Specialized BigHit + Mac build

[Timma2500]

Well i've finally made a start on my girlfriend's BigHit build. We picked up the bike a few weeks ago and have slowly been collecting parts to get it powered up.

We went with an 8t HP Mac kit from Cell-Man (can't recommend him highly enough) in a 24" rim. We're also converting the front wheel to 24" to keep it looking normal and to lower the front end slightly for Mel. We've got a few parts on their way from CRC at the moment and the spec will be as follows:

8t Mac
12 fet controller - 45a
12s lipo, 10ah for now. Frame will be modified to house 15ah
Turnigy Watt Meter mounted flush in frame behind headtube

24" Alex rims fr &rr, 20mm front hub
2.7" Maxxis High Roller dual ply DH tyres + DH tubes

203mm fr, 180mm rr rotors
Shimano 4 pot XT fr and Deore rr callipers

8spd freewheel 32t-11t
Sram X9 twist shifter LH mounted
Sram X5 derailleur
Shimano XT cranks, 32t chain ring
Torque arms

RockShox Pike 454 140mm air fork
Manitou Swinger 4 way air shock - 190mm x 50mm
160mm rear travel

RaceFace Next SL carbon fibre riser bars
Sunline V1 AM 50mm stem
WTB Speed V Comp seat

Like my previous builds, i'll be cutting up the frame and housing the batteries inside the downtube.
I'll be designing the frame insert soon and start cutting up the frame shortly after. Mels keen to get the bike done and out riding so i'd better not stuff around too long!

*Bike not pictured in final spec



Paul

 

[Tench]

You landed on a nice tidy Big hit there Paul, be interesting to see how you do the frame. I did consider putting my CA in the frame but opted for the bar mount instead.
Changing to a 24" front makes quite a difference, it looks more like an XC bike now, with longer travel suspension!

Simon.

 

[Kepler]

Mate, why didn't you get her something decent :lol:

You sure dont do things by halves do you Paul. Nice work. 8)

 

[Timma2500]

Simon: It didn't come with most of these parts, i raided them off my normal mtb to shed some weight off the bike for her. Things we do eh... lol

How come you went with bar mounted over in frame for your CA? I'm lucky with this build that the HobbyKing power meter is small and will fit nicely.
However on my M3 build, the new large screen CA is too wide to fit square on in the frame so i'll be mounting it at a 90deg angle instead. It'll make it slightly tricky to read on the go but i'll get used to it. Besides i only need to use it as a fuel gauge anyway.

Yeah i prefer the balanced same wheel diameter look over the small rear / larger front look. Plus for off road riding (90% of our riding), it means she can use the same type of tyre front and rear giving a more consistant tractional behaviour front to rear than using different tread types.

Kepler: Cheers mate. Yes, if i was any reasonable sort of a boyfriend i would have got her a Stealth Fighter but i'm a tightarse :wink: :lol:
Mind you we're looking to procure some jobs in the mining industry soon so if money permits, she just might end up being the 1st female Fighter owner some day


Nothing more to report so far, we're still waiting on the CRC order to get here and i've been working on my bike the last few days.

I've had an idea to try to incorporate the controller in to the frame leaving the main top surface area exposed for cooling but this will be dictated by the space available.
Then again it might just be a pipe dream lol :lol:

Paul

 

[Kepler]

How come you went with bar mounted over in frame for your CA? I'm lucky with this build that the HobbyKing power meter is small and will fit nicely.
However on my M3 build, the new large screen CA is too wide to fit square on in the frame so i'll be mounting it at a 90deg angle instead. It'll make it slightly tricky to read on the go but i'll get used to it. Besides i only need to use it as a fuel gauge anyway.

Paul

I have opted for the bar mount CA on my New Fighter also. I find that I look at it a lot and I really like the big screen and a bar mount is definitely best for viewing. I find the small screen mounted in the frame difficult to see especially in the fighter. The way trench mounted his CA showed me that you could still make it look like part of the bike rather then a bolt on accessory. I am mounting it a little differently due to a longer head stem but still in a similar low profile manor.

 

[Timma2500]

I have opted for the bar mount CA on my New Fighter also. I find that I look at it a lot and I really like the big screen and a bar mount is definitely best for viewing. I find the small screen mounted in the frame difficult to see especially in the fighter.

Yes i like the way Tench mounted his, looks like its meant to be there. Up on the bars is definately the best spot for it if you read it often, you won't have to move your eyes too far away from where your looking ahead compared to looking further down to the frame.

We'll just be using them as a fuel gauge so won't have to look at them too often

Your doing a very neat job on that Fighter too Kepler, I reckon the geared BPM will be a good match for the lightweight Fighter platform

Paul

 

[Timma2500]

Well its been a while since i've done anything on this build due to having setup all the running gear on a hardtail for my girlfriend to use, just to test the water and see if she really does like ebiking enough to warrent chopping up the BigHit frame. Turns out she liked it enough to sell her near new quad last weekend stating she won't want to ride it now after sampling ebiking - thats enough evidence for me! :lol: Having said that she's now ordering a 110cc pitbike just to ride when i take the Husky out

So with the 2012 Australian Safari coming up in 3 weeks time, the deadline has been set to get it designed, fabricated, powdercoated and re-assembled so we can take the bikes up north with us to help get to different spectator points at the Safari Prologue (1st stage) at Glengarry Station.

