DH Balfa bb7, **2.7:1** homemade content ;)

[henryg]

Hi guys,

Just a few photos of some significant changes I made to my bike over the last week.

The old 5th was getting tired, so I purchased a CCDB with an extra 1/2 inch stroke and a nice Ti spring. The new shock gives the frame a leverage ratio of 2.7:1, as opposed to the old 3;1.

New vs. old:

Obviously I couldnt just pop it in, so I set about CADing up some new linkage plates to accommodate the longer shock, and also drop the BB by an inch.

Jigging the bike for measurements:

Once the drawing was complete, I made a prototype out of wood, just to double check.

Template:

Prototypes intsalled:

Geometry? check...

On to the real thing. I couldnt afford to get them NC milled, so out come the band saw and files.....

Counterboreing:

New in progress vs. old:

Finished product now anodised vs. old:

While I had my hands dirty, I made a new chain guide and bash guard from carbon fiber:

Pics of the whole bike to come very soon, and hopefully action pics.

cheers.

UPDATE!

Got photos of the whole build now, action pics to come!

Frame - Balfa bb7
Rear shock - Cane Creek Double Barrel
Front shock/fork - Bos 40's
Handlebars - Sunline
Stem - Easton Vice - upside down
Saddle - Sunline
Brakes - Saint
Cranks - Saint
Chainguide - Home made Carbon
Pedals - DX, soon to be Candy
Wheels - DeeMax
Total weight - 19.0 kg

The new rotors:

I also 'straightlined' my levers:

 

[Zyphryss]

Very, very impressive!!

 

[Futile]

Thats amazing, great work.
Love the bb7 frames. Always wanted one.

 

[Tyler!]

So good man,

You're quite skilled in the Engineering department...

I'm assuming this gives it more travel?

Yes, no?

Edit: Just read, To Accommodate longer shock

 

[Nathan_S]

Holy crap! did you go to MIT?

really good work there mate

 

[rtd]

!! Finished pics please !! I love it, best frame ever. Anodising looks great -
much better looking than the original plates.

That guide looks mint too, good work!

 

[driftking]

Good work there mate,
You deffinatly put some thought into this before just going ahead with a random idea, be good to hear how the bike rides now compared to before.

btw in the picture of the whole bike with the proto on it it looks like the shock is bending backwards, it might just be me but didnt seem straight.

 

[henryg]

I'm assuming this gives it more travel?

Yes, no?

No, If I used the old linkage, it would have more travel. But the new ones are longer, actually giving the frame less travel (8" from 8.25")

What it changes is the ratio, so a softer spring is required. The wheel moves the same amount, but the shock moves more than it used to.

 

[henryg]

btw in the picture of the whole bike with the proto on it it looks like the shock is bending backwards, it might just be me but didnt seem straight.

Haha yeah it does, i think its just an optical illusion, or whoever sold me the shock forgot to mention something...

They were taken on a phone, so go easy.

Im working on stealing my uncles DSLR for sunday to get some action shots.

 

[brutasauras]

Great job mate most people don`t realize how simple the parts on thier bikes can be reproduced with everday tools and a bit of know how. I remember a post not long ago about some one who had broken one of them plates and was having trouble getting a replacement and i thought then they didn`t look too complicated to reproduce. And now someone has gone and done it four and a half stars you would of got five but you made your chain device out of carbon fibre.

 

[MTB MAD]

wow man what a great job u did
cool bike to

ride her hard buddy

 

[Yeti-Brenno]

.

have you installed the real thing yet?

 

[henryg]

have you installed the real thing yet?

Yeah Ive installed it, built it up and done a carpark test, but the guys phone I was using for photos has gone home

 

[madboy]

Jeez!! Crafty bugger aint 'ya. Very good work on making the new linkages yourself.

Should be an awesome build once done.

Ride her hard!

 

[jakey_trickster]

Cool.

That's cool, good work.

 

[soty]

Fuck I love you Henry.. That's so smicko. Still, get onto your serious project already.. Duct Tape Wallet MkII

 

[Bradster]

I saw this bike today, it's a really sweet rig. Good stuff.

 

[camby_mtb]

wow.
What you have done here is utterly inspirational.
very impressive work mate. (Y)
I think you may have just opened up a whole new world in custom parts for bikes my friend.
came up so nice for a home job, very professional work.
By the way, how is the CCDB? I know all about them but how does it ride?
Cheers dude.

 

[mountain_bike man]

Looks great, very professional.
Can we get a ride report?
Cheers.

 

[timbo #48 STP]

props man, thats sick!

when can we expect pics of it finished and together? and some sweet action shots?