Go Back  Bike Forums > Bike Forums > Framebuilders
Reload this Page >

Weird frame structure, need possible reasons

Notices
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.

Weird frame structure, need possible reasons

Old 06-15-10, 09:30 AM
  #1  
plutonium83
Bike Commuter
Thread Starter
 
Join Date: Jan 2009
Posts: 49
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Weird frame structure, need possible reasons

I'm thinking of buying a Gravity Avenue C, but I'm puzzled by the weird frame structure in the back. Why don't the two triangles match up (highlighted in yellow)?
Attached Images
File Type: jpg
avenue_c_blk2100..jpg (93.2 KB, 89 views)
plutonium83 is offline  
Old 06-15-10, 10:23 AM
  #2  
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 19,889
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 419 Times in 321 Posts
you're asking for a justification of that? I dunno, maybe they wanted to ensure there were warranty returns.
unterhausen is offline  
Old 06-15-10, 10:32 AM
  #3  
Doohickie 
You gonna eat that?
 
Doohickie's Avatar
 
Join Date: Sep 2008
Location: Fort Worth, Texas Church of Hopeful Uncertainty
Posts: 14,682

Bikes: 1966 Raleigh DL-1 Tourist, 1973 Schwinn Varsity, 1983 Raleigh Marathon, 1994 Nishiki Sport XRS

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 141 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
I don't think the mismatch is structurally significant. My guess is that the rear triangle was tooled with certain angles and is used on different size frames. On a taller frame it will hit the seat tube a little short of the top tube. Or.... the designer just designed it that way. If that was such a big deal, step-through frames would fail all the time, but they don't.

I wouldn't worry about it.
__________________
I stop for people / whose right of way I honor / but not for no one.


Originally Posted by bragi "However, it's never a good idea to overgeneralize."
Doohickie is offline  
Old 06-15-10, 11:18 AM
  #4  
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 19,889
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 419 Times in 321 Posts
it's not that uncommon among production bikes. Since there is no reinforcement of the seat tube/top tube junction, the seat tube is probably heavy enough to take the load at the seat stays without crumpling. If it was a lightweight steel frame, I would question the builder's judgement.
unterhausen is offline  
Old 06-15-10, 07:10 PM
  #5  
Six jours
Senior Member
 
Join Date: Mar 2007
Posts: 6,401
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
The bottom line is that it's just a marketing hook. It's designed to catch your eye. The maker may or may not try to justify it as "better". In reality it's a gimmick and most likely harmless.
Six jours is offline  
Old 06-16-10, 12:36 PM
  #6  
NoReg
Banned
 
Join Date: Aug 2005
Posts: 5,115
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 2 Times in 1 Post
I agree with the posts so far, though that kind of denial of the importance of details applies to a lot of custom frames also. What is the role of the Fleur du Lis on the lugs kinda stuff. Or the lugs.

In general that kind of thing looks intended to soften the rear end, and harden the front end. Why that would appeal in this case could just come down to marketing hooks as mentioned. Or it can be that for some reason they tried it, and for whatever reson that particular bike worked great. Like going into a shop and riding three seemingly identical bikes, and yet one feels alive and the rest are like riding a section of guard rail.

Why a deeply ovalized and curved tube. Sorta nets out at higher weight.
NoReg is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
albako
Bicycle Mechanics
7
02-13-18 02:29 PM
NOBLNG
Framebuilders
34
10-15-17 08:20 PM
Specialized2k10
Road Cycling
13
12-05-11 05:46 PM
Stickney
Framebuilders
2
07-30-10 07:48 AM
baribari
Road Cycling
13
07-07-10 05:09 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 - Do Not Sell My Personal Information

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