      For those of who still pedal them up the old fashioned way, I found out something while riding the Big Dummy today. The roads were damp and a bit slick. I lost traction and had to walk the bike up a hill while riding to the store lightly loaded. Plenty of gears left, but the back tire wouldn't hook up. Riding home with 75 lbs of groceries proved to be no problem. The bike climbed the same grade just fine. I guess I need to gain a few pounds or start keeping a case of beer in the bags.
       
      Fat rob
       
       
       
      In a message dated 1/2/2009 2:35:07 P.M. Central America Standard Ti, mcgurme@... writes:
      Hi Phillip,

      I just posted a video showing comparisons of the two high-powered,
      internally geared BMC hub motors on some Xtracycles.
      http://www.youtube. com/watch? v=YuPOj2SkgDc

      The internally geared motors (eZee, BMC) make
      a bit more noise than non-geared (Crystalyte, NineContinent, Wilderness Energy)
      But in normal operation it is not very much, and the tradeoff for the bit of extra
      noise is a motor that weighs half as much.

      In extreme conditions, such as loaded hill climbing under high power, it is
      noticeable sound, as you can hear from the video. But on the flats, it is minimal.

      Morgan

       



    • Mark Garvey
      ... Those videos showed that the sound was not too bad, my Currie is not a lot different. I have to pedal up hills (I pedal most of the time anyway, unless
      Message 2 of 8 , Jan 2, 2009
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        On Fri, Jan 2, 2009 at 3:25 PM, <ama3655@...> wrote:
        . I guess I need to gain a few pounds or start keeping a case of beer in the bags.
         
        Fat rob
         
        Those videos showed that the sound was not too bad, my Currie is not a lot different.   I have to pedal up hills (I pedal most of the time anyway, unless descending!)  the power assist simply helps me with the chore of climbing.

        As to carrying a case of beer...in my case, I suppose a case of empties would work??? Maybe not!  Damn!

        MArk
        --
        "I just like to blow things up!"

        Papa Balloon
      • Juergen Weichert
        I have had similar experiences when riding my Xtracycle lightly loaded (light or no cargo) in very snowy or icy conditions. The rear wheel is more likely to
        Message 3 of 8 , Jan 2, 2009
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          I have had similar experiences when riding my Xtracycle lightly loaded
          (light or no cargo) in very snowy or icy conditions. The rear wheel is
          more likely to loose traction than on a shorter bike. Fortunately since
          it is also longer it handles great. A slight swing of the rear doesn't
          really affect the heading much compared to a shortbike.
          Juergen

          ama3655@... wrote:
          >
          > Morgan -
          >
          > .....
          >
          > For those of who still pedal them up the old fashioned way, I found
          > out something while riding the Big Dummy today. The roads were damp
          > and a bit slick. I lost traction and had to walk the bike up a hill
          > while riding to the store lightly loaded. Plenty of gears left, but
          > the back tire wouldn't hook up. Riding home with 75 lbs of groceries
          > proved to be no problem. The bike climbed the same grade just fine. I
          > guess I need to gain a few pounds or start keeping a case of beer in
          > the bags.
          >
          > Fat rob
          >
          >
        • Morgan
          Hi Rob, Thanks for the feedback. Here are a few thoughts- The cells in the LifeBatt are made by PSI, and compare very nicely to the A123 cells. They can do
          Message 4 of 8 , Jan 2, 2009
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            Hi Rob,

            Thanks for the feedback. Here are a few thoughts-

            The cells in the LifeBatt are made by PSI, and compare very nicely to the A123 cells. They
            can do 10C rates without flinching. We are now making some custom
            packs out of those cells for customers who want the ultimate in high power/long life.
            The LifeBatt is great, but the form factor is not so good for a bike. The problem with
            A123 cells is that they come in only 3Ah cells, and it requires a lot of messing around
            with paralleling them to get serious capacity. Plus, they don't wholesale them, the only
            way one can get them is buying retail DeWalt tool packs and taking them from those.
            With the DeWalt approach, charging can be an issue (unless you like plugging in 10
            different battery packs after every ride).

            Note that on the LifeBatt, we were drawing a constant 35A load and voltage sagged only
            to 34.9 volts. That's about 4 V of total sag, which is very good for a constant 35A load.
            Most of the cheaper Chinese LiFEPO4 batteries will sag down to 32-33V at best under
            that kind of load (many will sag down to where the LVC cuts off battery power altogether).

