Frame alignemnt question

[Doug Fattic]

I think there are things a layman can learn from this subject thread. Issues of alignment and having wheels exactly center are common. They just aren’t often identified because a customer doesn’t have the tools to precisely check and/or they don’t notice. When steel is heated it moves whether it is held in some kind of fixture or not. The build process has to account for this movement. Top tier frame builders will hold alignment to within a half mm. Production frame standards are more loose and they could be out by a couple or more millimeters. The fastest ways to build are not the most accurate.

Alignment is more complicated than a non-builder may understand. A steel tube is not perfectly round or straight. They may curve by a mm or 3 or even more. The cost of making one completely straight would price it out of the market. A good builder will roll a tube on his flat table to find the curve and place the miters to minimize the effect of the bend. They will also find where the butts transitions start to optimize miter placement too. Just like politics there is not universal agreement on the best ways to build – and shortcuts mean more profit.

Adding to Imperfect tubes and the brazing process are imperfect fixtures. The antidote to these complications is extra time and care that not every builder is willing or knowledgeable enough to do.

[tigoat]

Doug, thank you for your honest insight. I don’t think it can be clearer than that from your explanation of the build process on this subject.

[yashcha]

Originally Posted by tigoat

Doug, thank you for your honest insight. I don’t think it can be clearer than that from your explanation of the build process on this subject.

Proper frame building is even more complicated than I had previously imagined.

[tigoat]

Building a bicycle frame is actually not that complicated with proper tooling and knowledge but to build a frame that is as perfectly aligned as possible will require some critical tweaks with patient. This means the builder must have the experience, not necessary in years though, and is willing to spend time to take some extra steps in the build process. As pointed out by Doug, manufacturing equipment can only be as accurate to a point so a builder must know to how compensate for it. With that said, I don’t believe that even a well-constructed bicycle frame made an expert builder will be perfectly aligned regardless of how perfect the dial indicator shows on a calibrated table, as perfection does not exist in my book. It is how close to perfectly aligned can he get would be something we want to go after. Metrology is actually a science itself that is not easy to master so it is more than just using a flat table and a dial indicator to gauge the alignment accuracy of a bicycle frame. I think I have enough said on this subject. Hope you will have it sorted out soon.

Originally Posted by yashcha

Proper frame building is even more complicated than I had previously imagined.

[zank]

There's certainly a point where better and better alignment transitions from practical importance (what the rider feels) to pride and challenge (what the builder feels). It's a balancing act because a builder can go mad and broke trying to chase some elusive alignment perfection. I raced a Carrera that was horrible on the table, but I could easily ride no handed, dig through my pockets, put on a jacket, and navigate the group. The head tube twist was a solid 1/8" over 18". It was a production frame though. I didn't think anything of it. It got the job done. Some alignment issues manifest more profoundly than others. Different riders will be more or less sensitive. But "we" raise the bar because we can, not necessarily because we have to. I don't think there will ever be a clear understanding of where "good enough" lies. There are just too many variables.

[soulspinner]

Originally Posted by zank

There's certainly a point where better and better alignment transitions from practical importance (what the rider feels) to pride and challenge (what the builder feels). It's a balancing act because a builder can go mad and broke trying to chase some elusive alignment perfection. I raced a Carrera that was horrible on the table, but I could easily ride no handed, dig through my pockets, put on a jacket, and navigate the group. The head tube twist was a solid 1/8" over 18". It was a production frame though. I didn't think anything of it. It got the job done. Some alignment issues manifest more profoundly than others. Different riders will be more or less sensitive. But "we" raise the bar because we can, not necessarily because we have to. I don't think there will ever be a clear understanding of where "good enough" lies. There are just too many variables.

thanks

[unterhausen]

Originally Posted by bikinchris

I always check every frame a build for alignment. Once when I took a Ti Serotta out of the box, the rep was there. When he saw that the rear triangle was out by just a little less than 1mm, he was a little surprised, angry and was adamant that it go back in the box to go back to Serotta.

