How much resistance should rear tire have to rotate?

[shortlid]

If I have my '80 GS850G up on the center stand and in (N) and I turn the rear wheel it moves OK kind of like a rear wheel of a car if it off teh ground. But I can't get it to spin a inch if I get it going by hand and let go of it. It stops dead, is something wrong with the rear end, final drive or rear brakes? Should it have this much drag? I know bikes with chains don't. Looking for a reason why I am only get 131 miles to a tank of gas!!

[gspaul]

The brake's allway's drag a bit on these bike's, but your's may be a little to much.
No harm in a strip and clean ,easy to do.
Yes the shaft has a bit of drag, that's what you pay for the joy of no chain!
As for the gas consumption, that I can't say , depend's on which model 850
(tank's not the same size!)

[shortlid]

'80 GS850"G" Gas tank.

I belive I have a 5.6 gal tank on my stock 1980 GS850G. Only geting 131 miles to a tank ges me 23 MPG!! My TURBO, 300hp 2 ton SAAB 9000 Aero gets 29-32 MPG!!! :twisted:

[shortlid]

Heat?

I guess if I rode it on the highway and did not use the rear brake to stop then felt the rear rim I would know if it was draging to much correct??

[IanFrancisco]

I guess if I rode it on the highway and did not use the rear brake to stop then felt the rear rim I would know if it was draging to much correct??

How would that work? I think a 500lb. bike would be able to overcome the drag of the shaft drive. One way to tell if its the brakes or not is to just back off on the adjuster till they're way too loose and see if there's a change...

[shortlid]

Adjuster??

Where is the adjuster on the rear disc of a '80 GS850G???

[IanFrancisco]

Sorry, I was thinking you were running a rear drum brake. If it's a rear disc then yank the pads out and see if that reduces drag. I had lots of drag from the front disc, took a while to work the caliper and master cylinder enough to get them to release properly. Calipers that don't let go decrease fuel economy and wear out pads in a hurry, as in 3000 miles from new to metal to metal on my first set of pads.

[shortlid]

Is that a "sticking"point on these bikes

Is it common for the calipers on a GS to not release all the way or "stick"? What is the fix, other than making sure the flot on teh slide pins correctly?

[IanFrancisco]

Any caliper that sits unused for a long time can get sticky. The pins need to be cleaned and greased so the caliper will truly "float" and the piston needs to be able to move back and forth freely, which on my bike is the problem. When changing pads I have to loosen the banjo bolt, let the fluid out then tap the piston in with a large socket in it to protect it. Other guys say the piston should be able to be pushed in with your fingers. No way could I do that. I'm looking for a caliper rebuild kit which includes a piston and the rubber boots and o-rings.

[Jethro]

The floating calipers are designed to rub the rotor a little bit, that's how they stay self centered. But it shouldn't feel like it's sticking at all. The wheel should spin just as well, only you'll hear the pads hitting the rotor.

When I rebuilt my calipers I put in new seals on the side pins. I think those made a difference. Also be sure there is no grit at all on those pins, and lots of moly.

[shortlid]

OK, I will look?

Thanks Jethro I will look at the pins and the floating ACTION of the rear caliper before I hop on to ride it home after work in a bit. Maybe you can help me take a better look at it tommorow in Maine?

[Jackrp]

Re: How much resistance should rear tire have to rotate?

If I have my '80 GS850G up on the center stand and in (N) and I turn the rear wheel it moves OK kind of like a rear wheel of a car if it off teh ground. But I can't get it to spin a inch if I get it going by hand and let go of it. It stops dead, is something wrong with the rear end, final drive or rear brakes? Should it have this much drag? I know bikes with chains don't. Looking for a reason why I am only get 131 miles to a tank of gas!!

Had the same problem on mine, the rear disk caliper needed to pulled apart and cleaned, reassembled, new fluid and bled, my rear wheel now spins very easily,Rear caliper (rebuild) cleaning is very easy, just follow your handy dandy maint manual.

[fastpakr]

How much fuel are you actually putting in when you fill up? The size of the tank has absolutely nothing to do with determining fuel mileage.

[shortlid]

OK got some opinions from Zook and Jethro on Maine ride.

OK, guys checked the temp of the rear caliper along the way to the Maine ride NEVER got very hot, but zook said his old "Eric the Half a Bike" was a shafty and was not as stiff as my rear wheel to turn. Looks like in this schematic: http://houseofmotorcycles.bikebandit...me~GS850GT.asp

The caliper it self is FIXED in place only the pads MOVE on the pins? Also you can just PULL the dust cover off to see how the rear pads are doing corrct? I am guess I will have to replace rear rotor (warped anyways have $5 Ebay part). Lube and replace seals (WHER are these does not look like they have any seals?) on slide pins or rear caliper, bleed system, replace rear pads. Might as well swap in the H-D shocks while I am at it, need to press out old shock bushings into after market H-D shocks. Jethro you have the part # for the rear caliper pin slide seal kits?

[sailor20034]

GS550E with similar problem

I replaced the rear disc pads some time ago. After a long ride with friends, I wanted to lube the chain while it was warm and found that the wheel wouldn't rotate freely - if my hand wasn't spinning it, it would come to a stop more quickly than I thought was right. And when I checked my mileage, I was shocked to find that it was only 34 mpg....and that from steady highway riding at 65 with only moderate winds. I'm going to check the brake drag first.