Current Projects chat and miscellany

Balsa and heavy are 2 words difficult to associate Dylan...

Balsa weighs literally nothing. I don't think he has an industrial carbon machine :P

http://i926.photobucket.com/albums/ad110/fozzibike/DSC_0447_2.jpg

http://i926.photobucket.com/albums/ad110/fozzibike/DSC_0448.jpg

bars and pedals coming black. no wondering what colour chain. i am very aware that colored chains can ruin bikes. any advice/shit storms?

EDIT: sorry its big, i cant sort it out for some reason. tricks i knows wont works...

Get a silver chain.

Balsa and heavy are 2 words difficult to associate Dylan...

Balsa weighs literally nothing. I don't think he has an industrial carbon machine :P

ok ok, learned something new, thanks guys.

I see, so the balsa wood is a part of the frame, but won't that make it extremely heavy, given the large chunks of it used and therefore negating the benefit of using carbon in the first place ?

Although balsa is less common than rigid foams such as polyurethane or polystyrene, the use of a low density solid former is quite common in composite structures. Although I'm not aware of it's current use in any mass produced frames, it certainly crops up in disc wheels and some carbon rims, e.g. Lightweight. In the olden days, there were even some aluminium frames with structural foam reinforcement in areas subject to severe buckling stress, e.g. BB area on some Bianchi U2 frames. The foam or balsa provides a high resistance to compression, which if not resisted would allow the very thin walled skin to buckle. As such, using a sandwich structure of a skin which resists tensile loads in plane around a core which resists compression orthogonal to the skin plane can be a route to a lighter structure than a pure hollow structure, which has to have its skin thickened more to resist buckling than the tensile loading otherwise requires.

Honeycomb structures such as Aerolam are structurally similar, albeit that the low density compression layer is made from macroscopic cells and often (but not always) in the same material as the skin. At the more prosaic level, foam cored mounting boards made from thin layers of card sandwiching a layer of styrofoam are significantly lighter than a solid board of the same stiffness.

Cheers for that MT, interesting references, i like, learned loads today, always a good thing.

Some other food for thought. Don't leave your bike out in the rain.

That's one hefty piece of wood too.

Ah thats very cool, I've got an 853 Rourke track frame. I'll try and get some pics up later, would be interested to know if you built it!

Send me your frame number, are you the original owner?

wow, what a pleasure! I saw you and Brian on that bbc show about building the perfect bike. lovely work!

Thanks! :-)

Dug this out of my grandparents garage; my old MTB I had when I was at school - had many a good time on this! Specialized Hardrock from sometime in the mid-90's, not high end or anything but should be good for some off roading this winter, just needs a clean up and some new pedals & grips.

Look like it got horizontal drop out.

single speed that bitch up.

Ha, I did think about it - will have to see how I feel after a few times out.

The dropouts are wierd actually; look like full length horizontal ones but are blocked halfway along (leaving a perfect circle closed off at the end).

Fascinate by the 'homage to Obree'. I had a look at the Swedish site, but don't speak Swedish so couldn't understand it.

Obviously you've used balsa wood to give it the shape and have wrapped it in carbon fibres and resin. It then looks like you've just a plastic bag and a vacuum cleaner to compress the carbon/resin mix whilst it sets, is that right? It also looks like you've used the tightly wrapped insulation tape technique as well - was that for a second layer?

Some of the other images suggested you were respacing the rear hub to make it narrower, and the bottom bracket as well?

How are you making the steerer tube? What will the headset be?

Why are the bars in one piece with the forks?

Really amazing project, look forward to seeing the finished product.

Fascinate by the 'homage to Obree'. I had a look at the Swedish site, but don't speak Swedish so couldn't understand it.

google translate?

http://translate.google.com/translate?js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&sl=sv&tl=en&u=http%3A%2F%2Fwww.fixedgear.se%2Fforum%2Fviewtopic.php%3Ff%3D1%26t%3D6007

Fascinate by the 'homage to Obree'. I had a look at the Swedish site, but don't speak Swedish so couldn't understand it.

Obviously you've used balsa wood to give it the shape and have wrapped it in carbon fibres and resin. It then looks like you've just a plastic bag and a vacuum cleaner to compress the carbon/resin mix whilst it sets, is that right? It also looks like you've used the tightly wrapped insulation tape technique as well - was that for a second layer?

Some of the other images suggested you were respacing the rear hub to make it narrower, and the bottom bracket as well?

How are you making the steerer tube? What will the headset be?

Why are the bars in one piece with the forks?

Really amazing project, look forward to seeing the finished product.

Vaccuum bagging is really common in building composite kayaks etc. helps remove excess resin and bed the figres better.

The mafia make good use of vacuum bagging.

Imagine if the saddle ends up being at an uncomfortable angle, doh!

A friend of mine has just started building frames, so I hit him up for one.

Its a 700c, fillet brazed, disc braked commuter with belt drive, It has one off laser cut 4130 dropouts and segmented fork, also has a one off bar/stem combo.

the front end is Reynolds 631 and the rear triangle is 753.

Its turned out great, better than I ever envisioned, and Tom has added some nice little finishing touches of his own.

Currently waiting on belt drive components so we can do a dry build to ensure it all fits and Toms calculations were all correct. After that, its final clean up and paint time.

Cant wait to ride it.

More details can be found here...

http://donhoubicycles.com/

very nice

yes, nice
not too tight - is that how you wanted it? esp the front wheel

Yeah, the idea was to have plenty of clearance so I can throw some big cyclo cross tyres on it and ride it off road without worrying about clogging up if its muddy.

I think he has a couple of lugged track frames in the pipeline which will have tiny clearances.