hueyhoolihan

ok, i'm arrogant and an a-hole, but as a life-long eccentric i resent being lumped together with others and referred to as part of a "bunch". that's just TOO much.

strock 

Filled? Surely you exaggerate. It can't be more than half full.

cny-bikeman

I would not agree that it's a viable option. For one thing, the wheel is not just shifted to one side when the rear triangle is off-center. It's actuallly pointed right or left when the front wheel is going straight ahead. That means differential handling on right and left turns and possibly slightly greater tire wear - probably is not a huge concern but something to be considered. However, the hub does not just interact with the rim but also with the chainwheels through the rear cogs. If the rear triangle is off then likely the chainline is as well, and there may be more chain noise due to the cog and derailleur pulleys being not in the same vertical plane.

cny-bikeman

FB, am I missing something, or in this day and age wouldn't it be better to use a digital level? They are no longer very expensive at all. For that matter I would think that one could do a passable job of determining on which plane the wheel is off by simply sighting from the front of the bike frame to the rear wheel.

cny-bikeman

Actually the process above is not necessarily the best. If you try to correct the process yourself you first need to arm yourself as fully as possible with knowledge about the problem and a logical approach to a solution, either with research or by going to this forum.

That way you can do the work yourself more efficiently and reliably, you are less likely to confound the problem with more variables, and you are more able to tell the shop what you have eliminated and judge whether or not they have checked everything.

In a different thread a member went "round the bend and back again" on a drive train issue because he and the shop "tried a bunch of things" without a systematic approach to the problem, resulting in weeks of unnecessary work and delay.

The other problem, as shown in some of the posts in this thread, is that one has to "consider the source." Some persons may sound very convincing and present their opinion in a non-"arrogant" manner but be totally wrong or partially misinformed. It's sometimes a good idea to check profiles of those who are giving advice when you receive conflicting opinions. Many of us who have worked professionally post our background. The mere fact that someone has made multiple posts is no assurance of competence.

p.s. On reflection, even "credentials" are no assurance. The best evidence is the person's other posts. If you find that a given forum member is very often correct early on in their diagnosis and advice, explains how they came to a particular conclusion, and importantly, admits to errors graciously, then that is someone to look for in the future... as opposed to those who say "One time I had the exact same problem and this solved it."

IthaDan 

Sorry, I thought YOU had redished the wheel. Either way, the wheel has been touched (redished by changing spoke tension) and needs now needs to be re-redished to where it was because of a bad diagnosis.

There's not so much an arrogant a$$hole vibe going on here, more one of frustration stemming from answering a question and the asker having selective hearing about where to go next. You're on the right track to getting this sorted out, and you'll ride this thing and love it. But I don't want to lose track of the fact that there is a lot to learn on all accounts. I know I'll ask if the bike is nearby from now on.

davidad

You are like me, an a-hole and proud of it!

FBinNY 

"Filled with" is probably a slight exaggeration.

FBinNY 

We're back to the digital/analog instrument debate. While digital instruments have the appearance of being more accurate, that isn't necessarily true. The readout might have very good resolution, but it's still dependent on the sensor unit that actually takes the reading. It's also impossible to interpolate digital readings because you have no way of knowing which way it's already been rounded.

The same is true for bubble levels which come in a few varieties depending on the accuracy desired. The very sensitive ones have less curvature in the glass and changes of a few minutes are easily seen. I level machines with a bubble level so sensitive that the bubble moves almost 1 to 1 when adjusting foot pads set 5 feet apart. (that is an error of 1/16" over 5 feet will move the bobble 1/16")

That's not to say that a digital unit is inferior to a good analog one, just that it may not be any better.

As for eyeball sighting, it'll spot a really bad case but you'd need really good eyes to see an error of 1/8" top and bottom.

As I usually do, I offered one method for solving a problem. It isn't the only one, nor do I present it as such. If one has a grasp of the principles involved, and a bit of creativity, there are many ways of doing any job.

The problem in working on any frame alignment issue is that there are a number of possible errors that can combine in funny ways to compound or mitigate each other. Before making any correction, it's important to see the whole picture, lest you make a bad problem worse.

unterhausen

I believe that even ignoring the wheel, you can see that the frame is offset due to the curve of the seat stays. It's possible that it is an aberration caused by the camera lens, but I doubt it. When I was building at Trek, they cold set after the frame was complete. Cold setting is best performed before you attach the seat stays, and if the bridges are installed, all bets are off. Furthermore, it seems clear that when most bike owners cold set for 130mm, they don't really check for symmetry.

