Strong GTS - fast road commuter build

So about a year ago i came across a local e-bike repair shop with a strong gts frame laying outside with rust and such, so i picked it up for about 80$ (300 nis)
a few weeks ago i gave this frame to a welder to add some meat to the fragile steel frame, i told him where to add the pipes and asked him to make the dropouts as thick as possible, so he did
so here's the 'before' picture, still in the repair shop i bought it from, this is how it looked -


and after the welding job -



After that, a friend of mine helped me with the sand blasting and re-painting in red


The plan is to take apart my 72v 3000w 20" folding bike and move the parts to this frame
i will be using 20" wheels with a rear 1500w leafmotor with a 72v 13ah battery, right now my battery is dying and im about to get a new one in the end of this month so i will be upgrading the controller from 45a to 60a as well, so its going to be about 4.5kw
up to now i've been riding this leafmotor with 72v 45a setup on this 20" wheel and never got it to more than 70 degrees Celcius, so i think i might try a delta\wye switch on this bike too, its working great on my other bike
Next thing i did is mounted the shocks, front is a 150mm manitou sherman and the rear one will be replaced in the future for sure


Last thing i did is start working on the battery box
im using 1mm thick black PVC sheets, pretty stiff stuff and easy to work with




Next things i need to do -
*close that battery box
*get a 20mm thru-axle front hub and build a 20" wheel on it
*move the parts from my other bike to this one, saving this for the end

for those of you interested, here's a video of my 3kw folding bike in action in the middle of rush hour in Tel Aviv, enjoy -
[youtube]9uNkJi8vxa4[/youtube]

Nice job. How much did welding cost you?

cwah said:

Nice job. How much did welding cost you?

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the welder is a friend of mine so he only took about 160$ (600 shekels)

Nice frame

Wow. Cool bike. Well done.

Good job.
I've built out a couple of Strong's. They are fun bikes when you kit them out right.
Looks like that's the plan for you.
There are a few other members that have modified their Strong frames, here is one that I'd recommend.https://endless-sphere.com/forums/viewtopic.php?f=6&t=46993
His higher power and faster riding style split his frame. I am slower and maybe luckier, my frames have been fine. Mostly street and light trail though. Looks like your solution should stop the situation he had, but a good read none the less.

Oh, 20" wheels on this frame. Be real careful. Shorter cranks at least.
As cautious as I was about pedal strike eventually it got me. Rooted, stopped the bike dead and shot me down the path at 40kph. Still feel it in my hip 3 years later.

Best of luck
I'll stay tuned for updates.

Brentis said:

Good job.
I've built out a couple of Strong's. They are fun bikes when you kit them out right.
Looks like that's the plan for you.
There are a few other members that have modified their Strong frames, here is one that I'd recommend.https://endless-sphere.com/forums/viewtopic.php?f=6&t=46993
His higher power and faster riding style split his frame. I am slower and maybe luckier, my frames have been fine. Mostly street and light trail though. Looks like your solution should stop the situation he had, but a good read none the less.

Oh, 20" wheels on this frame. Be real careful. Shorter cranks at least.
As cautious as I was about pedal strike eventually it got me. Rooted, stopped the bike dead and shot me down the path at 40kph. Still feel it in my hip 3 years later.

Best of luck
I'll stay tuned for updates.

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Thanks!
i've already seen pucksterpete's build thread, and i don't think i'll be tearing it like he does
i do admit with my DH bike on the trails i do break alot of stuff, but even when i used a stinky chinese folding frame for this 3kw setup i kept it whole riding every day for 30km's at 65-70kmh. in short - i'm alot more gentle with my road bikes
as for the cranks - i already tried putting 20" wheels on and it looks high enough, i think the long front shock is really helping getting this geometry up a little bit

[youtube]LqsWH9ynbCs[/youtube]

So you are the kid who posted "NO. thats not the way to make a downhill bike electric. not even close." on my youtube? :lol:

You seemed pretty happy to take a piss on my build, I guess it made you feel smart, but you couldn't back it up by explaining what you thought was wrong, or be community-minded enough to share that knowledge by explaining how to do it better. So, keeping in mind MY specific design criteria and duty cycle for that build (not yours), what exactly is the problem? 8)

-JD

Nice build Noamster! I like the bars you added in - makes it look much better.
Having the battery with a CofG close to the center of the bike should handle nice. Could never stand the idea of fork mounted batts.

