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Discussion Starter · #1 ·
looking at geometry tables the BH G4 frames all appear to have a really slack 72* STA. A guy on our club has one and say he's it fits better. The web site only list the 54 as the smallest. Is that really the smallest frame they make? anyone had a chance to test ride one?
 

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54 is the smallest they make currently. 52 is in the works.

the frames "fit" small, however. looking at the numbers, i would've though that i'd need a 57, however, 55.5 works well for me. i'm on a 56 Cannondale right now.

it's a fun bike to ride. those short stays make the bike nice and zippy. i plan on investing in one in 2009.
 

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info...

The 72 degree STA is not much different in fit than other frames with a STA in the 74 degree range, because they use a seatpost with no setback, while setbacks of 20-35mm are common on most road seatposts.

The slack STA will reduce the reach of the frame. The smallest may be called a 54, but there are no dimensions that would correspond to that number. The head tube length is a very short 11cm. Compare that to the 12.5cm length on my 51cm LOOK 585.

The reach of the "54" G4 is also about 7mm shorter than a 51cm LOOK 585, due to the slack STA.

Overall, the small G4 would be close in size to a 49 or XS size LOOK 585.

They need to offer 6-7 sizes like most other brands.
 

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Discussion Starter · #5 ·
any idea on how i would calculate reach, saddle tip to bars? trying to see if i could get the reach below 51 cm if i use a 10cm stem. Saddle height would be 67.5 from center of bottom bracket top of saddle.
 

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about reach...

cmg said:
any idea on how i would calculate reach, saddle tip to bars? trying to see if i could get the reach below 51 cm if i use a 10cm stem. Saddle height would be 67.5 from center of bottom bracket top of saddle.

Reach is the horizontal distance from the center of the BB to the TT/HT intersection point. There is not enough info to calculate it.

About the best you can do is take the TT length and figure that every degree that the STA is less than a frame you're comparing it to subtracts 8mm from the reach.

You would need to be sure that the seat mast can be cut short enough to get that saddle height.

I'd say the frame is too big. A saddle height of only 67-68cm calls for a very small frame and probably 650c wheels.
 
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