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mountain climbing

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    mountain climbing

    Both my son and i just purchased 2 fat tire ebikes with the BBSHD. I have been reading about the programming of it, and mostly understand the dynamics you can achieve. We are both running 42 tooth chainrings with 11-34 tooth 7 speed rear cassettes. We archery hunt here in Colorado and are looking for a program that is a good hill climbing setup. We do encounter fairly steep hills and as some days go, we may hike 8-12 miles also, and need our bikes to help us in getting out and back to camp without totally burning us out. We don't need speed, but would like to have the motor to be helping us enough to allow us to have enough energy to hike also. I am 66, so this thing is going to be my "mule" for the forceable future. Out of all the programming, any recommendations, or special settings? Thanks.

    There's nothing wrong with trying the stock programming but be sure to read the stickies and how to make the changes you would like to programming with Penhof's little app.

    You may want to drop the 42t front ring to something lower (30t) if you are expecting it use it as a mule.


      +1 on the gearing - one way or the other for "mule" you will almost certainly be better off with a much lower first gear

      Rule of thumb for me is that on typical 26" fatties the ring should be no larger than the tallest rear cog and I prefer the largest rear cog to be about 10% larger

      With fat-tires chain line isn't usually as much of an issue so you may be able to go a lot lower on the ring - the small ones have a lot less offset so you need to keep that in mind

      With a 7-speed cassette there's not a lot you can do, 11-34t is about as wide as they get so for how I run the ring would need to be in the 30t-34t like the previous post suggests


        Going down in chainring size is in the equation, but somewhat disappointed in these stock settings that Bbshd has. Stock PAS is a joke, told my son we may be able to leave our bows at camp and just run the elk long as its flat. Have a USB cable coming, possibly just do the Black Box when instock again. Thanks for response


          There's plenty to do with the settings and I'm a huge believer in tweaking them as every bike is different, every rider different and I've never seen a "factory" tune I thought was good and some are outright awful... however with your gearset no matter how much tweaking it's not going to make it a good steep climber and frankly if you do set it up to put a ton of power in at low RPM's you are tempting fate for trouble with the motor and/or controller... so I'd attack the gearing right away

          Once you can post your settings and get specific people will be happy to advise with that. You all posted you were looking for backcountry "mules" and only gave us some scant details on the bikes (fat, gears not well suited for climbing) so the responses were more addressed for the details you gave

          FWIW I'm an old guy (disabled) and do a fair bit of backcountry here in AZ... my fat tire (26x4.8") BBSHD is an excellent climbing machine and can haul some weight too and still has decent top speed (I can pedal easily at ~25mph)... I'm also running a 42t ring but I've got an 11-51t cassette

          Click image for larger version  Name:	cass_2704.JPG Views:	0 Size:	234.0 KB ID:	131839


            Also don't forget to include the rider+bike+gear weight. There is a HUGE difference (pun intended) between a 100 pound person on basically a road bike and a fat person on a fat bike. Even on flat ground the wind resistance and rolling resistance on the fat fat combo is much greater than the skinny skinny combo.


              Yes, there are a ton of variables to consider, and believe me, i've researched it all. But what i'm asking for is a simple place to start on the programming. Which reprogram out there has the basic variables that come semi close to addressing how this bike will be used. Limitless, Luna, Em3ev, Empowered etc, i'm just looking for a place to start, knowing that i will be tweaking the settings some from these. I see where some guys put limit speed to 100%, some fractionalize it to increase with each Pas level. Which is best for steeper terrain, which will give enough Pas to assist on a hard day of biking/walking?



                I tried running different speed limits and just plain hated that - I don't need the controller to limit speed... so I run 100% speed limit across the board and setup my current limits in a nice geometric progression (exponential) where each step up increases power about 42% and every two doubles it and it works superbly for me:

                Click image for larger version  Name:	PASlevels.png Views:	0 Size:	13.1 KB ID:	131966

                I made a little spreadsheet calculator if you want to fiddle the green values (attached)
                Attached Files


                  Thanks AZguy, just did first programming, but not after several hours of Usb issues. Started out with Luna hotrod settings, and will be trying some more. Will be trying speed limit variables too. No matter what, anyone who says stock settings are ok, needs a big hit of oxygen. Just with Lunas, I can see why the BBSHD, even though only cadence, can closely mimmick torque sensing. Can already tell that gearing is important, and for me the first 3 Pas settings will get tweaked a lot until i get that right amount of assist. With 21ah 48 volt, battery usage is not critical, at 66 and pedaling hard at 10,000 ft is.


                  • AZguy
                    AZguy commented
                    Editing a comment
                    Well as I said every rider, every bike is different and I haven't met a "factory tune" I liked... the latest tunes I've seen out of luna weren't terrible and good enough for some and I've seen tunes from other supplier that were just gawdawful. I think some are just setup for people that are riding cheap bikes on pavement and not intending to pedal much.

                    I've mentioned in other threads that I'm concluding that if someone has only ridden MTB's on single track they are more likely to feel more comfortable with torque sensing. OTOH if someone has a lot of moto time even if they are proficient MTB'ers they are likely happy if not happier with cadence sensing and a throttle for fine control... I definitely fall in the latter camp. Tried torque sensors and just plain hate them and I started riding MTB's in the early 80's! I love the PAS setup the way I posted when I'm riding where the terrain isn't varying much but when I get into off-road with fast changes I just turn the assist off or to PAS1 and use the throttle to control the amount of motor power delivered quickly and precisely while I pedal.

                    On the note of throttle I would highly recommend setting the mode to "current" if not already - "speed" mode sucks - and set the throttle start current very low, I set mine all the way down to 1% and it's great for me...