build thread: klein mantra hs3540 5kW 70km/h 20" (done)

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izeman   10 GW

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build thread: klein mantra hs3540 5kW 70km/h 20" (done)

Post by izeman » Apr 18 2012 5:48am

hi all

now that my bmc mountainbike with mac hub motor is finished, it's time for a new project.
i saw some bmx style conversion, and thought i could use my beautiful klein mantra which i bought 15 years ago (and still looks like brand new - i took great care) and modify that. i'd like to do the following:

.) 9c 2805 hub motor in a 20" rim -> crystalyte 3540 and alienation delinquent rims
.) maxxis hookworm tires -> pirelli ml75
.) infineon eb312 controller -> check
.) ~20s1p a123 pouch cells -> 24s1p a123
.) peli case 1300 mounted under the handle bars -> too small -> chose explorer 2717 at the handlebar
.) disk brakes front (already installed) and rear -> avid elixir3 and 200mm disc
.) cycle analyst -> v3

what do you think?

this is the bike as it looks like now. i love the look, but it always was a bit too small/short for me, and riding in the hills made the front wheel lift all the time.

Image

i'm still a bit woried how to mount torque plates/arms, as those dropouts look really thin and weak

Image

as i want to reach 40mi~60km/h i would have to feed it 2.5kw.

.) i'm also still unsure which kind of throttle to use. what do you prefer? half grip? thumb throttle?
.) should i use all 21 gears? or just the three front gears OR the seven in the back?

cheers izeman

update 20121214:

i bought a crystalyte 3840 and 12fet infineon controller.
i also switched from hookworms to pirelli ml75 2.75

update 20130201:

this is what it looks like now. found out that the controller is sensorless, so i ordered a new sensored.

Image

update 20130302:

frame welded

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update 20130321:

ready to ride, at least for a test ride. frame still needs to be painted, and some other stuff is to be done

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update 20130416:

almost done, some cosmetics to do, but it's done:

Image

update 20130527:

latest addition is a PAS, and a nice rear led light.

Image

bought a new fork. 120mm air/air. much better ride, and better looking as well

Image
Last edited by izeman on Aug 12 2013 6:01am, edited 13 times in total.

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Brentis   10 kW

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Re: klein mantra conversion 20"

Post by Brentis » Apr 18 2012 8:15am

Not bad for a light weight build.
izeman.jpg
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Battery on top tube, controller under. Docs plates holdin' ere together.
Done :wink:

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Re: klein mantra conversion 20"

Post by neptronix » Apr 18 2012 10:38am

If you have fitment/wheelie problems at bike speeds, it'll only get worse at higher speeds and you'll be regretting it after the conversion.. :(

It's a very cool bike, but i do advise you find another.
My first major build: 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w on a Turner O2 full suspension.
The wheelie machine: 20" Rear Magic Pie II on a Trek 4300 MTB

"The best time to plant a tree was 20 years ago. The second best time is now."- Chinese Proverb

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izeman   10 GW

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Re: klein mantra conversion 20"

Post by izeman » Apr 18 2012 10:44am

problems with frontwheel lifting are iminent at very steep hills with rocks blocking the way and stuff. on normal roads there is no problem.
the frame is not super small, it's just not perfect. and it's standing in the corner. and i think a second life would be fair :)

doc's plates are too big to install there. i would have to cut the dropout from the frame, and this is not what i want.
i will have to find a better solution.

the battery on to of the frame? i chose the pouch cells because they perfectly fit in the box. and in regards to center of gravity it's much better between the handle bars and the fork, don't you think? why would you place them there?

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izeman   10 GW

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Re: klein mantra conversion 20"

Post by izeman » Apr 18 2012 10:45am

one more thing to add: it's more a project to work on. i don't think that i'm gonna ride the bike a lot - unfortunately.
you know when projects are finished i'm not intereted anymore. on the other hand: range of that bike would be 20mi+, so it's enough for going to the office, charge it there and go back home.

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Brentis   10 kW

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Re: klein mantra conversion 20"

Post by Brentis » Apr 18 2012 11:38am

izeman wrote:problems with frontwheel lifting are iminent at very steep hills with rocks blocking the way and stuff. on normal roads there is no problem.
the frame is not super small, it's just not perfect. and it's standing in the corner. and i think a second life would be fair :)

doc's plates are too big to install there. i would have to cut the dropout from the frame, and this is not what i want.
i will have to find a better solution.

the battery on to of the frame? i chose the pouch cells because they perfectly fit in the box. and in regards to center of gravity it's much better between the handle bars and the fork, don't you think? why would you place them there?

