Coustom Frame(s)

[UK_SPAWN]

if its structual my couch engineering knowledge would lead towards Ti for brace and carbon for bash as you said it wrap locking on and even the potential to brake under ridiculous loads would be an advantage for the frame for sure for the bash guard...

Thanks for the feedback dude, ill see what program I can find to do stress test and test different materials in a simulation ( after I learn how to use it).

Cheers

[*gentlydoesit]

Seems most of you have access to machine shops?? Fair play. I'm a fabricator for classic preservation a car restoration business, in my experience pure ti is difficult to "weld" to ally but ti alloy is fairly easy. Also the way the carbon bolts on is the weak point not the body of it as tension/tortion is spread by the weave until its anchor point. But I make cars not bikes so wtf do I know:D

[UK_SPAWN]

Its a titanium bar (not solid) then wrapped in CF and bolted to threaded gussets on the downtube.

Carbotanium downtube

[*gentlydoesit]

Ye, reading all the posts mite help;) id like to build my own too, but too many balls in the air at the mo.

[Rob Leech]

Price varies depending on your design. If you want 3 brake mounts, a custom tensioner, bottle holder, flag mount, side stand and CNCed name badge this will obviously cost more.

My next personal frame is going to include a flag mount for sure

That bolt in carbon part would cost you the most, as it would require many hours making moulds for it. If it could be wraped rather than bolted in.

I would take a guess it would come in around the same price as a jaf frame build around £350

Plus the price of a large jaf carbon repair however much that normaly costs.

But that bolt in should cost around £1000 as a one off

You could make the mold quite happily in one go dez, it's the mold positive that would take the time, depending on complexity and tolerances .

If were designing carbon to those grades it would cost way more than that. You would be going into tens of thousands.

I was thinking pay josh a weeks wage plus the cost of materials your well into a grand. Which it would take at least a weeks work to produce a mould and the final product.

I wish I was on a grand a week . I would say, looking at the rough drawings, you could bang out the mold in 2-3 days if you concerntrated purely on it.

The idea is to remove the top tube and have a single down tube, but brace with other materials, so I had the idea of a removable top brace/seat/piece of carbon on a bike. But its also the top tube, buy now im thinking it shouldn't be removable and should be wrapped in carbon and be furthur up, have 2 brace pints on top instead of one... its a sketch, that were discussing the cost/possibilities of actually making it (not that im making it or having it made).

But if I made a frame, thats how id want it to look... hope that clears things up

Cheers

May practice with carbon though, start with headset spacers see how that goes.

Have you thought about bonding? Relatively easy to design the joints for and would simplify the overall design and look of the frame. Looks a bit "busy" if you get what I mean?

Deffinately have a play with carbon. Loads of places doing simply starter sets that can be used for more than they say if you put your mind to it .

I like the concepot yes in theory but idk...

surely though in a ideal world carbon is not the answer... its very weave dependant on directions of strength and you are probably going to have little idea of the materials flaws and subsequently manufactures are going to have little understanding of the real world application of a trials bike and the stresses applied to it... even if you spent thousands it would be pouring money down the drain imho.

why is it always carbon... surely Ti is a much better material.... in a ideal world surely a skeletonised Ti frame is way to go for strength rigidity and weight is it not?

and you could design and have fabricated a sick Ti brace for less than a CF one.

idk im not a structural engineer but just sharing my 2pence...

That's sort of the main advantage with carbon and the knowledge that is needed to produce parts that are structurally sound with a resulting advantage in the reduction of weight. You can use the different weaves and orientations to act against stresses that are know to act on a member, ie, the use of 0/60/150 degree layups with uni-direction cloth in forks to allow flex in one direction, but not allow this flex to affect the overal structure (if that makes sense?).

The one problem I've found with Ti (especially in the uk) is the cost. The cost for a one off in Ti would be around quadrupple that of the cost of materials to make a part in carbon. Add on the cost of labour and it probably comes a bit closer to equal, but if you're planning to experiment with this design, deffinately play with carbon first (or mayby other composites? Kevlar or diolen would be a cheaper starting point, with the process's involved being the same as used with carbon) .

That's my veiw on it anyways. Nice to see someone thinking out the box for once.

Get in touch if you need some help/advice chap .

Cheers,

Josh.

[UK_SPAWN]

Thats the best post ever on any forum ever... thanks for all that information! Gives a lot to think about..

And yeah its busy I understand, the reason I thought of removable was if you crack your frame then you dont havto buy all of it again. But I see that adding all the gussets and bolting it is adding weight etc and makes it complicated.

On a side note prince's trust is helping me try and open a local bike shop, so I definitly want to eventually make parts and maybe frames also

Cheers again for the inspiration

Edited July 9, 2013 by UK_SPAWN

[Shaun@FlawlessBikes]

How on earth are you coming up with that figure? Sure, send it off to a large firm to knock up a CAD model, run some FEA and produce it to aerospace tolerances and you'll be running up quite a tab, but for someone to create the basic structure, hell, you could do that in your own garage for £100 including buying the kit to do so if you put your mind to it.

OP: This does not mean you. Don't attempt this, Seriously.

If you send me the Geometry and some pictures, I can knock you up a 3D cad model (for free! I enjoy doing it), sadly Flawless Bikes doesn't have the capability to make it yet but I can help in that respect, if you interested message me on the Flawless Bikes facebook page.