Adrian's 2nd Build - Giant AC Full Suspension

[adrian_sm]

I just took it for its first spin, and wow. This is a totally different bike than my old one. The frame totally changes the feeling of the bike.
It just soaks up the bumps. Funny almost makes you feel disconnected from the road. Where as the hardtail you felt every ripple in the road.

Also makes it feel slower as a result. I am used to bashing into bumps, and that reminds you that you are going a decent pace. Now the bumps just melt away, and I went searching for things to run over.

I used to have the opinion that you shouldn't really go any faster than 40kph on a bike, but I am starting to realise that this was just a limitation of the suspension. I didn't feel like I was pushing the limits at all. Even going flat out on bumpy roads that I used to have to stand on the pedals to stop myself getting bucked off the bike.

Already starting to wonder what this 408 would be like on more volts. Lucky my controller can handle 72v.

[Mark_A_W]

Ha

Soon you'll be cruising at 50+. My bike is rock solid doing 75 down the big hill south of work


It looks really good (well till you sort mudguards..).


Is the frame "solid" with the battery in place? My Kona Dawg was all wobbly compared to my DH Team, with the battery weight in the frame (but still better than on a rear rack..ick).

[adrian_sm]

Yeah. Feels solid, but I have only taken it for a quick spin around the block. Will have to see what I think after a decent ride.

As for mudguard. I will probably do something pretty simple like this. Just need to improve the pivot/hinge point on the seat tube, or just put a more substational bracket under the primary mount point. That would let me fix up the angle a bit as well.

The front guard is the bigger challenge, as there is no mount point on the fork. Don't really want to duct tape it on, and really don't want to drill a mount hole in my nice "new" fork.

[adrian_sm]

I also need to fix up the geometry a bit I realise. As the seat is quite far back, plus a short stem, puts me quite upright, and not in the ideal pedalling position.
Felt more like an underpowered motorbike rather than a nice ebike when riding it.

So I'll slide the seat forward, and switch handlebars with the Avanti and see how it feels.

[Mark_A_W]

Try a longer stem, I stuck with a 90 or 100mm stem

[adrian_sm]

Yeah. My Avanti stem is longer, about 100mm, but it is for a different diameter handlebar in the centre portion. So I will have to switch the stem + handlebars. On the plus side it will let me use my new DIY CA mounting bracket. Got sick of the original one which was so flimsy. Felt like it was going to break everytime I pushed a button.

So here it is. Adjusted the seat while I was at it.
Now I have the CA,DC->DC, and lights all hooked up to.

- Adrian

Longer stem

Longer stem and set forward.

[adrian_sm]

Well made it to work without any failures. Glad I had it running, as I don't have a car at the moment, and am still getting over this flu.

Felt good. Definitely feels safer than the old bike. I used to get this "Oh shit, why would anyone go faster than this on a e-bike" feeling on the hardtail when you hit dodgy bits of tarmac. Now it feels in control.

Stuck to the roads so haven't tried it on bumpy stuff yet. Might take a detour on the way home.

Still a few things to do to finish it off:
1) Torque arms
- current set-up is too dodgy.
2) Rear brake
- I failed last time I tried to put a disc on my rear 408
- lets see if I can do better, or just buy a different motor. Hmmm.
3) battery enclosure
- thinking vac formed
4) Swap pedals
- need to put my SPD clipless peddles on.
5) New seat post
- have a 30.6 on a 30.9 frame, mounted beyond it's minimum insertion point.
6) Mudguard clean up
- probably just a better mounting bracket for the rear
- cable ties, and hot glue was Mark_A_W's recommendation for the front

All pretty minor stuff, so am pretty happy with how it all came together.
Now to spend the 80% effort, on the final 20%.

[adrian_sm]

Only minor updates:
1) Mudguards:
Well it was a wet ride home, and it highlighted how dodgy my first attempt at mudguard attachment was.
Nothing a bit of hot melt glue, a pair of scissors, and a small metal bracket wont fix.

2) Pedals
Got my SPD pedals on and am much happier. No longer have to worry about feet position on the pedals, and feet slipping off.

3) Battery Cover
Survived the wet trip home without getting electrocuted, or things stopping, but need a more permenent solution.
I couldn't work out a neat way to retain the batteries, protect from bumps, and weather proof using the vac formed plastic covers.
Also worried it might end up looking like a petrol tank as Mark_A_W puts it.

