Framebuilders Thinking about a custom frame? Lugged vs Fillet Brazed. Different Frame materials? Newvex or Pacenti Lugs? why get a custom Road, Mountain, or Track Frame? Got a question about framebuilding? Lets discuss framebuilding at it's finest.

which is better Ti?

Old 09-24-14, 05:14 PM
  #1  
ruirui
need to go out and ride..
Thread Starter
 
ruirui's Avatar
 
Join Date: Mar 2004
Location: Bay Area, CA
Posts: 1,435

Bikes: 2011 Scott Addict R1, 2014 Redline Conquest Team, 2015 BMC TMR02

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
which is better Ti?

I see many different types of Ti bikes with different materials and had some questions which I'm hoping framebuilders gurus can chime in on.

Regardless of brand, which type would be stiffer and why?

3AL/2.5V

vs.

6Al/4V

i'm looking to get a Ti road bike frame and wasn't sure which material would be better as i don't want it to end up riding like a noodle. comfort is one thing, but i'll be putting her through some climbs, so would prefer the overall frame and BB to be stiff.

much appreciated...
ruirui is offline  
Old 09-24-14, 06:11 PM
  #2  
Scooper
Decrepit Member
 
Scooper's Avatar
 
Join Date: Aug 2005
Location: Santa Rosa, California
Posts: 10,491

Bikes: Waterford 953 RS-22, several Paramounts

Mentioned: 64 Post(s)
Tagged: 0 Thread(s)
Quoted: 616 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I'm no Ti expert or guru, but here's my take based on the materials data sheets and what I've read in various framebuilders forums. Take this for the $.02 it's worth.

3Al-2.5V has a "stiffness" modulus (E) of 100 GPa, while 6Al-4V has a "stiffness" modulus (E) of 113.8 GPa, so the latter is about 14% stiffer, but frankly the wall thickness and diameters of the tubes are going to have a much greater effect of the frame stiffness than the alloy.

The density of both 3Al-2.5V and 6Al-4V is close to the same. 3Al-2.5V has a density of 4.48 g/cc, while 6Al-4V has a density of 4.43 g/cc, so 6Al-4V weighs a hair less for the same volume of material.

There is a significant difference in ultimate tensile strength (UTS) and yield strength (YS) between the two. 3Al-2.5V UTS=620 MPa and YS=500 MPa. 6Al-4V UTS=970 MPa and YS=880 MPa, so 6Al-4V is about 50% stronger than 3Al-2.5V.

Hardness (Brinell) for 3Al-2.5V is 256, while 6Al-4V is 334.

I believe most builders who work with titanium will tell you that 3Al-2.5V is easier to work with.

There are trade-offs, but if I were considering a Ti frame I would go with 3Al-2.5V personally.




__________________
- Stan

my bikes

Science doesn't care what you believe.
Scooper is offline  
Old 09-24-14, 06:28 PM
  #3  
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 41,928

Bikes: 8

Mentioned: 188 Post(s)
Tagged: 0 Thread(s)
Quoted: 6833 Post(s)
Likes: 0
Liked 212 Times in 177 Posts
seems 6/4 is used for machined parts, dropouts & etc. the 3/2.5 is used for the Seamless Tube. so .. both ..

same, stiffness is gained gained as tube diameter goes Up , so oversize wins..
fietsbob is offline  
Old 09-24-14, 06:47 PM
  #4  
Scooper
Decrepit Member
 
Scooper's Avatar
 
Join Date: Aug 2005
Location: Santa Rosa, California
Posts: 10,491

Bikes: Waterford 953 RS-22, several Paramounts

Mentioned: 64 Post(s)
Tagged: 0 Thread(s)
Quoted: 616 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Lynskey's R450 frame is made with 6Al-4V tubes and they call it their strongest frame, but the MSRP for just the frame is $5,154 (but it's on sale for $2,577).

In contrast, their R350 frame, which I believe has 3Al-2.5V tubes, has an MSRP of $3,234, but it's on sale for $2,263.

Based on the numbers, I'm just not sure a 6Al-4V frame is worth the premium, but YMMV. With both frames on sale, there's only a little over $300 difference. Hmmm...
__________________
- Stan

my bikes

Science doesn't care what you believe.
Scooper is offline  
Old 09-24-14, 07:02 PM
  #5  
Marcus_Ti 
Frozen Solid.
 