            Note that even with the Chinese cells, if they are Lifepo4, they WILL NOT turn into flames
            as you imply in your post (just to make sure nobody gets scared unduly). That is one of
            the benefits of Lifepo4 - they are more stable and not prone to going "poof", unlike the
            lighter but more volatile LiCoO2 chemistries (which we do not sell or promote for bike
            usage).

            It is true that higher current and higher voltage each contribute to going up the hill.
            Higher current makes a bigger difference at very low speeds, because the controller
            doesn't have to do as much down-conversion from volts to amps. But, at moderate
            and higher speeds, the higher voltage makes a big difference by overcoming the back
            emf and pumping more current through. Combining the two
            makes for a very fast ride.

            As for the power leads, most of those are 10 gauge copper. The resistance on the wires is
            low, there is extremely little heating in these (i.e. not noticeable), even at 35A currents. It
            is true that overly thin battery leads can reduce system performance, but only by a few
            percent (unless they are thin enough that substantial heating occurs).

            Anyway, I read about your ride home today - here's a thought. I've been in very sloppy
            traction conditions with my Firefly Big Dummy, and the cool thing is that the front hub
            motor pulls it, while my pedaling pushes it, and I have two wheel drive. I find that
            I can get through sloppy mud that would otherwise bog down and spin. A hidden
            bonus of electric assist!

            I hope you're enjoying your BD!

            Morgan


            --- In rootsradicals@yahoogroups.com, ama3655@... wrote:
            >
            >
            > Morgan -
            >
            > The data I gleaned from your video seems to support the fact that more
            > current at a higher voltage gets the bike up the hill better. No big surprise.
            >
            > Have you checked into A123 systems nano phosphate/lithium cells? They will
            > support some very high discharge and charge rates, abuse doesn't cause them to
            > vent hydrogen fueled flames. We've been using them for some model airplanes
            > that suck up the juice and they are pretty bullet proof compared to everything
            > else.
            >
            > Also, your power leads looked kind of wimpy. Short fat wires are a good
            > thing for DC current demands. Find a good welding supply, they will have some fat
            > high strand count copper cables that will let the current flow and are also
            > flexible. I'd like to see you smoke some tires going up that hill.
            >
            > For those of who still pedal them up the old fashioned way, I found out
            > something while riding the Big Dummy today. The roads were damp and a bit slick.
            > I lost traction and had to walk the bike up a hill while riding to the store
            > lightly loaded. Plenty of gears left, but the back tire wouldn't hook up.
            > Riding home with 75 lbs of groceries proved to be no problem. The bike climbed
            > the same grade just fine. I guess I need to gain a few pounds or start keeping
            > a case of beer in the bags.
            >
            > Fat rob
            >
            >
            >
            > In a message dated 1/2/2009 2:35:07 P.M. Central America Standard Ti,
            > mcgurme@... writes:
            >
            > Hi Phillip,
            >
            > I just posted a video showing comparisons of the two high-powered,
            > internally geared BMC hub motors on some Xtracycles.
            > _http://www.youtube.http://wwwhttp://www.yo_
            > (http://www.youtube.com/watch?v=YuPOj2SkgDc)
            >
            > The internally geared motors (eZee, BMC) make
            > a bit more noise than non-geared (Crystalyte, NineContinent, Wilderness
            > Energy)
            > But in normal operation it is not very much, and the tradeoff for the bit of
            > extra
            > noise is a motor that weighs half as much.
            >
            > In extreme conditions, such as loaded hill climbing under high power, it is
            > noticeable sound, as you can hear from the video. But on the flats, it is
            > minimal.
            >
            > Morgan
            >
            >
            >
            >
            >
            > **************New year...new news. Be the first to know what is making
            > headlines. (http://www.aol.com/?ncid=emlcntaolcom00000026)
            >
          • ama3655@aol.com
            In a message dated 1/2/2009 8:18:24 P.M. Central America Standard Ti, mcgurme@alifelikewater.org writes: I hope you re enjoying your BD! Morgan Oh yeah, I m
            Message 5 of 8 , Jan 2, 2009
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              In a message dated 1/2/2009 8:18:24 P.M. Central America Standard Ti, mcgurme@... writes:
              I hope you're enjoying your BD!

