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  1. #1
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    Question HELP?!? FSA & Dura Ace 7900 + 7800 mix?? Pro-bike replica

    I hope this is not as dumb as it seems, but here is my dilemma...

    I have always bought complete bikes but am now considering a Bianchi Oltre build based on the kit used by the 2012 pro-team Vacansoleil-DCM. They run FSA K-Force with Shimano Dura-Ace 7900 but... I would also like to use some 7800 spares.

    So... would it be possible to run together the red bits below in particular?

    Levers: SH DA STI-7900 - need new
    Derailleurs: SH DA FD-7900 & RD-7900 - need new
    Brakes: FSA K-Force Light - need new
    Crankset: FSA K-Force Light - need new
    Cassette: SH DA CS-7800 - a spare (pro-team runs an unknown DA CS)
    Chain: SH DA CS-7800 - a spare (pro-team runs KMC L gold)
    Wheelset: SH DA 7850 CL24 - a spare (pro-team runs FFWD wheels)

    (The levers, brakes and wheels mix are not the issue).

    Shimano Tech Dept has not been helpful, suggesting full 7900 instead.

    Don't bother suggesting Campag... this Italian frame is of Taiwanese manufacture anyway

  2. #2
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    Yeah...you'll be fine...no issues.

    I'm running 7900 drivetrain with 6600/7800 cassettes, KMC chains and Rotor cranks set-up with FSA rings. It shifts perfectly.
    formerly "backinthesaddle"

    Strava is Latin for 'bench-racing"

  3. #3
    zac
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    Second on that, you will be absolutely fine.

  4. #4
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    Cheers!

    Thanks guys, should have come on here first for REAL answers

    This is the best I got in 2 attempts with Shimano directly instead...

    "For best performance we recommend using the one series throughout the whole bike, so not to mix 7800 and 7900. I obviously cannot comment on FSA componentry except to say all Shimano products are designed and tested around each other not external companies products."

    "If using FC7900 CN7901 is compulsory, CS7800 will be a B compatibility"


  5. #5
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    The 7900 brake lever pull a 1.4 ratio where as the FSA expects a 1.3 ratio. (I have to assume because just about every other brake system and lever except Shimano 7900/6700 uses 1.3)

    The 7900 ratio will pull a little more cable than expected and you will loose some modulation feel or lock up the brakes somewhat easier. For best results use 6700 or 7900 brake calipers.

  6. #6
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    You said FSA crank, but what about bottom bracket? FSA crank with a Shimano bb will make the crank spin not as freely compared to an FSA bb. This happens to me personally and I've seen it happen to 2 other guys too. Apparently when I was googling I found out that certain FSA cranks do not have the exact spindle width matching that of a Shimano crank (24mm if I recall). Anyway, it's best to stick with FSA bb.

  7. #7
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    Quote Originally Posted by aclinjury View Post
    You said FSA crank, but what about bottom bracket? FSA crank with a Shimano bb will make the crank spin not as freely compared to an FSA bb. This happens to me personally and I've seen it happen to 2 other guys too. Apparently when I was googling I found out that certain FSA cranks do not have the exact spindle width matching that of a Shimano crank (24mm if I recall). Anyway, it's best to stick with FSA bb.
    How? Shimano bearings usually have more grease and tighter seals and doesn't spin as freely. But I am talking about the wheel bearings, pedals, or pulleys.
    When you buy aftermarket BB it's always Shimano/FSA, 1 size..

  8. #8
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    Quote Originally Posted by PoorCyclist View Post
    How? Shimano bearings usually have more grease and tighter seals and doesn't spin as freely. But I am talking about the wheel bearings, pedals, or pulleys.
    When you buy aftermarket BB it's always Shimano/FSA, 1 size..
    I forget all the details, but not ALL FSA cranks (especially their older ones, like FSA Carbon Pro Team Issue) match the exact specs with their Shimano counterpart. These FSA cranks would have a little wider spindle, so one would need to use a thin spacer when installing these wider spindled crank with a Shimano bb. And I believe it's this spacer that presses into the side of the bb bearing, causing the drag. I'm not the only one who have experienced this, my buddy sees the same thing.

    I did google around and found the same discussion regarding this issue.
    FSA Crank compatible w/Shimano BB [Archive] - Bike Forums


    Scroll down and look for the post by SushiJoe (FSA rep):
    here's what he wrote

    Answer from FSA’s Dae Oh

    The short answer; no, the FSA K-Force Light Rd. Crank is not compatible with a Chris King bottom bracket (made to Shimano compatible dimensions). Also, the K-Force Rd. crankset will not be compatible either.

    The FSA BB8200 (meant for K-Force Light) uses a 6 mm width bearing. This allows us to make the bottom bracket outside to outside dimension more narrow providing room for a wave washer. The BB8000 (meant for K-Force) does indeed use a 7 mm width bearing, yet its design does not allow for use of a Chris King bottom bracket.

