Electric assist.

I wanted to buy an electric assist trike so the dealer sold me a Terra Trike Rambler with a BionX assist (P350DX) motor. We live in the Texas "Hill Country" and that's why I wanted an electric assist. I'm a big guy 6'2" 275 that's why I went with the Rambler. This electric assist just doesn't have it!!!!! It works on the flat an mild inclines but NOTHING on the steeper inclines. Did I get the wrong thing? What can I do different?


  • I only recognize the Bionx name, not the performance specs but I just completed my 4th test ride on our Rover Tandem since a Bafang BBSHD was installed. At this point, we may have to much assist. I keep it in the 1 (of 9) settings and only increase on steep hills. I've ordered a smaller chain wheel thinking it might slow things down a bit. The BBSHD is factory pyogrammed to deliver 750 watts.
  • wow that's good. wish I had that problem.
  • I have BBSO2B and have reprogrammed the settings to my taste. I have derated the settings as not interested in speed. Has lots of umph...more than I generally need. Mostly running flat country, but when i am in the hills I draw up to 500 watts where normally I draw 50ish watts at 12mph . a little more with a head wind. Big thing with a Bafang BBXX is to use the gears to keep the rpm of the motor up. try to run mine with a 70 rpm cadence. I am very happy with the unit and have over 5000 km on it w/o major problems, but it is certainly a learning experience

    I readily admit have never ridden a unit with a hub motor like a Bionix or the Falco EVO on the Rambler, but I would think all hubs would suffer from efficiency and perhaps lack of power/range under really hilly conditions... nature of the beast. Should be great in flatter terrain.
  • Perhaps you can look at a smaller front chain ring to keep your cadence up or multi speed front gear box, or smaller rear wheel. Good luck
  • @Willie, Which Rambler did you buy, the 16 speed or 30 speed external dérailleur setup? Are you in your lowest gear when climbing a hill? Can you enclose a photo of your trike please? And is your human motor good and strong with plenty of endurance? Have you talked to anyone about changing front & rear cog/chain rings?

    One reason I ask is that I've been riding a trike (TT Rover i8 Nexus) since mid-June 2016. I hadn't ridden a bike for a quarter century. I struggled the first summer climbing anything resembling a hill even in my lowest gear. And while I did install a BBSHD (from Luna Cycle - highly recommended) last winter and a 13.5 amp 52 volt lithium battery (also from Luna - part of a Black Friday Special), I can now peddle up several small hills I had to walk up last year. I bought a Kinetic trainer last winter and tried to ride every day for up to an hour while watching TV. This year I committed to riding 1000 miles and hit that goal in September. I still have a ways to go, but my human motor is much better than when I started trike riding.

    All this said, I believe you will need to either make considerable modifications to your trike, or sell it and buy something like the TT EVO for a capable electric assist trike, or putting a Bafang BBSxx on the Rambler before you will likely be satisfied. But I'd call TT directly (they are awesome) and inquiry where you might be able to test drive an EVO and/or if there is anything they can do with their dealer who sold you the trike. Maybe TT can get the dealer to buy back the Rambler you bought, or sell you the parts at cost and have the dealer install the components that would convert your Rambler to an EVO Rambler. Best of luck.
  • gearing on probably all trikes is designed for flatland riders, rambler all-terrain being the exception.

    if you are a rat rider, your problem is the bionx. any other rambler configuration, changing to a mountain bike crankset [22-32-44, 22-44] should solve the problem.

    first gear for climbing mountains is around 10 gear-inches, 15 g.i. for hills, 20 g.i. for flatlands depending on engine - ymmv, etc.

    click on resources, then specifications, this site, to see what you have in the way of gear-inches.
  • I was never able to get up hills on a 2-wheeler as a young adult and I do it easily now on my trike. It has to do with being able to gear down low enough and being patient. You are not going to get up the hill instantly. Sometimes I think I could walk faster but the exercise is always good for me. I try to avoid the one major hill on my route that is difficult.
  • Thanks for the ideas guys. I think I will call TT tomorrow and talk to them directly. I have tried just about everything I can now. I am up to 10 miles a day on the flat so my legs are getting better. Hope TT has some ideas.
  • The TT guys are good. Really couldn't help much as there is nothing wrong with the trike.
    Will have to see what BionX comes up with to correct the issue.
  • a basic question, sir - can you climb those steeper hills unassisted?

    if not, you will need to lower your gearing with a smaller chainring to get the most out of electric assist.
  • m4wcmxtphd4u.jpg
    Here is the trike. If I could climb the hills un assisted I really wouldn't need assistance.
  • edited December 2017
    That a pretty small chain ring on the inside may be okay for moderate climbs. It highlights the problem in steep climbs of using a rear e assist vs a mid drive like a BBSXX where you can maintain efficiency at lower ground speed by keeping the emotor rpms up.