1mm is reasonable. Pretty easy to have 1mm in measurement error, and the tubes we build with are often bowed almost that much. The bike in the op is obviously more than 1mm off.

My All City obviously has some sort of alignment problem, because it's impossible to ride no-handed and it shimmies at low speed. I'm happily riding it though. I'd strip it down and check alignment, but then I couldn't ride it. Maybe this winter, when the gravel roads are covered in snow and I have to take the fatbike out.

[mhespenheide]

Originally Posted by zank

There's certainly a point where better and better alignment transitions from practical importance (what the rider feels) to pride and challenge (what the builder feels). It's a balancing act because a builder can go mad and broke trying to chase some elusive alignment perfection. I raced a Carrera that was horrible on the table, but I could easily ride no handed, dig through my pockets, put on a jacket, and navigate the group. The head tube twist was a solid 1/8" over 18". It was a production frame though. I didn't think anything of it. It got the job done. Some alignment issues manifest more profoundly than others. Different riders will be more or less sensitive. But "we" raise the bar because we can, not necessarily because we have to. I don't think there will ever be a clear understanding of where "good enough" lies. There are just too many variables.

I fully understand this, but this thread also makes me think that when/if the time comes for me to commission a custom frame, I'm going with Kirk, Fattic, Zanconato, or someone similar!

[ultraman6970]

Unter...

IMO you might not have a problem with alignment, probably is off a little but the reality is that you have to factor 2 things, the fit and the geometry of the bike.

If the fit is wrong the bike wont work with you as a unit, you can have the best bike ever but if fits wrong it wont work as intended. Typical example of that is the dude that goes to the lbs buys the 8000 bucks bike and the sales man fits the dude like in a hybrid. That bike wont work ever.

Then you have the geometry, some low end stuff is just plain bad geometry and design. Usually low end stuff.

Then you have the combination of the two. Bad fit and horrible wacky design. You can correct the fit so the bike work but always something will be there bothering.

No idea which bike do you have but if the frame is not like pulling you to the sides slowly, there is a big chance it is a problem with the geometry and just the wrong fit (weight distribution) to make that frame to work as intended you know.

[ultraman6970]

If you can get in their waiting list :P

Originally Posted by mhespenheide

I fully understand this, but this thread also makes me think that when/if the time comes for me to commission a custom frame, I'm going with Kirk, Fattic, Zanconato, or someone similar!

[David Kirk]

Zank makes a very good point - how close to perfect is close enough?

I don't have the answer to that question and I suspect that every builder has their own standards that they comfortable with. I also think that one can take a risk and generalize and say that the standards in the US handbuilt niche are a bit tighter than the Euro counterparts. I think there are different ways to look at this. Some might say that the US guys fetishize this stuff far past the point of diminishing returns and some might say that the Euro guys are fast and loose with the quality standards. Of course neither one is "right" and it's a matter of preference and personal comfort. I personally know that most of the time I spend sweating over these details is for my own benefit and when I'm chasing a 1/4 mm that it will not make the bike ride better. It will of course make me feel better and many of my customers also take comfort in it too but it will not ride better than a frame that was built to 1/2 mm. But is 1 mm close enough? 2 mm? 4mm? Somewhere in there is a tipping point when it goes from the frame being "fine" to it not being "fine".

And how much does a rider need to tip their hips to one side to get the non-perfect bike to track straight? How does one even measure that? At some point it becomes obvious that the rider is compensating too much. How much frame misalignment is needed to cause this and how sensitive is the rider? I used to train and race with a guy who was so damn strong and fast and he rode a old school metal Trek. He never noticed anything being amiss with the bike but I rode it and it pulled hard to one side and I hated it. It turned out the fork was pushed off to one side by a lot. He didn't care and I hated it. Who was "right?" He was more than happy with the bike and I would have put it on a hook.

