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  1. #1
    What??? Only 2 wheels? jimmuller's Avatar
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    How do you spell geometry?

    Subtitle - Does this bike fit me?

    Five bikes. I've put significant miles on all except the Bertin. The Raleigh, Masi, and Bianchi have a carefully chosen stem.

    BB to top of ST dimension:
    Peugeot UO8, Bianchi Brava, Raleigh Gran Sport - 59cm.
    Masi Gran Criterium, Bertin C32 - 56cm.

    When I mount the Bianchi I think "This is exactly right", but it does feel high up in the air. (And it is agile but it rides hard.) When I mount the Masi it feels different, smaller but extremely comfortable nevertheless, and very agile. I always thought the Raleigh felt perfect but I haven't ridden it enough this year to do a full comparison. The Peugeot feels long but a shorter stem would probably fix that. Nevertheless I've put many miles on it. The Bertin feels both close to the ground and small. Of course I haven't had time to dial it in, and don't know how much or when I'd ride it anyway.

    Some measurements - The BB heights are curious. One would have thought they'd be similar, but no. Why would the Bianchi be so much higher? Was it intended to be an entry-level criterium bike? Or the Bertin so much lower?

    Except for the Bertin for which the jury is still out, they all fit me just fine, thank you. It doesn't prove anything except that you can't judge a frame's fit by just one or two numbers. Or maybe that almost any frame can be made to fit.



    Real cyclists use toe clips.
    jimmuller

  2. #2
    Senior Member due ruote's Avatar
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    Is there much difference in tires, or did you forget to put tires on the Bertin?

    I generally eyeball my knee to the pedal spindle, and set the saddle height so it feels right. For the "tt" measurement, there are so many factors at play, I just try to measure from the sit bone spot on the saddle to the brake hoods, where I spend most of my time. That metric is more or less constant between bikes. No matter how much you tinker, no two bikes will feel identical, and if they did, you wouldn't need more than 1. What fun would that be?

  3. #3
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    You cant compare the bikes too much, all of them are different, the most racy one to me is the masi. Classic european road racing geometry. The bianchi sure is like +-20 years younger and the raleigh is maybe the oldest one you have in there???

    As i said before totally different bikes that you cant compare for example you can compare the bianchi to the masi because are around the same...

    You cant compare the raleigh, the peugeot to the ones above... totally different bikes, you can compare them to a and old Schwinn collegiate tho, same ugly ass geometry.

    Details, as shallow then seattube angle the shorter the reach, thats why those bikes specially the Peugeot and Raleigh came with longer top tubes and thats why u are planing in getting a shorter stem in one of them.

    The bianchi, the masi and maybe the bertin has similar geometry but the BB height will make them ride totally different, probably from all of them the one that handles the best is the bianchi?

    Well doubt this helped you because i dont know exactly what you want to now too hehehe

  4. #4
    What??? Only 2 wheels? jimmuller's Avatar
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    Ultraman: You cant compare the bikes too much, all of them are different...
    Well doubt this helped you because i dont know exactly what you want to now too hehehe
    Well, in fact, I didn't really want to know anything per se. This was just a study in differences rather than a quest for information. And yeah, they really are different! (Though you can certainly compare them and see the differences.) I just thought it was curious that the BB heights were so different.

    The Masi is the best handler, the Bianchi a close second. But even the Peugeot and the Raleigh are responsive in the twisty bits. As for ages, the Bertin and Peugeot are '72, the Raleigh '73, the Masi uncertain ('75-'77), the Bianchi said to be '89 (or '87).

    The Bianchi's height surprised me. That gives it lots of ground clearance so pedal strike isn't likely. Also, because it has 165mm crank arms the seatpost is 5mm further extended than it would be with a more common 170mm crank. That puts me even higher up in the air.

    And the Bertin's lack of height really surprised me. Maybe it was built for 27" wheels, but the brakes certainly reach the 700c rims.

    Due Ruote: ...tires?
    Doh! Lemme' go check...yeah, it's got tires.

    All seriousness aside however, the Peugeot and Raleigh have 27" wheels, the others 700c. The Masi has 23mm Vittoria Open Corsas, the Peugeot has 28mm Paselas, and the others all have 25mm Paselas. So tires don't account for all the height difference.
    Real cyclists use toe clips.
    jimmuller

  5. #5
    Ride, Wrench, Swap, Race dddd's Avatar
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    Clearly, the Bianchi's high bb suggests criterium racing.

    But the UO8's similarly-high bb is for other reasons.
    The Peugeot's long wheelbase means the bike must lean further for a given turn radius, and the Peugeot also was designed for and sold with 2-sided pedals, which use up even more clearance when cornering.

    Goemetry considerations like top tube length and seat tube angle also affect the fit while riding.
    The top tube height is more important when the rider is stationary.

    The seat tube length (frame size) will determine if the rider will be able to find a desired fit within the normal range of stem height adjustment.

    The head tube angle will affect steering characteristics and determine what range of stem extension lengths give stable handling.

    The actual fore-aft position of the saddle, relative to the bb, will determine how aero the rider can be before excessive bending at the waist restricts the rider's power output. Riding aero with a rearward saddle does not allow the rider to maintain high average power output.

    A geometry that allows a longer stem length, combined with a steeper head tube angle, can allow the rider to more-closely draft the rider ahead with lower risk of touching tires.

    The Masi GC I owned seemed to rule the corners, but not because of any bb height considerations. It just had a linear power-steering feel that inspired confidence.

  6. #6
    Senior Member Gary Fountain's Avatar
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    I had a really nice Benotto 5000 and it's BB was noticeably lower than any of my other bikes yet it measured the same in most other respects to my other bikes of a similar tube lengths and angles.

  7. #7
    What??? Only 2 wheels? jimmuller's Avatar
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    Quote Originally Posted by dddd View Post
    The Peugeot's long wheelbase means the bike must lean further for a given turn radius, and the Peugeot also was designed for and sold with 2-sided pedals, which use up even more clearance when cornering.
    Good point. A zillion years ago, within a year or two from when I bought it, I hit the ground with a pedal. It was not a pleasant experience. As I recall, it bent the crank arm.

    Quote Originally Posted by dddd View Post
    The Masi GC I owned seemed to rule the corners, but not because of any bb height considerations. It just had a linear power-steering feel that inspired confidence.
    That's been my experience. It has neutral behavior in corners seemingly regardless of either speed or turn radius. The Bianchi is equally quick to turn but seems to require more active rider participation to maintain the chosen line.
    Real cyclists use toe clips.
    jimmuller

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