Burton

OK So we`re really talking about Hayes Stroker Carbon calipers and Shimano Deope XT rotors but not sure the change in the title is gonna take.

Just mounted this combo for a customer who insisted on that particular combination.

In short - the insertion tabs on the inner brake pads contacted the tips of the spider holding the SS rotor. Rather than lose sweep area by spacing the caliper, we elected to grind 2mm off the inner brake pad insertion tabs for both the front and back installations.

Anyone know of another company that markets equivalent metallic pads that have shorter insertion tabs? Only a 5 minute operation, but one that I`d rather skip if there`s an alternative.

M_S

As far as I know those shimano rotors just don't play nice with any avid brakes. Even if the spider doesn't hit the insertion tabs, the brake pads will not wear evenly, instead leaving a lip towards the inside of the braking track, since avid (and everyone elses, afaik) brakes are designed around a wider brake track than shimano. This lip on the pads will eventually result in a serious loss of braking power as well as crazy pulsing. I've seen it happen. Your customer needs new rotors or new brakes.

Burton

Unfortunately looks like even though the title was corrected to read `Hayes` instead of `Avid` - the original listing stayed the same.

Will post some photos of the original/modded Hayes pads. Have checked the sweep area on the rotor and see only one possible issue myself. There`s actually a marginally larger sweep with the Hayes than with Shimanos.

On the outside edge of the rotor the Hayes pads will extend slightly and simply not get used. Thats incidental. On the inside edge they will also extend slightly and those areas will contact only the rotor extensions that mate with the inner rotor spider assy.

There I can see that there might be uneven wear and a contact area that MIGHT induce pulsing. Is this the nature of the issue mentioned? If so the simple solution would be to shim the caliper outwards 1.5mm so that there is no pad extension past the inside edge of the main rotor surface.

Your opinion?

Agreed this may not be the `perfect` situation, but the client apparently wants a functional setup with this combo if possible. We`re probably talking about a `toys for big boys` catagory and the bike probably won`t be ridden overly hard. Just to underline that this is largely a cosmetic upgrade - there were already Shimano XT SM-RT78 rotors on the bike that showed very little wear and the move is simply to a SM-RT79 rotor which has a slightly different spider design. The SM-RT78 design had a variable width braking area and 8 arms instead of 5 and was a non-issue.


The overall package runs Shimano 180mm XT rotors on Mavic CrossTrail rims. a DT Swiss XR Rigid carbon fork on a titanium frame. So expect that he might be fussy about anything unusual and would rather avoid any issues proactively if possible.

dminor 

I fixed the title. FYI - - In a thread of your own, you should be able to double-click to the right of the title (on the thread list page) and it will appear in an edit window; then you can just change it.

I'll check Brake Authority pads and see if the tab profile looks smaller.

Edit = Look on the profile of these and see if the tabs appear the same or shorter (I asume Carbons are the same as Trail/Gram?):

https://www.brake-authority.com/image...quettes_BA.pdf

M_S

I think hayes are going to have the same issues as Avid, so my reply is the same, although I don't have the experience to say for sure. But AFAIK Shimano uses a narrower braking track (on most rotors) and pads than everyone else. No getting around that. I would tell the customer that the components are simply incompatible. Any workaround is bound to be a kludge IMO and not worth it since the only reason for the switch was "cosmetic."

Burton

Pretty much agree with you. I did a few quick measurements and calculations and just moving from a Hayes to a Shimano has already reduced the potential swept area by 15% based on the differences in pad widths.

I`ve also estimated that any area of the oversized Hayes brake pad that extends past the inner swept area on the Shimano rotor will sweep the rotor spiders 33% of the time and thin air the other 66% of the time which will likely gradually cause a wave effect on the rotor that changing the pads won`t cure. Probably won`t show up noticably for about 800kms or so but I expect it`ll eventually show up.

The only option I`ll recommend if he insists on going ahead is to waste the entire 15% of the extra pad width by extending it over the outer edge of the rotor. But I`ll be seriously recommending simply going back to the original Hayes rotors.

Burton

dminor - thanks very much for the title fix. Still can`t quite figure why it didn`t take when I tried to do it myself.

Will be checking out your link for future reference but will be recommending that the mix of caliper / rotor in this case isn`t ideal and that a :ayes / Hayes combo would perform better and avoid all issues.