Maybe you can shave down Docs plates to fit. Can you post a better close up drop pic..

As for the battery placement, I dont think there is anything wrong with the idea of the Pelican case mounted out front on headtube, dont like the handlebar idea as much. Would certainly help with wheelie'ing & makes for an easy install.
Oatnet IIRC & others have proven its doable.
So is a Goat. Nothing wrong with goat, but I like Kitties.
Just dont believe it to be the best solution. The more weight you get centered the better.
Look @ 100 years of motorcycle development, & show the case where weight in that location has advantages to centered.
It basically doesn't exist.

I like the bike alot.
Unique ride to convert.

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Re: klein mantra conversion 20"

Post by Brentis » Apr 18 2012 12:41pm

A 2nd concept.
izeman Klein Brentis mod.JPG
izeman Klein Brentis mod.JPG (67.76 KiB) Viewed 12665 times
Battery hanging low, controller up the seatpost.
Lil' odd looking though.
:mrgreen:

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izeman   10 GW

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Re: klein mantra conversion 20"

Post by izeman » Apr 18 2012 2:47pm

a LITTLE ??? ;)

but let the ideas coming. befor i spend $2000 i want to be sure to do it right.

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Re: klein mantra conversion 20"

Post by john7700 » Apr 19 2012 9:36am

I will be fallowing this build. I have a retired Mantra in my basement that I am eye balling for a next
build. I see lots of challenges and it will be interesting to see how you work some of them out. I don't
find this bike that much of a wheelie machine. I have tens of thousands of woods miles on it and lots of
mods for my ride style however. Now the cinch-bugging, where the rear wheel feels like it wants to
come up over your shoulder on a hard stop, that's a very real thing. You just have to get use to it.
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izeman   10 GW

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Re: klein mantra conversion 20"

Post by izeman » Apr 23 2012 5:34am

ok. starting to getting more into detail. i read something about moped tires and bmx rims, but i am not sure if those will fit.
does someone know it this rim and tire will go together, and is this rim ok for 2kw power?
Last edited by izeman on Dec 14 2012 7:30am, edited 1 time in total.

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izeman   10 GW

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Re: klein mantra conversion 20"

Post by izeman » Apr 23 2012 5:37am

this is the case i want to use. someone else on the forum already does use it and it seems a perfect fit for 24s1p a123 prismatic cells. still looking for a bms as well.

Image

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izeman   10 GW

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Re: klein mantra conversion 20"

Post by izeman » Apr 23 2012 5:54am

i chose that hydraulic disc brake. it's a proven brand, and are not over priced. for the price i'd like to take the shimano xt, but the avid has all hydraulic components on the outer side of the disc (not between the disc and the wheel), so they should fit the 9c motor - as this afaik only has a 16mm gap between disc and side cover plate.

Image

edit: it now is the elixir3 not the exlixir1, and i will go for a cylte 3540. so no worries about gap for disc caliper.
Last edited by izeman on Dec 20 2012 7:06am, edited 1 time in total.

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Re: AW: klein mantra conversion 20"

Post by izeman » Dec 14 2012 1:52pm

Started to make the battery today. I bought a 350x150mm epoxy board.
You can barely see the scratches I made to mark the slots which I will cut with a Dremel.
uploadfromtaptalk1355511150378.jpg
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izeman   10 GW

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Re: AW: klein mantra conversion 20"

Post by izeman » Dec 14 2012 3:05pm

First attempt. Not as nice as I did hope.
I will make a new one. Took me 30min. I wish I had a laser cutter :-)
uploadfromtaptalk1355515423118.jpg
uploadfromtaptalk1355515423118.jpg (32.22 KiB) Viewed 12476 times
Some of the cuts are too wide.

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Re: klein mantra conversion 20"

Post by docnjoj » Dec 14 2012 5:09pm

Was the dremel stationary in a drill press?. If so you can make a fence and the cuts can be fairly precise. How are you going to attach the metal compression blocks to the board?
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izeman   10 GW

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Re: AW: klein mantra conversion 20"

Post by izeman » Dec 14 2012 5:41pm

Unfortunately it was all freehand. But it's not so important to have all slots 100% accurate. I did another board where I took care to make the surfaces 7mm wide and the distance between them smaller. I will post a picture tomorrow.
There will be 2x6x45mm aluminum strands, drilled with 3 holes on top, and a 4x6x45mm steel one on the other side of the board with 3 threads. It will be a self made copy of Agniusms boards.

