My Surly troll half fat e bike

[Spotty dog]

Hi to everyone this is the second rebuild of my Surly troll I recently got the funds together for my e bike conversion,after seeing Courts reviews on youtube I felt the banfang crankdrive was the way to go.Having first tried the kit out on another less valued bike I was not happy with the far out chainline and harshness of the derailuer gear change, under power if u got it wrong it sounds and feels pretty hard on the driveline, I didnt feel the bottom 3 gears on the 9spd cassette was useable either.
The troll was treated to a Nuvinchi N360 hub and a dished Alcedoitalia chainring this corrects the chainline alignment bringing the chainrings teeth inwards 5mm just right for the new N360 hub.
The motor is a BBS 01 250w I have changed the controller to one obtained from EM3ev to an 18a unit so motor is now 350w he also reprograms them so in 0 mode I have full throttle and the same in all other modes too.
I found some shorter 165mm tandem cranks in polished alloy which also look a bit nicer than the standard 8fun cranks.To monitor battery condition and motor performance etc I opted for a Speedict Mercury it works with my smartphone via blue tooth connection.The phone sits visible in its pouch in the top tube bag, and all the connections for brakes throttle and function switch sit nicely protected from the elements inside the same toptube bag.The small triangle frame bag houses the Speedict control unit and the spare loom and conections from the motor and battery, the battery pack is 15.0Ah 36V Li-Ion using Samsung 29e cells.
The bike rides very well has good hill climbing ability and the CVT gears are working very smoothly its way nicer than other rapidfire 9spd setup I tried first.The new chainring is 42T so the rear sprocket was 21T but it feels undergeared topping out at about 22/24 MPH I have a 16T and 18T sprockets on order to try out.
Bike is semi fat and runs on 36 spoke 37mm wide halo SAS rims, BOA-G 3.45 x 26 on rear, and Vee speedster 3.5 x 26 up front which is a much bigger tyre than the rear.
A pair of 3" steel mudguards keep the muck off big tyres throw alot of spray up! A mudflap to extend front guard is the next job.
Its enough to give the fat bike look but I have the benifit of the 73bb which ment the Banfang kit fitted with no mods.

 

[Ravi Kempaiah]

This is one of the best fat bike build I have seen. Excellent setup.
Could you please share the links for the handlebar and mud guards?

 

[Spotty dog]

Hi Ravi thx for your nice comments, the bars are Jones loop H bars I got mine from a UK suplier www.charliethebikemonger.com To checkout the Jones bars go to www.jonesbikes.com for details and other variations on the design.They are nice quality but quite expensive and use a 31.8mm stem.
A cheaper alternative quite similar in size and shape "altho the loop area is smaller" are Ergotec city trekking space handlebars, go to www.humpert.com check out the wide range of bars they make I have an excelent set of butterfly bars they make which can be folded in for storage travel purposes.The city trekking space bar uses a 25.4mm stem and is about 1/5 of the price of the Jones loop bars at £18 mine came from practicalcycles.co.uk
The mudguards are from (Link Removed - No Longer Exists) they are "fender set 28" x 80mm wide with ducktails" and come in black and chrome,
I did not like the mounting straps that came with guards so fabricated my own from stainless steel bars.
See pic for cheaper Ergotec bars.

 

[Ravi Kempaiah]

Thank you.
I have heard of Jones H and Loop bar but haven't used it myself.
Your bike is a pure pleasure to look at. I hope the BBS-01 holds up for many more years.
Enjoy the ride

 

[Gus]

That thing is beyond awesome!!! I am actually building up a Troll as well with a Bafang but still about 1 month from completion. Went with Jeff Jones bar too. Rode a Surly ECR with it installed and loved it.

Excellent build!

