Im having a prototype Ti frame built for me and I need help with the tubing specs, whats typical for a trail bike for example, I have a fare idea, but I could really do with more info…My knowlege is steel based, havn't worked with Ti before..Should I be matching pretty much the wall thicknesses for steel?

Be great if any designers on here could chip in?

Also there was a guy who designed and got a frame built for himself in the far east on here, he had a blog about it but I cant find the link, anyone know what Im talking about?!

Thanks a mill for any advice that anyone can give, much apprieciated.. 😀

B

Ahh, hello, that could be me then…

Spanner Bikes

Feel free to drop me a line via the contact page on the blog,

Cheers,

Andrew.

If you're used to building in cromo rather than fancy steel, then like for like on the wall thickness is a good start. You need to think about stiffness though. As ti is half the stiffness of steel, you'll need to go up a tube size on most of the tubes to get the level of precision you'll want for trail riding.

min of 34.9 top tube / 42mm down tube if using 120mm + forks – even that will feel whippier than most current steel frames. ti tubes tend to be available in the same wall thickness as cr-mo so up the diameter to keep the stiffness. i have a few butted and PG ti frames, i generally prefer the stiffer PG versions but in reality diameter affects stiffness more effectively.

Be great if any designers on here could chip in?

I'm pretty amazed that Cy and James have been quite so detailed in their replies. That's really very nice of them!

When you buy a Cotic or a Genesis frame, this is the expertise that you pay for.

All I say is that there's quite a lot more to it than wall thickness and diameter, and a frame will break at the weakest point 😉

Andrew, Cy, James and Brant, thanks a lot for replys…

Andrew I will be in touch with you later today…Your site has been really really usfull..thanks

Cy and James, Ive built my own proto's up till now with a mix of crmo and fancy tubes. but i get what you mean alright..Will be going with Plain guage as its a good bit cheaper for this early stage of development and i dont mind the extra weight because it'll still be way lighter than the steel versions ive built…It'll be a bit stiffer too..

Am well aware of how much diameter affects stiffness and the maths there of..Good recomendation on the min diameters….thanks a lot…

Brant i guess the weakest point may be the designer 😀