Samd said:

Could never stand the idea of fork mounted batts.

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Hi Samd, I didn't know you built one with a front-mounted pack, what didn't you like about it?

I rode two on group rides in Melbs in 2013 (using a kiwi forklift) and again in July of 2015 with ES user Alan C. Maybe only 15km per time. I just couldn't take the weight up front down any fast technical areas. Single trail wasn't as bad.

In my opinions the rear end on the Norcos (under licence from Specialized) represents the most sophisticated and finest travel of any ebike donor frame.
A stealth or any single swingarm bike could never touch the travel profile of the Norco.
I just can't imagine shifting the weight to the front. But that's me.
I collect Alines and Shores now. Timma does too. I have stopped welding midsections and will start using Kevlar and Carbon fibre in tension.

You can have your thread back now Noamster.

haven't noticed all those comments lol
first of all - oatent, maybe i made this comment a long time ago and i changed my oppinions since
but still, i rode a few bikes with heavy motor at the front and heavy battery on the back and the experience was awefull, feels like the bike gets teared apart from both sides every time you take a corner, not to mention the weight on the steerer.. and as far as i can imagine.. a front battery with rear motor will be pretty similar to a front motor with rear battery

Now as for my bike -
today i started stripping my folder down, and moving the parts to the GTS
i was anctious to see how it will look with wheels on, so i got the front wheel ready and just stuck the rear wheel for the photo for now (the cap on the other end is still open lol)
the front wheel im using is a alu-magnesium 20" wheel that i took to a machinist to fit it to a 20mm thru axle, fits pretty nice, i just need to make spacers for the axle to fit it perfectly
the tyres are 20x2.5" bmx tyres, and the rear motor is a 1500w leaf motor 13x5, i still need to fix the motor wiring since it doesn't look too good

so today i started upgrading my 1500w leaf motor
i wanted to add a delta switch inside the motor with 80a relays, so i did
id required also replacing the wires with more wires for the relays, so now i have 3 phase wires (2.5mm), 5 hall wires, and 4 more hall wires - 2 to power up the relays and another 2 for the temp sensor
so thats 12 wires going through the axle
and inside the motor the wires i used for the relays are a couple of 1.25mm wires running together, so its like 2.5mm wires also
its almost finished now

Ah another Strong build, nice work, lets rip it up

Hi guys, sorry for not updating for a long time, i was messing too much with my other bike lately that i left this project a little bit behind
but no worries! cause its time to continue
remember the relays i was trying to get inside the motor? well after i finished mounting them and soldering i closed the motor caps and whoops! theyre rubbing the relays! so i had to take the relays out of the motor, and get 6 phase wires inside the motor out of the shaft, i took 2mm phase wires because 2.5mm wouldnt fit the axle (with 6 wires), bike is going to work at 72v 60a so i hope its enough
so after all there are (coming out of the axle) 6 phase wires, 5 hall wires, and 2 wires for a temp probe, all going through a leaf motor axle
after that i needed to connect the phase wires to the relays which are now outside the motor. i wanted to make the relays as sturdy as possible since they are not meant to go on a bike, so i took a broken controller i had, took it apart, cut and angle grinded and finished up with this, which you can call it a 80a Delta\WYE gearbox pretty proud of that
you can see 12 wires in the photo but these are all double wires so its actually 6, the zipties are for mounting on the rear triangle



i did that about a week ago, and today i finally mounted the motor and the gearbox on the frame


after that picture i also mounted the front brake
the batts are supposed to be here any day now and when they arrive i can finally finish this build

I'd be sneaking the controller just in front of the rear wheel with a guard, off the side looks like it might get hit/come off? Perhaps your more careful than me 8)

Lurkin said:

I'd be sneaking the controller just in front of the rear wheel with a guard, off the side looks like it might get hit/come off? Perhaps your more careful than me 8)

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look again mate, this isn't a controller but its a delta\wye gearbox
the reason for mounting it so close to the axle is that the shorter the wires are the more efficient the motor will be, so its better to keep it in this area, haven't kicked it in my other bike so i think it'll be fine
controller will probably go in the black box next to the battery, if there will be enough space, if not, probably under the downtube

Stand corrected [goes off to get educated on delta/wye gearboxes].

