Dropouts not parallel
04-19-18, 10:52 PM
#51
Senior Member
Join Date: Feb 2015
Location: Mission Viejo
Posts: 5,806
Bikes: 1986 Cannondale SR400 (Flat bar commuter), 1988 Cannondale Criterium XTR, 1992 Serotta T-Max, 1995 Trek 970
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 1943 Post(s)
Liked 2,164 Times
in
1,323 Posts
Thanks Andy!
Your contributions have been invaluable reflections of the real world.
John
Your contributions have been invaluable reflections of the real world.
John
04-19-18, 11:27 PM
#52
Senior Member
Join Date: Apr 2011
Posts: 7,047
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 4391 Post(s)
Liked 1,555 Times
in
1,020 Posts
Real life does things to theory, speculations or hope. When I read people saying that a jig insures alignment and I see frequently enough misaligned carbon/bonded frames I have to side on what I see. I've seen many minor wheel sitting "offnesses" on many brands and types of bikes (mostly road as they comprise most of the carbon built bikes I've worked with), both forks and rear ends. The tight clearances of TT bikes have been especially prone to power induced tire rubs when this off center wheel stuff happens. I have shifted the dish of a few wheels to compensate, not the best solution but sometimes you do what you need to. I have filed quite a few drop outs, mostly on forks, to allow the wheel to center at the brake/crown/stays.
This is rather interesting to me as a many year "gentleman builder" and also as a front line shop wrench. What I do in a LBS isn't always what I am happy with at home in my own shop. For years I have wondered about carbon frame alignment, seeing what I see and knowing what I do about steel frames. I've never bothered to pursue carbon frame tolerances in a setting where real numbers are found. But this thread has me rethinking my lack of motivation to measure carbon frames on my flat surface and use the same methods of testing I apply to my own (and other's) steel frames. (Why take time when I had no interest in trying to make one and also knowing that any corrections are limited?) So I have a new project that I'll follow up on in my own sweet time. At some point, likely this fall, I'll do some checking on whatever carbon frames I can come across (and take home for a while) and post back. Andy
This is rather interesting to me as a many year "gentleman builder" and also as a front line shop wrench. What I do in a LBS isn't always what I am happy with at home in my own shop. For years I have wondered about carbon frame alignment, seeing what I see and knowing what I do about steel frames. I've never bothered to pursue carbon frame tolerances in a setting where real numbers are found. But this thread has me rethinking my lack of motivation to measure carbon frames on my flat surface and use the same methods of testing I apply to my own (and other's) steel frames. (Why take time when I had no interest in trying to make one and also knowing that any corrections are limited?) So I have a new project that I'll follow up on in my own sweet time. At some point, likely this fall, I'll do some checking on whatever carbon frames I can come across (and take home for a while) and post back. Andy
So when we see CF frames that aren't straight, it is because they weren't clamped in the jig correctly or the jig was not aligned. Or with CF forks, the dropouts were inserted after the rest of the fork was molded without the proper use of a fixture.
It would be dispiriting to check an expensive production carbon frame on an alignment table since there is so little you could do about it.
04-20-18, 12:32 AM
#53
Senior Member
Join Date: Dec 2007
Location: San Jose, California
Posts: 3,504
Bikes: 2001 Tommasini Sintesi w/ Campagnolo Daytona 10 Speed
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 145 Post(s)
Likes: 0
Liked 35 Times
in
30 Posts
I don't think every thread starter is obliged to jump through hoops for any poster that demands a picture or wants their opinion acknowledged. Especially posters that largely ignore the information already posted in the thread. THe OP sounds VERY thorough in his inspection of his frame and in trying multiple wheels.
If you believe there is some avenue left unexplored, you should point to what it could be rather than imply that withholding a photo from you is some sort of cover up.
If this was a metal frame or hadn't been closely inspected already there would be more to check or other solutions to consider. But the fact that this bike consists of small pieces of aluminum glued decades ago into unbendable carbon tubing limits what can be done without causing damage. Minorly truing up the dropouts with a file accomplishes what the OP needs without extra inspections that won't yield solutions - it doesn't matter if the whole frame is crooked if you can't fix a crooked CF frame or the dropouts can't be bent without straining the bonds.
If you believe there is some avenue left unexplored, you should point to what it could be rather than imply that withholding a photo from you is some sort of cover up.
