Topic: Is my frame bent? Is my method flawed? Lot of pictures!!

[albertaboy]

Alberta - look at pic 3 you posted: did you by chance hold a second level at 90 to the one laying across the top? I'd be curious with the plumb bob, steering and center of frame all "lined" up, whether the frame is racked vertically?

From the picture (#3) it looks like the rear fender/seat brace is off center. May simply be the angle of the photo, but use that setup and measure the center AT&T he rear, line up as you have the steering head, then measure vertically for 90. Just confirm its a photo anomaly and not that the rear seat hoop area is racked over.

No, I did not hold a level at 90.  I could mock it up again easily. Might go back out tonight anyways.
Picture 3 is just the angle.
I've a second frame almost stripped bare except for the wiring and I've spent at lot of time comparing the two without being able to spot a problem. But the naked eye is so deceiving.  I'm going to put in tapered bearing races into the steering tube, mount a triple, forks and wheels, put a swingarm in mount a  rear wheel and do some of the checks suggested here.  I likely dont have a grasp where to begin checking once I do this so I'll come back with more questions and photos and get your guidance.

Thanks everyone so far. Your input and suggestions were greatly appreciated.  Stay tuned for follow up on this later.

[Kickstart]

I don't have any experience with this... but I'll throw in my two cents

I think you need to find out exactly what the test procedure was that the shops did. What specifically did they measure? 

Also:
Did they do these measurements on the bare frame... without the swingarm installed?  I believe the frame sometimes gets pulled in a little when the engine and swingarm are bolted in... so if one side "springs" out some more than the other I could see how this might cause an out of alignment measurement on the bare frame.

[albertaboy]

I don't have any experience with this... but I'll throw in my two cents

I think you need to find out exactly what the test procedure was that the shops did. What specifically did they measure? 

Also:
Did they do these measurements on the bare frame... without the swingarm installed?  I believe the frame sometimes gets pulled in a little when the engine and swingarm are bolted in... so if one side "springs" out some more than the other I could see how this might cause an out of alignment measurement on the bare frame.

Hey
Thanks.  I'm kinda starting over now, trying to see if this frame is bent or not. Back in 2010 when I took the bike in for the OOP test, it was a complete running bike.  I since have stripped all the parts off of it onto a second frame and got riding. Now I want to make sure this frame isn't useable before I cut it up or otherwise. 

[albertaboy]

This is where I got to tonight.  Same wheels, same swing arm, same triple and top clamps except upgraded to tapered roller bearing, same axles, same wheel spacers, new cycle x fork uppers, same fork lowers. Shouldnt matter about the upper fork tubes as they checked out straight.  Am too tired to go on now and much more reading to do to check it's alignment.  I need to double check I tighten properly here and there.  Will it matter there's no engine???

[albertaboy]

Is this how it's done?? what do you guys thinK?  This is a 2:41 you tube vid on checking alignment.
MOT: Prepare & Pass - Wheel alignment

[Ewan 500K1]

dunnoa about all that messing with string carry on ..... flourescent light tubes do it for me as a straight edges for wheel alignment checks

[calj737]

Alberta - the video is a perfect example of how to do it at home. If you did follow this method, what results did YOU have?

Did you ever determine from either bike shop, "how" your 3/4" appeared? Was it an alignment front/back or vertical racking, etc?

[754]

Btw all levels are self checking, turn them 90 degrees to check if you set up off motor mounts or swingarm pivot use a straight rod .. You can see if your swingarm has any twist, easily with that method.

[albertaboy]

Alberta - the video is a perfect example of how to do it at home. If you did follow this method, what results did YOU have?

Did you ever determine from either bike shop, "how" your 3/4" appeared? Was it an alignment front/back or vertical racking, etc?

I'm going to try the string test if I can get time later today.
 
I did not ask enough questions at the time. It would be different today with as much wrenching, reading and interest I have today. To my disadvantage, I'm going on misunderstanding the problem and my faded memory of what I was told.   I recall shop 1, questioned the swingarm bushing and wheel spacing, but he seemed focused on the front end. He told me to go home and "just stand back and look you can see it".    But that was just that I couldn't see it so I found shop 2.  Shop 2 after much denial, eventually agreed with shop 1. and shop 2 wanted to start with the front end.  A little bit of hot headed frustration, I took the bike home and dismantled it.  I might be asking the impossible from you guys. 

If I could restart this thread maybe the better question would be:
I'm in a position of taking an untitled frame , that If I build a bike on, I risk failing an inspection.  How to I check that this frame is suitable with a reasonable amount of certainty??  Seems like the string or fluorescent tube idea, also suggested, is my best??

[albertaboy]

Btw all levels are self checking, turn them 90 degrees to check if you set up off motor mounts or swingarm pivot use a straight rod .. You can see if your swingarm has any twist, easily with that method.