So current theory, is to keep the duct tape retention, as it seems to be holding things nice and firm, but add some bash plates to side and rear of battery. Then create a fabric weather cover (cut down to a snug frame hugging fit) from this....

http://www.torpedo7.com.au/products/R7JKVN8SS/title/route-7-softshell-vest
It will cover all the duct tape, and wrap around the front of the frame, back of the battery, but probably leave the controller exposed to keep the shape and size in check. If I get it snug enough it should improve the looks a bit, and keep the rain out. For $30 I thought it was worth a try.

- Adrian

[adrian_sm]

Rear Disc Brakes & rear 408's part 2

On my last build I bought a disc brake mount side cover for my rear 408, but things didn't go according to plan.
Essentially it spaced the disc so far over it clashed with the frame. Eventually I sold it off to another forum member who assured my he could get around the issue.
This left me with rim brakes on the back, disc on the all important front and I was happy enough.

Now this frame doesn't have rear rim brake mounts. So I have to find another solution.

The options I have found are:
1) Custom ~225m rotor
- this will allow me to place the disc caliper such that it clears the outer diameter of the motor
- the disc could be bolted directly on the existing side cover.

2) Standard 203mm rotor
- this brings the caliper inside the outer diameter of the motor
- even if I go to low profile button head screws for the side cover, the position of the caliper would put the disc to wide and it would hit the frame...
- don't really want to try and modify the frame to create clearance.

3) Try different brake calipers
- might find something that has less bulk between the rotor and the motor, as this is causing the main clearence issues

4) No rear brake.
- not ideal

.............. OR ...............

5) Go to a different motor
- sensored Bafang BPM, with a fast wind sounds like a good option
- it can fit a disc
- will be faster, with out requiring me to upgrade my batteries
- higher torque, so quicker up the hills
- will free wheel
- it would be lighter


I feel some upgradeitus coming on....

[adrian_sm]

Couple of minor updates.

I have order some 8" discs for front and back, along with adapters.

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And had an idea in my head when looking a LiPo pack I got for an RC plane, that I just had to try ....

Not the right size, but had to try it anyway.

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[adrian_sm]

It is amazing how much difference a few volts make. That tiny little LiPo pack really helped my understand what extra volts would mean for my bike.

The main thing I noticed is the available power. Not too surprising really, since I usually cruise at 40kph using WOT as my "cruise control".
With the extra volts, at 40 kph I now have about 300w reserve power. So rather than slowly settling towards 40kph, I race towards it.
It really changes the whole feeling of the bike, especially with the new DH frame. It felt less like a push bike, and more like a motor bike.
To me this is about the tipping point for what is a "pedal assist bike", and what is a "why pedal type bike".

This graph probably highlights the change in performance the best. It shows the output power for the motor at various voltages 48, 60 & 72 (solid lines), as well as the power required to go up various grades of hill. 1%, 5%, 10% & 15% (dotted lines)

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For example if you look at where the 1% curve intersects all the power curves, this tells you the typical WOT cruise speed on the flat.
48V = ~40kph
60V = ~48kph
72V = ~56kph

If you do the same for a 10% curve, it tells you how fast you can climb a decent hill.
48V = 22kph
60V = 32kph
72V = 36kph

Or look at a particular speed, 40kph, and see what sort of grade you can maintain 40kph.
48V = 1% grade
60V = 5%
72V = 8%

So at 60V and a bit of peddling I could basically maintain 40kph for my whole commute. Rather than drop down to 30kph on the hills like I currently do.

Sooooooo. The question is: What will it take?
Let's see. Based on http://www.bmsbattery.com prices.

US$66 - 4 more headway cells
US$36 - 20cell, 40amp BMS
US$35 - 240W charger (times two)

Total $172 + shipping

But hell if I am doing that, I might as well go for 72V. $5 extra for the BMS, $66 for batteries.
So $242 + shipping.

Just need to repackage things a bit on the bike to fit it all.

[Mark_A_W]

You could just do what I did, and add booster cells, with or without a BMS.


And add a second charger.


Might save some money, and save rewiring your pack for a new BMS.

But it is more hassle.


Umm....where would you put four or EIGHT extra cells? Along the downtube end to end?

[adrian_sm]

You could just do what I did, and add booster cells, with or without a BMS. And add a second charger.
Might save some money, and save rewiring your pack for a new BMS. But it is more hassle.

I love the simplicity of single plug, and walk away charging too much. Don't have to think/worry about it at all.

Umm....where would you put four or EIGHT extra cells? Along the downtube end to end?

If you ignore the fact that I have the CA shunt and DC-DC converter in front of the pack (not shown in picture), there is a little bit of room..... maybe.... for 4 cells....
Would have to be more creative for 8 cells.

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[adrian_sm]

Actually, It might just be cheaper and easier to change motors.

