HOT: Active* forum members generally gain 5% discount at starbike.com store!
Weight Weenies
* FAQ    * Search    * Trending Topics
* Login   * Register
HOME Listings Articles FAQ Contact About




Post new topic Reply to topic  [ 10 posts ] 
Author Message
PostPosted: Thu Aug 20, 2009 6:23 pm 
Offline
User avatar

Joined: Mon May 18, 2009 2:23 am
Posts: 628
Location: Indiana
Some titanium builders refuse or at least try to steer away from butted tubes (Eriksen and Moots immediately come to mind) while others (Seven and Lynskey immediately come to mind) will do either.

The Eriksen argument is based on consistency throughout the frame and their approach is have larger diameter/thinner walled tubes rather than small diameter butted tubes.

I am curious as to experiences with both as my Seven is a custom butted frame. I don't recall riding a straight guage tubeset in the past and welcome input.

_________________
Seven Axiom Ti, Reynolds UL Fork, Campagnolo Super Record 11

In Progress: Salsa Podio, Alpha Q GS10 Fork, Campagnolo Chorus 11


Top
 Profile  
 
Posted: Thu Aug 20, 2009 6:23 pm 


Top
  
 
PostPosted: Thu Aug 20, 2009 7:15 pm 
Offline

Joined: Sat May 12, 2007 3:40 am
Posts: 411
Location: Triange, NC
The design and execution of the frameset is far more important (ride, performance, etc) than whether butted or straight guage Ti tubes are employed. Ti is already a pretty lightweight metal. Some of the happiest Ti customers I've met are on Moots and Erikson bikes. Of course Sevens are highly respected and liked too, as well as IF. My opinion is to pick a builder that you can converse directly with and go from there. The butted/straighguage issue would not carry any importance in the grand scheme of my preferences.


Top
 Profile  
 
PostPosted: Thu Aug 20, 2009 7:27 pm 
Offline
Shop Owner

Joined: Wed Mar 12, 2008 6:53 pm
Posts: 892
Location: United States
I am not sure why, but my Moots YBB Air, the decal on the downtube says that it has butted tubing.


Top
 Profile  
 
PostPosted: Thu Aug 20, 2009 7:57 pm 
Offline

Joined: Wed Nov 23, 2005 5:39 pm
Posts: 65
Location: Colorado
I would suspect the manufacturer will tell you the straight gauge tubing is easier to work with. Its a bit more predictable during tube bending operations. with most bent tubes, the manufacturer only gets 2 maybe 3 trys to get the required shape. after that, the titanium work hardens so badly that it becomes to difficult to work with.

I would also suspect the Sevens and Lynskey are more expensive. the butted tubing requires a custom draw added to the higher degree of difficulty of bending a non-constant wall tube. its like trying to guess what you think how the tube might bend.

I hope that helps.

metalman

_________________
metallurgy will only get you so far, after that, use carbon fiber


Top
 Profile  
 
PostPosted: Thu Aug 20, 2009 9:22 pm 
Offline
User avatar

Joined: Thu Sep 25, 2003 9:11 pm
Posts: 840
Location: SC, USA
My impression was that Lynsky and others were not custom drawing their tubes, but rather milling them down!!! Furthermore, it's done by hand, a special sander, and a caliper. Scary if you ask me. All that work to save 15g, seriously. Maybe it's just me, but making a super light Ti frame defeats the wonderful durability that Ti offers. Stick with 3/2 0.032" air craft tubing all around and be happy with a 1500g frame that will last a lifetime.

_________________
:-) Toys-R-Us


Top
 Profile  
 
PostPosted: Thu Aug 20, 2009 9:43 pm 
Offline

Joined: Mon Feb 18, 2008 9:47 pm
Posts: 258
Location: CA
My Seven is straight gauge, simply because I couldn't afford to go butted.

I don't feel like I'm missing anything, and the cost difference is substantial.

From what I remember, butting the tubes allows you to remove material where you can, while retaining the integrity of the tubes in places where the added material is beneficial.

_________________
Turn down the suck knob.


Top
 Profile  
 
PostPosted: Fri Aug 21, 2009 2:43 am 
Offline
in the industry

Joined: Sat Nov 17, 2007 4:35 am
Posts: 113
Location: Singapore
i think the OP has it the other way around. You either go butted and bigger diameter or straight gauge and smaller diameter.

Bigger diameter and butted frames will ride closer to aluminium, feel a little stiffer but harsher. Smaller diameter and straight gauge will ride close to steel, a little flexier but more compliant. The choice really boils down to the philosophy of the manufacturers/ brands.

Some titanium brands are more performance (ie. stiffer, lighter) related. Brands like Litespeed/ Lynskey. Others prefer to use titanium for a more lifestyle, 'ride feel' based marketing strategy moots etc.

