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  1. #1
    Wheelsuck Fat Boy's Avatar
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    BB height on a race bike

    I'm looking at a new race bike. My trusty Lemond Poprad is a fine bike, but I want something new and I want to have some disc brakes. Because of this, I've been looking at several race bikes. I've got connections with 2 different shops, and I can get a good deal at either. This pretty much means I'll be buying a Specialized (Crux Apex Disc) or Felt (F65X). The Specialized has BB7 brakes instead of the Felt's BB5's, but the Felt is owned by a better friend and I'll probably get a better deal from him than I would on the Specialized.

    The sizing geometry on the bikes are similar (although the Felt is slightly better for me in this regard), but there is one standout dimensional difference. The Crux has a BB drop of 71mm, which from what I can find is the same as my Poprad. The Felt has a BB drop of 65mm, which is meant to be a fairly significant difference. Now, I know that the Euro approach is a very high BB, like a drop of only 60mm or so on Ridley. What I don't know is how this will effect my riding.

    I race in Southern California. Mud clearance is pretty much a non-issue. I'm not nearly fast enough to bunny hop barriers. Those are 2 things that are supposedly positives of a higher BB. The other biggie is that it reduces the possibility of a pedal strike. I do this all the time on my Poprad, so this would be a good thing. The lower BB supposedly gives better handling characteristics. A lot of our courses are very tight, so what is the give-take of the better handling-fewer pedal strikes equation?

    I started out racing a hard-tailed mountain bike and then went to my Poprad. I really have no idea what these BB drop changes would feel like to ride, and a spin around the bike store parking lot isn't going to tell me much. I'm sure I'd have to actually ride it in anger to notice it. So for you guys (flargle) that have experience with bike geometry, could you fill me in on what I should expect?

  2. #2
    Team Water Andy_K's Avatar
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    I find it really hard to believe that you'd feel 6mm of difference in how the bike handles. In terms of center-of-gravity, that's less difference than you'd get by raising yourself up off the saddle a bit.

    If you otherwise like the Felt better, get it and swap in some BB7's.

  3. #3
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    I have no real experience comparing, but my basic mentality is, don't overthink it, and just rock the bike you have (i.e. the bike you eventually choose). Whatever the bike, you need to ride it a lot to ride it well.

    Also, the typical idea might be, dry = low BB, but there's still an advantage to being able to pedal through corners, whether it's dry or wet.

  4. #4
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    I have raced a ridley with 63mm drop and a carbon redline with 70mm drop. There are a couple of other geometry differences (head tube angle), which could account for differences, but i definitely noticed a positive improvement on the redline. I am 6'3, but definitely appreciate the improvement of the handling on the redline... that thing rails!!!

  5. #5
    Riding like its 1990 thenomad's Avatar
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    whats your crank length and pedal type? if you're running long cranks that may make more of a difference. I experienced toe overlap issues but not pedal strike
    My blog about rides, bikes and builds: ridesgoneby.blogspot.com

  6. #6
    Wheelsuck Fat Boy's Avatar
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    I use 172.5 cranks with egg-beater pedals. It's not really that unusual of a setup.

    From what I understand, 5mm is a pretty pronounced difference in terms of BB height. Would it matter more to a pro, sure, but in the end, he's going to ride what he's given. I have to pay for the damned thing, so I'm trying to make an informed decision. No hand-wringing here, just trying to educate myself.

    I guess that dry weather hints at fast courses which would give the advantage to the Crux. I don't think I remember many fast corners through the season. Maybe a couple at SpookyCross, I guess. It seems that most of our courses are pretty zig-zaggy with pretty tight corners. If you can start pedaling a 1/2 second before the next guy, then that's got to be an advantage.

  7. #7
    coprolite fietsbob's Avatar
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    Data point: 11", 28cm with 33 wide tires ['90 steel Pinarello]

  8. #8
    Tiocfáidh ár Lá jfmckenna's Avatar
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    What year Poprad do you have? If you have the last year in White OX platinum then I have an off topic question for you.

    BB5's will stop you just as well as BB7's. If you like to ride your cross bike on the road then the lower BB is better IMO. Higher is better for racing cross but over all it really comes down to which one you think rides better. So if you can test ride then do it.
    If you don't talk to your cat about catnip, who will? =^.^=

  9. #9
    Wheelsuck Fat Boy's Avatar
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    Quote Originally Posted by jfmckenna View Post
    What year Poprad do you have? If you have the last year in White OX platinum then I have an off topic question for you.

    BB5's will stop you just as well as BB7's. If you like to ride your cross bike on the road then the lower BB is better IMO. Higher is better for racing cross but over all it really comes down to which one you think rides better. So if you can test ride then do it.
    What's your Poprad Q? I've got an old one. It's about a 2000, I'm not really sure because I bought it used from my club/team president. I has the 853 tubeset, but a 1" steerer. Honestly, it's a pretty good bike. No doubt it's heavier than the new stuff, but in terms of being a work-horse, it's hard to beat.

    The stopping power of the BB5's vs. the BB7's really isn't the issue for me. It's the fact that the 5's only move one pad and flexes the rotor. It seems like that would be both a PITA to get set up correctly and easy to get out of adjustment. Besides that, it just seems wrong.

    My cross bike spends very little time on the road...basically whatever riding I have to do to get to the dirt/sand/grass. I've got road bikes for road riding. I know that neither shop will have a bike for me to test ride, so I basically have to make my decision based on homework (and finances). At the end of the day, I look at guys like Wells and Trebon. They seem to be able to cope with either. The differences between the 2 is probably less important than I'm making it out to be. I think they will both be a good step forward from the Pop...although, to be honest, that's not a bad bike, either. I could use more braking power and it gets pretty damned heavy late in a race, but it responds well to pretty much anything I can through at it.

  10. #10
    Tiocfáidh ár Lá jfmckenna's Avatar
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    I think my Poprad is a 2008, what ever the year it was the last year they made it and it's OX Platinum. I wanted to get the disk version at the time but some of the UCI races I was going to do would not allow it.

    Anyway on mine, the left chain stay has a curve to it starting about thre quarters the length from the BB shell to the drop out and it curves out towards the drop out. The right stay is dead straight. Is yours like that? I have an old Paramount MTB that does something similiar.

    But the reason I ask is because I got hit by a car and the frame got banged up pretty good but it rides straight and true and the rear wheel is dead center in the drop outs and where the two stays meet the BB. I only noticed it months later, that there was a curve. But if this curve developed as a result of damage then that would essentially mean that the length of the chain stay has been shortened which would put the wheel at an odd angle. But it doesn't seem so.

    Anyway, just curious. And Yeah they are great bikes, my wife has an 853 one that is black and purple.
    If you don't talk to your cat about catnip, who will? =^.^=

  11. #11
    Wheelsuck Fat Boy's Avatar
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    I got a call from the bike shop today. The Felt will be arriving soon (within days). I've got a work trip, so I won't see it until at least next Monday.

  12. #12
    Wheelsuck Fat Boy's Avatar
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    Just put the money down. Done deal.

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