Do roll pins wear?

[NonComp]

I noticed that the only thing that holds the front brake rotors in place on my r1100r is a series of plastic donuts (called roll pins?). The rotors tend to float and I can grab them and rattle them a bit. Do these roll pins wear? How loose should they be?

[Joe Frickin' Friday]

I noticed that the only thing that holds the front brake rotors in place on my r1100r is a series of plastic donuts (called roll pins?). The rotors tend to float and I can grab them and rattle them a bit. Do these roll pins wear? How loose should they be?

 

They're not plastic; they're aluminum. And they do wear, albeit slowly. Presumably at some point they could wear enough to allow the rotor to flop out-of-plane in a catastrophic fashion, but that would take a long time. I replaced mine at about 50K, only because they were getting annoyingly noisy. I think it was about $100 for a complete set of replacement hardware (excluding the rotors), including new Circlips for holding the aluminum buttons in place.

 

Some rattle and a small amount of lateral play is normal.

[Ken H.]

Common;y referred to as bobbins, they do wear. Some rotational play is normal. When side-to-side play gets annoying it's time for a new set. It's a fairly straightforward repair. They can be replaced one at a time with the wheel, rotor, etc. on the bike where is.

[flars]

'some rotational play is normal'...

I thought that NO rotational play is allowed. Side to side is normal.

I replaced my bobbins at about 100K, and now I have a shudder under braking which was not there before I replaced them. Shudda left well enuf alone.

[Ken H.]

'some rotational play is normal'...

I thought that NO rotational play is allowed. Side to side is normal.

I replaced my bobbins at about 100K, and now I have a shudder under braking which was not there before I replaced them. Shudda left well enuf alone.

Oops. yes you're right, I typed it backward.

[NonComp]

Thanks for your replys. I had noticed that I hear a clicking noise when hit the occasional pothole or rought bit of road and was trying to figure out where it was coming from. I'll check for rotational wear.

[Mark K]

I think it was about $100 for a complete set of replacement hardware (excluding the rotors), including new Circlips for holding the aluminum buttons in place.

 

 

I heard these have almost doubled in price since you (and I) replaced them. Make sure you really really need new ones before you go shopping.

[NonComp]

Well, how do I know if I really, really need them. I took a quick look at them this morning. Some rotate with my finger tip, some don't. The left rotor seems a little looser than the right one. I can move it a bit up and down as well as left to right.

 

Hamersley lists roll pins at US $4 each.

[flars]

If there is rotational movement, i.e. you can make the discs turn in the direction of travel (forward or backward), replace them. If not, leave them alone. The parts are about $100 to do both discs. You can search on 'bobbins', using 'newer than 1 year' to get the actual parts list.

I wish I had not messed with mine. They were fine, but I replaced them because I had 100K on them. Mistake.

[AndyS]

Well, how do I know if I really, really need them. I took a quick look at them this morning. Some rotate with my finger tip, some don't.

Hamersley lists roll pins at US $4 each.

The bobbins can rotate, it is the disc rotor that must not have rotational movement (with respect to the mounting flange).

Andy

[NonComp]

'some rotational play is normal'...

I thought that NO rotational play is allowed. Side to side is normal.

I replaced my bobbins at about 100K, and now I have a shudder under braking which was not there before I replaced them. Shudda left well enuf alone.

To what do you attribute the shuddering?

[NonComp]

I have a slight amount of rotation of the rotors. The left side is more pronounced than the right side. Enought to get a bit of a click out of it when move the rotor clock-wise and then counter clock-wise.

[flars]

"To what do you attribute the shuddering"

Not sure. It could be one of the rotors is warped, and it didn't rear its ugly head until the rotors were more closely held. Or it could be I didn't put the wrong washers on the bobbins. I used all flat ones because that was what the shop sent me. I couldn't see any difference in any of the washers that I took off, so I thought that maybe it didn't make any difference whether I used wavy washers on some or not...I wuz prolly rong.