Brake bobbins

[MGN54]

Hey everyone!

 

Tired of my rattly/clunking/knocking front discs. Bobbins are shot. Need a good source for bobbins. I will need to measure the front discs first, I know, but just planning ahead.

 

Mark

 

[edit: removed classified ad]

[Mark K]

I called Chicago BMW. Told them what I had and what I wanted to do -- they sent the correct #s of each of the required parts. Gotta like that discount.

 

I've read more than one method of swapping these out. I did it without removing the wheel. When reinstalling, I offset the bobbins by one hole rotationally around the disc carrier as I noticed some wear in those with the circlips.

 

Mark

[bmwmick]

Mark,

When you replace the rollers, it is a good idea to reinstall the rollers with the spring-clip (3 per rotor) one hole to either side of the original hole. The spring clips WILL wear a groove in the carrier (but not the stainless rotor) and allow the other 9 rollers to wear prematurely. Keep the rotor and carrier in the original relationship by marking it with a grease pencil or crayon before disassembly. I had no problems replacing the rollers with NO disassembly of the front wheel. Work your way around the rotor and replace one roller at a time. Every 4th roller is a spring-clip roller. You 'may' get away with just replacing the spring-clip rollers if the 'plain' rollers are not worn.

 

34-11-2-310-086 Quan 18 plain rollers

" " " " 088 Quan 18 wave washers

" " " " 089 Quan 6 in case you break some C-clips.

" " " " 995 Quan 6 These rollers have the spring rings to stop the rattle

 

There are 12 on each rotor, 9 without springs and 3 with.

http://www.chicagobmwmotorcycles.com has the best prices so far.

 

 

Mick

[Couchrocket]

/hi-jack: but related..../

 

Could worn "bobbins" also be felt when braking? As in a stuttering sort of feeling, akin somewhat to the feeling of a warped rotor? Inquiring mind wants to know. TIA for any feedback.

[Green RT]

<Another hijack - but still related/>

I am getting ABS faults occasionally. But they don't occur on startup. They seem to occur during a low speed turn combined with a bump, like a badly matched driveway. They are hard faults, meaning I have to pull the seat up and reset. Turning the key off and on doesn't do it. It has never happened when it was convenient to read out the fault codes. It is my list to do that next time I can. However, I am wondering if play in the bobbins/rollers can produce this. I notice there is perhaps 1/2 mm of lateral play in the front disk with the ABS wheel/sensor. The bike has 72K miles on it. Is it time to replace the bobbins?

[Clive Liddell]

<YET Another hijack - but still related/>

I am getting ABS faults occasionally. But they don't occur on startup. They seem to occur during a low speed turn combined with a bump, like a badly matched driveway. They are hard faults, meaning I have to pull the seat up and reset. Turning the key off and on doesn't do it. It has never happened when it was convenient to read out the fault codes. It is my list to do that next time I can. However, I am wondering if play in the bobbins/rollers can produce this. I notice there is perhaps 1/2 mm of lateral play in the front disk with the ABS wheel/sensor. The bike has 72K miles on it. Is it time to replace the bobbins?

 

I don't think the bobbins have anything to do with the ABS faulting - the sensor ring is firmly mounted.

 

However the faulting could be due to front or rear wheel bearings allowing a drift in ABS sensor clearance under the conditions you describe.

[Green RT]

Clive, On thinking about it this morning I came to the same conclusion. Like you say, the sensor ring is rigid and movement of the disk wouldn't affect the ABS sensor.

 

I will check for play in the wheel. Last time I checked it there wasn't any, but that was a while ago.

[bmwmick]

Will,

I would check for a damaged front sensor wire or a loose connection. I'm going to bet you see a front sensor fault when you get time to actually read out the fault. Trace the sensor cable all the way to the front sensor.

 

Mick

[MGN54]

Mick, thanks for the tip on the bobbin install and especially the part numbers! I have to find someone with a micrometer so I can measure the thickness on the rotors. Hopefully I can get by with the bobbins.

 

Mark

[Rocketman51]

Another source for replacement bobbins is from the UK. At this web site: http://www.motobins.co.uk/search.php

 

Part # 20393 BOBBINS WITH WASHER & CIRCLIP FOR FLOATING DISCS (MADE BY GRIMECA) SET OF 12 IN BLACK FINISH TO REPLACE WORN BMW OEM BOBBINS.

 

They are oversize to help tighten up disc rattle. Now I have a set, but have not installed them yet. Good Luck

 

[MGN54]

Thanks for the link Rocketman51! What did these set you back USD and how long on delivery?

 

Mark