Almost Done:Tuning a 2004 Jetstream XP
Tuning a 2004 Jetstream XP
I started this project with an eye towards getting the total weight of a stock 2004 Dahon Jetstream XP down to something competitive with the lightest folders ever made. At 9.2kg, the bike began life light; now 870g lighter, it's almost as light as it can be.
Some of the highlights:
Stronglight Pulsion cranks are the current world's lightest @ 451g with all bolts, including BB mounting bolts, and the chairings included. Since I've traded the small chainring for the bashguard, I'm probably 15g up on that. The Stock Truvativ Elita crank should've weighed in at around 680g's but when I took it off, I could instantly tell it was far heavier than that. I'll try and weigh it, with all of its associated hardware tonight. If I had to just guess, I'd guess 890g's.One other thing: When I put the new freewheel on,I had a bear of a time getting a smooth drivetrain running and had almost given up on ever having it smooth again. Turns out, most unexpectedly, the CNC chainring on the Stronglight was the complete cure! Keep that in mind should you find the same action on your bike.
Shimano Dura Ace half-titanium freewheel weighs almost exactly half of what the stock SRAM did. 177g (174g measured).
Paul Motolite Brakes are not the lightest V-brakes available, but they are among the most beautifully made. 364g for the pair.
The stock SRAM7 levers were very light 195gr but, man, were they ugly.SRAM 9.0SL levers are _much better looking and a good bit lighter. 158gr weighed.
Titanium, titanium everywhere. Aluminum nuts, titanium bolts. Replacing the QR levers on the rear wheel and on the front handlebar saved 90g alone. When I finish getting the frame hinge bolt sets made, I'll have saved around 300gr just in bolts.
Other than the few titanium bits left, I'll be changing the rear derailleur (I bought a Sachs Plasma DiRT on ebay. 200g and inexpensive. When that wears out, it'll be Dura Ace 10 with SRAM rocket gripshift. Interesting thing is that that combo will only save 10g or so. Maybe I'll titanium bolt the Sach derailleur as well and tune the cage).
A lighter seatpost seems possible and definately a lighter seat (I really want a new generation Selle SLR 125g to replace the current 235g saddle I'm running now. Do have to say that this SDG i-flex saddle I'm riding now is extremely comfortable. One of the best I've ever ridden). Continental racelite slim tubes save around 40g over the stock tubes for the set, so I'm running those.
All in all, at least until I get a CNC house to work on a few things for me, I've put together a bike that's pretty impressive. I guess I'm fishing for your opinion, so tell me what you think! Here's a pic: