By Casey
Sometimes customers ask us what tubesets we use in our frames. Different tubesets can offer different benefits to the frame builder, but what difference does it make to you, the rider?
First, what isn't different between tubesets (intensive properties):
- Elasticity of the steel
- Weight by volume of the steel. (A cubic cm of high-end bike tubing steel weighs the same as a cubic cm of gas-pipe steel.)
Let's say you had two top tubes from two different tubing manufacturers. Assuming those top tubes have the same dimensions (length, diameter, thickness), then they would weigh the same and have the same rigidity.
So what is different between tubesets (intensive properties)?
- Tensile Strength
- Hardness
Tubes with a higher tensile strength can be made thinner; this in turn decreases their overall rigidity. It can also be tempting to think of this as meaning weight savings. Let's do a quick comparison of how much weight is saved within in the Tange line of tubing. Taking a top tube from the Infinity line and from the Prestige line, both are 590mm long and have an outer diameter of 28.6mm. The
Tange Infinity tube has a thickness of 0.9mm on the ends and 0.6mm in the middle. The
Tange Prestige tube has thickness of 0.7mm on the ends and 0.4mm in the middle. The Infinity weighs 287 grams, the Prestige weighs 207 grams. So you've saved a little less than a fifth of a pound in the top tube. You'll probably end up saving less than that between the down tube and the seat tube. That's not horribly insignificant but it is important to consider the trade off.
One of my friends used to commute on a nice steel track bike. About a year ago he unlocked his bike from a bike rack. He left it leaning against the rack while he bent over to roll up his pant leg (should have had one of
these). A substantial gust of wind blew his bike over and it hit the bike rack next to it dead center on the top tube, that 0.4mm thick section. This gave the top tube a nice dent, which eventually turned into a nice crack. The moral of the story (besides that track bikes might not be the best for commuting) is that different tubing sets offer different advantages. It can be tempting to look at them from an entirely monetary sense, but more expensive doesn't necessarily mean better.
Thin-wall tubing is very easy to dent. That's why we wouldn't recommend it for a commuting bike or a touring bike. It's also more likely to be destroyed in a crash, even a mild one. That high end thin-wall tubing may be okay for racing bikes, but you must still be careful with them.
At the end of the day, the best choice is usually to just trust your builder. They generally have specific tube sets that they prefer to work with and they will choose a tube set appropriate for your application (touring, track, racing, etc.). Sure, you may not be able to see everyone swoon when you tell them that your bike is made of 853 Reynolds, but your pockets might not feel as light, either.
By the way, VO uses a high quality 4130 double-butted tubing made in Taiwan (where a lot of "name brand" tubing is now also made). We feel that that the quality is equal to that of tubing from the old line companies, but by using this tubing we can knock $100 to $200 off our frame prices without losing ride quality or gaining weight.
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I see there is lots of fuss on the VO blog over the arrival of the new Campeur frames, as well there should be, they look to be an excellent design, but let us not forget that the workhorse Polyvalent is also capable of doing a fine job at loaded touring as well. This summer I assembled a Polyvalent using many VO parts with my eye on making it an all-rounder - one equally adapt at commuting, loaded or unloaded touring, or using on club rides. So far it has met all my expectations quite easily, the only exception being that it was a bit slower on the club rides than my other bikes, no matter though as my desire to keep up with the hammer-heads get lesser all the time. As for it being a capable touring/camping rig, or a daily commuter, I couldn't be happier.
As a christening tour my friend Lydia and I set out on a week long, cross-border bike camping trip from Vermont to Montreal and back. Most of the riding was over flat terrain with about 30 to 40% of it on gravel bike paths or roads, and the rest of the time on pavement, including the very bike friendly city streets of Montreal. A more thorough test aver a hilly route is next on the list but one thing I am sure of is that for me, the 650b is the way to go on a touring or city bike. Over the years I've used 26", 27" and 700c bikes, with fat, medium and skinny tires but the Polyvalent with it's cushy riding Col-de-la-Vies really make me smile. It seems to be just the right combination of frame geometry and tire size that suits me. Currently the bike is getting a good workout as my daily commuter. Here are a couple of pictures towards the end of our trip;