 

[Spotty dog]

Thankyou the troll frame is so versatile and a great basis for an e bike enjoy ur build

 

[Brambor]

it's beautiful

 

[Spotty dog]

Thankyou its a keeper for sure, have now changed rear sprocket from 21T which felt undergeared with the 42T chainring, to a 16T which seems just about right full throttle with wheel off floor is showing 30mph on speedo.
Riding on flat road was able to hold 25/27mph with fairly relaxed cadence about 70/75 on full throttle.On level 7 is quite easy to ride along at 15/20mph.

 

[Spotty dog]

My bike has now receved some upgrades which now I think make it the finished article with really nice performance.
I really wanted the extra power of the BBS02 so have now fitted a 9 fet 750w motor,with recently gained knowledge on lipo battery's I switched to lipo Power.
This set up for short range is a pair of 6s 8000 Ah Zippys in series from hobby king, they help give a more stealth look the batt pack sits easily in the small carradice saddle bag, not done many rides yet but 12+ miles seems attainable.
When funds allow will go for a pair of Multistar 6s 16000 Ah for longer rides with panniers back on could carry the two packs giving me 24Ah of battery power for long range.
Got lucky last week and found a retro fit Harmony autoshift kit on ebay from germany for my Nuvinchi hub, this I run off a seperate zippy 6s 2000 Ah batt that fits into triangle frame bag snuggly.This works really well with the N360, having the advanced control shifter gives the choice of manual mode or fully automatic, it was with a slightly heavy heart I had to remove the derailluer hanger with my angle grinder to allow the Nuvinchi unit to fit, it sits close to the dropout when mounted to the hub. As I didn't envisage returning the bike to rapid shift gears I went ahead and removed it.
It really does work you set the controller to the pedal cadance you want and off you go you don't really feel the changes happen you just find yourself spining the cranks at the same speed whatever the road condition.
When you stop it's in low ready to move away, am mostly riding in level 3 if roads gets hilly level 4 seems bout right, with a squirt of throttle the pick up is really impressive but your pedal speed remains the same be it 10mph or up to about 32mph max on flat.
It just feels very easy and effortless to potter along or when needed pick up speed rapidly, the N360 with harmony shifter really helps to make up for the lack of torque sensing that bosch ebikes benifit from.
The lipo batts mean I have regained the use of my bottle carrier in the frame, and have a more stealth appearence, the high discharge rate 30c means they are never stressed by the amps the motor pulls from them, I can parallel charge them from storage voltage to ride ready in about 20 mins.
But must stress never take lipo for granted I always balance charge mine in fire proof bags and store them out of my property in a metal box at correct lipo storage voltage.
The bike is now fab to ride my local bench mark killer hill is covered at average 16mph, my 350w motor does it at 9mph the difference in uphill grunt is very noticable, my gearing allows me downhill at full throttle to hit 39mph! So I think the 16t x 42t setup with the rear tyre close to 700c circumference gives nicely matched gearing for the motor to work with, some new pics below.

 

[LouisQ]

Nicely done on the stealth Lipo. That frame was not a fat bike frame? Rather you upgrades wheels and tires? Perfect having the 69-73mm BB. The new 100mm kit is out of my current fun money budget by a welcome addition to the BBS02 family.

 

[Shea N Encinitas]

But must stress never take lipo for granted I always balance charge mine in fire proof bags and store them out of my property in a metal box at correct lipo storage voltage.

Hey nice customizations! I was happy to hear of your awareness and precautions in the Lipo dept., saves me from being a Debbie Downer. -S

 

[Spotty dog]

Yes frame is the Surly troll wheels are halo SAS 36 spoke they are 37mm wide, heavy but strong wheels well suited to ebike use.
The 100mm kit I saw was megabucks these tyres are as big as I could go in this frame I have had a black floyd on the front but it felt a bit unwieldy at 30mph+ the 3.5 vee speedster handles rock solid downhill at 40 mph the ride is nice they dampen out alot of road vibration and the wide short contact strip of rubber gives good grip for hard stopping it feels surefooted,
downside in wet is the front throws up huge amounts of spray hence the need for full 3" wide mudguards.
Yep always careful with the lipo are some scary vidios of them goin up on you tube.

