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

Changing Head Angle

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.

Changing Head Angle

Old 05-03-20, 04:59 PM
  #1  
TiHabanero
Senior Member
Thread Starter
 
Join Date: Nov 2012
Posts: 3,026
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1038 Post(s)
Liked 306 Times in 173 Posts
Changing Head Angle

Just rode a new frame and have found that I pushed the envelope too far with the head tube angle. Thinking about how to change the head angle I came up with removing the down tube, bending the head tube/top tube to get to the desired head angle (needs to move about 3 degrees) to steepen the angle. Any thoughts or is it replacement of the top tube/head tube/down tube and rebuild the front triangle?
TiHabanero is offline  
Old 05-03-20, 06:28 PM
  #2  
Canaboo
Senior Member
 
Join Date: Dec 2009
Posts: 445
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 25 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Originally Posted by TiHabanero View Post
Just rode a new frame and have found that I pushed the envelope too far with the head tube angle. Thinking about how to change the head angle I came up with removing the down tube, bending the head tube/top tube to get to the desired head angle (needs to move about 3 degrees) to steepen the angle. Any thoughts or is it replacement of the top tube/head tube/down tube and rebuild the front triangle?

How is it joined?
Canaboo is offline  
Old 05-03-20, 08:54 PM
  #3  
Andrew R Stewart 
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 13,603

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: 2434 Post(s)
Liked 493 Times in 381 Posts
3 degrees of bending? That's a lot IMO. Better to remove the HT and see if the existing TT and DT can be remitered for the new head angle. Andy
__________________
AndrewRStewart
Andrew R Stewart is offline  
Old 05-04-20, 04:09 AM
  #4  
guy153
Senior Member
 
Join Date: Dec 2019
Posts: 191
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 63 Post(s)
Liked 29 Times in 25 Posts
Originally Posted by TiHabanero View Post
Just rode a new frame and have found that I pushed the envelope too far with the head tube angle. Thinking about how to change the head angle I came up with removing the down tube, bending the head tube/top tube to get to the desired head angle (needs to move about 3 degrees) to steepen the angle. Any thoughts or is it replacement of the top tube/head tube/down tube and rebuild the front triangle?
I agree with Andy Stewart better to remove the HT altogether. But why not instead make a new fork for it? Give the fork enough offset to get your trail back where you want it. Then the existing fork can be re-used on another project.
guy153 is offline  
Old 05-04-20, 04:37 AM
  #5  
dsaul
Senior Member
 
Join Date: Jan 2013
Location: South Jersey
Posts: 1,555
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 453 Post(s)
Liked 202 Times in 152 Posts
What kind of frame and what is the current head angle? I doubt you could have gotten it that wrong.
dsaul is offline  
Old 05-04-20, 04:52 AM
  #6  
TiHabanero
Senior Member
Thread Starter
 
Join Date: Nov 2012
Posts: 3,026
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1038 Post(s)
Liked 306 Times in 173 Posts
Here is what happened. I designed the frame around a 60mm fork rake, then changed my mind on the fork as I wanted the bike to look more modern, but the frame was already built by that time. Decided to install a 45mm rake fork and try it anyway. It is ridable, but rides like a chopper, lots of rise and fall with the front end, and it is a handful in high winds. The frame is lugged and figured redoing the whole front end of the bike would be best, but figured if there was a short cut, someone here will know.
TiHabanero is offline  
Old 05-04-20, 06:58 AM
  #7  
dsaul
Senior Member
 
Join Date: Jan 2013
Location: South Jersey
Posts: 1,555
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 453 Post(s)
Liked 202 Times in 152 Posts
What is the purpose of the bike? Road, gravel, touring? My bikes vary in trail from about 60mm on the road bike to 75mm on the gravel bike and 90mm on the MTB. The longer trail bikes are not so easy to ride with no hands, but winds don't seem to be a problem. The only time I have problems with cross winds is with a deep section front wheel.

