Rear wheel and preload question

[ralphy]

A couple of questions for the knowledgable here. ;-)

1) Taken the real wheel off and found this:

So I’ll clean the rust off and apply copper-slip before reassembly, but why is the central hole in the wheel there? Given it allows water, etc to get into the void on the final drive should there be some bung, seal or something else to stop this happening?

2) Probably me being thick, but how does the rear pre-load actually work on my bike (R1150R)???

I can see it’s a collar arrangement and that presumably allows an increase in pressure from the oil reservoir to push down on the spring, is that correct? Mine doesn’t seem to have much effect on the bike, i.e. raise or lower the height when off the stand and also there doesn’t seem to be much stiffness until I’ve wound down the adjuster until it’s nearly at the bottom of it’s range. Does that mean it needs some more oil adding to it and if so, how do I do that?

Thanks in advance.

R

 

[Flipfly]

Reference the preload. You may have to work with it as the collar can seize.

First thing is to remove the adjuster and fill with oil (I've used engine oil in the past, it doesn't really matter. Make sure it's on min when you do this, reattach and then wind it on. If the collar doesn't move then it's seized and will require copious amounts of oil soaked into it to loosen it up. The collar should move down about 20mm iirc

Make sure that the adjuster is clicking because sometimes the plastic knob can round out meaning it just turns and doesn't actually turn the adjuster.

Hope this helps.

 

[Comfy Old Boots]

And don't loose the ball bearing if you take off the plastic handle. Damhik.

 

[Comfy Old Boots]

Re the hole... Weight saving on an already heavy bike? Less metal less cost?

 

[casper]

And dont copaslip the bolts.

 

[ralphy]

Reference the preload. You may have to work with it as the collar can seize.

First thing is to remove the adjuster and fill with oil (I've used engine oil in the past, it doesn't really matter. Make sure it's on min when you do this, reattach and then wind it on. If the collar doesn't move then it's seized and will require copious amounts of oil soaked into it to loosen it up. The collar should move down about 20mm iirc

Make sure that the adjuster is clicking because sometimes the plastic knob can round out meaning it just turns and doesn't actually turn the adjuster.

Hope this helps.

Yes it has. I’ve stripped it down and the collar was semi-seized, but got it moving fine now. Also there was very little oil in there, so I need to re-fill it - but how did you do yours: I can’t see a way of bleeding the air out??

And don't loose the ball bearing if you take off the plastic handle. Damhik.

I took care and retained it, but I can see how you knew. ;-)

Re the hole... Weight saving on an already heavy bike? Less metal less cost?

I’m assuming your comment means there is nothing that’s supposed to block access to the FD? If so, ISTM that it’s a bloody stupid design to allow crap to build up inside the ‘cup’ on the FD

And dont copaslip the bolts.

I won’t.


As an aside, I think it’s quite a marvel that the entire weight of the rear of the bike is relying on a tiny wire circlip to support it:

R

 

[Welshman]

To fill it, just filled the resevoir bolted it all together and cycled it a couple of times with the shock as the low point, then unbolted and refilled the resevoir.
One problem on the GS, is that the spring rubs on the sealing faces on the adjuster and over time the seal fails, we had a supplier here who hard chromed it and reground it again.

 

[Keith Chapman]

Here are simple instructions to refill your preload reservoir. It is not a GS but they are all the same. Click here

 

[ralphy]

Here are simple instructions to refill your preload reservoir. It is not a GS but they are all the same. Click here

Bugger.

Just followed that and upon reassembly the oil started leaking out from the collar, further inspection shows the o-ring is not sealing anymore. :-( (I guess that was the cause of the problem initially). I’ll try to source a replacement for that and the other two o-rings as well.

R

 

[ralphy]

O-rings arrived, fitted and assembly er, reassembled, filled with 10-50 and the resistance to adjustment was immediately noticeable.

Hyperpro fitted and the shock refitted to the bike. Now, after 4 turns I can feel the resistance starting and on full preload it’s moved about 10mm, so am well pleased with that.

R

 

[Slipperyeel]

Well done! A useful post, especially with the pictures. I hope to reach much the same point within the next couple of weeks.

 

[(RIP) Bin Ridin]

Must check this on my 1150.....

 

[ralphy]

Must check this on my 1150.....

It’s not so easy to see with the rear wheel in place, but possible with the aid of a torch. On top of the spring is the black collar and you should see this push away from the alloy of the cylinder by about 10mm from off to full pre-load adjustment.

HTH.

R

 

[Comfy Old Boots]

It’s not so easy to see with the rear wheel in place, but possible with the aid of a torch. On top of the spring is the black collar and you should see this push away from the alloy of the cylinder by about 10mm from off to full pre-load adjustment.

HTH.

R

Thanks. Job for tomorrow.

 

[Bendy toy]

It's easy to see how a small hydraulic pump could quickly raise & lower the bike. Ride height change on the fly No more leg length issues for those of us not blessed with German height

 

[Comfy Old Boots]

Here are simple instructions to refill your preload reservoir. It is not a GS but they are all the same. Click here

That made such a difference to my bike. I was missing half the oil!