              Morgan
              Oh yeah, I'm enjoying the BD. I find myself looking for excuses to go for a ride in sloppy weather, going to grocery stores that are farther away than necessary.
               
              It was a good deal, Thanks!
               
              Fat rob



            • Cara Lin Bridgman
              I had a really interesting near wipe-out this week when my rear wheel skidded on a painted turn arrow. This was downhill in the rain, just after slowing down
              Message 6 of 8 , Jan 2, 2009
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                I had a really interesting near wipe-out this week when my rear wheel
                skidded on a painted turn arrow. This was downhill in the rain, just
                after slowing down for for the right-hand turn that resulted in the skid.

                The rear wheel was loaded with the large StokeMonkey battery and papers
                for a class (and all the usual stuff crammed into the free-loader bags:
                tools, tire kit, free-radical bars and extenders, rain gear, dry bag,
                straps, spare batteries, and spare lights). This was on the light side,
                as usually I'm hauling a few more kilos of books, papers, and water
                bottles.

                The right foot came out automatically to brace the falling side and I
                continued on my way with a "What the heck was that?!?" and a backward
                look.

                I've noticed before how paint smooths out the road surface. In fact, on
                one of my climbs, I tend to ride the white line as it seems to make the
                climb easier.

                CL
              • Mark Garvey
                ... Um...yeah....those suckers are slippery! any paint on the pavement will be much more likely to dump you in the rain. Even in normal conditions. Maybe it
                Message 7 of 8 , Jan 3, 2009
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                  On Sat, Jan 3, 2009 at 1:25 AM, Cara Lin Bridgman <cara.lin@...> wrote:
                  I had a really interesting near wipe-out this week when my rear wheel
                  skidded on a painted turn arrow.  T


                  Um...yeah....those suckers are slippery!  any paint on the pavement will be much more likely to dump you in the rain.  Even in normal conditions.  Maybe it is more noticeable on motorcycles or something, but I make it a habit to pull the bike upright on any painted bit on the road.  Motorcycle OR bicycle.

                  My boss has a T shirt that says, "If you are laying in the ditch upside down, you have just done something wrong!"

                  He received it as a present from an "admirer" after he found himself upside down in a ditch one morning!

                  MArk
                  --
                  "I just like to blow things up!"

                  Papa Balloon
                • Cara Lin Bridgman
                  Yes, I ve definitely noticed the slickness of paint (turn arrows, pedistrian crossing, lane indicators) when on a motorbike! The paint can raise the level of
                  Message 8 of 8 , Jan 3, 2009
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                    Yes, I've definitely noticed the slickness of paint (turn arrows,
                    pedistrian crossing, lane indicators) when on a motorbike! The paint
                    can raise the level of the road enough to catch a bicycle wheel.

                    As for laying in a ditch upside-down, it is rather drastic instant
                    feedback of having done something wrong!

                    CL
                    who well knows that we tend to be much more lucky than smart!

                    Mark Garvey wrote:
                    > On Sat, Jan 3, 2009 at 1:25 AM, Cara Lin Bridgman
                    > <cara.lin@... <mailto:cara.lin@...>> wrote:
                    >
                    > I had a really interesting near wipe-out this week when my rear wheel
                    > skidded on a painted turn arrow.
                    >
                    > Um...yeah....those suckers are slippery! any paint on the pavement will
                    > be much more likely to dump you in the rain. Even in normal
                    > conditions. Maybe it is more noticeable on motorcycles or something,
                    > but I make it a habit to pull the bike upright on any painted bit on the
                    > road. Motorcycle OR bicycle.
                    >
                    > My boss has a T shirt that says, "If you are laying in the ditch upside
                    > down, you have just done something wrong!"
                    >
                    > He received it as a present from an "admirer" after he found himself
                    > upside down in a ditch one morning!
                    >
                    > MArk
                    > --
                    > "I just like to blow things up!"
                    >
                    > Papa Balloon
                    >

                    --

                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                    Cara Lin Bridgman cara.lin@...

                    P.O. Box 013 Shinjhuang http://megaview.com.tw/~caralin
                    Longjing Township http://www.BugDorm.com
                    Taichung County 43499
                    Taiwan Phone: 886-4-2632-5484
                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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