Double butted? Triple butted? Help!

[Jon C C on a Bianchi]

Hi, gents - need to tap into your substantial bike knowledge...

You gave me all sorts of ideas for Sam's new bike and I'm going to buy this week... Pinnacle, Boardman, Decathlon. My question...

does it make a difference? triple butted, double butted? My Bianchi's frame is triple butted - the Boardman Comp's is double butted - otherwise it appears to have a better spec and is ridiculously priced @ £539.99 (including a 10% off all bikes extra discount) and has a 8/10 review in cycling news. I've got Halfords Bike Hut to build one up for me and we're going to have a look on Thursday. What's the catch? Is it too good to be true??

WORRIED

Jon

[Ivor]

fyi: http://www.gtgtandems.com/tech/materials.html

[quote]What is a "triple butted" tube? While triple butted sounds like a 50% improvement, it's usually an easier-to-produce variation of a double butted tube where the two thick ends don't match (i.e. 10/7/8). Because the optimal .3mm differential only exists at one end of the tube, a triple butted tube is typically less expensive (removing the taper-producing mandrel is relatively simple when one end of the tube is only partially butted). While many tubing companies hyped triple-butted tubing in the early '80s, enlightened consumers have made these tubes rare.

[mrP(Boonen)VT]

The "butting" of the tubes means the variable thickness throughout the main tubes. Each "butt" excuse the expression is a reduction in thickness of the wall of the tube. A "triple butted" tube will therefore be thinner in the middle of the tube (and weaker??) than a "double butted".

In reallity, it means didley, as a triple butted frame can be heavier than a double butted because it starts off thicker, so you pays your money and takes your chance.

Guru P

Which Halfords are you using?

[Jon C C on a Bianchi]

Thanks, fellas

I think I get it - nothing to worry about seems to be the message - if anything double butted is better than triple!.



the only Halfords that had the bike was in Crawley - nothing remotely local to SE25 - going there tomorrow. Where does your son work?


thanks again

Jon

[mrP(Boonen)VT]

Mark is based at Crawley, but has taken this week off to watch the tour.

He is shortly being promoted to Store Manager at West Wickham.

Guru P

[Mike I]

Definition of 'butted' from the late great Sheldon Brown:

[quote]Thicker at the ends. Said of spokes and frame tubing. (Butted spokes are also called "swaged") Butted tubing is usually made with a constant outside diameter, but thicker walls at the ends. The idea is to make the part stronger at the ends, where the stresses are greatest, and lighter in the long middle section, where stresses are less.
Some writers have objected to this term being applied to spokes, and maintain that "swaged" is more correct, since the operation that produces a butted/swaged spoke is one of thinning the middle, not thickening the ends. For some reason they don't generally object to the use of "butted" in reference to tubing, though the process is also one of thinning the middle, not thickening the end. This objection is based on a misunderstanding of the origin of the origin of the term "butted." "Butted" means having a butt, i.e. a thick end, and has no reference to the means of fabrication.

[quote="Mike I"]Definition of 'butted' from the late great Sheldon Brown:

[quote]Thicker at the ends. Said of spokes and frame tubing. (Butted spokes are also called "swaged") Butted tubing is usually made with a constant outside diameter, but thicker walls at the ends. The idea is to make the part stronger at the ends, where the stresses are greatest, and lighter in the long middle section, where stresses are less.
Some writers have objected to this term being applied to spokes, and maintain that "swaged" is more correct, since the operation that produces a butted/swaged spoke is one of thinning the middle, not thickening the ends. For some reason they don't generally object to the use of "butted" in reference to tubing, though the process is also one of thinning the middle, not thickening the end. This objection is based on a misunderstanding of the origin of the origin of the term "butted." "Butted" means having a butt, i.e. a thick end, and has no reference to the means of fabrication.

[Marky Mark]

[quote="Jon C C on a Bianchi"]Hi, gents - need to tap into your substantial bike knowledge...
Jon

[Jon C C on a Bianchi]

does that mean they are only ladies in a technical sense?

[Marky Mark]

Keep digging ones hole Jon, you're braver than me