XTR vs XT weight?
Not including wheelsets or cassettes, what's the approx weight difference? I'm considering the purchase of the shifters, brakes, and front and rear derailleur only.
Thanks for the link. Looking for current product on their listings.
What a great website.
Originally Posted by Ilikebmx999
"What is this? A center for ants?"
Very cool thanks for the link.
Everything I see in the link is 2008 or older.
edit: nvm, there is some newer stuff, just looking at brakes in general there is alot of old stuff.
-It's time to shred some mild to moderate gnar!!
I just was working on this question tonight, using the data from bikescale. Comparing a complete XT kit to XTR, you'd save about a pound (.92lbs, 418g by my math). Half of that weight savings is in the shifters and brakes alone - and they're a lot less than half the price difference. Rear derailleur will save you a little bit, and the front almost nothing.
Edit: I wrote the above with some faulty math. I was comparing two XTR "race" front brakes to two XT front brakes with Ice-Tech pads. This has been corrected and the listings are both now for a front/rear combo with Ice-Tech pads. Furthermore, the shifter comparison is between XTR SL-M980-I and XT SL-M780 with the optical indicators - I can't find weights for I-Spec XT shifters.
Both errors served to unfairly tilt things in favor of brakes and shifters, and undercut the advice I first gave.
My data (forgive the messed up columns):
xt weight xtr wt xt price xtr price delta-w delta-$ dw/d$
brakes 586 510 298.8 514.8 -76 216 -0.351851852
shifters 277 220 142.11 226.332 -57 84.222 -0.676782788
front der 153 145 53.298 106.596 -8 53.298 -0.150099441
rear der 246 208 124.344 239.832 -38 115.488 -0.329038515
crank 779 691 302.004 577.368 -88 275.364 -0.319576996
cassette 339 271 82.674 263.052 -68 180.378 -0.376986107
10 chain 275 268 41.328 60.12 -7 18.792 -0.372498936
totals 2655 2313 1044.558 1988.1 -342 943.542 -0.362463992
All weights are in grams. Prices are approximate computer garbage, but roughly in line with MSRP. Most parts are Mx80. "Brakes" are a complete pair, "trail", rotors not included. Cranks are trail triple, rear derailleur is Mx86-GS Shadow+.
I can't find weight differences between chainrings, unfortunately. I suspect a large fraction of the weight reduction in the XTR cranks lies in the chainrings.
Last edited by lazarus2405; 10-28-2012 at 11:10 PM.
I have a brand new, completely disassembled 2012 FC-M780 170mm silver sitting in front of me. My Weigh 7001DX
Originally Posted by lazarus2405
42t = 77g
32t = 56g
24t = 25g
granny bolts = 12g
outer bolts/nuts = 8g
BB = 87g
spacer 2.5mm = 1g (all 3 spacers = 4g)
end cap = 4g
ND arm 170mm, silver = 219g
DS arm/spindle, 170mm, silver = 365g
Total = 766g (all parts minus BB and spacers)
Edit: OK, figured it out. That 779g looks correct for a 175mm FC-M780. Mine is 170mm. I initially didn't notice the 779g was excluding the BB and spacers. Duh!
Last edited by steiny; 10-31-2012 at 01:15 AM.
Reason: Fixed my broken/missing gallery pic.
There is something wrong here.
Thanks for your weight breakdowns. That's pretty nifty. You'd pretty much negate the weight difference between XT and XTR cranks if your riding allowed you to simply discard your big ring and save a few hundred dollars. I'd certainly underestimated that.
Originally Posted by steiny
As for the weights, I compared this: XT FC-M780 - Cranksets - Bike Scale
to this: XTR FC-M980 - Cranksets - Bike Scale
Both are most certainly FC-Mx80 42/32/24 triples. It seems that BikeScale did the measurement without the bottom brackets. Without your BB, you'd get a weight of 767g, right?
It would also seem reasonable that they would have measured a 175mm crank by default (though I have no way of determining that). I'd estimate that the difference between that and a 170mm crank is maybe 10g-15g. Extrapolating from your non-drive arm: 2*219*(175mm-170mm)/170mm=12.9g.
Add in the difference and you're at about 780g compared to the 779g they listed? So that would put your crank (without BB) in pretty good agreement with the measured weights at BikeScale. I don't think there's anything fishing going on.
Edit: I did catch a couple of apples-to-apples mistakes in my earlier math, namely comparing i-spec XTR shifters to non-ispec XT, and not making sure the brake pairs were front/rear. I can't find weights for XT SL-M780-I shifters. I updated it above.
Last edited by lazarus2405; 10-28-2012 at 10:57 PM.
While I was re-weighing the parts and writing up the edit to my post you must have posted and I didn't see your response. Looks like we're pretty much in agreement on everything. Cheers!
Originally Posted by lazarus2405
If you're comparing XT and XTR cranks you should also consider the SLX which people claim is stiffer than the XT yet the crankarms are lighter - Cinfirmed...SLX arms lighter than xt
my 2012 FC-M780 170mm double chainrings 38T/26T weight 720g with BB 820g