Hello, I've got a steel framed touring bike (Surly Disc Trucker) that I'd like to convert.
I'm a heavy rider (260 lbs) and wanting to carry camping gear with me. I do not need to reach max speeds, and would likely be pedaling almost always. Not a lot of throttle.
My intended use with this bike is multi-night camping trips on Rail-to-Trail routes. I'd likely have spots here and there for recharges along the way, but I'd like to pick a motor and battery that helps me maximize my range.
I like what I've seen from the BBSHD. I'm very new to ebike batteries, and really don't know what I'm looking for. Would the 52V 25ah Jumbo Shark be appropriate for this bike, motor, and use case?
Anything else I should be considering or making sure of? Thanks very much.
Hey Scott!
I have a 2022 Surly Disc Trucker w/ a BBS02 I suspect that your battery will be best mounted on your seat tube than your down tube as there are braze-ons on your down tube for you cable management that will protrude into where your battery cradle would normally go on my DT it wont sit flush. While the seat tube is not the usual first choice it has worked well for me.
That said I also ordered a "Triple Bob" battery clamp, and seeing as you are considering an even larger battery (I have a 17ah Jumbo Shark) I think that the triple bob would be a good investment for you. You might loose access to your water bottle mount on the top of the down tube when using the seat tube as battery mount as I think with the Whale Shark (25ah) larger size it would protrude into the spot for the bottle on the down tube. TBH not sure. Measure twice, or three times, purchase just once, hopefully.
You could opt for a rear rack battery but that significantly raises your center of gravity, and is--you guessed it--not prime. Alternatively I guess you could weld off / cut off the braze-ons, *But* Surlys are works of art! And though I'm not an expert on modding frames, I'd be hesitant to do so as maybe the frames integrity could be affected?
As for battery longevity? Cold weather=less efficient. Hills? Eat up batteries quicker. Wind? again, can affect your mileage. I would simply suggest taking your new build on short trips to start and get an idea for distances you can accomplish. I also have a BBSHD (on a Yuba Cargo Bike) that is modded to 750 watts, and even with the 250 watt reduction it eats up battery charges quicker than my BBS02 (and I had originally had a BBS02 on the Yuba). Your Mileage May Vary!! There are different "levels of assist" available on your BBSHD that will, probably be a larger determinant to your journey's battery longevity. Lower assist setting? You work your legs harder and your battery will last longer. I would suggest to purchase a display that has a "voltage indicator". (The "battery icon" is not terribly efficient). Most if not all? the color displays have a voltage option when programming. Learn your battery equivalency values.+ (you can print up a little grid of voltage vs. percentage and tape it to your frame to keep an eye on your ride / battery).
I think your plan for a 25ah battery is reasonable. Be advised that it's best practice when on the road (or anytime) when charging your battery is to wait an hour after riding for the battery to cool down / adjust to room temperature before charging. This not only is a safety tip, but also should extend the life of your battery. I'm guessing 40 mile range on average for your rides--that may be a tad conservative... But it's a guess taking into account the vast array of differences as I've listed.
As for weight? I weigh 225 lbs and while I don't have a front pannier system on my DT (yet) with the two 20 liter rear panniers fully loaded it handles admirably. By uneven comparison, my Surly Troll with front panniers gets squirrelly when I have weight up front. --But your planning on a "slow ride" anyway!
One small point, I've found that a torque arm (like Johnny sells) and a Lekkie "One Nut" help clamp down the Bafangs which like to squirm out of any cinching down we might do with the stock components. It costs a little more up front, but from experience I find it's a great help.
This sounds like an exciting project! Good luck! And keep us posted if you can!