Marcus_Ti's Avatar
 
Join Date: Sep 2014
Location: Lincoln, Nebraska
Posts: 4,667

Bikes: Roadie: Seven Axiom Race Ti w/Chorus 11s. CX/Adventure: Carver Gravel Grinder w/ Di2

Mentioned: 27 Post(s)
Tagged: 0 Thread(s)
Quoted: 1921 Post(s)
Liked 55 Times in 36 Posts
3/2.5 is easier to work worth, Scooper...further the aerospace and military industry has been gobbling up most all of the 6/4 supply there is in the USA. And most builders no longer can source enough for a semi-reasonable price to bother marketing whole framesets anymore. Even the Lynskey Scooper cites is not entirely 6/4, only the front triangle.

Originally Posted by Lynskey
[snip] sheets are rolled into tubing and seam welded together by Lynskey. These newly-formed tubes are then welded together to create the R450’s front triangle. [snip]
6al-4v titanium front triangle for maximum stiffness and power transfer
https://www.lynskeyperformance.com/store/r450.html

Now as with any material, a builder can make any frame so stiff that you will not want to ride it...as it will rattle your fillings out. The question is how much it would weigh. Unless you OP weigh 300+lbs (or badly lie bout your weight to the builders) it would be hard for a reputable framebuilder who knows what they are doing to make a custom Ti frame a noodle. And material would factor in, but in and of itself 3/2.5 does not make a frame noodly. It is what you do with the material.
Marcus_Ti is offline  
Old 09-24-14, 07:20 PM
  #6  
ruirui
need to go out and ride..
Thread Starter
 
ruirui's Avatar
 
Join Date: Mar 2004
Location: Bay Area, CA
Posts: 1,435

Bikes: 2011 Scott Addict R1, 2014 Redline Conquest Team, 2015 BMC TMR02

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
OMG... if you guys are not Ti gurus.. I don't know of any others that is as informative as you all.

My buddy recently bought a Litespeed T1 frame, which is listed with 6/4. Not bad for $2K on a 2014 model from fleabay.

I on the other hand don't have that much and looking at the Motobecane Le Champion Ti w/ 3/2.5. I weigh about 148lbs and like to hard sprint on flats and occasional standing attack on climbs.

I use to have an aluminum frame and that flexed a lot, but it probably cuz it's a cheap frame. But would hate to have that flexy feel on the bb part when sprinting or out of saddle climb.
ruirui is offline  
Old 09-24-14, 07:32 PM
  #7  
Marcus_Ti 
Frozen Solid.
 
Marcus_Ti's Avatar
 
Join Date: Sep 2014
Location: Lincoln, Nebraska
Posts: 4,667

Bikes: Roadie: Seven Axiom Race Ti w/Chorus 11s. CX/Adventure: Carver Gravel Grinder w/ Di2

Mentioned: 27 Post(s)
Tagged: 0 Thread(s)
Quoted: 1921 Post(s)
Liked 55 Times in 36 Posts
Originally Posted by ruirui View Post
OMG... if you guys are not Ti gurus.. I don't know of any others that is as informative as you all.

My buddy recently bought a Litespeed T1 frame, which is listed with 6/4. Not bad for $2K on a 2014 model from fleabay.

I on the other hand don't have that much and looking at the Motobecane Le Champion Ti w/ 3/2.5. I weigh about 148lbs and like to hard sprint on flats and occasional standing attack on climbs.

I use to have an aluminum frame and that flexed a lot, but it probably cuz it's a cheap frame. But would hate to have that flexy feel on the bb part when sprinting or out of saddle climb.
Your buddy's Litespeed is not entirely 6/4. It too is most likely half-n-half, if that

Originally Posted by Litespeed
The frame is made of a proprietary blend of 6/4 and 3/2.5 titanium and has innovative features that include PF30 bottom bracket and oversized head tube for more fork-tuning capabilities and precision handling.