If you find somewhere to attach the string that is guaranteed to be symmetric, you should be able to see this fairly easily. Dropouts are notoriously misshapen, going up on the seat stays will guarantee a bad measurement. Although I take it that someone pointed this out.

blamp28

Define "filled". In all fairness, you came hewre with a question framed with the fact that and ace mechanic could not find anything wrong and then refused to acknowledge that there were some simple tests you could conduct that would point you in the right direction. It was not until you shared that toy did not have access to the bike that this made a little sense. There are very few, if any ******** here. On the other hand, if you ask a bunch of bike mechanics how to solve a problem, it would be helpful if you assumed that their suggestions might have a little validity. Particularly if they are repeated several times.

mrrabbit 

Funny thing about us proud ***holes on this forum is:

1. We are typically the people contractors come to when they have a "drop dead" deadline to meet and can't afford chatty "socialites" and "groupies" on the job.

2. That which is unresolved and gets passed around finally ends up with us - and gets done.

3. Our friends tend to be people who've known us for 20+ years and appreciate the real "McCoy's".



There...another ***hole done with his rant!

FBinNY 

The problem with the a-holes on this forum is that they fall into two basic categories.

1- those who know what they're doing and can seem pretty arrogant about it.
2- those who only think they know what they're doing and can seem pretty arrogant about it.

There's a big difference, but god help anyone trying to sort them out.

mrrabbit 

Careful there FBinNY...you are setting yourself up for "label" to be applied to you that has been applied to me in the past as well...

=8-)

FBinNY 

Sometimes it might seem (or even be) appropriate, but the devil is are we talking the first or second type?

cny-bikeman

I must have missed that one. I'm not an all-or-nothing guy - I use bubble levels also, was just curious why you specified that. You're points about digital are certainly well taken, but when using it for comparative purposes rather than counting on zero degrees to be exact there should be minimal concern, and certainly few people have a really good bubble level.

What one would check is not the dropouts but the wheel itself. If I sight along the side of the bike I find it is not hard to determine whether the wheel is "leaning" to one side (not parallel top to bottom) which would indicate dropouts at two different levels, or is not pointing parallel to the frame from front to back, which would generally indicate a rear triangle deviated to one side.

Absolutely correct. Any type of problem solving has multiple solutions and even multiple paths to that solution. However one always needs to start with the proper information about and understanding of the system involved. Frame alignment and drive train problems are just two areas where it is easy to overlook all of the factors that come into play.

FBinNY 

How's that possible? it keeps coming up when folks talk about pressure gauges, calipers, and lately wheel tension meters, and even chain wear gauges. Many years ago (when Wang Labs was a startup) my college buddies called me "an analog man in a digital age" and I guess it stuck. I still tend to prefer analog readouts for many applications - can't stand the digital speedometers in some cars - but I've no technical objection to digital stuff except for the assumption that digital means accurate.

I referred to a bubble level because most people are familiar with it and know what I'm talking about, but a level is a level so folks should use what they have.




I knew that's what you meant. I eyeball lots of stuff, and often spot badly aligned frames this way. But I don't know how sensitive eyeballing is. You can only use the top half of the rim, since there isn't a reference for the lower half, and the distance rim to seat tube varies on the arc which can introduce parallax error. Not saying it can't be done, just not sure. I also wear glasses and often curvature of field makes eyeballing this sort of stuff hard.

The key in making a decent diagnosis of anything subtle like frame alignment is to avoid snap judgments and/or tunnel vision. There are many factors involved, and it's important to keep an open mind and get a good overview before jumping in and possibly making things worse.

rothenfield1

I apologize for this rant. After all these years of posting, you’d think that I would have evolved a thicker skin. I must have been overly protective of the one and only wheelset that I have built. 36H Open Pro rims/ DT Swiss DB 14-15 spokes/brass nipples/Ultegra hubs. I built the front entirely myself reading Brandt, https://www.amazon.com/Bicycle-Wheel-...9105091&sr=8-1 and some references by Sheldon on tensioning. However, I only laced and tensioned the rear and I left the dishing to a bike mechanic friend.

The Mech Forum is an invaluable resource for me, and although this is my first bike build in well over a year and half, I know I will need your assistance again at some point in the future.

You have a keen eye Unterhausen; I also see, now, a slight bow outwards to the right seat stay. It seems correctable.

Thanks to all the repliers, it has been a very helpful read, as usual.

blamp28

It's all good. I hope that solve the issue. Nice bike! Let us know how it works out.

Chris Chicago

whatever happened to that operator guy?

FBinNY 

I've been wondering the same. Probably too busy since it's been so warm this winter, or maybe just ran out of vitriol.

mrrabbit 

Au contraire...I find him to be funny.

I love it when he decides to highlight everyone's FUD in a discussion with: "It's gonna explode causing you to run off a cliff and DIE!!!"

Maybe he's working on coming up with new lines...

Like myself, I think he prefers people to get straight to the point...saving the egg shells for another forum.

=8-)

FBinNY 

Non contraire. You read the words, but missed the sentiment hidden within. I guess I'm going to have to start using smiley faces. God, I hope not!!!

mrrabbit 

The smiley faces are free. Use 'em while you can before BF starts charging for 'em.

=8-)

rothenfield1

The frame builder was able to swing the rear triangle over to straightness. It’s all good.


Thanks again you Mech Heads.