Old 03-18-07, 11:18 PM
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NoReg
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135, or even 145 (tandem) would be optimal. 135 is the only number you need to know for 99% of touring bikes today, It's MTB sized and there is lots of stock, it is also stock for those who do stuff like touring specific hubs, Phil Wood as an example. Your weight and luggage, you can get by with 36 spoke wheels at 700C, though if you are going custom I would specify 26" wheels for a host of reasons, see discussions on touring forum. I'm talking here about a road bike, not trying to slide you over into an MTB. Consider Thorn, Bruce Gordon, and Sakkit sites for more info on 26". The short answer is more wheel strength and stability, more replacement parts on the road, overall better performance though not probably in a range where it's noticeable, but it sure isn't worse.

Wheel base is a toughie. 42 is pretty typical for a touring bikes, and some make the WB the same for all sizes (though not your size). At the other extreme you find touring bikes with WB as long as 52 in standard sizes. Longer is better for ride quality, stowage of gear, etc...

My torso measurement is for a person 6'3", my current bike is around 58 cm in the top tube, and I am moving to a 62. The 58 has a WB of 43". So my new bike will be nearly 45, but I am going for at least 47-48" Wheel base. Your TT length is going to be longer, ideally you have a bike that you ride in a similar style with a TT you like, you can just add that TT length differential to my numbers. Like if your comfortable TT was 72, that would be 4" more than my 45" with a 62 cm TT, (the extra 2-3" referred to is all chainstay).

It's hard to know, some makers make the top tubes in larger bikes proportionally shorter. Which is the opposite of what I need. Bruce Gordon, I believe, is real tall, he could be a good guy to get to build, and he uses 26" wheels.

Here is a recent thread, for a guy who is 4 inches taller than me, has 3 inches shorter legs, and ended up with a 1.5 cm longer TT, and only 1" longer WB, hard to see really. Nice bike by a good builder.

http://www.bikeforums.net/showthread.php?t=278615

Ultimately it is hard to be prescriptive over touring bikes since the term covers a huge range of bikes, from credit card to expedition from ashphalt to off-road mountain. I think it's easiest to start with a cockpit measurement you know is comfortable for your ride. That will dial in the three main tubes. These may need to be tweaked slightly for differnces in seats, or for the steering geometry (angle). Then you need to pick a BB height. Then you dial in the front and rear ends. For the front look at the head tube angle you want, and the fork offset. Then you add the chain stays you need for ride quality and luggage, your main issue may be foot size. All that will determine your WB.
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