Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

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.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 12-12-12, 09:50 AM   #1
ak08820
Senior Member
Thread Starter
 
Join Date: Jun 2008
Location: Central NJ
Bikes: MGX MTB, Fuji Supreme, Miyata 90 and a Trek 700 in the works
Posts: 550
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Main Tube Angle

Why do more and more bicycles now have the main tube at an angle?
How does it affect bike handling if any?
I really prefer the clean and honest look of the horizontal main tube, which is so hard to find nowadays.
ak08820 is offline   Reply With Quote
Old 12-12-12, 10:43 AM   #2
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Bikes:
Posts: 14,491
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
it's called the "top tube". I think slanted top tubes make sense, you get more stand-over height and people think they have bad backs so they want their handlebars to be higher. Plenty of bikes have horizontal top tubes, you might have to spend a little more. You aren't going to find many horizontal top tubes on aluminum or carbon frames though. They do exist, however. Spooky and Colnago come to mind.

Last edited by unterhausen; 12-12-12 at 12:49 PM.
unterhausen is offline   Reply With Quote
Old 12-12-12, 12:19 PM   #3
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 18,086
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
I tend to think the Down-tube is More "Main".. but sloping top tubes appeal to the younger customers,
coming off BMX and MTBs, that also have sloping top tubes.. its the familular-ity, thing..

Cyclocross Race bikes will have a more horizontal top tube
because they have to be shouldered and run, bike on the shoulder,
up steep hills in races, occasionally..

they are not hard to find if you go to bike shops and ask..

Quote:
How does it affect bike handling if any?
not any more than any other double-diamond frame at the same price point.

Last edited by fietsbob; 12-12-12 at 12:22 PM.
fietsbob is offline   Reply With Quote
Old 12-17-12, 05:25 AM   #4
qwertzy
Junior Member
 
Join Date: Jun 2008
Location: Geneva, Switzerland
Bikes:
Posts: 6
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by ak08820 View Post
Why do more and more bicycles now have the main tube at an angle?
I think bike manufacturers also want to keep their costs down by having less sizes of each model of frame.
"Few sizes fit many" kind of thing.

Keeping stock of different sizes is expensive, as are the molds for building carbon frames.
qwertzy is offline   Reply With Quote
Old 12-17-12, 06:37 AM   #5
Canaboo
Senior Member
 
Join Date: Dec 2009
Bikes:
Posts: 321
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
There is also the crucial saving of a few grams of material that can give a more flattering frame weight. The shorter seattube is also stiffer. Of course a longer and heavier seatpost then has to be used to span the resulting gap.
Canaboo is offline   Reply With Quote
Old 12-17-12, 08:10 AM   #6
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Bikes:
Posts: 14,491
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Over the years I became accustomed to seeing horizontal top tubes, but really, what's so special about a top tube zero degree slant that makes it superior to any other slant? Although it doesn't take much before the seat tube/seat stay juncture starts to be a structural issue
unterhausen is offline   Reply With Quote
Old 12-30-12, 07:36 PM   #7
TiHabanero
Senior Member
 
Join Date: Nov 2012
Bikes:
Posts: 759
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I recall being told outright by the good folks at Giant when they introduced the "compact" frame design it was simply a matter of dollars and sense. As mentioned above, the compact frame design allows a manufacturer to cover 2 frame sizes with a single frame. There is nothing inherently better about the compact frame vs. traditional frame with horizontal top tube. Just reduces many costs for the manufacturer.
TiHabanero is offline   Reply With Quote
Old 12-30-12, 11:38 PM   #8
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Bikes:
Posts: 14,491
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
that was the story when it started, but almost all companies have just as many sizes now as they did when all bikes had horizontal top tubes. If they drop any sizes, it's small frames and large frames which have a much smaller market
unterhausen is offline   Reply With Quote
Old 12-31-12, 06:31 AM   #9
TiHabanero
Senior Member
 
Join Date: Nov 2012
Bikes:
Posts: 759
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Yes, at that time they had 4 frame sizes for the compact design. Now they have 6 sizes which is maybe only 1 or 2 shy of a full size run in a traditional frame. Interestingly, from out of the compact design the "comfort" road bike has risen. If it weren't for that smallish frame the extended top tube might not have gained in popularity and the "comfort" or "endurance" road bike not be with us. Quite possible if one looks back into history this has been done before, as history typically repeats itself!
TiHabanero is offline   Reply With Quote
Old 12-31-12, 08:06 AM   #10
Andrew R Stewart 
Andrew R Stewart
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
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
Posts: 6,589
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I let the fit/sizing of the bike drive whether the TT is sloped or not. The first sloping TT bike I built was in 1979. As I have built far more small bikes then large ones many of my bikes are sloping. I do find that the junction angles are harder to work lugs for but that's why we have brass. Andy.
Andrew R Stewart is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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



All times are GMT -6. The time now is 08:55 AM.