Bicycle Mechanics - Dropping a bit of weight
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08-25-02, 03:50 PM
Ok guys, Ive heard the complaints about my steed... its heavy when passing over a fence....
It weighed in at 29 lbs
I want to lighten it some, I know that there is a limit to what I can afford, but what would be the best places do do so?
Its a GT Rebound frame,
Marzocchi Z5 air fork,
STX-RC drive train
Sun Rhyno lite rims laced to STX hubs.
Zoom bar and stem,
GT true temper seatpost and a cheap but light selle Italia saddle, model unknown,
Radical clipless peddels
Im thinking that rear cassette, BB & cranks are probobly the biggest weight saving items aside from the frame and fork.
but what are your thoughts?
Im riding strictly XC, and some road here n there... just for milage.
08-25-02, 04:14 PM
save your money up and buy a SID if you want to drop a pound or more. wheels will make a huge difference (Rhyno Lite's aren't very light, but they're durable). Change your BB if you haven't already (i'm using a Race Face Ti bb---squaretaper). Seat post makes a bit of a difference too (if you can, go for a Thompson post--i'm running a CT2 carbon). If you really want to do a weight loss, you might want to change the frame..i assume it's a heavy frame..compared to a Zaskar/Avalanche? So maybe leave your bike till you have a light frame to build upon.
I'm running an Easton 7005 Elite tube set. After going on a gram counting phaze for the past 2 years, i've gotten my bike down to 21.5lbs w/ mtn. bike tires on. I felt the biggest difference when i got a set of Mavic CrossMax wheels (non-tubeless) and changed my Z2 bomber to a SID. I think i dropped almost 2-3 lbs just from those 2 things (mind you, they costed a pretty penny).
what's your price limit?
08-25-02, 08:45 PM
29lbs is heavy? Tell whoever is complaining to hit the gym. My hardtail weighs in at 38 pnds now.
08-26-02, 12:39 AM
You didn't mention your specific tires, but tires do vary widely in weight, and they're actually one of the heaviest single components on the whole bike. And they rotate on a large scale, so they should get priority when you're considering weight-reduction plans.
In the tire market, tires with Kevlar beads save a bit of weight over their steel-bead counterparts, and some manufacturers also use lighter casings that further differentiate their Kevlar-bead version. There are also lighter-than-average tubes available that may help reduce weight just as much as the light tires, so check that option out too. The WTB NanoRaptor Race looks interesting, at a claimed 510 grams: link to WTB's site (http://sgs-staging.stoneground.com/wtb_staging/products/2002/products_tires_xc.cfm#velociraptor) A typical steel-bead name-brand 2.1" tire is going to be around 600-650 grams, so that has some potential.
You might consider rebuilding your wheels too. RhynoLites are a bit overkill for XC unless you're not a finesse rider. As a quick-&-dirty estimate, if you presently have 32-spoke RhynoLites with 14-gauge spokes and brass nipples, and had the wheels rebuilt with Mavic X221's, alloy nipples, 14-15ga. rear and 15-16ga. front spokes, I'm estimating about 140 grams lost on spokes and nipples, plus 110 grams per rim, for a total of 360 grams lost. Combined with a light pair of XC racing tires, I think you'd notice a difference when riding. I used to have two sets of wheels, and the race-weight ones were noticably easier to climb with.
The STX-RC crankset is not very light, and uses flexy, suck-prone steel chainrings too, so you might also consider upgrading to a DeoreLX with the big-bore splined bottom bracket, to chop off some weight while improving functionality. My estimate is that the STX-RC crankset and bottom bracket are about 1100-1200 grams (educated guess), and a DeoreLX combo would be about 900 grams.
The steel seatpost is an easy 100-150gram weight reduction if you can get a plain old Kalloy Uno, a light seatpost that is under CA$30. You might consider removing the handlebar to see if it's some 300-gram monster too. The fork is not exactly light but that's one area where I wouldn't go gram-counting if it works well for you.
Hope that helps :)
08-26-02, 05:10 PM
yes sorry the Tires are 2.1 Specialized rockster's with a kevlar bead. around 530g each, so they are light enough I guess.. Just installed them so Im at 28.2 lbs now
Well.... about the finess bit yeah Im an Ox, hence the Z5, and the ryno's, but they are still as true as when I built them.
I was actualy thinkin going XT or race face Prodigy XC for the cranks, 620g and 680g respectivly and 255g for a BB. and an XT rear cassette, 8 speed of course, this 9 speed thing is a weight boon innit?
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