Rear wheel alignment; string method - you're joking !

dansidi · Nova Slayer Joined: 24 Nov 2011 Karma :

Right.

I've been attempting to do the rear wheel alignment using the 'string along the length of the bike' method. It's impossible.

There are so many variables that can screw up the measurement that I'm convinced this method is useless. From the tread on the rear wheel being different on left and right sides forcing the string out one side more than the other, to the sting pressing against the centre stand or front disk, or any number of objects, to the front wheel needing to be excatly straight. The bike needs to be exactly level, the string perfectly straight without and kinks or twists. It just cannot work precisely enough to be worthwhile.

In fact, I'll bet (0.5p) than NOT A SINGLE ONE OF YOU on here reading this actually uses this method to align your rear wheel. I bet EVERYONE takes their bike to a shop to have this done. Yes, EVERYONE !!!

calm... calm.....

Also, I have one link on my chain which is utterly jammed solid. I can just about straighten it using a hammer but it will not loosen. Is it time for a new chain & sprocket set? None of the components seem worn out, just that one link.

Thanks for your advice.
____________________
current bike to first bike: SV650s K3, YBR125, Vespa GT125, Vespa ET4-125, Suzuki CS-50 (!!)
Mod 1 passed 02-11-2012
Mod 2 passed 05-12-2-12

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

DrDonnyBrago · World Chat Champion Joined: 03 Jan 2010 Karma :

I have used the string method before, was fiddly but worked ok. A straight edge such as scaffold pole or length of angle iron is simpler though.

You only need to do it once. I ground new notches onto the chain adjusters on both sides and use these when adjusting the chain and therefore the wheel alignment, measuring the distance between back of swingarm and notch with with a vernier caliper Laughing

(original markings are notoriously inaccurate).

Once the alignment is set you just need a way of keeping it the same on both sides when you adjust (i.e. new, accurate marker notches, count turns, count threads etc etc).

As for your stuck link, working them back and forth whilst covered in oil can help but only as a temporary measure, your chain is basically shagged and needs replacing.

anthony_r6 · World Chat Champion Joined: 31 Mar 2011 Karma :

I've just dropped my bike in for it's MOT yesterday. Only thing I couldn't do was the rear wheel alignment. It was far to fiddly for me and I couldn't be assed with the hassle, told the garage to do it for me.
____________________
Ted : "Maybe he's agoraphobic."
Dougal : "Jack scared of fighting? I don't think so, Ted."

Ericck · Scooby Slapper Joined: 21 Jul 2011 Karma :

Just made a right pigs ear of the chain adjustment on my bandit.

The adjuster plate was bent and after taking it off to straighten, couldn't remember what I done to the adjuster bolts so now fear wheel is misaligned.

Someone recommended the string method but it looks complicated,
think I'll just take my bike to a mechanic and know better next time.
____________________
Current Bike: 2004 Suzuki Bandit 600S
Previous Bikes: Yamaha FS1E, Mobylette Moped Thingy, Suzuki GS125, Kawasaki Zephyr 550, Kawasaki Zephyr 750, Kawasaki ER500, Suzuki Bandit 600, Honda CBR600F, Triumph Street Triple 675, Suzuki V Strom 650, Suzuki Bandit 1200, Suzuki SV650N, Honda CB500F.

Ichy · World Chat Champion Joined: 15 Jul 2005 Karma :

pits · World Chat Champion Joined: 22 Apr 2008 Karma :

My bike as little marks on the swing arm, align either side to both things, job done.....I hope?
____________________
Stinkwheel: You have no right to free speech
00:32:08 Blau Zedong: yes, i am a massive CB400 fan and collector
00:33:00 Blau Zedong: the CB400 is my favourite road bike

Bendy · Mrs Sensible Joined: 10 Jun 2002 Karma :

I've never checked (or asked anyone else to check) wheel alignment in my entire life.

Babba · Banned Joined: 05 Jan 2012 Karma :

Suntan Sid · World Chat Champion Joined: 07 May 2009 Karma :

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

I did it with string. I usually use it as a check when I think the alignment marks might be a bit off. I don't think I've ever soley used string, and I've only done it when I think the handling is a bit sus or when I've replaced the entire swinging arm on a bike.

I didn't have any problem with it TBH. I just made a piece of wood the same width as the rear wheel to help the front bit of the alignment.
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

dansidi · Nova Slayer Joined: 24 Nov 2011 Karma :

Rogerborg · nimbA Joined: 26 Oct 2010 Karma :

mysterious_rider · World Chat Champion Joined: 11 Sep 2010 Karma :

Just use something that is long and straight. A thick wooden ruler or something tends to do the trick for me.

