Topic: cb550 F - front end seems crooked?

[koendd]

So,

I'm busy rebuilding a CB550 F. All parts came back from powder so I've started putting it back together and I've noticed something strange with the front end, it seems crooked?

Took the front apart again, dis assembled the fork legs, they are straight (thought 1 was bent but they line up perfectly).

looks like the lower triple is not symmetric, is this normal? Cause with the wheel straight, the steering wheel looks really out of line...











thought's?

[Bankerdanny]

Since the triple assembly is 2 pieces part of setting up the front end is getting the top and bottom tree properly aligned. Loosen the top tree bolts on the fork tubes and the big nut and pin nut on the stem and stand facing the bike with the front tire between your legs looking down on the triple. Use the bars to move the top triple until everything is lined up and then tighten the bolts.

It's a fairly straight forward process.

[scottly]

Since the triple assembly is 2 pieces part of setting up the front end is getting the top and bottom tree properly aligned. Loosen the top tree bolts on the fork tubes and the big nut and pin nut on the stem and stand facing the bike with the front tire between your legs looking down on the triple. Use the bars to move the top triple until everything is lined up and then tighten the bolts.

It's a fairly straight forward process.

The process is commonly referred to as "knee tweaking the forks".

[koendd]

I don't get it either how they can not be alligned when the holes match the tube it should be straight?
But I'll have a look at it..

(did some searching and does exactly like my problem...
http://forums.sohc4.net/index.php?topic=132248.0

so that should do it I guess 

Just doesn't look logic in my mind that that would be possible but hey, if it does the trick, I'm happy!

By the way Cal, bot forks were sitting flush in the top triple (one is rusted more then the other, probably why it looks that way from my excellent cell phone pictures )

Bearings are new, and fully seated, spanner nut locked down all the way.

[Pan1cReaper]

Because they are round, and that lets the trees twist ever so slightly. There are several pieces involved here and after 40 years of flexing and moving, they may not all be 100% perfect match. Loosen the top tree pinch bolts and twist, you will be suprised how much it moves.

[754]

That is a long ways out. I suspect bent tube.
How do you know they are straight?  What did you check with?
 They are actually to an extent self checking..
On bike,
Loosen clamps and axle, then turn fork tube in the trees, and watch for movement. Into or away from the wheel.  Check both sides.
Off bike,
 Pull leg assemblies, the lay on bench with fork tube against fork tube...as in lower legs to the outsides.
 Now leave one tube, and bring the other against it. Then turn 90 degrees, check turn 90 degrees..check.
Do that 4 places. Looking for air gap.. Then repeat with the other fork.

Try that and see what you find.

[Bailgang]

Since the triple assembly is 2 pieces part of setting up the front end is getting the top and bottom tree properly aligned. Loosen the top tree bolts on the fork tubes and the big nut and pin nut on the stem and stand facing the bike with the front tire between your legs looking down on the triple. Use the bars to move the top triple until everything is lined up and then tighten the bolts.

I'm sorry, I don't understand this? I see no possible way the top and bottom clamp can not be aligned when the tubes pass thru them, and the tubes are straight.

What I do "see" in the first picture, it appears the right fork is higher above the top clamp than the left. They need to be equal in length, and that will help with any perceived "canting" of the top clamp. What I can not see, is whether or not the steering bearings are installed and seated, whether the spanner nut is locked down properly. These things can cast the stem off center quite a bit.

I couldn't either and assumed the trees would self align until the same thing happened to my 550 when I first put it back together. Before disassembling the bike everything was straight and forks compressed and rebounded as they should but when I put it back together the handlebars were crooked and forks wouldn't compress at all once everything was tightened. I thought the forks were messed up so I pulled the forks off a 500 parts bike I had and of course they too worked just fine before I removed them but same thing happened when I put them on my 550. I ended up doing something very similar to what Bankerdanny described and that did it.

[Ace Blackwell]

Too bad you can't just hold the front tire between knees and yank the hell out of the handle bars like we used to on bicycles. LOL

[Pan1cReaper]

Too bad you can't just hold the front tire between knees and yank the hell out of the handle bars like we used to on bicycles. LOL

Thats exactly what I do!

[BomberMann650]

I had a lot of fun illustrating this process to the gal with the ninja250 project.

After she dropped the bike on the lawn the upper triple budged out of alignment.

So i loosened things up and starting shaking the wheel just for fun.  It looked like one of those air fan noodle dancer things at the auto mall.  Those forks and trees do turn into a couple of wet noodles when the clamps are loose.

[koendd]

Too bad you can't just hold the front tire between knees and yank the hell out of the handle bars like we used to on bicycles. LOL

Well actually that's what I did last night and it worked

@754: I disassembled the tubes from the lowers. Put them next to each other and "rolled" them. couldn't see any gap anywhere... Have dealt with messed up tubes before and you could clearly see which one was off with this method...

So problem solved for me, wheel is in center, so are the tripples and the handlebar. 

[Kenzo]

Too bad you can't just hold the front tire between knees and yank the hell out of the handle bars like we used to on bicycles. LOL

Well actually that's what I did last night and it worked

@754: I disassembled the tubes from the lowers. Put them next to each other and "rolled" them. couldn't see any gap anywhere... Have dealt with messed up tubes before and you could clearly see which one was off with this method...

So problem solved for me, wheel is in center, so are the tripples and the handlebar. 

The twist between the legs(or up against a tree) is exactly how we do it with modern dirt bikes. Especially racing enduros and hare scrambles where we're always banging off roots, rocks, etc... Typically the lower clamp has a significantly lower torque spec to allow self alignment in most cases.

Cheers,
Kenzo

[alacrity]

Too bad you can't just hold the front tire between knees and yank the hell out of the handle bars like we used to on bicycles. LOL

We do the same thing because these are just fat heavy bicycles with engines crammed in them.

Put the bike on the center stand.   Loosen (just enough so the trees don't start slipping downhill) all the upper and lower pinch bolts, and the axle nut AND YES even the 4 m8 pinch bolts at the very bottom of the fork leg.  If you wanna be even more thorough in your quest for straightness and no stiction, loosen the four main central fender stay bolts too. Now do that bicycle thing as described.  Center it as best you can. Walk away.  Look at it from further back - straight at the front and again straight at it from the rear.  Go back and tweak a little if needed.  When you at clmfoetable that it's straight and level, start tightening (to OEM specs per service manual) from the bottom up. Stop at each level and check again. Keep going to all are tight. The. Go back to the bottom and check torque on all again.  Take it Off the center stand and plunge the front end a few times to check action. 

[Duanob]

I had to knee jerk my 550 straight before. Loosen everything in the trees but not enough where the tube slides up. Once tweaked straight, hold it steady and have a friend tighten everything. I don't know what is about the 550 but it does happen.

Once he gets it straightened out, a fender brace would go a long ways in keeping it straight.

[koendd]

don't think a fork brace will work with these tires...
Will have to adapt the stock brace for the front fender..