If this was a metal frame or hadn't been closely inspected already there would be more to check or other solutions to consider. But the fact that this bike consists of small pieces of aluminum glued decades ago into unbendable carbon tubing limits what can be done without causing damage. Minorly truing up the dropouts with a file accomplishes what the OP needs without extra inspections that won't yield solutions - it doesn't matter if the whole frame is crooked if you can't fix a crooked CF frame or the dropouts can't be bent without straining the bonds.
Intended or not, it DOES carry the odor of "something to hide." Keywords = "intended or not"
Actually, it's kinda rude...and it is certainly NOT unreasonable to request pics / images for a further look.
It's par for the course almost here in the Bicycle Mechanics forum.
=8-P
__________________
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
04-20-18, 12:40 AM
#54
Senior Member
Join Date: Apr 2011
Posts: 7,047
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 4391 Post(s)
Liked 1,555 Times
in
1,020 Posts
It's not cool for the OP or someone else working with em to take something private -and expect US to take their word for it - on a thread that was PUBLIC and OPEN to start with.
Intended or not, it DOES carry the odor of "something to hide." Keywords = "intended or not"
Actually, it's kinda rude...and it is certainly NOT unreasonable to request pics / images for a further look.
It's par for the course almost here in the Bicycle Mechanics forum.
=8-P
Intended or not, it DOES carry the odor of "something to hide." Keywords = "intended or not"
Actually, it's kinda rude...and it is certainly NOT unreasonable to request pics / images for a further look.
It's par for the course almost here in the Bicycle Mechanics forum.
=8-P
He doesn't need to prove anything to you just because you assume people are knuckleheads. The purpose of this subforum is to solve people's mechanical problems, not to satisfy subsequent posters' desires for vindication. The OP asked the right questions, checked the right things and got useful answers which he successfully executed. It's a win all around.
04-20-18, 06:28 PM
#55
Senior Member
Thread Starter
Join Date: Aug 2012
Location: Los Alamitos, Calif.
Posts: 2,475
Bikes: Canyon Endurace
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 1041 Post(s)
Liked 923 Times
in
540 Posts
It's not cool for the OP or someone else working with em to take something private -and expect US to take their word for it - on a thread that was PUBLIC and OPEN to start with.
Intended or not, it DOES carry the odor of "something to hide." Keywords = "intended or not"
Actually, it's kinda rude...and it is certainly NOT unreasonable to request pics / images for a further look.
It's par for the course almost here in the Bicycle Mechanics forum.
=8-P
Intended or not, it DOES carry the odor of "something to hide." Keywords = "intended or not"
Actually, it's kinda rude...and it is certainly NOT unreasonable to request pics / images for a further look.
It's par for the course almost here in the Bicycle Mechanics forum.
=8-P
I have actually PM'd 2 participants in this thread. Neither of those 2 PM's were regarding the repair or soliciting additional advice. Everything I had to say about the repair has been presented in this thread. The basis of these PM's were to introduce myself to these members while thanking and agreeing with their comments and input throughout this thread. Nothing more, nothing less.
The reason I dropped out of the conversation was that I thought I had been clear that the problem had been fixed to my satisfaction. At that point, I did not revisit the thread that often. If others want to continue this conversation regarding dropout alignment or who thinks they have the best answer... then go for it. I came and asked a question, I got some good advice, I applied what I thought was the best solution and confirmed that solution worked.
04-21-18, 03:19 PM
#56
Senior Member
Your frame is bent. The rear triangle is pushed over. Use the string test to measure the rear triangle Frame Alignment.
If you don't know what the string test is look it up it's really easy and it works.
If you don't know what the string test is look it up it's really easy and it works.
04-21-18, 07:00 PM
#57
Senior Member
Join Date: Apr 2011
Posts: 7,047
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 4391 Post(s)
Liked 1,555 Times
in
1,020 Posts
If you don't know that a CF frame can't bent it's easy to look up.
04-21-18, 07:34 PM
#58
Senior Member
Join Date: Feb 2012
Location: Rochester, NY
Posts: 18,073
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4201 Post(s)
Liked 3,857 Times
in
2,305 Posts
How do you know this (set aside the "bent"/"pushed over" reference) that the frame's rear end is off center? A wheel can sit off center at it's rim/stays location and have the hub on center very easily. Andy
