Tarmac S-Works Disc, how to make it lighter.

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mnmasotto
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Joined: Mon Jun 06, 2011 7:16 pm
Location: Irvine, CA

by mnmasotto

One more question....The bike comes stock with a very long steer tube. I drastically lowered the stem and have way too much extra rear brake line. I there a way to shorten the rea brake line? Do I buy a new one in shorter length???

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dwaharvey
Posts: 470
Joined: Thu Oct 26, 2006 8:54 pm
Location: USA

by dwaharvey

Just get a new hose barb and olive (LBS will have them) and follow the instructions for installing the brakes. New line not needed as long as you don't cut the existing one too short.

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mnmasotto
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Joined: Mon Jun 06, 2011 7:16 pm
Location: Irvine, CA

by mnmasotto

Any particular hose barb and olive I need to order. They all seem to be labeled as Shimano XTR?

mnmasotto
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Location: Irvine, CA

by mnmasotto

I ordered titanium bolts for the stock seat post, brake calipers, etc. Hope to loose about 50-75 grams replacing these large diameter M6 steeel bolts.

What do you guys think about replacing the heavy, stock S-Works Seatpost for a Ax-lighness or MCFK Seatpost. Not such an obvious answer because the 2015 Specialized bikes have a unususal, built-in seat post clamp which seems to apply more clamping force on the anterior segment of the seatpost.

mnmasotto
Posts: 581
Joined: Mon Jun 06, 2011 7:16 pm
Location: Irvine, CA

by mnmasotto

Few more questions:
1) Are the XTR calipers a direct bolt on upgade? i.e. Same bolt pattern, spacing?
2) Can I buy the calipers only? I only seem to find vendors selling the front and rear kits which includes front lever, hose and caliper.

MichaelB
Posts: 993
Joined: Tue Apr 22, 2008 4:31 am

by MichaelB

Yes to (1), and just keep looking. Most sites have the caliper only, that is how I got my Zee's for my bike.

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cerro
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by cerro

mnmasotto wrote:I ordered titanium bolts for the stock seat post, brake calipers, etc. Hope to loose about 50-75 grams replacing these large diameter M6 steeel bolts.

What do you guys think about replacing the heavy, stock S-Works Seatpost for a Ax-lighness or MCFK Seatpost. Not such an obvious answer because the 2015 Specialized bikes have a unususal, built-in seat post clamp which seems to apply more clamping force on the anterior segment of the seatpost.


AX-Lightness seatpost is always right :)

Lighter stem, tubular wheelset, lighter chainrings if it's not the SLrings, light saddle if some lighter fits you, lighter bartape like Deda Perforated.

mnmasotto
Posts: 581
Joined: Mon Jun 06, 2011 7:16 pm
Location: Irvine, CA

by mnmasotto

Cerro,
Thanks for your response and I really like your blog. My concern is the seat post clamping method used on the new, 2015 Specialized Tarmac Frames. I am concerned it may damage the more fragile, thinner carbon tube used on the weight weenie seat posts such as Ax, MCFK, etc..... Are you familiar with the new integrated Specialized seat post clamp? Instead of applying the clamping force throughout the circumference of the seat post it focuses the clamping force on the anterior portion of the post. Have you used this setup?
Thanks Mark

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cerro
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by cerro

Very familiar to that clamp after mounting 10+ bikes with it ;) Understand how you're thinking but seems a bit stupid if it wouldn't work with a light quality seatpost.

Fun to hear that you like my blog :)

nagge
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Joined: Mon May 21, 2012 6:36 am
Location: Sweden

by nagge

Ive ridden since last summer with a mcfk seatpost in my tarmac, no problems at all.
SuperSix EVO III Ultegra 8070

mnmasotto
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Location: Irvine, CA

by mnmasotto

So, I looked at the calipers. They are RS-875 models without the banjo fitting. The brake hoses screw straight into the caliper! Does this mean it is not a direct swap? I just saw a thread in a mtb forum which compares the XTR race to trail calipers. The weight savings appears to be minimal. Any other ideas?

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eliflap-scalpel
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by eliflap-scalpel

dwaharvey wrote:Changing hydro calipers to me seems like a crazy way to try to save weight. It's going to be expensive, non trivial (you'll need to do a very thorough bleed), unknown savings (at present), and who's to say that the amount of fluid that the road levers push is identical to the XTR mtb levers? Maybe it is, but are you really that eager to find out?

Also, I know that the XTR brakes have changed since this post, but check out the savings between trail and racehere
I suspect that your R785 are similar in design to the XTR trail, and that by changing calipers most of the weight savings you'd see would be just from the elimination of the cooling fins on the pads. I suppose you could instead just get different (lighter) pads for your calipers, but reducing cooling capacity in a disc brake seems a bad way to save weight.



Sven Nys in his bike rides Ultegra Di2 brake set with XTR calipers

expensive, sure. but a good way to shave weight
http://eliflap.it/

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eliflap-scalpel
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by eliflap-scalpel

mnmasotto wrote:So, I looked at the calipers. They are RS-875 models without the banjo fitting. The brake hoses screw straight into the caliper! Does this mean it is not a direct swap? I just saw a thread in a mtb forum which compares the XTR race to trail calipers. The weight savings appears to be minimal. Any other ideas?



best saving and best money spent will be for wheels

seems to be very heavy that wheelset
http://eliflap.it/

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