Do your discs rattle?

[AndyS]

A note for the group. Do your disc rattle? I just inspected a set and the rotor moved not just side to side (normal & designed to), but radially (ie in the direction of wheel rotation) - not normal. How this bike passed its annual Safety (MOT) test I don't know.

When I removed the bobbins from the RH disc, every one was worn through in about three places per bobbin. It would only be a matter of (short) time before they totally gave up. The result does not bear thinking about.

 

Please go check your discs.

Andy

[Joe Frickin' Friday]

I put 135,000 miles on my 1100RT before selling it. I think I replaced the front-rotor bobbins a couple of times, and yes, they were severely worn when I did so. I never had them actually worn through, though. Wow.

[AndyS]

I shall post pictures when I get back to the workshop to retrieve the aforementioned knackered bobbins.

Andy

 

[OoPEZoO]

Mine were in horrible shape by the time I replaced them. I always new they were loose, but I didn't realize how bad they were until I was on the middle of a tire change one time and noticed that almost every single one was worn through. They were completely mangled. I replaced them with the stainless steel bobbins from Motobins and they have stayed tight ever since.

[Danny caddyshack Noonan]

Because I'm too lazy to go look in the book, is there a service limit? Although it would have to be in degrees or carry a "when measured at" caveat.

[AndyS]

If the discs rotate forwards & backwards radially (ie in the the direction of wheel rotataion), they need to be replaced. If they wiggle from side to side.....they are working correctly.

Andy

[simonB]

ahem, Andy - where these my "new" second hand ones? as a-posed to the non floating EBC versions?

[4wheeldog]

Yes, my discs rattle.......Mostly when going down the stairs. The ones on my bike, however, are tight enough........and easier to replace!

[SKYGZR]

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[Rockrib]

Hi Guys, perennial nOOb here. What are 'bobbins'? Do I have them? Should I be greasing, oiling, torquing or polishing them?

Thanks. End hijack.

[AndyS]

ahem, Andy - where these my "new" second hand ones? as a-posed to the non floating EBC versions?

 

Yep, dem da ones!

[AndyS]

Hi Guys, perennial nOOb here. What are 'bobbins'? Do I have them? Should I be greasing, oiling, torquing or polishing them?

Thanks. End hijack.

 

Hi Rockrib, you have a '97 RT, so yes your front discs are held to the wheel (via a carrier) using bobbins.

On the attached picture, the bobbins are the arrowed items. There are three parts. a/. the bobbin, b/.either a wave washer or a belville (dished) spring washer & c/. a circlip.

 

You certainly should check that they float sideways but not radially.

You could lube them, but most folk just ignore the fact that they are there and when they have worn out, replace them (they do not cost the earth).

I am sure some folk polish them! (but I have never met them yet). If you lube them, you should use a dry lube like Moly powder, but nothing that could fling out and spoil your brakes.

 

Andy

[Selden]

If the discs rotate forwards & backwards radially (ie in the the direction of wheel rotataion), they need to be replaced. If they wiggle from side to side.....they are working correctly.

Andy

Nice tip; I went out in the garage, and confirmed that while they wiggle side to side, I don't notice any radial movement. "knackered bobbins" -- now there's a term to toss into a conversation that will generate confused looks for most people, especially in the USA.

[AndyS]

"knackered bobbins"

 

Yep, it worries me when we think we talk the same language!

Andy

[Clive Liddell]

This is a repeat of a suggestion I made some years ago:

 

With left hand ready to apply brake gently rotate front wheel and apply brake (this should position both rotors at the end of their wear clearance). Now, while still holding the brake lever, check the rotational wear by aiming at the tire over the front of the mudguard.

 

At the moment my R1100RT with 95000km has about 2.5mm at the tire and I have no plans to replace bobbins any time soon.

 

If we could use this method as a quick check we could at least discuss what play (at the tire) worn out bobbins give. It could end up giving with some agreement on a "safe" wear limit.

[AndyS]

.....

At the moment my R1100RT with 95000km has about 2.5mm at the tire and I have no plans to replace bobbins any time soon.

 

....agreement on a "safe" wear limit.

 

Unfortunately Clive, the bobbins in LH disc & RH Disc do not necessarily wear at the same rate. Therefore using your method could lull you into a false sense of security. It really needs to be checked at the interface between the disc rotor and disc carrier on both sides independantly.

 

Andy

[Clive Liddell]

Andy, yes I thought of that and also possible pad movement - but - I believe for a quick and dirty go-nogo check a simple test is called for.

 

I do the test as described for myself and "trust judgement" to tell me when to contact Motobins for the new bobbins.

 

If some consesus could be arrived at to say, for example, when the tire moves x.x mm then it's "time" to start taking further action.

 

 

[AndyS]

I shall post pictures when I get back to the workshop to retrieve the aforementioned knackered bobbins.

Andy

Here they are - all 6 were the same.

[oldyam]

I shall post pictures when I get back to the workshop to retrieve the aforementioned knackered bobbins.

Andy

Here they are - all 6 were the same.

 

Really frightening ...............

 

Compared to those the ones I replaced last year were like new !!!

 

[OoPEZoO]

I shall post pictures when I get back to the workshop to retrieve the aforementioned knackered bobbins.

Andy

Here they are - all 6 were the same.

 

Yup, mine were that bad if not worse when I finally noticed and replaced them.

[Linz]

I've seen threads here where somebody has replaced worn bobbins with 3rd party new ones (from Britain I think). I've done a search but can't find mention of the supplier.

 

Can anyone assist please?

 

Linz

[enfoman]

Try this website and look for Bobbins. The page I am posting should direct you to it.

 

http://www.motobins.co.uk/displayfinal.php?q=bobbins&go=GO

[AndyS]

Try this website and look for Bobbins. The page I am posting should direct you to it.

 

http://www.motobins.co.uk/displayfinal.php?q=bobbins&go=GO

 

Yep, that's the company.

Andy

[Linz]

Thanks gents.

 

Linz

[rich t]

Try this website and look for Bobbins. The page I am posting should direct you to it.

 

http://www.motobins.co.uk/displayfinal.php?q=bobbins&go=GO

 

Yep, that's the company.

Andy

 

I recently ordered the bobbins from motobins, though I haven't installed them yet. A couple of notes.

1. Motobins is in the UK, and I'm in the US. They do ship to US though, and have pretty good turnaround. Can't remember how much the bobbins were, but it was cheaper than OEM, even with shipping.

2. BMW OEM bobbins are aluminum, or other alloy, while Motobins version is stainless, so there is a weight difference if that matters. The Motobins version, being steel, will last longer.

 

I haven't installed the bobbins yet, because I tightened the slop with stainless shim washers that I got from McMaster carr. I plan on donig the bobbins the next time I start to hear a rattle.

 

Don't be afraid to order from Motobins if you are in the US. They have an option for shipping quote, and have excellent turnaround, you just have to bear with their pricing being in euros.

[Boffin]

Don't be afraid to order from Motobins if you are in the US. They have an option for shipping quote, and have excellent turnaround, you just have to bear with their pricing being in euros.

 

Motobins is in the UK - we do not use the euro. The pricing will be in Pounds Stirling (GBP).

 

Andy

[AndyS]

..... The pricing will be in Pounds Stirling (GBP).

 

Andy

 

Ah Amen, I love the sound of £'s not those plastic Euro thingies.