Locating the rear wheel

[storm 64]

Well heck Allie, I'm not sure what you have going on. In my situation, I was mounting a spoked 750 hub on my 1000. I had to space the brake rotor out .200 Maybe you have a inner spacer problem, I don't know. I'm sure Steve or someone more knowledgeable than me will come along. Good luck👍

[Allie]

With any luck I'm doing something really simple wrong. That would be a lot easier to correct than magic grits. I may have to take some pics and measurements. It's the same setup as the 1000 though, the parts diagrams are eye-dentical.

[sharpy]

Have you put this one back in the LHS? It sits between those paddle thingys slip right into the rubber damper doohicky. Other wise if ure reinstalling same wheel isnt much difference. But i had someone have the brake bracket reversed somehow on one problem.

Gs Spacer.jpg

[Allie]

Have you put this one back in the LHS? It sits between those paddle thingys slip right into the rubber damper doohicky. Other wise if ure reinstalling same wheel isnt much difference. But i had someone have the brake bracket reversed somehow on one problem.

[ATTACH=CONFIG]56442[/ATTACH]

If that's the one with the taper facing in then yes I left that on the shaft the whole time (between the paddle thingys). Maybe something will occur to me after I sleep on it. I work tomorrow morning but I think I'm going to pull the wheel off and take a 'sploded pic of everything.

It seems so simple. The rotor position on the hub remains constant. The spacer width between the rh bearing and the brake carrier is a constant. The caliper position in relation to the rotor is determined wholly by the relative position of the carrier which is determined as far as I can see entirely by the width of that top hat spacer. The only thing that could possibly be variable is the bearing position in the hub... Is there any way they could have messed that up at the shop? Pushing it into the hub too far would decrease the distance between the carrier and the rotor but I would not think it possible to do that to the bearing. Am I mistaken in my assumption that the rotor should ride more or less in the middle of the access window for the pads when the caliper is properly mounted?

[GregT]

The only thing that could possibly be variable is the bearing position in the hub... Is there any way they could have messed that up at the shop? Pushing it into the hub too far would decrease the distance between the carrier and the rotor but I would not think it possible to do that to the bearing. Am I mistaken in my assumption that the rotor should ride more or less in the middle of the access window for the pads when the caliper is properly mounted?

The bearings go in against a shoulder in the hub so should be the same....Yes. the rotor should be in the middle of the caliper opening - but if I had a dollar for every time I've seen both pads on the same side of the rotor....

[sharpy]

bearings sit in the wheel on a ledge and there be no reason to remove bearings if you didnt ask for them to be replaced. Look/feel inside the bearing and should be a metal tube "floating" around inside between the bearings. Sometimes it a fraction loose, DONT worry as when it in and the axle gets tighten the slop goes away. FYI, the "Paddle" is called a Sprocket carrier(pics below) and the "rubber damper doohicky" are called the cush drive rubbers.


Sprocket Carriers.jpg

[standswithabeer]

just took a gander at my 79 GS750L, and noted the plain spacer between the chain adjuster and caliper bracket is just 5mm wide. moving that spacer to the opposite side of the caliper bracket will cause the disc to be incorrectly centered in the caliper window by the same amount.

can take a pic of mine if you'd like.
bob p

[Allie]

just took a gander at my 79 GS750L, and noted the plain spacer between the chain adjuster and caliper bracket is just 5mm wide. moving that spacer to the opposite side of the caliper bracket will cause the disc to be incorrectly centered in the caliper window by the same amount.

can take a pic of mine if you'd like.
bob p

You are correct Sir. I know this empirically .

Here are some photos of the apparatus in question:

An exploded view:


Number represent the order the parts go on the axle, with 0 being the axle itself. The taper on 4 faces the LH bearing inside the Rubber Baby Buggy Bumper (did I get that right?). The 'brim' of the top hat spacer (6) faces the RH bearing.