Frank,
I have never looked the swingarm too closely. I'll do that too.

[754]

The pic in #28;
 Get two lighttubes..fluorescent type put one against rear wheel vertical, hold with maybe a bungey cord,
 Now block front wheel so it looks straight to frame. From behind
 NOW, FASTEN a second lighttube. Vertical to front wheel.
 THEN stand back ...have a look..and what do you see..when eyeballing the two tubes against each other

 Should take 20 minutes, nothing to do with wheel allignment, but will tell you if frame is straight..

[lucky]

Is this how it's done?? what do you guys thinK?  This is a 2:41 you tube vid on checking alignment.
MOT: Prepare & Pass - Wheel alignment

The film is ok for the back wheel as far as measuring from the swing arm pivot center to the center of the rear axle.

On the FRONT you must measure the gap at the front and rear of each side of the front tire..
IF the steering head is straight just make sure the tire is the same distance from the tire to the inside of the front forks. Use inside deviders.

[lucky]

You cannot measure the frame as shown in this photo.
That is why you must have the fixture with the cones,
That way the steering head is vertical measured by the CENTER of the axis of the steering head pivot.
Not by sheet metal stampings that were welded to the steering head neck.

[lucky]

While i am certain your response is technically correct, it's not relevant to "his" situation. We have seen the pictures of his frame, and it certainly does not have a removable cage. So, any ideas on "this" frame where the 3/4 could be IF the frame doesn't visually  show damage to it?

Everything I said IS relevent to the OP about measuring his frame.

[lucky]

You are on the right track .


Just use this modified photo and you can find out what you need to know.

Just make sure the swing arm pivot tube is the same distance from the ground on both sides AND LEVEL. Then if the front forks are level by putting a level on the side of them,  it means the steering head is NOT twisted.

On the rear swing arm if the center of the axles are the same distance from the ground and the bike is level (swing arm pivot tube being level allready) ,it means the swing arm is NOT twisted.


You are done!

Click on this photo for a larger version.

[heffay]

LOL lucky... you know there's a text option in your editor, right?   

[Kickstart]

Lucky,

What's the best way to make sure the swing arm pivot tube is level?
I assume you can't just put a level on top of it, or can you?

Thanks,
Chris

[albertaboy]

Lucky,

What's the best way to make sure the swing arm pivot tube is level?
I assume you can't just put a level on top of it, or can you?

Thanks,
Chris

Lucky, Thanks very much. I'll run these checks and yes, as Chris asks, how do you.  I dont want to assume at this point.

[calj737]

Measure each end of the pivot bolt to the floor. Double check with a level set up below it that the level itself is "leveled".

Alberta - if you're feeling ambitious, measure from outside left edge of rear tire to outside right edge of front tire. Then do opposite side. Each side should be equal (measure the hypotenuse of 2 rectangles). Nothing like math to verify anything.

[Kickstart]

Measure each end of the pivot bolt to the floor. Double check with a level set up below it that the level itself is "leveled".

So mark a dot in the center of the bolt and measure from that? 

I guess you'd place a level on the floor (and level the level), then measure from the center of the swing arm bolt down to the level - making sure to shim under the center stand until the measurements were equal.... then measure the rear axle.  I suspect you also have to make sure your floor is level (or move your level to the back of the bike when you measure the rear axle.)

Alberta - if you're feeling ambitious, measure from outside left edge of rear tire to outside right edge of front tire. Then do opposite side. Each side should be equal (measure the hypotenuse of 2 rectangles). Nothing like math to verify anything.

Not sure if that will work based on Hondaman's description of the front wheel hub offset. (or maybe you would just measure one side 4mm off the tire?)

[brooze72]

If you are using the measuring from each side of the axel centre to the floor method, you have to make sure the neck is perpendicular to the floor.  I wouldn't use the centre stand

[754]

Floor may not be level, pull swingarm check shaft for level.

[Aurelia B20]

During the 70's in France, a company named Ydral sold a kit for controlling a frame, example with a 500 Four frame :




After mounting the kit you had to control if the two bars were perfectly parallel. Cheap and easy 

[calj737]

I've never seen a post where so many people had good and different techniques for establishing square. It's neat to see.

If the OP can't get this straight ended out (pun intended) we may have to all board an RV and go up and show up. That would be really I nteresting for me to meet many of you...

Cheers all!

PS Aurelia - will this approach still work if I don't read French? ;-)

[albertaboy]

Lol.  Thanks everyone who stickin this out with me. That's great!!. I had an unexpected guest for two nights. We had a 12 inch dump of snow and they were stranded here.

I got out this am and did the string test.  First 4 shots of each wheel both sides just for reference of the spacing. If you see anything wrong??