Any ideas on making an axle alignment tool?

[ScottRNelson]

any particular reason why you don't trust the alignment marks?

I don't trust the alignment marks when I see the axle plate shift by up to a millimeter when I tighten the bolts.  It's one of the worst I've ever seen.  The typical motocross bike is much more accurate and easy to get aligned properly.  And my XR650L has snail adjusters where all you need to do is get both sides clicked into the same setting and you're good.

I normally use a tape measure and occasionally the string method when lining things up on my bike.  Although I've found that I can just eyeball it and get about the same accuracy.

I want my front and rear tires aligned with each other, I don't care about the sprockets if the tires aren't aligned properly.  But you can always shim the sprockets if they're not lined up when the wheels ARE in line.  It seems kind of stupid to me to ride a bike where the sprockets are aligned but the wheels aren't.  Surely you'll get strange handling that way.  At a minimum left turns and right turns won't behave the same.

[Spidey]

any particular reason why you don't trust the alignment marks?

They're notoriously innaccurate.  Line 'em up sometime and then use a tape measure or some other device.  The alignment will be off.

I get a better alignment by looking down chain and over the rear sprocket and eyeballing it than by using the marks. In fact, eyeballing it is my method of choice.  That said, sometimes I'll use a piece of bar stock against the rear sprocket, but most of the time, I just eyeball.  Works fine for my monster and has worked just as well with my race bikes. 

[Howie]

<snip>

Howie, are some swingarms offset to one side?  I could swear that from behind some bikes one side of the swingarm seems to sit farther out than the other.  I guess this is to accomodate chains and sprockets, etc. but it's the reason I don't measure from axle to swingarm pivot.  If one side is further out than the other then the measurements would not be the same.

Scott

Good question.  In theory or reality?  Since manufacturing tolerances are less than perfect either or both can be off, aligning the sprockets or the wheels or splitting the difference is your choice.  Most shops will just use the marks on the swing arm and call it a day. 

[scott_araujo]

Not talking theory here, or a few mm in manufacturing tolerance.  I mean looking at the rear and seeing that one side of the swingarm is out from it's pivot notably more than the other on purpose.  Maybe the pivot on the drive side is more inboard to make room for the chain.  Maybe the tail end is outboard more on one side to fit the brake.  Gotta go down to the local shop and look at the tail end of some bikes.  Maybe I'm misremembering.

And part of the reason I try to do all my own maintenance is because of the practices of 'most shops'. 

Scott

[Howie]

Not talking theory here, or a few mm in manufacturing tolerance.  I mean looking at the rear and seeing that one side of the swingarm is out from it's pivot notably more than the other on purpose.  Maybe the pivot on the drive side is more inboard to make room for the chain.  Maybe the tail end is outboard more on one side to fit the brake.  Gotta go down to the local shop and look at the tail end of some bikes.  Maybe I'm misremembering.

And part of the reason I try to do all my own maintenance is because of the practices of 'most shops'. 

Scott

BMW does that on purpose on some models, other manufactures may also.  I thought you were talking about our Monsters. 

[scott_araujo]

Original question was Monsters, but I was speaking in general terms.

Scott

[monsta]

I can post pics if ya want, but its late here and I cant be bothered...  

ok, heres a pic.  I guess insted of square key steel you could use something round, so's that you dont have to file the hole square that the bolts slide up and down on...  

[darthmoto]

Thats really cool! It looks like for the points I could use dies from a pipe flaring tool...have no idea where to source those parts tho. And perhaps instead of using bolts I can use 2 piece threaded rods attached with long couplers to change the length..

ideas churning..... thanks!

[DarkStaR]

Plus those steel alignment plates are not an exact fit and twist in opposite directions when you tighten the axle.

Howie, are some swingarms offset to one side?  I could swear that from behind some bikes one side of the swingarm seems to sit farther out than the other.  I guess this is to accomodate chains and sprockets, etc. but it's the reason I don't measure from axle to swingarm pivot.  If one side is further out than the other then the measurements would not be the same.

Scott

I was thinking the same thing a while back.  The DSS swingers are off set on the sprocket side.

I still use the measuring tape method, and it's been working fine so far on the DSS bikes I've worked on.

This is one reason I'll be sticking with SSS bikes for a while...

[dlearl476]

I've always used an aluminum yardstick.  With the straight edge against the tire, it's readily apparent if the wheel and the chain don't line up over the span of 3 feet.

[Doctor Woodrow]

You could just buy a set of Trammels from home depot for just under $30, and slap them on a board. Align them on one side by moving them clsoer together and farther apart, and then just move the arrangment to the other side, and adjust until both sides match up. Thats what I would do, that super expensive tool just lloks like a board with sliding trammels on it to me.

The Doc