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hobbs

Wheel Alignment

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hobbs
So, I adjusted my chain and lined up yhe marks on both sides of the swingarm.
 
The bike feels like it's constantly trying to wiggle or turn now, and the chain seems to be making a little more noise than usual.
 
My assumption is that the front and rear wheel aren't perfectly aligned, and the front and rear sprocket too maybe.
 
Anyone know any fix? tried the string method to get the wheels aligned, but that hasn't seemed to do much. I was by myself and it was a massive PITA I'll add.

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howlinhoss
While the marks are a good starting point I like taking it a step further and using an alignment tool from motion pro. It allows me to do a second visual check in addition to using the swing arm markers. Also, did you torque the rear axle bolt to the right setting?

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bmwpowere36m3
Does it happen to follow the crown on the road?
 
Wheel alignment would be a good place to start, either you do the string method, use long straight edges or lasers. Sometimes the factory marks are not accurate.
 
I would also check the front fork alignment. Forks at the same height in the triples, that they are not twisted (i.e., handlebar is straight when going straight) and they are not preloaded in/out on the front axle. There are various methods to achieve the above.
 
For fork height, I set them the same height at the upper triple clamp and then try to slide the front axle into the lower lugs, no wheel installed. The axle should slip in and rotate easily. If not, adjust one fork slightly up or down till you find the best position.
 
To check if their twisted, lay a piece of plate glass across the chrome stanchions. It should sit flat and when pressed in the corners, NOT "click". Search google: "BMW fork alignment y-axis".
 
Finally for fork preload on axle, install front wheel, torque axle nut and fork axle clamp bolt, but ONLY on nut side. Leave other clamp bolt loose. Spin front wheel and apply front brake hard, spin again, brake again.... do it a few times. Now without moving the fork or lowering the front end down, tighten the other axle clamp bolt (one left loose before).
 
Or it could all just be in your head... lol
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bmwpowere36m3
I'll also add that as miles accumulate... the steering stem bearings will wear in/set and loosen up a little. That'll lead to the steering becoming easier and requiring less force. Some MX guys like to tighten the bearings a little more to act as a pseudo steering damper and thus minimize the front wheel from flopping side to side.

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bmwpowere36m3
Is it always wanting to turn in one direction or lean? Or are you saying the front end just moves around, left/right following cracks, road surface, tar snakes, etc...

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hobbs
It feels like it's trying to turn a little more than usual. Inbetween road imperfections and wind, the bike always wandered a little bit, but it feels more pronounced now. I could hold a straight line pretty well before but now it seems to take a bit more focus and steering input to do so.
 
I found the flattest road I could. (Newly paved tarmac near new construction). At 60 mph if I center myself as best I can and let go of the bars, the bike tracks straight for about 3 or 4 seconds, then as speed drops it steers to the left pretty hard. Like enough to change lanes. Did that 3 or 4 times with the same result. The road could be crowned, it's hard to tell though.
 
It's hard to put my finger on it precisely, the bike just feels.. different. Maybe it's mileage? I'm at around 9.5k on the odometer.

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pattonme
when you let off the gas, there is a torque moment induced by engine braking which can cause the bike to lean one direction and having done so ever so slightly, cause the tire contact patch to shift, QED turn one way or the other. However it should be pretty mild input. I have NEVER used the swing-arm markings. A 12" steel rule slapped up against the sprocket is how I do it.

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hobbs
So you use the straight edge against the sprocket to get the chain aligned? Which I assume in turn aligns the wheel.
 
I will have to try that. Was considering the motion pro tool or a laser variant, but the laser is sort of costly.
 

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steviede
I've always counted the turns it took to undo the adjusters on my sled which is the same idea as a bike tire and that gets you pretty close when you tighten them back up, then you can fine tune with a ruler like Pattonme said

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hobbs
Looks like I'm getting new tires mounted tomorrow, so crises avoided. I did order the motion pro tool for future use.
 
Thanks for everyone's insight.

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cndnmax
I had the motion pro tool but returned it. I go a laser alignment tool that works great with no room for error.

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hobbs
I had the motion pro tool but returned it. I go a laser alignment tool that works great with no room for error.
 
 
Didn't like it, or just not precise enough? I considered the laser option, but it was around $70.
 
I know motorcycles existed well before lasers, so I went with the old tech for cost reasons.

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bmwpowere36m3
I had the motion pro tool but returned it. I go a laser alignment tool that works great with no room for error.
Didn't like it, or just not precise enough? I considered the laser option, but it was around $70.
 
I know motorcycles existed well before lasers, so I went with the old tech for cost reasons.
That's it… I thought they were a couple hundred.  I've done the string method before and its seriously time consuming… for $70 I think I'd go laser.  Got a link?

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cndnmax
You have to look directly above or behind the aligning rod to get an accurate alignment. With the laser I just place it on the sprocket rotate up and down slowly, there's not guesswork. With a little creativity you could easily use the laser tool to align with the front wheel as well.

