Uneven braking

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Moose · #31 Post by **Moose** » Tue Jun 03, 2014 6:35 pm

I don't think they turn in?

I used a very small flat blade screw driver to carefully pry the clips away from the surface, once done (if this is your problem) the discs float, rattle, I also sprayed them with more brake cleaner and a lot of crap came out.

I figured I had nothing to lose if it didn't work, as everything else I had tried hadn't made a difference, so if a messed up I would have to purchase some more anyway.

Good luck

spiderwheels · #32 Post by **spiderwheels** » Tue Jun 03, 2014 7:15 pm

I follow you now; full floating instead of semi-floating.
Yes, nothing to lose :)

D-Rider · #33 Post by **D-Rider** » Tue Jun 03, 2014 11:13 pm

Yes - a few years ago there was a bit of a "fashion" for turning your Aprilia semi-floaters into full-floaters - especially on the AF1 forum.

It was quite effective in sorting this problem out but is not so frequently mentioned recently (I guess because cleaning the bobbins works well most of the time - and it's a lot less hassle)

NickyT · #34 Post by **NickyT** » Wed Jun 04, 2014 10:01 am

I had the same problem with heavy juddering under braking, which wan't alleviated by turning the bobbins and spraying with brake cleaner. I too went down the route of prying the tabs away from the rear face of the discs, resulting in the rotors now being rattly on the bobbins (both sideways and forwards/backwards). Here's a video I took:

https://www.youtube.com/watch?v=yloUzuhhOmc

I have since given them the most extreme testing possible by doing two track days, the first at Snetterton in early May and then again at Anglesey on Saturday. I found that when cold there would still be some very mild judder, but when hot it had been eliminated. I have been advised however, that forward/backward movement of the rotors on the bobbins is not ideal.

There's not really any way to improve mine any further, and in any case they've done 35k miles. I don't know whether they'll go through an MOT like they are either, so I have decided to buy some more.

If anyone has any discs for sale, or good recommendations, please will you let me know. Thanks.

#35 Post by **mangocrazy** » Wed Jun 04, 2014 6:33 pm

I've got a set of rotors only that are virtually new (done less than 500 miles). But you would need to source bobbins (I don't think the OE ones can be re-used once separated). 50 drinking vouchers for the pair if you're interested. I replaced the OE rotors with PFM ductile iron ones.

spiderwheels · #36 Post by **spiderwheels** » Wed Jun 04, 2014 9:58 pm

mangocrazy wrote:I've got a set of rotors only that are virtually new (done less than 500 miles). But you would need to source bobbins (I don't think the OE ones can be re-used once separated). 50 drinking vouchers for the pair if you're interested. I replaced the OE rotors with PFM ductile iron ones.

Are they Brembo rotors or the other sort (sun.. something?)

That would be very useful thanks. I've been studying up on AF1 and I believe bobbins are available. However I will try the spring bending trick first as unfortunately one of the allen bolts has rounded off and I can't remove one of the discs

#37 Post by **mangocrazy** » Wed Jun 04, 2014 10:11 pm

I'm pretty sure they're Brembo, but will check. They came off a brand new bike that was one of the early 'facelift' models with the black frames. I've just checked and there are no markings on the rotors, but I'm pretty sure the carriers were Brembo. They're so new they've still got the cross-hatching markings from the final grind...

D-Rider · #38 Post by **D-Rider** » Thu Jun 05, 2014 9:29 am

spiderwheels wrote:
Are they Brembo rotors or the other sort (sun.. something?)

Sunstar (the company that makes the "Braking" brand amongst others)
http://www.sunstar.com/products/safety_ ... technology

Good discs - very happy with mine

spiderwheels · #39 Post by **spiderwheels** » Thu Jun 05, 2014 11:24 am

D-Rider wrote:
spiderwheels wrote:
Are they Brembo rotors or the other sort (sun.. something?)

Sunstar (the company that makes the "Braking" brand amongst others)
http://www.sunstar.com/products/safety_ ... technology

Good discs - very happy with mine

I have read they are good. It's just I wouldn't be able to attach Sunstar rotors to Brembo centres (different number of bobbins I believe)

D-Rider · #40 Post by **D-Rider** » Thu Jun 05, 2014 12:43 pm

spiderwheels wrote:
D-Rider wrote:
spiderwheels wrote:
Are they Brembo rotors or the other sort (sun.. something?)

Sunstar (the company that makes the "Braking" brand amongst others)
http://www.sunstar.com/products/safety_ ... technology

Good discs - very happy with mine
I have read they are good. It's just I wouldn't be able to attach Sunstar rotors to Brembo centres (different number of bobbins I believe)

Correct

spiderwheels · #41 Post by **spiderwheels** » Sun Jun 08, 2014 3:49 pm

mangocrazy wrote:I'm pretty sure they're Brembo, but will check. They came off a brand new bike that was one of the early 'facelift' models with the black frames. I've just checked and there are no markings on the rotors, but I'm pretty sure the carriers were Brembo. They're so new they've still got the cross-hatching markings from the final grind...

I have no idea how I would get them attached to my centres so thanks for the offer.

Finally did the full-float conversion - no different. It's a shame I spent too much time one these bleeding discs. I will buy some non-brembo replacements - that is as soon as I can get the bloody left hand disc off the wheel :(

jonnie_r · #42 Post by **jonnie_r** » Sun Jun 08, 2014 4:56 pm

I've just fitted Blackshadow discs to mine, right before my TT trip. Much better now I don't feel mild pulsing back through the lever. The quality looks good too.

spiderwheels · #43 Post by **spiderwheels** » Tue Jun 10, 2014 2:02 pm

jonnie_r wrote:I've just fitted Blackshadow discs to mine, right before my TT trip. Much better now I don't feel mild pulsing back through the lever. The quality looks good too.

I've been reading on the Blackshadow site about how important it is to ensure the new discs are fitted completely flat to the wheel without even a spec of dust to knock them out of true and have them checked with a dial guage. Did you? :)

Edit - and can you use the standard bolts?

Edit 2 - I think I found the problem.. after finally getting the discs off I measured the thickness at 6 equidistant points. The left hand disc was 4.85mm-4.89mm (0.04mm variance) and the right 4.82mm-4.89mm (0.07mm variance). I think that is too much.

#44 Post by **mangocrazy** » Tue Jun 10, 2014 9:08 pm

If you want to go the whole hog and convert to full floaters, then I think these are the bobbins/washers/circlips you need:

http://www.motorworks.co.uk/vlive/Shop/ ... 20BRA10086

If you use these to replace the rivetted OEM items and get your disc rotors bead or grit blasted, I reckon your problems would disappear.

spiderwheels · #45 Post by **spiderwheels** » Tue Jun 10, 2014 9:14 pm

mangocrazy wrote:If you want to go the whole hog and convert to full floaters, then I think these are the bobbins/washers/circlips you need:

http://www.motorworks.co.uk/vlive/Shop/ ... 20BRA10086

If you use these to replace the rivetted OEM items and get your disc rotors bead or grit blasted, I reckon your problems would disappear.

I'm contemplating buying your rotors and trying to transfer onto mine with new bobbins..