Hey All,

I'm going to start by giving a bit of back story, it might help to clarify my motives for this project later on. Not so long ago a friend was selling for a good price a single speed Marin Inverness. I hadn't cycled for a good while but I was instantly taken by it, decided I could start cycle commuting in London and bought the bike. Largely I liked the fact that it was around 8.2kg (supposedly) which made it very easy to lug about. Unfortunately I had it for about three weeks before it got stolen from outside of my work in central London. There seems to be something empty about the idea of just biting the bullet and buying a new bike, so I decided to build a completely new one; still single speed with freewheel but to make it as light as possible within a budget. It'll be a challenge as well as a good winter project with a ridable end product to boot.

Looks are no object and scratches / cosmetic damage are of no concern. I'm happy to drill and make modifications etc and of course I expect most parts to be second hand / from eBay.

Now for the big question, no matter how subjective the answer may be: For a budget of £350 - £400, how light could I build such a bike? I was hypothesising 6kg but that could be pure fantasy! If anyone has part recommendations or any other relevant advice I would greatly appreciate it!

Cheers,
Tom

Yep, I believe it is possible.
Frame: Lightish alu 1300grams (cannondale/principia/trek etc.)
Fork: full carbon 400grams
Wheels: in 1300-1500 grams range (alloy or used carbon, depends on brake setup) Look for a bargain.
Tires: 200 grams models with decent protection layer (GP4000s/ etc) I like Duranos for commuting with light tubes
Crank: nice and light and used for fraction of the pricew (dura ace 7700 if you can get hold of it cheap)
Components: lightweight alloy stem/bars/seatpost rideable saddle like Flite or whatever suits You
Brakes: standard road? or V's? Get high end ones (xtr/ da/ kcnc or Avid SD Ti)
I love this:
http://weightweenies.starbike.com/articles.php?ID=63

Great! Thank you very much for the info Victor. That bike is certainly a brilliant example of a wolf in sheep's clothing. At the moment I'm looking at the following frame, quoted at 2kg by the seller

Durace parts are never cheap though. A £400 single speed is readily doable

Frame/fork 1800g
Cranks Miche Express ~600g
BB ~300g
Wheels ~1500g
Seat 300g
Seatpost ~300g
Bars ~300g
Stems ~170g
Tyres 420g
tubes 200g
rim tape 20g
Brake levers 260g
brakes ~ 330g
cables 150g
tape 40g
chain 250g
freewheel?

I think a build will come in around 7kg. Your budget will be blown on frame/fork + wheels and tyres. Thant leaves not much for the other parts, that means cheap heavy ones. The wheels for 1500g would have to be pretty special and not your standard track wheels. You would find itr easier to use a vertical dropout frame and cassette rear wheel and use a single speed sprocket + spacer with a cheap tensioner. Most track wheels in the budget you will be looking at will be heavier than 1500g. Most track hubs are not light.

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www.thecycleclinic.co.uk

Thanks bm0p700f, I agree once the frame and wheels are purchased the going will get a bit tougher. I won the frame I previously linked for £91 so we'll see how that weighs in once I get it and go from there. On a side-note I also originally hail from Woodbridge in Suffolk!

Although my fervent research is going well, can someone please give a personal opinion on whether converting the rear hub on these to single speed would be a good idea?
http://www.ebay.co.uk/itm/290787906309? ... 1423.l2649

Edit: I have determined that it is, still feel free to disagree!