 

[LouisQ]

Scary but well managed do just fine as you are experiencing. I haven't jumped in because of no secure safe indoor heated area to charge in the winter. Not something I want in the basement. Old guys post stroke need to charge in outdoor cabinets or BBQ's :wink:

 

[LouisQ]

Where did you find the offset crank arm for the chainring side?

 

[Spotty dog]

Worth trying bike shops that deal in tandem kit, I found my pair of tandem cranks at sjscycles.co.uk in England I was not very pleased with the finish of the thorn cranks and thought them badly finished and poor value for money at £25 each. I emailed SJS with pics of the swarf around the threads and notch marks on the inside of the cranks around the square taper not something you can see when fitted but at £50 for a pair of cranks felt they should be perfect.
To my suprise they said the cranks was only cheap and not worth the cost to them of postage to return them, I was refunded my money and asked to destroy and dispose of them responsibly !!!
Taking my enviromental responsibilities seriously I put my perfectionist tendencies to one side and fitted them, they are working fine and the shorter 165mm length suits me better.They appear to be a little better in quality than the standard banfang and look nice against the black colour of the rest of the bike.
Another option may be unicycle cranks tho these tend to be quite short, I have experimented with short cranks and do like them I have used them as short as 150mm and may try them again.

 

[LouisQ]

Sadly reducing the size reduces mechanical advantage significantly. I did a cursory search last night and found a few "standard offset" crankarms. Reported to be good replacements. But as I wrote, I'm building a small database and BBS0x FAQ, the report of failed arms is a bit of sensationalism. I think more cranks have been damaged by stripping and poor mechanical practice. I am certain two were in fact the stresses of very powerful riders, playing very hard and putting far more than average strain on the units. They weren't designed as off road mountain motors. I have been hard on one of mine, hauling well over the weight one would normally haul on a flat foot frame. No problems. I do need to snug things up and do an occasion "preflight". After all we've added motors to machines that weren't designed around the motor and the revers is also true. I have found a loose crank arm on one occasion and I had used a torque wrench to properly seat it. That could have torn up the aluminum crank on the steel BB shaft. Sorry I drifted off there. I will finish looking and find alternatives for replacement to add to the FAQ. If you find 170-175MM offset that fit, please share.

 

[MLB]

Sadly reducing the size reduces mechanical advantage significantly. I did a cursory search last night and found a few "standard offset" crankarms. Reported to be good replacements. But as I wrote, I'm building a small database and BBS0x FAQ, the report of failed arms is a bit of sensationalism. I think more cranks have been damaged by stripping and poor mechanical practice. I am certain two were in fact the stresses of very powerful riders, playing very hard and putting far more than average strain on the units. They weren't designed as off road mountain motors. I have been hard on one of mine, hauling well over the weight one would normally haul on a flat foot frame. No problems. I do need to snug things up and do an occasion "preflight". After all we've added motors to machines that weren't designed around the motor and the revers is also true. I have found a loose crank arm on one occasion and I had used a torque wrench to properly seat it. That could have torn up the aluminum crank on the steel BB shaft. Sorry I drifted off there. I will finish looking and find alternatives for replacement to add to the FAQ. If you find 170-175MM offset that fit, please share.

That's excellent information. Thank you!

 

[Ann M.]

Thanks for sharing all your experiences on the retro-fit--valuable info. and a cool looking ebike, too!. Your parts details are great!

 

[ken ferris]

Have a 500 watt bafang in the mail. Its going on my Surly Troll with a 14 speed Rohloff. I have found a very nice battery solution for my commuter bike a Karate monkey, I use the a 20 AH 36V all cell that just fits in the Ibara frame bag, I would encourage anybody to pick up a couple of these bags that for some reason where selling on amazon for $15

 

[Brambor]

Thanks for the tip Ken. Bought the bag.