Just slam in on the sprocket a few inches on (dont have it on the edge or it will throw the angle out) and just make sure it lines up with the front sprocket.

Sorted....

pits · World Chat Champion Joined: 22 Apr 2008 Karma :

Vincent · Banned Joined: 16 Oct 2006 Karma :

It's a fact that not all of the notches on factory adjusters are exactly true.............although they're never far off. I check mine with a metre rule from the centre of the swingarm pivot to the centre of the axle. It's worth measuring to check how close the adjuster notches are.
____________________
Space Is Deep

HD · World Chat Champion Joined: 16 Dec 2009 Karma :

I just whack them all the way forward then wind them evenly out. Can't be that far out and never had any adverse handling effects, its not exactly motogp is it Laughing

____________________
Rusty '02 Vito Camper + CBR600F3

dansidi · Nova Slayer Joined: 24 Nov 2011 Karma :

Well, here is how I did it in the end:

Vernier callipers to measure the distance between the very end of the swingarm and the inner surface of the chain adjuster.

As long as there is not too much crud built up on the inside surface of the chain adjuster I think it should work.

I took the bike out for a test and survived and it felt OK too so I guess doing the adjustment that way gives a reasonable approximation. Obviously doing the measurement so close to the axle is not ideal - being out by just 0.5mm could be crucial.

Many thanks for all the suggestions I will need to this this all again soon when I replace my gammy chain.

All this hassle because of one dodgy link in my chain.

Do they sell scaffolding poles on ebay...?
____________________
current bike to first bike: SV650s K3, YBR125, Vespa GT125, Vespa ET4-125, Suzuki CS-50 (!!)
Mod 1 passed 02-11-2012
Mod 2 passed 05-12-2-12

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

dansidi · Nova Slayer Joined: 24 Nov 2011 Karma :

Walloper · Super Spammer Joined: 24 Feb 2005 Karma :

String is easy enough.

The string has to come from the RH side wall of the back wheel from the rear Point 'A' past the RH sidewall of the back wheel at the front Point 'B'.

Then you 'project' the straight line that 'makes' along to the same area at the front wheel.

Move the end of the string away (towards the RH) from the front wheel. This should make the only part of the string touching the bike Point 'A' at the back.

Move the string toward the bike (towards the LH) and watch as the string touches the second point at point 'B'.

Measure the gap between the string and Point 'C' (back side wall of front wheel) and Point 'D' (front side wall of front wheel).

This is measurement 1 and 12

Go to the other side of the bike and do the same thing to get measurement 3 and 4.

If there is a difference when you subtract measurement 1 and 2 from measurement 3 and 4.

Or if you can't get your head around the geometry go to a bike shop.
____________________
W-ireless A-rtificial L-ifeform L-imited to O-bservation P-eacekeeping and E-fficient R-epair

dansidi · Nova Slayer Joined: 24 Nov 2011 Karma :

G · The Voice of Reason Joined: 02 Feb 2002 Karma :

I did once make a DIY laser alignment system, but otherwise used string when I've been bothered.
Also used string on the car, which also worked well enough.

Don't see why the bike needs to be level. Of course the front wheel needs to be straight, same when 'the garage does it'. I use kink-free string.

On the car, it certainly was useful. On the bike, I've never seen a big difference in handling even when the rear wheel is out a bit.

dansidi · Nova Slayer Joined: 24 Nov 2011 Karma :

Well, after a 10 mile commute this morning I am confident that either I got the wheel aligned exactly right using the vernier callipers or it doesn't make too much difference if the wheel is out by a little bit.

The only problem this morning was the freezing morning air and the thick frost on the roads. The back wheel skidded while I was leaning on a mini-roundabout. Nasty one.
____________________
current bike to first bike: SV650s K3, YBR125, Vespa GT125, Vespa ET4-125, Suzuki CS-50 (!!)
Mod 1 passed 02-11-2012
Mod 2 passed 05-12-2-12

neil. · World Chat Champion Joined: 24 Feb 2008 Karma :

Meanwhile in the real world - a bit of misalignment on a YBR won't really matter. I never ever had any issues with handling or weird tyre wear in all the time I owned a YBR - 3 years and just shy of 40'000 miles of riding it. Always used the swingarm markings, never failed an MOT. I did once make a mistake and offset one side by one notch longer than the other (would have been about 5mm). Noticed no effect on handling in the few hundred miles I rode with it like that. I'd imagine it would have to be REALLY out of alignment to make a noticeable difference on these bikes, and by that time I think you'd visually see that the wheel was pointing the wrong way.