[snip]

  • Premium 6Al/4V radically shaped top tube shaped for maximum stiffness
http://www.litespeed.com/bike.asp?content=T1-2014

Now I am not personally familiar with this frameset...but given the very specific way the above marketing is phrased, it is very possible it is not even half-and-half 6/4 and 3/2.5. It reads in legalese like the top tube is 6/4 and everything else is 3/2.5. That being said it doesn't matter a whole lot aside from impressing people with marketing and trying to justify a higher price. Now older Litespeeds, as well as older Moots/Sevens/etc back half-a-dozen years or so were available in full 6/4

Buying a cheapo (relatively) online and sight unseen is a crapshoot, especially for someone concerned with sprinting/climbing stiffness. I certainly wouldn't do it. Better to spend the money on a ride I can test in person, than be out $3000 on a bike I couldn't try and is no better than what I have.
Marcus_Ti is offline  
Old 09-24-14, 11:06 PM
  #8  
ruirui
need to go out and ride..
Thread Starter
 
ruirui's Avatar
 
Join Date: Mar 2004
Location: Bay Area, CA
Posts: 1,435

Bikes: 2011 Scott Addict R1, 2014 Redline Conquest Team, 2015 BMC TMR02

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
thanks marcus, yea i was a bit weary when he asked me about litespeed.. sure they make good bikes, but since he never rode one before, it was too late for him as he had already won the auction. i saw it last sunday and it looks used, but seller said it was a demo at a bike shop.. so who knows.

as for the motobecane Ti, i've only read positive reviews on it from here and RBR. wish i can test ride one, but dont know of anyone that owns that Ti nearby. but for $1K, guess it's not too bad as long as it doesn't ride like aluminum.
ruirui is offline  
Old 09-25-14, 08:05 AM
  #9  
Andrew R Stewart 
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 11,654

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Raleigh Pro, Trek Cycle Cross, Mongoose tomac ATB, GT Bravado ATB, JCP Folder

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1730 Post(s)
Liked 45 Times in 32 Posts
The concerns I have with low cost TI frames is what was taken out of the manufacturing (or is it only the distribution chain that gives up the costs) to allow selling so cheaply. Was the frame well welded? Properly back purged? How well aligned is it? How well chased and faced is it (or reamed too)?

TI does crack and warp with the stress of manufacturing. It does corrode/react galvanicly. It is a pain/expensive to correct once made.

Given all that if I were starting my building again I'd learn to weld TI and find a facility that has the tooling to make frames with. Andy.
Andrew R Stewart is offline  
Old 09-25-14, 10:51 AM
  #10  
ruirui
need to go out and ride..
Thread Starter
 
ruirui's Avatar
 
Join Date: Mar 2004
Location: Bay Area, CA
Posts: 1,435

Bikes: 2011 Scott Addict R1, 2014 Redline Conquest Team, 2015 BMC TMR02

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
thanks Andy. i've read in the past that their lineup of motobecanne le champion Ti is made by Ora Engineering Co. in Taiwan. they've been around for a very long time welding Ti frame and doing OEM for many other companies, one of which is Rikulau.

i've emailed bikesdirect.com and waiting to get their confirmation on whether or not the frame is stil made by ORA. if so, then i'm pretty confident in their welds, as i have friends in the cycling industry in Taiwan that told me they are reputable. the strange part is, if i were to source the frame through friends from ORA in Taiwan, it would cost more than getting the frame from bikesdirect.com, because ORA said bikesdirect.com buys in bulk to get the discounts.
ruirui is offline  
Old 11-03-14, 06:37 PM
  #11  
79pmooney
A Roadie Forever
 
79pmooney's Avatar
 
Join Date: Oct 2014
Location: Portland, OR
Posts: 6,917

Bikes: (2) ti TiCycles, 2007 w/ triple and 2011 fixed, 1979 Peter Mooney, ~1983 Trek 420 now fixed and ~1973 Raleigh Carlton Competition gravel grinder

Mentioned: 92 Post(s)
Tagged: 0 Thread(s)
Quoted: 1635 Post(s)
Likes: 0
Liked 57 Times in 48 Posts
I have 2 ti bikes which are both (I am quite sure) all 3/2.5. Both TiCycles customs. We talked briefly of 6/4 for both but it seemed hardly with it. After 17,000 miles, I do not regret that at all. In fact, I never think about it. Both are stiff. 59 and 58 cm. I weight 150. For me, very stiff, in fact the stiffest bikes I've owned. I have zero need for more. I have also ridden an early Merlin which, though perfect for me, was not stiff. It's all about the tube diameters and details. TiCycles has been known for making stiff ti frames for years.

Ben
79pmooney is online now  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
seedsbelize
Classic & Vintage
5
01-18-16 09:19 AM
cg1985
General Cycling Discussion
8
05-18-10 09:48 PM
Caleab
Classic and Vintage Bicycles: Whats it Worth? Appraisals.
7
06-03-09 04:46 PM
mrjhmm
Commuting
17
04-24-09 08:32 PM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.