Both make great frames. Nothing wrong with either. If you want lighter you have to obviously go with butted. The trick is knowing which/ where/ what tube to butt to optimise ride feel, stiffness, weight.


Top
 Profile  
 
PostPosted: Fri Aug 21, 2009 6:00 am 
Offline
Shop Owner

Joined: Sun Jan 08, 2006 9:12 am
Posts: 2194
Location: Alto, NM
The reason for using a butted tube is so they can be stronger at ends where they are welded and there are stress risers... and then the middle of the tube can be thinner and lighter. But... it can get complicated if the limiting factor is actually stiffness and oil-canning, rather than strength at the ends. Basically with Ti, if you optimize the dimensions and stiffness in the middle of the tube, then you can use the same thickness at the ends (joints) and not have a strength issue... most of the time.


Top
 Profile  
 
PostPosted: Fri Aug 21, 2009 4:24 pm 
Offline
User avatar

Joined: Sat Apr 18, 2009 2:49 pm
Posts: 96
This is Habanero Cycles philosphy:

"Why not double butted and tapered tubing?

Double butted tubes are thicker at the ends, and thinner in the middle. This allows the builder to use tubes that would otherwise be too thin to weld reliably. This does reduce weight somewhat, but it also increases the flex in the thinner portions of the tubes, and makes the tube much more prone to dents. Besides, most bikes built with "butted tubing" have only one or two butted tubes (usually the seat tube and/or the down tube). Realistically, there are a lot better and more cost-effective ways to save weight on your bike than buying a butted frame (calculate the $/gram cost - you'll be amazed). Habanero frames are built from 0.9mm wall straight gauge tubing which is thick enough for reliable welding, prevents frame flex, and produces a very strong, yet lightweight frame.
Making a tube's outside diameter smaller makes it more flexible. Tapering a tube has the same effect. While there are those who would argue that a tapered tube makes a more beautiful frame, I take a "form follows function" approach. Massive 7/8" (22mm) straight chainstays and 5/8" (17mm) straight seatstays reduce rear end flex to almost non-existent levels. To me, that's beautiful!

Double butting and tapering of titanium tubing are both very difficult and expensive processes that add cost but little or no value to a bicycle frame..."

_________________
~ Men of steel need fibre ~


Top
 Profile  
 
Posted: Fri Aug 21, 2009 4:24 pm 


Top
  
 
PostPosted: Sun Aug 23, 2009 10:46 am 
Offline

Joined: Sun Aug 23, 2009 10:38 am
Posts: 413
You have to remember that companies are going to market and talk up what they sell, as well as talk down what they don't sell.

Moots used to have double-butted Ti tubes. They don't offer any now and it isn't because they've had some shift in philosophy of straight vs butted tubes. Reynolds no longer sells double-butted Ti tubes and Moots used to use these tubes in their double butted Ti frames. So, the issue is supply for them, and shouldn't indicate that straight is better than butted. I suspect the same is true when it comes to the real reason why Erikson doesn't do butted frames, as Kent was at Moots previously when they actually were making butted Ti tubes, and he was probably more influential at Moots than anyone else in deciding what tubes Moots would use.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 10 posts ] 


Who is online

Users browsing this forum: Google [Bot], Majestic-12 [Bot], pmclamb, RMcC, TimmS and 42 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

   Similar Topics   Author   Replies   Views   Last post 
There are no new unread posts for this topic. Best racer's fork for straight 1.125"

in Road

CXTony

6

280

Thu Aug 28, 2014 5:21 am

CXTony View the latest post

There are no new unread posts for this topic. Dedacciai titanium K-19 experiences?

in Road

gb103

2

1133

Sat Sep 21, 2013 5:05 am

TopQuark View the latest post

There are no new unread posts for this topic. Titanium Hill Climb Build

[ Go to page: 1, 2, 3, 4 ]

in Road

viney

53

4368

Wed Oct 16, 2013 11:14 am

mattr View the latest post

There are no new unread posts for this topic. Internal cam skewers with titanium shafts?

in Road

crimsonbadger

9

1264

Sun Jun 29, 2014 2:10 am

landdnl View the latest post

There are no new unread posts for this topic. KCNC titanium brake cables

in Road

bazmac

10

1232

Mon Jan 27, 2014 11:42 pm

drainyoo View the latest post


It is currently Mon Sep 01, 2014 8:57 am

All times are UTC + 1 hour




Advertising   –  FAQ   –  Contact   –  Convert   –  About

© Weight Weenies 2000-2013
hosted by starbike.com


How to get rid of these ads? Just register!


Powered by phpBB