Wallie Posted April 12, 2021 Report Share Posted April 12, 2021 More of a curiosity thing more than anything. I've got a slight judder on the front when trail braking (although not when bolt upright). Caliper was deep cleaned so thats been ruled out, headstock bearing is new and no front to back play in the forks, so last thing for me is a warped disc. I was mentioned it to one of the other guys on the test day who said to free the bobbins up with a bolt/washer/nut combo and some brake cleaner. Now I've never once done this and a quick google says the internet is divided over whether this is bollocks or not. I've already resigned myself that I need to buy a new disc more than likely, but I'm curious to see if anyone does it? Quote Link to comment Share on other sites More sharing options...
CMSMJ1 Posted April 12, 2021 Report Share Posted April 12, 2021 Which discs are you using? EBC used to give out rebuild kits to refresh the bobbins once they got loose and manky rather than solid and seized. You should be able to clean them up enough to move them - It would be a toothbrush and brake cleaner job and using a wooden dowel/thingy to get the bobbins moving. Quote Link to comment Share on other sites More sharing options...
Wallie Posted April 12, 2021 Author Report Share Posted April 12, 2021 Armstrong discs, they are the go to ones in the paddock. There is definitely no movement in them now (at least by hand) but I can't say I noticed they had any movement to start with. I always just give them a quick spray and rub with brake cleaner as part of the usual maintenance but never moved them. I'll be picking a spare disc up anyway so might be worth a punt to see if these can be salvaged. Quote Link to comment Share on other sites More sharing options...
CMSMJ1 Posted April 12, 2021 Report Share Posted April 12, 2021 not got a little flat spot in the tyre, just off centre? has it been sat on that bit over winter? Quote Link to comment Share on other sites More sharing options...
Wallie Posted April 12, 2021 Author Report Share Posted April 12, 2021 Nope it's been sat on stands all winter. It's odd as it's only tipping into Gerrards (cause I was being a fanny and braking instead of just rolling off) and it was fine everywhere else. It was just enough to annoy more than anything, not that you want a judder tipping in to a corner like that! Quote Link to comment Share on other sites More sharing options...
CMSMJ1 Posted April 12, 2021 Report Share Posted April 12, 2021 Ringpiece flutter... I get it bad these days 2 Quote Link to comment Share on other sites More sharing options...
Gobert Posted April 12, 2021 Report Share Posted April 12, 2021 1 hour ago, Wallie said: More of a curiosity thing more than anything. I've got a slight judder on the front when trail braking (although not when bolt upright). Caliper was deep cleaned so thats been ruled out, headstock bearing is new and no front to back play in the forks, so last thing for me is a warped disc. I was mentioned it to one of the other guys on the test day who said to free the bobbins up with a bolt/washer/nut combo and some brake cleaner. Now I've never once done this and a quick google says the internet is divided over whether this is bollocks or not. I've already resigned myself that I need to buy a new disc more than likely, but I'm curious to see if anyone does it? Seems a popular thing to do on a lot of Kawasaki forums I've been on. 1 Quote Link to comment Share on other sites More sharing options...
TLRS Posted April 12, 2021 Report Share Posted April 12, 2021 Wheelbearings checked? Quote Link to comment Share on other sites More sharing options...
Superdunc Posted April 12, 2021 Report Share Posted April 12, 2021 I bet it's head stock related. I chased this problem for a season on the Slabbie, turned out I'd missed out the washer under the nut on the top yoke, the blind nut was bottoming out on the stem rather than clamping the top yoke down. Handles like a 250 gp bike now. 1 Quote Link to comment Share on other sites More sharing options...
Wallie Posted April 12, 2021 Author Report Share Posted April 12, 2021 1 hour ago, TLRS said: Wheelbearings checked? Yup they were fine. 4 minutes ago, Superdunc said: I bet it's head stock related. I chased this problem for a season on the Slabbie, turned out I'd missed out the washer under the nut on the top yoke, the blind nut was bottoming out on the stem rather than clamping the top yoke down. Handles like a 250 gp bike now. Probably the most likely outcome. I'll whip the top yoke off at the weekend and double check everything. Quote Link to comment Share on other sites More sharing options...
Thunderbolt Posted April 12, 2021 Report Share Posted April 12, 2021 3 hours ago, Wallie said: More of a curiosity thing more than anything. I've got a slight judder on the front when trail braking (although not when bolt upright). Caliper was deep cleaned so thats been ruled out, headstock bearing is new and no front to back play in the forks, so last thing for me is a warped disc. I was mentioned it to one of the other guys on the test day who said to free the bobbins up with a bolt/washer/nut combo and some brake cleaner. Now I've never once done this and a quick google says the internet is divided over whether this is bollocks or not. I've already resigned myself that I need to buy a new disc more than likely, but I'm curious to see if anyone does it? Front end chatter? Quote Link to comment Share on other sites More sharing options...
coombehouse Posted April 12, 2021 Report Share Posted April 12, 2021 (edited) I've had similar that only showed up on the mot brake tester rollers. It was caused by a spot of corrosion pitting where the pads had sat in contact with the disc over the winter. Edited April 12, 2021 by coombehouse Quote Link to comment Share on other sites More sharing options...
Arran Posted April 13, 2021 Report Share Posted April 13, 2021 Definitely clean the bobbins up so that they turn reasonably freely. As you said use a drill and a bolt. It's a common problem on RSV April I as and cleaning the bobbins usually helps. It's a free fix so you have nothing to lose by trying it anyway Quote Link to comment Share on other sites More sharing options...
Wallie Posted April 19, 2021 Author Report Share Posted April 19, 2021 Dunc was right, it was the headstock. Bobbins did move with some persuasion (although one was slightly stuck so still worthwhile). As I was using the underyoke stand I thought I should be able to feel any play with the forks off the ground, but sure enough I cracked the car jack out and there was a knock. After a right game trying to find the sweet spot we should be good to go. Will still be taking the jack to Mallory next week to nip it up a bit more if needed. 3 Quote Link to comment Share on other sites More sharing options...
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