    Note the front chain ring has no guard... that's dangerous.... nasty cuts from those bare teeth
  • some of the other bad-knee types can testify as to the benefit of installing a mountain bike crankset.

    install this jewel on your rambler -

    consider the trike as a rehab machine - keep at it and a coupla years from now you may decide you dont want electric assist.

    been there, done that kinda thing.

    note also, per squirrelpie0, the lasco comes with a chainguard. if you ever brush against the big chainring, after the bleeding stops you will appreciate such.
  • @JamesR I'd use that crankset except for one thing - the short arms. I'd think you would lose some of the benefits of the small 22T ring by using a 155mm arm set. Mine is 22/32/42 with standard 170mm arms so I feel I get the most push in that small gear.
  • 350 watts isn't much for hill assistance. From what I read 500 watt was the minimum for moderate, rolling hills. 750 watts is as that maximum allowed legally on most streets & of course most recommended.
  • Unless you ride in the EU, which has a 250W limit IIRC. Silly limit, very low.
  • Thanks everyone. I'm going back to the drawing board. I will keep the trike as is but will remove current Electric assist as it does me no good. Anyone here have good experience with climbing 12-16& grade hill over 1/2 mile please send me you comment of email so we can visit.
  • @Willie - the pictures helped. you have a 24-inch rear wheel, not a good choice for doing hill climbs.

    if you keep the bionx, install an mtb crankset with an 11/32 cassette on the bionx and experience an unassisted 45% decrease in hill climbing effort.
  • JamesR wrote: »
    @Willie - the pictures helped. you have a 24-inch rear wheel, not a good choice for doing hill climbs.

    if you keep the bionx, install an mtb crankset with an 11/32 cassette on the bionx and experience an unassisted 45% decrease in hill climbing effort.

  • Jrobiso2 wrote: »
    Unless you ride in the EU, which has a 250W limit IIRC. Silly limit, very low.

    I would alter the tag. Politician types telling me what to do.....well I just can't conform. >:)
  • I have a Bafang BBS02 motor on my Rover. With it I can climb almost any hill I've encountered here in Western Washington (Paved or graveled.) and still maintain 6-10mph while pedaling with the motor providing assist during the climb. (Some of them as steep as 12-15%) In fact, my riding program has shown me that I have the 12th fastest time climbing a local 12% hill on Highway 204. This is a fairly short highway, only about 3-3.5 miles long, but it's 10-12% grade when going NE for most of that length. I averaged 9mph during this ascent. Not bad for a broken down sailor!

    Hub motors can't climb the way mid-drives can. Hubs don't use the gearing on the rear wheel as part of their power train. Mid-drives do.

    I ride in western Washington. Hills are a fact of life here. Steep ones are the norm... If I had a hub I wouldn't be riding at all. Riding with eFreedom I've lost over 60# in the last year or so.

    If you decide to bite the BBSXX bullet, buy from Luna cycles. Give them the measurements from the crank to the handlebar, crank to the battery and crank to the rear wheel, so you can get cable extensions for the display, brake levers, power and speedo. They can make the cabling for you out the gate so there isn't any hidden surprises... Also buy the programming cable, so you can tweak the settings to fit your riding style. (You also need a laptop PC for this part, but it's fairly straight forward to make small changes then test them.)

    If you want to know more, you can email me at elrique64(at)gmail(dot)com. Since we can't send PM's on this board...
  • fwiw department: grin-tech now has a 250-500 watt bafang geared wheel that may prove to be quite an economical alternative to the bionx.

  • 9 mph for 3 miles on a 10 to 12 percent grade must use a lot of motor vs pedal.
  • TCEd wrote: »
    9 mph for 3 miles on a 10 to 12 percent grade must use a lot of motor vs pedal.

    It does, but it also used a lot of pedal, too. And the run is actually only about 1.5 miles at 12%, the rest is at like 8%. and that was, of course, the average speed of the section of the ride.

    I have the throttle installed, but I only use it crossing busy intersections. The rest of the time it's pedal assisted.
  • Elrique
    What are you pulling for watts during the climg? Whats the motor temp? How much PAS do you have programmed ?
  • The display I had at that time of that ride didn't give watts. The one I have now gives watts, but it only gives it right NOW, and nothing historical. I would guess it was pulling about 1200 watts, though, since that's the highest I've seen the current display show at any point, and that was the steepest hill I've tried. I've only done that hill one time, and have since found a less steep route. It's also a fairly busy road, and I don't like all that much traffic.

    Motor temp was still cool enough to touch with my hand. Haven't installed a thermometer in the motor, like some people have done. One of these days I will have to do that I suppose.

    One thing I found about climbing hills is that I have to increase the PAS mode as I'm making the ascent. I listen for the motor sounds bogging down, and increase the PAS if it sounds like it's lugging. I haven't ridden that particular hill in a while, but if I remember right I was in PAS 8 or 9 and in 1st or 2nd gear. Any other PAS or gear would have been lugging the motor down too much.

    Lugging the motor down is how excess heat is created, and since you are asking those questions you already know that heat in a motor is a bad thing.

    The BBS02 is pretty sturdy with the current builds. The beefed up FETs in the "B" model make a lot of difference, compared to the "A" models. I have an "A" model but a "B" model controller.
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