Guidelines for choosing tubing size?

[Danielvetpath]

Hi: I am looking for any resources or general recommendations for choosing tubing size/diameters/thickness. I have read that custom builders will choose tubing based on a riders size/weight and intended use, but haven't come across any guidelines that give me a starting place. I am just a hobbyist interested in building a gravel grinder for myself (5'7", 158 lb, 51 yrs). Thanks for any advice or references I could read. Daniel

[Clockwork]

It also depends on your brazing or welding experience. If it's one of your first frames just use 9/6/9 True Temper Verus or something from Nova.

[Andrew R Stewart]

Yes, this topic is full of grey area and opinion. But this is really only an issue with consequence when trying to have a very light weight frame. Which is where experience enters the equation. Skills and understanding of expected life span come with time and practice. Frames are not all equal given the same materials and geometry. Experience/skill results in less of the material's capacity being "used up" during the building. It also speaks to the discussion with the rider as to what they can deliver and expect to "hold up" for "how long".

So if the frame is for yourself much of this is all internal and a crap shoot for the beginner builder. You makes your choices and sees what happens. But if this is for a customer then you had better already have gone there enough times so it's not a crap shoot.

BTW Henry James use to have a tubing selection chart for a range of building goals. While a good spot to start from much of the same can be gleamed from build specs out there. Again though, this assumes a basic competency of building skills and an ability to discuss expectations with the rides. Andy.

[Danielvetpath]

Thanks Clockwork and Andy. I should have specified steel for material with intention to Tig weld. Yes, I am a noob still learning to tig weld. I had come to the conclusion that nova tubing, 9-6-9 or something similar would be a good place to start. A specific question I have, other than using the info on the True Temper website would be what, if any are, considered "standard" tubing diameters for seat tube, down tube and top tube. Thanks for helping me get started. Daniel

[Andrew R Stewart]

Again looking at the mass of existing bike specs will show you a lot. "Traditional" seat tube ODs are 28.8mm. OS diameters grow up from there. Top tubes started at 25.4mm and Down Tubes from 28.6. But in the last 30 years these shift to larger diameters so the thinner walls favored now don't result in too flexible a frame (or maybe a stiffer frame which is a design/marketing goal, take your pick, won't be heavier).

I hate to be the rain on your parade but this is really very basic research stuff. While asking for answers is great knowing how to study the existing product offerings (both published frame/bike specs as well as offered tubing) is a VERY important skill. Lacking this skill (of self discovery and study) will mean more complex or judgmental points will be hard to overcome in the future. I really suggest that you start this even if someone gives you the current answers you seek. Andy

[jaybeeboston]

The first bike I built for myself (long since stolen and last seen with its handlebars turned up riding through Dorchester) was TIG welded on Nova 9/6/9, 28.6 ST/TT, 31.8 DT. The welds weren't pretty, but it stayed solid for the couple of years I rode it. I wouldn't start out with anything skinnier unless you've already got some serious experience TIG welding thin-walled steel.

[Danielvetpath]

Thanks, Jay, for your input! Sounds like a great plan to me. Daniel