Size and weight appropriate.
I just got this frameset for Joan back from JB and tomorrow it gets a new Dura-Ace kit hung on it. I thought I might share it with you as a good example of the proper tubes being used for a given size rider. Joan is neither tall nor heavy and frankly most bikes out there would be too stiff for her. She originally came to me for a JK Special but after getting to know more about her and how she was going to use the bike I thought that the JKS would be stiffer than she needed and that she’d be better off with a bike make from smaller diameter tubing than the JKS uses.
The diameter of the tubing used on a bike has much more to do with how stiff the frame will be than the wall thickness of that tube. So in Joan’s case I chose to use ‘standard’ diameter tubes to make the bike lighter and to give it the appropriate stiffness. In the old days most all bikes used standard diameter tubes that had 1″ diameter top tubes and 1 1/8″ diameter down tubes. Somewhere during the 90’s this all changed and these diameters were bumped up by 1/8″ to 1 1/8″ top and 1 1/4″ down tubes to add more stiffness to the bike. This larger tube became known as ‘oversize’. Currently almost every builder out there only offers oversize tubes and to my surprise some don’t even know that other sizes are available. Most builders, even some that are highly renown, use the same tube diameter and wall thickness for every bike they make regardless of the size, weight, or power of the rider. So the 120 pound gal has the same tubes that the 220 pound guy has. And when you consider that the smaller person is getting a smaller bike that is inherently stiffer due to it’s smaller size it’s easy to see that the lightweight rider gets the short end of the stick.
If you are a smaller, lighter rider like Joan you most likely don’t want or need the extra stiffness that oversized tubing will give. It’s too bad that more builders don’t offer standard sized tubes for their lighter clients and most smaller riders will never even have a chance to ride a bike that is the right stiffness for them. They won’t even know what they are missing. Most light riders will think that being rattled and bounced around on the road is just how it is and that it’s that way for everyone. But it’s not. Designing and building the bike with smaller tubes can help make the bike be much more comfortable for Joan and give the bike the life and snap that a stiffer bike just won’t have. In addition the smaller diameter tubes are lighter than their larger cousins so the lighter rider gets a lighter frame. Serendipity.
Joan’s fillet brazed frame has a sloping top tube to give a bit more standover room and to give it a modern race look. Tomorrow I hope to have all the parts to build it up and get it sent off to it’s new home. I think I might look a bit silly test riding it around my neighborhood as I’m 6’4″ but that’s why I’m paid the big bucks.
More after I get the bike assembled.
Dave
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I love the look of this … very elegant lines … light, graceful, and smooth like cream.
Thanks of the comment. I think the smaller tubes, combined with the fillet brazed joints do give an elegant look to the bike and I’m glad you agree.
Dave
Hi Dave,
What do you think about non-OS tubes for bigger and taller riders? Was the two-tone blue bike that you did for yourself for the San Jose show standard size tubing? Thank you for your thoughts and your always informative writings.
Tim
Hey Tim,
I think standard sized tubes can make for a wonderful bike even for a pretty big guy. They may not be the best tubes to use for a larger rider’s race bike but for a dirt road bike like I showed in San Jose they can be the ticket. The blue bike you mention was indeed my bike and while I’m tall I don’t weigh much and the bike was built to hammer the endless dirt roads we have around Bozeman. It’s a sweet ride.
Dave