So how far off is too far? That is the big question. I suppose the issue could be that some might assume that there is an industry standard that all builders adhere to and all agree on. That just isn't the case. The burden ends up falling on the customer to find a builder who has the right combo of philosophy, experience and price to match their own needs and that can be tough to do.

dave

[fa63]

The human body is amazing in its ability to adapt. So I think it becomes a problem when it is aesthetically noticeable and bothersome to the end user. And of course everyone has different standards when it comes to that.

For example, I had a custom US built frame where the wheel wasn't perfectly centered between the chainstays. It was small enough where it was fine functionally and it didn't bother me aesthetically, so I rode it that way for a couple years. When I sold it, I had forgotten about it so I didn't mention the issue in the ad. The new buyer noticed it right away and was bothered by it, so we worked out a deal (which meant that I pretty gave the frame away, but I was fine with it).

[weisan]

Something just popped in my head...with the issues or concerns mentioned so far about building a frame using steel as the material, would this be one area that maybe carbon has a leg up because of its totally different fabrication process?

[Doug Fattic]

Originally Posted by weisan

...with the issues or concerns mentioned so far about building a frame using steel as the material, would this be one area that maybe carbon has a leg up because of its totally different fabrication process?

With the right knowledge, hand coordination skills, materials and patience, a good builder can make a steel frame within acceptable tolerances every time. That does’t mean it isn’t faster or cheaper to make a frame out of some other material. In 1985 I visited the Trek factory where at that time they were making frames by gluing aluminum tubes to investment cast aluminum lugs. I watched a lady use a brush to apply the epoxy and place the pieces into a fixture so they could take a set and then after a few minutes put it in an oven to cure. The whole process to make a frame – not including the baking time – might have been taken her all of 15 minutes. And I’m guessing she might only have needed about 15 minutes of training to do what she was doing. I thought I saw my career as a builder disappear right in front of me and was glad I had degrees and certifications in teaching education to fall back on. But steel hasn’t fallen out of favor yet even though it takes more time and skill to make a frame with it.

A customer I had made a steel frame for in the early 90’s come by the shop this last week. He wanted to get his frame refurbished again. He has the disposable income to have bought a number of bicycles made out of a variety of materials since that time. However he wanted to keep his custom steel going because he still liked it better than his other options. At least that is what he told me .

A frame doesn’t have to be just a functional tool. They can be made to look good by more than just the paint job. This is important to me and it might be to others too. I gave a lug cutting seminar a couple of weeks ago at the Philly show. I was pleased that someone that went to my presentation last year could bring by some fine examples he was able to do with the written instructions I handed out. The right knowledge gained from experience can make a frame that looks good as well as rides well possible.

One of the reasons I am not very tolerant of poorly made steel frames is that almost every student that takes my frame building class can leave with one they have made themselves that will stay within a mm of tolerance on their 1st try. Well not everyone has the ability to work with their hands so some need my help. However having said that we don’t know yet that the frame that started this subject thread was made to a sub par standard. A picture showing a tire off center to a brake bridge hole is not proof the builder is at fault. Something could have happened during shipping, it is possible the wheel/tire has some issue. I think it would be wise to not pass judgement until a pro builder (not related to either party) has examined the frame and we have heard from the builder of the frame.

[oldpotatoe]

Originally Posted by fa63

The human body is amazing in its ability to adapt. So I think it becomes a problem when it is aesthetically noticeable and bothersome to the end user. And of course everyone has different standards when it comes to that.

For example, I had a custom US built frame where the wheel wasn't perfectly centered between the chainstays. It was small enough where it was fine functionally and it didn't bother me aesthetically, so I rode it that way for a couple years. When I sold it, I had forgotten about it so I didn't mention the issue in the ad. The new buyer noticed it right away and was bothered by it, so we worked out a deal (which meant that I pretty gave the frame away, but I was fine with it).

I think the OP's example is a combination of wheel not even close to centered and the builder's, 'stop whining' response, IMHO.