I see. So you can get multiple speed motors out of one motor by switching between wye and delta configurations, provided you use one of these switches. This is relevant to me because I have one of these Leafmotors (5T) sitting about for the next build... hmmm thank you!

Lurkin, look up Matt's build of the motoped. https://endless-sphere.com/forums/viewtopic.php?f=28&t=62040&hilit=delta%2Fwye

MORE STUFF!!
today i finally got my new batteries for this build
what are those batteries? long story short my father is an e-bike importer, so i asked him to ask one of his chinese cell factories to make me a li-ion pack of 72v 10-15ah with the best C rate they can get, and they ended up with this - 72v 13ah 18650 li-ion with 5c discharge (as the factory says), i really hope i wont have any problems with them, but i got them in a special price which i cant even tell you, sorry lol
i asked them to make the pack splitted to 2 pcs with 1 bms because i thought i would mount it on my folder, which ended up replaced with the GTS project, and it fits perfectly!
here are some pics
i managed to mount both packs under the rear shock with enough clearence, and theres enough space in the plastics for the 15fet greentime controller and all the wiring

Ok now i'm getting really close to finish
in the last few days i made a few upgrades - got 140mm cranks (instead of 170mm) to make more clearence with the floor
also got a Manitou Swinger rear shock
besides the upgrades i also mounted a front 'chopper' headlight and a rear scooter light, both for 12v, and i finally finished the wiring. the motor wire harness was a bith to make but its finally finish, going through a delta gearbox to the controller
last things remain to do - find a controller and connect it, and then i'll need to close the platics. other than that i need to fix the rear brake and a chain and thats it
this is how it looks now:




this is how the whole motor mess looks like, pretty clean for 6 phases, 3 relays and 6 pairs of bullet connectors, not to mention all the small wires going through as well


im also thinking of adding a bag in the space left on the rear triangle in front of the rear wheel, just for cargo, anyone got a got idea for a bag that fits this area?

Hey Noamsal,

I use a few of these recumbent style packs for my Strong to store tools and what not.

http://t-cycle.com/fastback-hydration-packs-c-6/storage-packs-c-6_36/

FINISHED!!!!
i finally finished this thing
tried it out with 40a peak (3kw, the plan it to use 60a peak eventually so this was just for the test ride) and got to 87kmh on delta mode!! unloaded speed is 140kmh!!
i wonder how fast will it get with 60a peak eventhough im starting to think i need more than 60a to pass the 60mph
anywayyyyy thats how it looks, controller and batteries are inside the PVC

ok so good news and bad news -
bad news - something isn't good with the battery or the connections, today i went with this bike out to work and the battery cut out after 2.5ah.... weird... i came back home and suddenly it was going again, im not sure if the BMS cut off because of failure inside the battery or something went wrong with my connections\controller\anything... gonna have to check that before i go any further
and for the good news -
yesterday i tried the bike for 15km's at star mode with 70a peak, efficiency is great and the speed is awesome, almost 80kmh on flats in star mode (100% mode, no halls yet)
i also tried the delta mode for a short run and reached 103kmh in no time, i was just testing the bike so i wasn't going like this for all the ride, and good that i didnt because there is some failure somewhere on the bike...
BUT i can know for sure that when i have myself some good batteries im gonna have a dreamy bike, 100kmh on flats and stable as a motorcycle
im too afraid for those batteries, these are chinese 72v 13ah "5c" li-ion, im starting to get sceptic...

Noamsal said:

FINISHED!!!!
i finally finished this thing
tried it out with 40a peak (3kw, the plan it to use 60a peak eventually so this was just for the test ride) and got to 87kmh on delta mode!! unloaded speed is 140kmh!!
i wonder how fast will it get with 60a peak eventhough im starting to think i need more than 60a to pass the 60mph
anywayyyyy thats how it looks, controller and batteries are inside the PVC

Click to expand...

Nice work. Look forward to a full delta/wye report when you are alll powered up with plenty current and no hickups.