[CR]Re: Classicrendezvous Digest, BB Drop!!!

(Example: Framebuilding)

From: <CYCLESTORE@aol.com>
Date: Wed, 13 Apr 2005 10:07:22 EDT
To: classicrendezvous@bikelist.org
cc: CYCLESTORE@aol.com
Subject: [CR]Re: Classicrendezvous Digest, BB Drop!!!

In a message dated 4/13/05 9:50:22 AM, classicrendezvous-request@bikelist.org writes:

<< << Most people when talking about BB height refer to it as "drop" when it comes to road bike design, however, being a track bike you would measure from the ground up to the center of the BB spindle. >>

Hey Don! Drop is drop on any bike for any purpose.. BB height is ditto. It is often more useful to talk about drop because it eliminates the tires size. In other words, a part=icular track bike or road bike can have different BB heights off the ground with different "fatness" of tires mounted... Now, maybe the range of tires used on the track can vary less than those on road bikes.... But you are correct, steeply banked tracks can dictate higher bbs, 11" + +. But remember, that also takes away a little stability, so folks don't go ordering high bbs just for the heck of it. As with most frame dimensions, it's always a trade off.

Dale

Dale Brown Greensboro, North Carolina USA >>

Now most honored and respected Mr. Brown of the House of Oro,

While you comment is above is true and well reasoned as can be expected there are some exceptions and comments worth noting. I sure like the BB height ground to center for comparison as I was raised on old fashioned (Classic?) standards of measurements like 6 oz tires, 21 LB bicycles and 11 inch bottom bracket heights for me track bikes.

Drop is a useful measurement for comparison until you change the wheel size it would seem. A 650 B or 26 inch ATB wheel (used properly on a road bike) would distort the comparison value of BB drop but the measurement of BB height might be useful. Smaller wheels lower the center of gravity of a bike and can increase stability and I have found a lower BB height has a similar effect. The Heron bicycles use a lower than common Bottom Bracket height and their stability is very noticeable and distinctive though their pedal through corner performance is hampered by this.

My 17, 18 and 20 inch wheel Alex Moulton bicycles have a negative BB drop (or is it called BB HOP when this occurs).

Yours in Cycling,

Gilbert "One Hop is anothers Drop I suppose" Anderson

North Road Bicycle Company

519 W. North St.

Raleigh, NC 27603

USA

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