After giving Mel a few frame design options, she's opted for a similar design to my M3, namely a tall but thin / narrow setup.
The insert will be 150mm high by 80mm wide. It was originally going to be 70mm wide but at the last moment I added another 10mm width to give a bit extra room for wiring etc. Lessons learnt from previous frames lol...

So after a few nights in the shed with CAD MK1 (pencil, paper and rulers :wink: ), the design was locked in. Tonight i transfered the design to the 3mm aluminium sheet and started cutting the insert's panels, starting with the top and bottom panels in the 3rd pic below.







They're finished apart from a few cutouts to the top panel underneath where the original frame sits on top, these are to loop some of the wiring from the throttle and Watt Meter up and over the battery storage area to keep it uncluttered as much as possible and will also be drilled at the rear for the phase wires to exit the frame. The cutout visible on the bottom panel is for wiring coming up from the 12fet.

More to come tomorrow


Paul

 

[Timma2500]

Oky doky, its been a busy day in the shed:















I start my new job tomorrow but will try to get some more done in the evening time permitting.


Paul

 

[ejay]

Looks great!

In your experience, if I were to try something similar but with steel sheet (no tig welder/knowledge), what sort of thickness would be strong enough? I have done a little framebuilding, but only with thick tube/box section.

Cheers
Jay

 

[ROG130]

ha ha fast work paul i think she will love it

 

[Timma2500]

Jay - Cheers mate. Hmmm i've never used steel on a frame myself however i have seen 1.6mm used on a copy of one of my previous frames and it seemed fine if a little weighty. With a lot of bends along it to give strength, you could probably get away with 0.8 or 0.9mm to reduce the weight but don't quote me on it!

ROG130 - Haha she'd better like it! :lol: She saw it lastnight and was happy with the progress so far. She's even got a colour picked out for it already, Dulux iridescent French Blue....


Paul

 

[Timma2500]

Another busy day in the shed, she's all welded up Theres no headset on it so the forks look more raked out than they really are.



View attachment 6



View attachment 4









Now its off to the powdercoater this week for a coat of French Blue before coming back for re-assembly and whipping up a torque arm for it.


Paul

 

[litespeed]

Wow, in your pictures you sure made that look easy. I really need to get a tig welder. Sure would beat making battery boxes out of wood. Very nice.

Tom

 

[Whiplash]

Awesome...... You're getting better at this as you do more aren't you?!

 

[rodgah]

looks good Paul,

funny your GF and mine have the same frame....except she says she doesnt like it. That will change when she rides it :lol:

 

[Beachcruzer]

Thinking of trying out to be your next girlfriend . . . .

 

[Timma2500]

Thanks guys

Wow, in your pictures you sure made that look easy. I really need to get a tig welder. Sure would beat making battery boxes out of wood. Very nice.

If only it were as easy as the pics suggest lol. Tigs are very handy to have in the workshop, an acdc machine preferably so you can do aluminium and steel.

Awesome...... You're getting better at this as you do more aren't you?!

I dunno about getting better but i'm certainly learning a few lessons as i go :lol: You bought a tig yet?

looks good Paul,funny your GF and mine have the same frame....except she says she doesnt like it. That will change when she rides it

Hey mate. I'm sure your missus will love it when she twists the throttle - especially if you leave it setup at 24s! Are you going to leave the HT on it for her?

Thinking of trying out to be your next girlfriend . . . .

If your a 5ft 9" brunette, size 10 with D's, i'll shoot you a PM


The front half of the frame is off to the powder coater tomorrow but may not be back till next week due to the iridescent colour being a non standard item.
This and the missus buggering off for a girls weekend away this coming weekend will buy me free time to make a proper torque arm setup for her bike and get my bike rewired and setup for the following weekend away up north watching the Safari :wink:

Paul

 

[Idontwanttopedal]

Nice build again form you

 

[Samd]

Funny to get girlfriend offers!

 

[Whiplash]

Still trying to get the TIG, but I am getting closer. Almost done with the mustang so time available will increase dramatically! And I have my fingers crossed for another job so pay should go up a little too! Wish me luck!

 

[Timma2500]

Cheers idontwanttopedal

Funny to get girlfriend offers!

Indeed! Never happens when i'm single lol.

Still trying to get the TIG, but I am getting closer. Almost done with the mustang so time available will increase dramatically! And I have my fingers crossed for another job so pay should go up a little too! Wish me luck!

Goodluck man! Cool, hurry up and finish the 'Stang so you have more time for the bikes!


Ok, finally got the frame back from the powdercoaters this arvo and i'm not impressed Its got scuff marks, a few small chips and has been dropped at some point resulting in a dent front and rear... in the end i just wanna get it finished so i didn't bother saying anything to them, i just won't go back to them if i do any more frames.

The pics below show the last few hours work and i should have the rest of the bicycle bits on tomorrow night, then its a matter of doing the ebike bits - finishing the bolt clamp torque arm, wiring in the controller / throttle etc. After that i've gotta re-configure a 12s 15ah hardwired long pack into a 10ah pack to fit in there till Mel has the $$$ to buy 6 x 6s 5ah brick packs later on to go back up to a 15ah pack.














Paul

 

[BATFINK]

Awesome, you are becoming a dab hand at that

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[Spicerack]

Nice work Paul!

 

[Timma2500]

Cheers boys

More work done tonight, its a peddleable bike now yay. Tomorrow night i'll do the wiring and torque arm then all it'll need is the battery re-configured, charging / balancing and its good to go


Paul

 

[crusoe]

Tigs are very handy to have in the workshop, an acdc machine preferably so you can do aluminium and steel.

What's an acdc machine?