It just seems like a radical approach to re-build the front triangle, when riding the bike a few more times might allow you to become accustomed to the way it rides.
dsaul is offline  
Old 05-04-20, 07:15 AM
  #8  
Trakhak
Senior Member
 
Join Date: Jan 2005
Location: Baltimore, MD
Posts: 2,063
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 529 Post(s)
Liked 177 Times in 127 Posts
Originally Posted by dsaul View Post
It just seems like a radical approach to re-build the front triangle, when riding the bike a few more times might allow you to become accustomed to the way it rides.
That's a sensible suggestion. I bent the (steel) fork on a 1986 Cannondale in 1990, left it unused for 20 years with a vague plan of replacing the fork, and then started commuting on it. Took a few rides to get used to the handling, but I've since ridden it for a good proportion of my annual mileage.
Trakhak is offline  
Old 05-04-20, 07:58 AM
  #9  
mikeread
Senior Member
 
Join Date: Nov 2015
Posts: 166
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Likes: 0
Liked 26 Times in 12 Posts
Would a straight blade fork with 60mm rake look modern?
mikeread is offline  
Old 05-04-20, 08:22 AM
  #10  
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 19,886
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 415 Times in 318 Posts
have you put your proposed numbers into a trail/flop calculator? 45mm rake fork is going to need a steep hta to get it to reasonable flop. What is the current HTA and proposed HTA?

Seems like it's time for a new frame, chalk this one up to experience. But if you really want to do this, replace the TT/HT/DT.
unterhausen is offline  
Old 05-06-20, 05:12 PM
  #11  
TiHabanero
Senior Member
Thread Starter
 
Join Date: Nov 2012
Posts: 3,026
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1038 Post(s)
Liked 306 Times in 173 Posts
I find my trail preference is between 71-73 mm. I have considered a straight blade fork with 60mm taken but need to draw it to get an idea of how it will look. As it is, I will give the thing another ride and see how it goes.
TiHabanero is offline  
Old 05-06-20, 05:24 PM
  #12  
Cynikal
Team Beer
 
Cynikal's Avatar
 
Join Date: Apr 2004
Location: Sacramento CA
Posts: 6,072

Bikes: Too Many

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 43 Post(s)
Liked 15 Times in 12 Posts
A 7 degree fork crown with a 390-400 ac would get you really close to 60 mm.
Cynikal is offline  
Old 05-06-20, 09:14 PM
  #13  
Nessism
Senior Member
 
Nessism's Avatar
 
Join Date: Jun 2004
Location: Torrance, CA
Posts: 2,831

Bikes: Homebuilt steel

Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 175 Post(s)
Liked 33 Times in 28 Posts
Originally Posted by Andrew R Stewart View Post
Better to remove the HT and see if the existing TT and DT can be remitered for the new head angle. Andy
I agree with Andy too. Shouldn't be too hard. Don't think I'd work too hard saving the lugs though, although that's possible.
Nessism is offline  
Old 05-06-20, 09:53 PM
  #14  
base2 
Random Internet Person.
 
base2's Avatar
 
Join Date: Jun 2015
Location: Pacific Northwest
Posts: 1,328

Bikes: 5 good ones, and the occasional project.

Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 683 Post(s)
Liked 248 Times in 153 Posts
Rodriguez had someone contract build them bunches of 55mm rake forks (1&⅛) for their disc braked bikes. You might give them a call. Maybe they have one on the shelf.

Rodbikes.com

55mm is not 60mm, but it'd get you closer than you are. They are aluminum, smooth, disc. Nothing retro or lugged about 'em.

They also do custom to whatever your specs are.

Mine is 55mm rake for a 26 inch (559) wheel for a 69 degree head tube angle. ~55 to 62mm of trail depending on tire.

Last edited by base2; 05-06-20 at 10:05 PM.
base2 is offline  
Old 05-06-20, 10:10 PM
  #15  
TiHabanero
Senior Member
Thread Starter
 
Join Date: Nov 2012
Posts: 3,026
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1038 Post(s)
Liked 306 Times in 173 Posts
I believe I will try to save the head tube as it is special to me. Last of the 531 tubes my brother gave me, and replace the lugs and TT/DT. Winter project.
TiHabanero is offline  
Likes For TiHabanero:
Old 05-21-20, 06:58 PM
  #16  
TiHabanero
Senior Member
Thread Starter
 
Join Date: Nov 2012
Posts: 3,026
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1038 Post(s)
Liked 306 Times in 173 Posts
dsaul, I have been riding the bike with the inappropriate fork and am becoming accustomed to the low speed weirdness. I will say once I am up around 17+ mph, the thing settles down and is very comfortable to ride. Does not like to deviate from a straight line so a little extra effort on the bars is required for cornering. Oddly, this does not bother me at all. Only the low speed instability is bothersome, but I bet that can be overcome in time.

The OS down tube seems to make a difference in the responsiveness to heavy input such as climbing and sprinting. At 40mph on a downhill the bike was very stable, but as mentioned before, it did not like to deviate from a straight line without some heavy handedness. Again, I can deal with that. Thinking that using the wrong fork is livable. Thanks, dsaul!
TiHabanero is offline  
Likes For TiHabanero:

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.