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Re: klein mantra conversion 20"

Post by maydaverave » Dec 15 2012 12:36am

Seems a shame to put a heavy motor on such a light bike. I have dreamed of putting a friction drive on my specialized 24" bmx but I don't think anyone has perfected a commercial one yet.
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izeman   10 GW

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Re: klein mantra conversion 20"

Post by izeman » Dec 15 2012 2:11am

yes. lightweight is gone after the conversion. but this bike is of no use if it starts rusting in the garage. so better convert it into something new. i can revert it to original state anytime. there will be no non-reversible modifications.
that's why i will weld a completly new rear frame. work on that may start within next month.
next step is the battery and lacing the wheels.

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Re: build thread: klein mantra conversion 20"

Post by izeman » Dec 21 2012 12:50pm

opened the crystalyte 3540 today. just to peek inside :)
i want to swap the 14awg for 12awg, and add a termistor to check stator temp with the newly ordered ca-v3 (thx to justin!)
i also checked the rubber seal, and there was not metal spring installed - maybe crystalyte improved their design.
Attachments
IMG_1777.JPG
3540 opened, looking clean
IMG_1777.JPG (117.91 KiB) Viewed 12204 times
IMG_1778.JPG
original phase wire - 14awg
IMG_1778.JPG (82.53 KiB) Viewed 12205 times
IMG_1780.JPG
new phase wires - 12 awg with heat shrink
IMG_1780.JPG (90.78 KiB) Viewed 12205 times

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izeman   10 GW

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Re: build thread: klein mantra conversion 20"

Post by izeman » Dec 21 2012 12:52pm

i removed the cap as well, and will make one out of aluminium. i personally don't see why the cable could be cut. no revolving parts in touch with the cables where they enter the axel.
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Re: build thread: klein mantra conversion 20"

Post by mikebikerad » Dec 22 2012 2:37am

I converted a black and red Mantra last year. I can't find any pics but I am looking forward to see how you do this!
I used 48 volt 20ah Ping pack split in half: one half on top one on bottom and Nine cont rear hub. The older fox air shock need alot of PSI to handle that heavy of a battery.

The seat tube needed to be cut because it would bottom out on cross bar of seat stay. I used grin tech universal torque arms on both sides. looking back the dp420 doc dropouts would have been more appropriate with this bike.

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izeman   10 GW

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Re: build thread: klein mantra conversion 20"

Post by izeman » Dec 27 2012 12:27pm

my spokes from catsnapper arrived today, and the rims arrived just before christmas. so i could start lacing the wheel.
i started with the read wheel, as this is radially laced, and was quite easy.
13g spokes and washers.

first spokes in:

Image

all spokes in, but not centered:

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a valuable tool. bought it 2 years ago but never used it :)

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a special made bit. dremeled away two sides from the philips bit

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the pirelli ml75 slipped on quite easily. no pressure needed. a perfect fit

Image

BEEEEFYYYY :)

Image

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izeman   10 GW

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Re: build thread: klein mantra conversion 20"

Post by izeman » Dec 27 2012 1:59pm

weighed the wheel. 10.0kg. the rubber is heavy, the motor is heavy - so i did not expect a light weight wheel. but my other fully mountainbike is 10.5kg ;)

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izeman   10 GW

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Re: build thread: klein mantra conversion 20"

Post by izeman » Dec 31 2012 8:22am

torque plates (which will be clamped as well) are taking shape.
made of 10mm wide st52 they are quite strong. the little hole is to relieve stress from the cut which will be made between the 10mm slot and to hole - to make clamping possible. right now they are a super tight fit, almost too hard to insert the axle. ;)

Image

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Re: build thread: klein mantra conversion 20"

Post by vodk1c3 » Jan 09 2013 11:58am

I like how you laced the wheel, look really great !
First bike (Nitro XT) :
Vpower 1000w 48v 26" rear kit
Vpower LiFePo4 48v 12a battery / 5a charger
20km+@35km/h | 45km/h max speed

Second bike (Everything working, snow is fun ^^) :
Crystalyte HS3540 24" rear
25s1p 5000mah LiPo @ 100v / iMaxb6 charger / Hua tong 72v 35a instant start controller
65+ km/h and lot of torque; battery sag alot; http://www.youtube.com/watch?v=nqf8drRaj9k


Currently working on my first high power build with DH frame / A123 pouch

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