    However our popular alloy cranksets, the Gossamer Rd. and the Energy Rd. is compatible with the Chris King bottom bracket (made to Shimano compatible dimensions). These cranks use BB6000, this BB's dimensions are compatible with Shimano.
    Dae Oh
    Full Speed Ahead
    So based on his post, certain FSA cranks are compabible with Chris King bb (made to Shimano specs), and therefore also compatible with Shimano bb. And certain FSA cranks are not compatible with Chris King bb, and by extension not compatible with Shimano bb.

    But this was the case for FSA 3-4 years ago? Maybe today all FSA cranks made are all Shimano compatible? I don't know. The OP did not say what model FSA crank he has and how old it is, so I brought it up so he could be aware just in case he has an older FSA model.
    Last edited by aclinjury; 03-28-2012 at 11:19 AM.

  9. #9
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    Quote Originally Posted by PoorCyclist View Post
    The 7900 brake lever pull a 1.4 ratio where as the FSA expects a 1.3 ratio. (I have to assume because just about every other brake system and lever except Shimano 7900/6700 uses 1.3)

    The 7900 ratio will pull a little more cable than expected and you will loose some modulation feel or lock up the brakes somewhat easier. For best results use 6700 or 7900 brake calipers.
    I'll go ahead and call BS on this one.

    7900 levers work just fine with other brakes. I'm running Mavic SSC brakes with 7900 and they feel better than they did with 7800.
    One of my ride partners is running 7900 with house-brand (Tektro) Colnago brakes.
    Both work just fine. No issues whatsoever...
    formerly "backinthesaddle"

    Strava is Latin for 'bench-racing"

  10. #10
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    Quote Originally Posted by MMinSC View Post
    I'll go ahead and call BS on this one.

    7900 levers work just fine with other brakes. I'm running Mavic SSC brakes with 7900 and they feel better than they did with 7800.
    One of my ride partners is running 7900 with house-brand (Tektro) Colnago brakes.
    Both work just fine. No issues whatsoever...
    Use whatever brake calipers you want!

    When I bought my brakes there was 1.3 vs 1.4 cam arm to choose from. I chose 1.4 cam to match up with the latest Shimano shifter.

    That said the reverse of the situation discussed here would be the worse combination, e.g. using SRAM levers and 7900 calipers.

  11. #11
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    Quote Originally Posted by deus View Post
    I hope this is not as dumb as it seems, but here is my dilemma...
    I don't think it's dumb, but comparability aside, I don't see how you're accomplishing a replica build.

    Have the matching paint scheme, sure, but it stops there if you're not finishing with the rest. That's not to say the bike will be worse - it'd be great regardless - but it's not really much of a replica.

  12. #12
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    Quote Originally Posted by PoorCyclist View Post
    Use whatever brake calipers you want!

    When I bought my brakes there was 1.3 vs 1.4 cam arm to choose from. I chose 1.4 cam to match up with the latest Shimano shifter.

    That said the reverse of the situation discussed here would be the worse combination, e.g. using SRAM levers and 7900 calipers.
    The gist of your original post is that anything other than 6700/7900 will not work properly, which is patently incorrect.

    There is NO loss of modulation whatsoever. If anything, the modulation and stopping power is better because of the increase in cable pull.

    Practical application and knowledge trumps reports, published or otherwise, every time.
    formerly "backinthesaddle"

    Strava is Latin for 'bench-racing"

  13. #13
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    Quote Originally Posted by MMinSC View Post
    I'll go ahead and call BS on this one.

    7900 levers work just fine with other brakes. I'm running Mavic SSC brakes with 7900 and they feel better than they did with 7800.
    One of my ride partners is running 7900 with house-brand (Tektro) Colnago brakes.
    Both work just fine. No issues whatsoever...
    I have read somewhere mentioning that the 7900 and 7800 levers have different actuation ratio. 7900 brake calipers are more powerful than 7800 calipers. So that is why 7900 levers have a different (weaker) lever to mate with a now more powerful 7900 calipers. In the same post, the author also mentioned that you don't want to use 7800 levers (designed to work with the weaker 7800 calipers) with 7900 calipers because this combination would produce too much braking. This makes sense in theory. In practice, use anything you want. I use single pivot calipers with 7800 levers and it's fine!

  14. #14
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    I much appreciate the input and knowledge shared above from those with practical experience - it's the only type of valid advice and confirmation I was after. and off I go shopping soon!

    BB - I will use FSA with an FSA K-Force Light crankset, so no issues there (thanks for pointing it out though).

    Replica comment - I don't quite get it, sorry. Are you suggesting the Oltre frame will differ? If so, well, not from what I have seen during the inaugural yearly UCI race here, the Tour Down Under in January. My would be bike will be built up using exactly the same frame and (for better or for worse) the above FSA/DA mix just as used by Vacansoleil ... only exceptions will be the (consumable) cassette and chain. Matching celeste FFWD F4R wheels (or ghosted Fulcrums or Zipp) may follow in future too - for now my existing DA 7850 CL24 will have to do

    An alternative build would have been SRAM Red / FSA K-Force / Fulcrum wheels as used on the 2012 Androni team's Oltre, but I have too many Shimano bits and pieces laying around... and if I had to jump ship, I would go with the more patriotic choice of Campag.
    Last edited by deus; 03-30-2012 at 03:11 AM.

  15. #15
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    I agree with MMinSC, you'll be fine ;)

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