Rotor side assembled:



Shhhhhhprocket side assembled:



Some photos of what it looks like with the wheel installed and the carrier pressing the caliper against the rotor:

[Allie]

Stay tuned for photos of what the entire wheel assembly looks like after taking a couple rounds of 00 buck shot.

[standswithabeer]

either the caliper is mounted too far to the left, or the wheel/disc too far to the right.

the caliper bracket/spacer appears to be mounted correctly, so how can the disc be located 5mm +/- to the right? the wheel hub seems very close to the socket head cap screw that that holds the caliper together. doesn't even look like the wheel can spin. is the right-hand bearing spacer missing? crazy, i know.

i think the problem is that somehow the bearings are mounted incorrectly.

[sharpy]

So looking at the pics. the spacers on he RHS havent been changed due to same oil/dirt on all the parts. so i presume all the spaces where left at home and none where taken with wheel to the shop. Before you use the buck shot. when the wheel is out next time can you measure how deep the bearing are from the outside ledge on the hub please. BOTH sides, and ill measure my spoked hub in my morning. almost bed time here. Ive been in wheel tyre changing shop half my life and this IS a simple job. murphys law. lets shoot murphy. Sadly my 1000 setup has diff discs and brake bracket.

[Boriqua]

I cant be more helpful .. I just kept seeing the thread titled .. "Locating rear wheel" and figured I could come in and let someone know .. its on the back of the bike.

Happy Monday Everyone!

[Allie]

So looking at the pics. the spacers on he RHS havent been changed due to same oil/dirt on all the parts. so i presume all the spaces where left at home and none where taken with wheel to the shop. Before you use the buck shot. when the wheel is out next time can you measure how deep the bearing are from the outside ledge on the hub please. BOTH sides, and ill measure my spoked hub in my morning. almost bed time here. Ive been in wheel tyre changing shop half my life and this IS a simple job. murphys law. lets shoot murphy. Sadly my 1000 setup has diff discs and brake bracket.

I took my vernier scattergun out and took some measurements:

LH (sprocket side) bearings: 9.93mm
RH (rotor side) bearings: 10.15mm

Both measurements are from the outside perimeter of the bearing to the outside ledge of the hub.

More measurements:

Rotor thickness: 7.3mm
Caliper slot: 10.1mm (ish)

For the rotor to ride centered in the caliper slot there can only be about 1.4mm clearance on either side of it. It therefore seems that the carrier is missing approx. 1.4mm of distance from the bearing.

One more measurement:

Top Hat spacer width: 23.48mm

That spacer butts directly against the bearing, and the carrier butts directly against that spacer. I don't think there was a thin washer involved anywhere here. Therefore the carrier distance from the wheel is determined by two things:

1) The depth of recess of the RH bearing (10.15mm)
2) The width of the Top Hat spacer (23.48mm)

My conclusion is that the caliper carrier as mounted is now sitting 1.4mm too close to the rotor (1.4mm left of where it should be).
Correcting this can be accomplished two ways:

1) Decrease the bearing recess in the hub (move it 1.4mm to the right)
2) Increase the spacing between the bearing and the carrier (add a 1.4mm spacer to the Top Hat spacer)
2a) Cook the Top Hat spacer in a pan of grits until it grows 1.4mm)

Am I missing anything?

[Allie]

I cant be more helpful .. I just kept seeing the thread titled .. "Locating rear wheel" and figured I could come in and let someone know .. its on the back of the bike.

Happy Monday Everyone!

Hah that would be my first inclination. However while searching for similar issues to mine I grasped at the more esoteric definition of 'locating' and... Bingo

I notice though that it's under 'general/maintenance', I would have expected such an issue to be in 'tires/suspension/brakes'.

[Allie]

Sharpy I appreciate your time and thought on this, I'm sure the answer is looming around the corner.

I also think it may be time to rebuild that caliper and do the SS brake line for the rear.