Shaft drive trouble?

[Argee]

Fine Members of the GSResources Forum - yet again I ask for the benefit of your knowledge and wisdom!!

I have just had my 1982 GS 1100GL in for inspection (over here it's called an MoT....which is short for a Ministry of Transport inspection) and it did not fare as well as it has in the last couple of years where it sailed through.

There are a few minor issues which I should be able to sort out without problem, but there's one that is worrying me a little.

The report said that there appears to be an issue with the rear brake binding and causing too much drag on the rear wheel. It sounds like it should not be too much problem to sort that out, but seeing as I had to ride around 10 miles back home, I was surprised that the rear disk was not hot.

It has got me wondering if the issue might be a problem in the shaft drive.

Has anyone heard of such a problem? - or perhaps a solution?

As ever, all advice very gratefully received.

[almarconi]

Perhaps the inspector didn't know what he was talking about. I would ask him to show me the binding rear brake. If it is binding, make sure the wheel is not bent (out of round) or the rotor badly warped. Put the bike on the center stand, spin the wheel by hand and see if it binds. You could also remove the brake caliper and check the rotor to see if it warped. Not sure if there is a spec in the service manual for this.

[Big T]

Your brake issue has nothing to do with the shaft drive

You need to pull the rear caliper apart, clean it and replace the seal. If the piston is damaged, replace that also. Check the master cylinder also

Ever flushed the brake fluid?

It could probably use a new brake line as well

[Argee]

Hi Almarconi, Thanks for the reply. The rear wheel is a little tricky to rotate. I did think that removing the caliper would be the best way to tell if it was a brake issue or not, but I suspect it isn't...

[Argee]

Hi Big T, thanks for the reply. I overhauled the brakes when I got the bike in NH about 4 years ago. I thought that if the back brake was truly binding then dumping 10 miles worth of riding energy into it would have made the brake disc really hot - but it wasn't....
As Almarconi suggested, I will take the caliper off and then see how freely the wheel rotates to determine what is causing the drag.

[bwringer]

Baaaaaaaack up a minute -- the inspector may have been ignorant of the fact that GS shafties exhibit a certain amount of drag in the rear wheel. In other words, you can easily move the wheel by hand with the bike in neutral on the centerstand, but there's enough drag in the drive gears and seals that the wheel won't coast freely as with a chain drive bike. This drag is completely normal and healthy.

[tkent02]

What he said, if the brake was dragging AT ALL it would be HOT after ten miles.

Go to a different inspector who knows about older bikes.

[Guest]

You can also check it without pulling the caliper.

Start with the bike on the center stand. Try rotating the wheel to evaluate the effort involved. Use a screwdriver or pry bar to gently pry the pads away from the rotor. With them hanging loosely, try turning the wheel, see if the effort has changed.

Don't forget to use the pedal to 'set' the rear brake before riding again.

[Argee]

One serving of Humble Pie please!

I finally got the chance to have a look at my issue. Hats off to the Inspector and to Big T - it was the rear brake binding! (I think a lot simpler to fix than if it had been the shaft drive!)

I took off the caliper, removed the pads and extended the pistons so I could clean and exercise them. Fingers crossed - it seems to have done the trick.

Yet again, thank you all for all your advice

[londonboards]

When you are back on the road, take a trip to Canterbury or lets meet up half way somewhere and catch up.

See our Facebook page UK GS Owners Group in my signature below.

Good to see another 1100 so close to me.

I would concur on all of the above. The shafties back wheel is difficult the turn by hand - there is a lot of drag. And then if the MOT guy says the back brake was sticking, I would tend to believe that too even though your evidence of the disk not heating up contradicts this. The brake pads would actually need to be binding enough to cause you to feel some braking effect in order for the disk to start heating up - I suspect.

The words of the MOT inspector "causing too much drag" are the ones that lead us to suspect he was thinking drag = brake binding.

[Guest]

Sure am glad they're not THAT thorough here in the states, at least not where I live. I had just gotten mine running and ran it up to the inspection station. It started dripping gas and the guy still passed it.

[exdirtbiker]

I'm not convinced ( by your description of work done) that you fixed the problem.
when you say "clean and exercise them" I hope you mean " rebuild caliper with new seals, bleed out ALL old brake fluid, inspect /replace brake hose".
If you really just "took it apart, cleaned it, and put it together" I fear you will do it all over again in 6 months or less. Possibly on the side of the road.

[Argee]

Hi exdirtbiker - Unfortunately I didn't have the time to completely strip down the caliper. I will keep a good eye out for signs of future binding and prepare myself for some more in-depth servicing!

[exdirtbiker]

Great. Hope your pads never look like mine:

[habsdoc]

I think you really got your monies worth out of that set, but then again it did cost you a rotor too right???