Giant AC-E / GNG

Tinto

100 W
Joined
Mar 2, 2012
Messages
128
Location
Perth, Australia
Hello,
After lurking for about a year now and learning a lot, I thought I'd contribute my bike as it is now in frankenGhetto-ready-to-show-others mode.
I built this up over the long weekend here in WA from a mountain bike I had split up into parts ready to sell... but I'll be keeping it now.
It is a Giant AC, SRAM X7, Manitou Swinger Shock, Marzocchi Z1 Fr1 forks, Sun MTX wheels, Imperial Hubs and 203mm Saint Brakes & 2.4" Maxxis Holy Rollers.

The kit is a GNG 48v mid drive that I picked up last Tuesday along with a swallow balancing charger and 2x Turnigy Nanotech 8000mAh from a seller here in WA.

It started like this late last week...
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and came together like this for my maiden commute to work this morning.
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There was a teething issue with my mount (I made it too soft so the rubber popped off as the torque twisted the motor on/off throttle), and I'll probably try to keep my batteries in my backpack rather than on panniers.
But I think I'm going to need to add panniers to allow me to carry my laptop etc.

Ride into work this morning was great - cruising past stationary cars over the Narrows bridge, ghost pedalling all the way ;)

I look forward to learning more and making improvements to the bike as time passes - like a better mount for the controller - but zip ties and an old bottle cage worked for me today. The surround on the pulley side is mounted a bit weirdly so I'll need to clean that up with some new spacers and a bit of dremel action.
I'm already very pleased with the concept and how it has come together on my frame.

Hope to meet up with some of the WA crew in the near future.
Your feedback and comments are welcome.
 
Awesome. Another one joins the ranks- and a quick build too! I saw that GNG drive FS the other week and wondered when it would surface... :)

We should probably get another group ride going- and I'd better fix my bike!

Andy
 
Nice ride Tinto, i'll be interested to see one of these GNG kits up close
been thinking of building a few MTBs up for selling and the GNG kit was one option i
was considering, until i read the GNG thread here on ES and saw the "teething" problems
albeit mainly with those over volting their setups... welcome to ES anywayz always good to get another
West Ozzie on the boards :)

Spicerack said:
We should probably get another group ride going- and I'd better fix my bike!

Be all over that soon as i get my bike ride-able, shouldn't be too far away Andy, hoping
before end of month closer to middle actually... just waiting on couple items and its go go go..

KiM
 
I quite like the gng kits but yes there have been problems with powering them over the stock levels. Which is what we all do. By the looks of it, the best solution for the short belt life is to convert the primary drive to chain. Looks easy enough with the components available on the net. Keep us informed, MG! :wink:

Kim, yeah, you'll probably have your bike fixed before mine. I need a new freewheel cover for my mac or lace a 9C into a rim.... not enough time, too many projects...
 
Spicerack said:
Keep us informed, MG!
haha nice work.

So good so far - pretty happy at standard 48v.
After yesterday's shakedown run in and a switch to a proper biking backpack the ride in this morning was much more comfortable.
Tightened up the front end, engine mounting strap and the seat post last night - made for a much better ride in.
 
Cool. Two questions- what's the noise like, and on a private road, what sort of speed are you cruising at? :D
 
Noise is pretty minimal - slight whirring but you could easily still have a conversation over it. There's a bit of a hum from the motor, but it isn't a high pitched scream like smaller RC motors.

The chain drive is as silent as it would be on a standard bike drive train. I need to get mine tuned as I'm popping in/out of mid range gears under load.

The bottom bracket is a nasty piece of kit as are the freewheel and crank arms really.
That may be a bit harsh an assessment but they need to be better protected in transit and better finished in terms of threads.
It was so weird to be removing nicely engineered / finished stuff like truvativ ISIS crankset / BB and replacing it with something poor in comparison.
I'll be investigating some trials-based cranks like Echo if these don't last.

As for speeds - I've only been clocking top speeds so far using the sports tracker iphone app, not analysing as I go.
On my way home tonight I'll wind it out on a flat section of the... private test track to see what an honest flat land speed is without pedal input from me.
 
I've ordered a couple of spare belts for the GNG and a seatpost rack to get the batteries off my back and the controller towards the rear.

Even though I'm not all that keen on what it will do to the weight distribution, I'm done having shortish cables running to my backpack that means I can't stand up to soak up a bump.
...although you'd think with 6" rear travel it would do that just fine on its own - but the pogo-bucking effect over a bump (I've got the shock pumped up a bit too hard for the amount of pedaling I'm going) isn't pleasant.

Having my body movement restricted in the saddle is more dangerous than having a lighter nose in my eyes.
...plus I'll be able to lug my laptop etc.

Still loving the ride - am experimenting with the gearing for hills and so on.
It seems more than happy to crank out the torque (and pace) in a in a higher gear once you're moving - if anything it seems to not be as happy in the bigger rings where it can spin up a bit more freely.

