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Put my RacerX on a diet?

2025 Views 36 Replies 10 Participants Last post by veritechy, Mar 3, 2010

fsrftc

Discussion Starter · Jan 4, 2010

my large 2007 racer x is coming in at 26 pounds even with a decent component set what have i overlooked? i have xt shifters/derailleurs, full titanium/aluminum bolt kit for everything, juicy 7 brakes, ashima rotors, crossmax slr wheels, carbon seat post and bars, xtr 960 cranks, f100 rlc fork, king cage...the only real weight loss i see from here on out would be tires and a few other titanium bits like the pedal spindles.

I have a cobalt headset that'll save an ounce over my chris king, and going to a 11-32 cassette will save about another ounce, changing out the grips will be another ounce or so too..but i'm being really picky here...i don't see how i can get this bike in the low 24 pound range...help! I think the tires can get me another 1/2 pound (racing rons) but sill not close to sub 25 range that i was shooting for.

I'm about to remove the power coating!!!!!!!

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Limon

· #2 · Jan 5, 2010

fsrftc said:
my large 2007 racer x is coming in at 26 pounds even with a decent component set what have i overlooked? i have xt shifters/derailleurs, full titanium/aluminum bolt kit for everything, juicy 7 brakes, ashima rotors, crossmax slr wheels, carbon seat post and bars, xtr 960 cranks, f100 rlc fork, king cage...the only real weight loss i see from here on out would be tires and a few other titanium bits like the pedal spindles.

I have a cobalt headset that'll save an ounce over my chris king, and going to a 11-32 cassette will save about another ounce, changing out the grips will be another ounce or so too..but i'm being really picky here...i don't see how i can get this bike in the low 24 pound range...help! I think the tires can get me another 1/2 pound (racing rons) but sill not close to sub 25 range that i was shooting for.

I'm about to remove the power coating!!!!!!!

Dura Ace rear der tuned 140g should save you about 80g
Ti bolt on skewers 46g saves about 60g from mavic skewers
what carbon seatpost and bars? what stem?
supersonic race king 2.2 450g
keep the king headset the cobalt won't look right on the Aluminum frame
11-32 XTR cassette
kcnc SL 10speed chain 226g
foam grips
Rox rim strips
light tubes
what seat?

veritechy

· #3 · Jan 5, 2010

+1 to the foam grips. Less than $10 and weigh as little as 25g/pair.

fsrftc

Discussion Starter · #4 · Jan 5, 2010

max 309 seatpost and monkeylite low risers 31.8 wtb rocket v seat

Mr Magoo

· #5 · Jan 5, 2010

My 2005 lg RX 100 goes 28

My rx weighs 28lbs.
Feel better yet?

fsrftc

Discussion Starter · #6 · Jan 5, 2010

Mr Magoo said:
My rx weighs 28lbs.
Feel better yet?

lol well....i don't want to look back and feel that i could have won a race if i lost 2 pounds on the bike

veritechy

· #7 · Jan 6, 2010

You can probably cut weight on the seat too..
The rocket V isn't superlight.

kikoreta

· #8 · Jan 6, 2010

You could still shed some weight by changing your brakes to a lighter option like Avid Elixir Mag or Formula R1s. Tires and going ghetto tubeless might get rid of a pound or more. Would you have the carbon or aluminum seat stays?

lucifer

· #9 · Jan 6, 2010

My ti 2008 with xtr drivetrain and wheels (except the crank) is 25.25 lbs. So you are doing good.

fervor

· #10 · Jan 6, 2010

SLR wheels are not light. Are you running tubes? What tires? The brakes and fork are not light either. Those are the biggest areas to save weight.

fsrftc

Discussion Starter · #11 · Jan 6, 2010

fervor_1 said:
SLR wheels are not light. Are you running tubes? What tires? The brakes and fork are not light either. Those are the biggest areas to save weight.

i have every piece of hardware in the brakes swapped out for titanium, they are surprisingly light, i can weigh them if you'd like.

no tubes, i have to run tubeless due to my style. Currently have a weirwolf 2.1 front and a python 2.0 airlight on the rear IIRC i measured the python at 705 grams and the weirwolf at 730, I'm expecting at least a 1/2 pound reduction just in my tire choice but i need something that can handle a beating.

After seeing everyone's suggestions, I think a 24 pound build is possible.

fervor

· #12 · Jan 7, 2010

Weigh those brakes! I bet they are 350g-ish with all the hoses, brackets, rotors, etc. Juicy's are not light.

Wheels, tires, brakes and fork will easily get you under 24lbs.

Pedalfaraway

· #13 · Jan 7, 2010

2 lbs is not going to lose you a race

I would replace things as they wear-out and brake with lighter ones but run what you have for now. Lighter tires will make a noticeable difference. I run Specialized Captain pros which are like 550 grams and I find them to be pretty durable. They are about the lightest tire that my 200 lb ass does not turn into Confetti in the XC race variety. You could lose a ound with tires and grips for 100 bucks. 25 lbs is superlight and you bike is bascially ready to win national level races are you?

fsrftc

Discussion Starter · #14 · Jan 7, 2010

Pedalfaraway said:
I would replace things as they wear-out and brake with lighter ones but run what you have for now. Lighter tires will make a noticeable difference. I run Specialized Captain pros which are like 550 grams and I find them to be pretty durable. They are about the lightest tire that my 200 lb ass does not turn into Confetti in the XC race variety. You could lose a round with tires and grips for 100 bucks. 25 lbs is superlight and you bike is basically ready to win national level races are you?