For example if I dropped your motor, in my bike at 48V, the specs look very similar to a 408 @ 60V.

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I am pretty keen to see how the faster wind BPM that full_throttle is getting performs. As I prefer the construction of the internals over the dramas you have had.

[adrian_sm]

Made a soft enclosure for the batteries. Mainly to keep the water out, and make it look a bit better.
I'll add some bash plates underneath in case I drop the bike.

Anyway here is how it turned out.

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[torker]

I like the simple cover. How did you close it up? Velcro?

[grindz145]

Very well done, nice and clean.

[adrian_sm]

I like the simple cover. How did you close it up? Velcro?

Thanks. Yep velcro. Allows me to stretch and adjust the fabric for a nice snug fit.
The cover drapes over the top tube, then has the velcro under the down tube, infront of, above and below the controller. And finally behind the battery in font of the shock.

I also left the fabric longer at the front so it can wrap around the steering tube, and velcro close right at the front if needed. This will have less of a gap to let water in, but is a bit more of an issue for all the control cables to enter. This has just been left undone, folded back on itself and tucked in so you can't see it in the photo. Might just leave it like this if it proves water proof enough. Will have to wait and see.

Very well done, nice and clean.

Thanks for the kind words. I just had look through your build log and I like the way you mounted your bb7s. I might just have to steal that idea and see if it helps me squeeze my 203 disc onto my rear hub. Cheers.

[adrian_sm]

Time for an update.

I didn't maange to fit a disc brake on the rear end, due to a few clearence issues.

So I decided to try out regen braking, to see if that would help. I also wanted to neaten up the bike a bit so I decided to hook myself up with a 6x4110 Lyen special Mini Monster After a lot of reterminating cables, and repackaging things on the bike here is how it turned out.

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Found the controller yet?

How about this angle?

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The controller is actually narrower than my battery pack, so I now have the batteries sitting on top of the controller.
Worked out pretty well I think.

So I no longer have a huge 12x4310 Crystalyte controller hanging off the down tube. Makes for a much cleaner look IMHO.

Regen braking appears to be working pretty well. Easy to use to slow down for lights etc. But it is a on/off affair. So definitely not a substitue for real brakes. But my 203mm Avid BB7's upfront can take care of the rest. All in all pretty happy.

- Adrian

[adrian_sm]

For those interested in the battery cover here are a few more pics. I need to adjust it a bit now that it isn't hiding a bundle of cables down near the bottom bracket.

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- Adrian

[adrian_sm]

Finally thought I would show what is happening up on the handle bars.
Notice the left brake lever has no cable, as I don't have rear brakes. Just regen.

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I made a custom mount for the CA, as I was sick of the wobbly original mount. Especially since I put a switch on the front to turn my lights on and off (including the CA backlight). The mounts are from some DealExtreme gun sight mounts, that just happened to be the right internal diameter for my handle bar near the stem.

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Finally, I now have the 3 speed switch, so I can put it in go slow mode for when my wife gets on the bike, or I am dragging the kiddy trailer around.

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- Adrian

[adrian_sm]

Maybe it's just because I have never been able to do this before, but I find it pretty cool to be able to hook a laptop up to the bike, and reprogamme it.

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I am sure the novelty and usefullness will quickly fade.

- Adrian

[grindz145]

Maybe it's just because I have never been able to do this before, but I find it pretty cool to be able to hook a laptop up to the bike, and reprogamme it.

IMG_2162.JPG

I am sure the novelty and usefullness will quickly fade.

- Adrian

Once you get everything set up properly It will fade, but it is nice to have to begin with!

[adrian_sm]

Okay. Got bored browsed the hobbycity site, and ended up buying a couple of these Turnigy 5000mAh 6S 20C Lipo Pack:


Plan is to use these as a 6s 10Ah LiPo booster pack with my current 16s 10Ah LiFePo4 pack.

While I wait for them to arrive, I amused myself with a quick play with Justin's simulator. Amazing what a little extra voltage will do for the bike.

This graph shows the power of the old set-up, versus the new, still @ 30Amp limit on the controller.
The curves going up from the bottom left are the power required to go various speeds on the flat, and up various grades of hill.

So I currently cruise on the flat at 40kph, and go up most hills on my route @ 30kph.
Now I should be able to cruise @ 55-60kph, and go up the hills @ 40-45kph.

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[bandaro]

so hows the extra booster cells going? running it at the higher voltage yet, and is it much faster?

i like how the shirt turned out, seems a nice neat breathable way to conceal everything. how wide is the battery pack now? do you ever hit them while pedaling? im wondering how wide my build can go....