A stand alone CycleAnalyst will give me more info on the sweetspot though - that is on the wishlist.
Just waiting for someone to abandon their V2 for a V3 and sell theirs to me ;)
 
...The bottom bracket is a nasty piece of kit...It was so weird to be removing nicely engineered / finished stuff...and replacing it with something poor in comparison.

Here is the thread that is searching for stronger BB crank-set options:

http://endless-sphere.com/forums/viewtopic.php?f=28&t=47618

If you are using the stock motor-pulley, you might consider sanding off the sharp edges from the pulley teeth, and that might help the belts last longer.

Looks great! I had the pleasure of visiting Perth back in 1981...nice people, fun place!
 
I actually like the idea of the water bottle cage holding the ctrlr. Thinking of stealing that idea! Welcome to the forum. You should whip it over for frockfest... :twisted:
 
spinningmagnets said:
...The bottom bracket is a nasty piece of kit...It was so weird to be removing nicely engineered / finished stuff...and replacing it with something poor in comparison.

Here is the thread that is searching for stronger BB crank-set options:

http://endless-sphere.com/forums/viewtopic.php?f=28&t=47618

This thread just became much more relevant, thanks!
I managed to flog out the standard warm butter crank arm thread on the ride home tonight!
It was hinting at blowing out right from the start but I had assumed it was just tightening over time since I'd only put it on finger tight... Guess not!

I prefer to replace things when they break rather than by indulgence so a new freewheel/crank setup is now on the menu.
 
Wow, that's a very clean build. :D

I've run into the same dilemma as you regarding backpack space. I run my 5x 8400mAh LiFe Zippies in my CamelBak which goes into my bigger backpack on work days. On days where I need to transport a lot of case files, I end up having to ride my human powered Giant Roam.

Have you thought about placing the controller in the same spot as mine? I was originally planning to run batteries in the frame triangle. I may run two LiPos in there inside a frame bag somewhere down the road.
 
Bit of an update. This has been performing well as a commuter.
After a few weeks out of the saddle with some back pain, I'm back into it.

This is it in winter commuter mode. I'd still like to work out some form of in-frame pack and controller case, but the rack is a necessity for commuting, so they're storing my batteries and controller for now. The bike weighs a tonne, and isn't at all what I'd call front heavy thanks to the location of the GNG. I wonder if I'd feel the same with a hub in the rear wheel?

New cyclone ISIS crankset installed. Works great.
New belt went on, and I take it easy on the throttle at launch.
Magura throttle will be next, along with a switch to single speed at the rear.
I've found a happy place in terms of gearing ( for mid range and top end rather than acceleration from launch) and I think I'll stick with it.

Cabling could do with a tidy up, but I'm yet to find a side entry sleeve that I'd be happy with.

Racked and mud guarded for commuting
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CycleAnalyst - batts were charged then left for a few days - 2x22.2v nanotech lipos adding up to ~50v
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Belt & bounce
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203mm stoppers front & rear
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Front end detail
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Rear detail
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Tonight I rigged up some LED bulbs into some old vistalite halogen shells and connected them to a 12v converter from grin ( via gloworm). Spliced it into my 48v pack tonight and it works great! Very dispersed light pattern though - not exactly a pencil beam.. And probably no longer waterproof with their exposed led design.
 
Hey Tinto - I am considering purchasing a 2006 Giant AC here in the States for about $500 US. I'm still debating whether to go with the GNG2 mid-drive or a MAC 10T rear hub. Primary purpose is commuting as well. Overall, do you like the frame geometry and handling?

And how do you like that Topeak front fender. Looks pretty gnarly in a Mad Max sort of way.
 
Hi Josh, I like the way it handles with 6" travel up front and 5.3" in the rear.
Any more than that in the rear and the extra weight makes it feel a bit too spongy - the wheel was making contact with my rear fender if I went over bumps on the rear 6" setting.

But the geometry is spot on for me - I like my weight a little more towards the rear and this frame does that. It's not too laid back like a DH bike nor too far over the bars like an XC bike. It has always been a bit of a pig to pedal, but the electric motor brought this thing back to life for me. I'm a little rear heavy with racks and panniers, but the GNG motor weight is centred, so that certainly helps counter that and improves handling. These bikes came with 150mm forks from the factory, so I stuck with that formula.

The topeak fender could be better! Love the way it looks but I still end up with (a little) water spraying in my face if I have to go through a puddle. I've lowered the fender on the wheel further today to give a bit less tyre clearance to see if that makes a difference to what water gets through it. Can't work out if it is coming through the gap in the middle or getting thrown forward by the wheel, and then I move into it. I suspect being 29er friendly means it may not be perfect for a 26, but I wasn't keen on the typical fender which makes the front end look like a moto cross bike. I bought it as a kit with a matching rear fender that has hidden itself nicely under the rack.

A 2006 will be the last year the ACs were made as far as I'm aware - after this bike everything went to their more compact maestro suspension design.
 