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so1102
Didn't like it, or just not precise enough? I considered the laser option, but it was around $70.  
I know motorcycles existed well before lasers, so I went with the old tech for cost reasons.
That's it… I thought they were a couple hundred.  I've done the string method before and its seriously time consuming… for $70 I think I'd go laser.  Got a link?
Here's one:  http://www.amazon.com/Profi-Products-Laser-Chain-Alignment/dp/B003110118

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bmwpowere36m3
That's it… I thought they were a couple hundred.  I've done the string method before and its seriously time consuming… for $70 I think I'd go laser.  Got a link?
Here's one:  http://www.amazon.com/Profi-Products-Laser-Chain-Alignment/dp/B003110118
 
 
I was interested in laser wheel, not chain alignment. Your chain might be aligned, but that doesn't guarantee the wheels will be. If both are, great and they should be. However, which is more important?

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sorkyah
Looks like I'm getting new tires mounted tomorrow, so crises avoided. I did order the motion pro tool for future use. 
Thanks for everyone's insight.
I was having a similar pull issue. It wasnt as bad as yours but mine did have a vibration aspect to it. Tech at the dealership took me back with him and showed me the chain was inline(used a straight edge off the front and rear sprockets). Then he checked the balance of both tires. Neither were out of balance according to the machine. Needed a new rear tire anyway so new tires were put on today and seemed to have helped, despite the wallet hit. Ill know more once i put more miles on em over the next week.

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hobbs
Rad... what tires did you go with, or just the original offerings?

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sorkyah
Rad... what tires did you go with, or just the original offerings?
Ended up with the road 4 gt's Didnt need em, but they gave em to me because they couldnt find the regular pr4 set they had in stock
 

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mjh937
Rad... what tires did you go with, or just the original offerings?
Ended up with the road 4 gt's Didnt need em, but they gave em to me because they couldnt find the regular pr4 set they had in stock

 
 
I thought the gt's are made for heavy motorcycles. If that is correct would that be a good idea for our light bikes?

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so1102
Ended up with the road 4 gt's Didnt need em, but they gave em to me because they couldnt find the regular pr4 set they had in stock

I thought the gt's are made for heavy motorcycles. If that is correct would that be a good idea for our light bikes?
They are.  Not sure what effect a stiffer tire would have on our bikes, but someone's gotta be the guinea pig, right?  :) 
(I call "not it")
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rick
I thought the gt's are made for heavy motorcycles. If that is correct would that be a good idea for our light bikes?
They are.  Not sure what effect a stiffer tire would have on our bikes, but someone's gotta be the guinea pig, right?  :) 
(I call "not it")
stiff sidewalls = harsher ride. If the suspension was good enough to soak up the bumps and bruises that are our roads, it might not matter much.  
Given that choice, I'd have said no for my Futura. It's 130 lbs heavier with decent suspension bits and wears the same size shoes. 
 
 
 

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sorkyah
I thought the gt's are made for heavy motorcycles. If that is correct would that be a good idea for our light bikes?
They are.  Not sure what effect a stiffer tire would have on our bikes, but someone's gotta be the guinea pig, right?  :) 
(I call "not it")
Ill be the guinea pig, im 250 plus my gear so somwhere in the vicinity of 275-80 added to the bike weight. It doesnt seem too bad so far

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hobbs
They did say good for sport touring 2 up, do they're probably fine. Might last longer if anything.
 
Had a new PR3 put on the rear this morning. Decided to keep the front a while longer.

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bmwpowere36m3
Since owning the bike, I've gone over various things for my own knowledge and to double check the dealer/factory assembly. While checking the chain slack, I looked at the wheel alignment. From the factory, the axle blocks were pretty spot on to the alignment marks on the swingarm... however the shape of the axle block makes it difficult/error prone when performing the alignment. I looked down the chain and it seemed pretty straight, but the rib on the upper swingarm chain slider was skewing the chain slightly as it passed over the swingarm.
I proceeded to check the wheel alignment via the "string method" using mason's string (brightly color poly-line ~1/16" thick). Wrapped the string around the back of the rear wheel/tire, pulled it forward past the front wheel and set the strings so they barely touch the front edge of the rear tire. My measurements were the same on each side of the front wheel, but differed side-to-side by ~11 mm, i.e., the left side read 29 mm (front/rear edge of front tire) and the right 40 mm.
 
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That either meant the rear wheel was not aligned or could be offset from the front by X mm (Harley does it to clear wide tires and/or belt drives). Half the difference would be offset, so 11 mm / 2 = 5.5 mm (not a crazy amount of offset, if in fact it is offset). I looked through the service manual and found nothing as far as offset, chassis geometry, etc... that would give me an answer.
 
I revisited the chain alignment, took off the chain and front sprocket guards and used:
[ul type=disc][*]12" machinist rule against chain's inner side plates[*]Ran a string from top of chain at front sprocket to rear[*]Motion Pro chain alignment tool[/ul]
All the methods indicated the chain and/or sprocket were pretty well aligned, not perfect (but there is inherent error).  The motion pro tool would be better if it had a longer rod.  Again the chain being skewed around the swingarm slider makes it difficult to judge.
So I went back to the string method and got the front wheel aligned within 0.5-1 mm via the measurements at the front wheel.  I found that 1 turn of the adjuster nut equaled ~10 mm change in the side-to-side measurements of the front wheel.  Now the axle blocks are off by ~ 1/2 an alignment mark on the swingarm.  I threw the Motion Pro chain tool one last time and it still looked good.  So I think I'm good :P
I should note, that even with the rear tire being "off" I never noticed any handling issues.  Even letting go of the handlebars while riding would usually keep the bike going straight... sometimes a little left or right (but you factor in road crown, wind, weight distribution, etc....).
 
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