I should be working with my thesis, but I find myself looking Excel charts, and how to squeeze my next project's weight to sub 12 kilograms.
Now, I already have a Pugsley, but I felt that I need another fat bike. In fact I felt that I had earned a new one. I did not wat another heavy one, especially as the Pugs gives enough floatation with 82 mm rims and 4" tyres. Thus, it had to be light. Options were basically 9 : zero : 7 with Carver O'beast fork, and Salsa Beargrease (cannot afford titanium). And as the BG is - save for perhaps (custom) ti - the lightest frameset out there, to LBS I went to discuss about options.
So, I ordered a Beargrease frameset. With headset, it should weigh little over 2500 g, and the wheels (Marge Lites, DT Comps and Hope hubs with modified QR:s - see pic below) approximately 2400 g. The drivetrain will be some nice fat bike cranks (probably Race Face or Middleburn) with single ring and the rest will be some reasonable SRAM stuff. Pedals will be Ritcheys, as I am an SPD man, and the Pro Paradigms are 90 grams lighter than my Shimanos. Probably the bearings will fail prematurely, but this is a WW project, not some bombproof steel anchor built as my Pugs is.
As for brakes, if I find some light hydraulic brakes in sale, I'll take them - otherwise I'll settle to Avid Elixir 5's or something like that. And in any case if the WW fever gets aggravated, I can buy Ashima Airotors and save 100 grams when compared to Avid's stock discs. Of course there are some durability issues which may mean my horrible and futile death as the ultralight brake discs explode in downhill...
I already have some weight weenie-ish parts - for example handlebar + stem + grips (foam! I like it, it's warm in winter, and light) should weigh in about 370 g. Seatpost and saddle combo will be relatively porky, as I have a SDG Formula FX saddle which I like very much with 400 mm seat post. Their total weight is about 460 g.
The greatest problem in getting the weight to desired 12 kg will be the rubber parts. Rim strips + Schwalbe FR tyres make 500 g of rotating mass which is good. But the tyres have to be either 45NRTH Escalators, or 120 tpi Hüsker Dü's (providing that I can get a pair from LBS that weights about 2400 g). The lightest reported Dü I know has weighted in 1180 g, but the average weight is closer to 1250 g, which is a little too much. 45NRTH bragged that their Escalators' weight should be 1115-1130 grams, but alas, their real weight seems to be somewhere around 1200 grams, which I find a little disappointing.
The price of the project? About 3K€, if I cannibalize some parts from my FGCX bike* and swap them to Pugs which in turn will provide some parts to BG. Ouch. But then again, some people put ten times more money to their fume-producing, metal coffins - and in any case, vita brevis.
More to follow, hopefully before next March. As of now, my project looks like this:
*probably I'll sell what's left of it and buy some CX fork to my Vigorelli, as it has enough room to 35 mm rear tyre - but that will be another story ;)
PS: My fat bike musings are in english because most fat bike enthustiasts can read it :)
Ei kommentteja:
Lähetä kommentti