Nice Bike. I don't have my Giant AC anymore, but loved it with a high power setup. But I also found it an absolute dog to pedal, one of the main reasons I got ride of it.

As for fenders, I just cable tie and hot glued my front fender in place. Worked a treat. I would probably have preferred it if it was a bit longer towards the front, as I still got spray being flung forward then the wind would push it back nto my face.
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=47832&view=unread#p702787
file.php
 
It sure is a dog to pedal Adrian! When I get off the throttle it reveals just how much weight the motor is pushing - especially up hill!
The weight gives confidence in its solidity at speed for a first ebike, but I can understand why people turn to whippet bikes for their next build.

Here's my ~15/20 min commute - I'm very fortunate to be spoiled with so many bike paths here in Perth.
I'll break out the gopro one day soon - this was my iPhone on a shaky bar mount.

[youtube]EIuvV4c748c[/youtube]
 
The HK Nanotech batteries came with the kit when I bought it.

They're great for getting me to work and back on a single charge (17-18km round trip)
I was charging them at either end, and tracking voltages.
I got a bit tired of having a lipo charger on my desk at work so iIve gone back to charging at home in the garage once a day.

Got to start tracking the voltages though - I don't want to discharge too deeply.
 
Managed to snap a belt on tuesday after extending its life for a few weeks by reversing it.

I haven't had that much exercise in a long time.
Almost blew a lung pedalling across the narrows bridge into a mean headwind (ok, more of a weak crosswind).

It was motivating in terms of how much I could be putting in on the way home, and how much I need to make sure all the bearings are in good shape. Some of them (not sure which one) are notchy as hell right now which makes pedalling even worse than just the bike weight.

4x Goodyear Hawk belts finally arrived today from Amazon, so I'm back on two wheels after a single day break...
My trip to work via public transport is over an hour.
On my ebike it is around 17 mins... I know which I'd prefer, even in the pouring rain.
 
Tinto said:
Managed to snap a belt on tuesday after extending its life for a few weeks by reversing it.

I haven't had that much exercise in a long time.
Almost blew a lung pedalling across the narrows bridge into a mean headwind (ok, more of a weak crosswind).

It was motivating in terms of how much I could be putting in on the way home, and how much I need to make sure all the bearings are in good shape. Some of them (not sure which one) are notchy as hell right now which makes pedalling even worse than just the bike weight.

4x Goodyear Hawk belts finally arrived today from Amazon, so I'm back on two wheels after a single day break...
My trip to work via public transport is over an hour.
On my ebike it is around 17 mins... I know which I'd prefer, even in the pouring rain.

I reversed my belt too. It doesn't look as happy as it did when it was facing the other direction. :(
 
Spotted Tinto in a hilarious ironic episode where he has the higher power kit and I'm the one getting run off the path and receiving the abuse on the stock standard legal electric bike =D

http://1motorcyclist.wordpress.com/2013/10/02/road-raged-by-an-agro-knucklhead-anti-electric-bikes/

I didn't click somehow it may have been Tinto until looking at the video now now 5 days later and connecting a few dots before captioning the stills =D

PS: I was wearing a skeleton jersey so this casual humour may have incited the red mist in the miserable git. He continued up the Narrows bridge as I turned off under it so I suggested he jump and end his miserable life... that seems harsh writing it here but seemed a perfect solution at the time =D
 
HAHAHAAAAA ohhh thats beautiful.
I've often wondered whether I've left people in a fit of rage, but never stuck around to see.

I did think I was being tailed pretty hard down the hill too!
I distinctly remember those roadies on the left - slowed right down for them.

Nice work :)
 
Haaha, yes despite the humour on this occasion it could turn nasty so in the future I will avoid the shenanigans by not slowing down =D

I had to pedal quickly on the downhill to keep you within camera shot and was out of my comfort zone for any emergency moves, the A2B Metro would handle badly compared to yours. I'm not a fan of that section at best of times and normally coast through from the top and it still becomes my highest speed portion of trip with sudden drop at the Halo on Mount construction site it's like riding off a cliff =D

Having the guy chase us and dive bomb me with his brakes screaming after I thought time to abort this high speed chase =D

The roadies hugging was bizarre, I don't get the feeling it would have been about any good news, but the image with each having a foot clipped in like a standing kiss with one leg kicked up was a kodak moment.

Good to hear about the range on the Nanotech 8Ah, I love those packs, getting away with just 2 to run a GNG is a bonus. Using just one for the Commuter Booster fitting in a water bottle is a dream, but hasn't eventuated for reliable use just yet.

Any details on the ISIS crankset to get from Cyclone, does it come with a 68mm Bottom Bracket? I read skyjungae mentioned you couldn't get the one he is running, I still need to get this right as it's been holding me back from the get-go.

With the fair weather now I'm not on the A2B Metro, I'm rolling on this baby today, but you'll be flying by compared to my pedalling ;)
 
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