I'm currently at 4.4 w/kg at 5000 feet with 10-12 pounds (i'm currently 187) to lose. I'm training for a sub 8 hour leadville 100 (if i get in)...if I don't I will have to re-evaluate my schedule for next year. I'm currently riding 12-14 hour weeks - early winter in 20 degree weather (colorado). The way my training has been progressing, I am anticipating reaching over 400 watts for a 60 minute FT come spring, and if I can reduce my body weight to 80kg thats 5 watts AT 5000 feet. I'm not throwing out random numbers, I was able to reach well over 4 watts without a training plan (read that as just riding hard), I've since hired a real coach and have done an evaluation with a nationally known sport physiologist. Since hiring my coach and having my evaluation done I was able to increase my repeatable 10 minute interval power by 7% in 3 weeks (and i have already done over 400 watts for 10 minutes)

So to answer your question, yes..you will be reading about me this year as long as I don't get injured.

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lucifer

· #15 · Jan 7, 2010

There are much lighter forks than the F100RLC but none that feel as nice.
Whatever you do do not remove the powder coating on an aluminum frame. Ever. Although swapping your frame for an ano one might be worth considering as it's an ounce or so lost with no difference in performance.

My post about my titus has actual weights for everything on it if you want to use it for comparison.

http://forums.mtbr.com/showthread.php?t=538295

FWIW XTR derailleurs are lighter. The front alone is about 20g lighter. So are the cassettes and shifters but that's serious money. My XTR wheels and your SLRS are theoretically about the same weight but I bet the centerlock xtr brakes are lighter.

Ck headsets are heavier than advertised but I wouldn't swap it for a cobalt to save weight. I also wouldn't change anything comfort related if my goal was to race leadville. If you like your saddle don't change it just to save weight.

fsrftc

Discussion Starter · #16 · Jan 7, 2010

there is a laser v saddle with ti rails that i just ordered, i also ordered a 12/27 ultegra cassette and ti spindles. I have to be careful with REALLY weight weenie stuff since i'm a pretty heavy guy. after i tune the cassette i'm guessing it'll be close to 200 grams a 100 gram savings over my 11-34 xt, the pedal spindles are about 40 grams saved, the saddle is supposed to be 55 grams. Add grips (-120 grams HOLY COW THE BOLT ONS ARE HEAVY) by going to foam. So I'm at 1/2 pound off the bike already before i swap out tires. Tires will get me under 25 for sure and I can get close to 24 if i want to spend another $500 on weight weenie items. Realistically I see a 24.5 build for this season.

I'll be doing the kcnc skewers (-40 grams) and a 10 speed chain (-45 grams). A few more titanium bolts and the like should net another ounce, i think there are only 6 bolts taht aren't ti or aluminum right now on the entire bike. That'll put me in the mid 24.5 range for sure. A new front derailleur is a probability for another ounce. I don't have the current model XT on there it is the previous series 760 IIRC so i can save about an ounce there too. Probably as much as I'm willing to spend on this bike. I think 24.5-.7 is pretty good for a heavy steed like the racer x.

Who knows i might just say heck with it and get a carbon blur if i hit my goals before leadville.

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jimmyd

· #17 · Jan 8, 2010

I have my Racer X under 22 pounds. Full XTR, Rock Shox Sid, Stans ZTR wheels.

It can be done, and is fully worth it

Pedalfaraway

· #18 · Jan 8, 2010

Then free bikes are in your future.

Sounds Awesome. Love to hear about riders dedicated to what they do. I don't mean to be a dissenter or burst your bubble but I still don't think the performace increase of losing 1 lb by changing your brakes, Drivetrain, and saddle are going to be signifigant. Lighter tires make a difference, and foam grips cost nothing and weigh nothing so they are such a good idea for any light bike. I still think its smarter to ride what you have and replace things as needed. If you continue to train it won't be long before you are riding your teams bike with whatever parts they have deals to get on it. Best of luck in the leadville lottery may you have a fast, injury free, 2010

lucifer

· #19 · Jan 8, 2010

jimmyd said:
I have my Racer X under 22 pounds. Full XTR, Rock Shox Sid, Stans ZTR wheels.

It can be done, and is fully worth it

Can you post your build. I'd be interested to see how you did it. What size is your frame?

fsrftc

Discussion Starter · #20 · Jan 8, 2010

Pedalfaraway said:
Sounds Awesome. Love to hear about riders dedicated to what they do. I don't mean to be a dissenter or burst your bubble but I still don't think the performace increase of losing 1 lb by changing your brakes, Drivetrain, and saddle are going to be signifigant. Lighter tires make a difference, and foam grips cost nothing and weigh nothing so they are such a good idea for any light bike. I still think its smarter to ride what you have and replace things as needed. If you continue to train it won't be long before you are riding your teams bike with whatever parts they have deals to get on it. Best of luck in the leadville lottery may you have a fast, injury free, 2010

Weight matters a LOT bike/ride/wheels doesn't make a difference, This article http://www.training4cyclists.com/how-much-time-does-extra-weight-cost-on-alpe-dhuez/
Says weight make HUGE difference.....4 pounds makes almost 1 minute of difference climbing L'alp Duez ~3800 feet of vert, multiple that by 10,000 feet of climbing could make 2-4 minutes diffference in a long race easy. Thats significant IMO. Even short cross country races it would help, I lost a race by 40 some seconds this year and if my bike would have been 24 vs 27+ who knows if i would have won or not but...we won't ever know now.

How much are a few seconds worth to you? Thats the question you need to answer and the only one that matters. And thanks for the good wishes

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