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Whilst fitting new brake blocks to my road bike yesterday I wondered why (on Shimano at least) there is a fin on the block holder, and why on Ultegra is there a grub screw in it (it's not on 105 - no other series to check though)?
Does anyone know the answer?
The fin is to aid super swift wheel changes when the Skoda with Mavic on the side pulls up.
So they can charge you more?
Does it help guide the tyre into gap between the brakes to help you put the wheel in easily...that’s my best guess. Oh, and it must be aero too!!
The guide thing is what I thought, but wasn't sure.
The grub screw in the Ultegra that's not in the 105 though - what's that all about?
the pros have the fins to guide the wheel in for 8 second wheel changes from the team car. you have it because the pros have it.
The grub screws are to hold the pad in but on some holders and not others. you might find it handy if you get some undersized refills but you probably won't.
I think the fin is both a guide and an aid for water dispersion.
The grub screw is a safety feature to stop pad ejection, in the case that someone holds the brakes on and pushes the bike or wheel backwards.
Are you sure your 105 brakes have cartridge type replaceable pads?
Thanks
The grub screw I'm referring to isn't the one to hold the pad in.
It's through the fin. It doesn't seem to serve any purpose and does go all the way through. The screw just fills the hole.
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You can see it on the fin under the main attachment
Damnit new forum!
The little plastic nub?
It goes DING DING DING DING DING DING DING DING on the spokes when you wear your pads out and pull the brake lever. Except on wide rims, or if the wheel isn't exactly like shimano were expecting it to be.
Oh, and it pings out after about 5 seconds of braking.
So it's useful for about 5 seconds, then you need new ones.
pad wear indicator - Ah, good shout.
Probably wouldn't work on deep section aero rims though
No, it only works on narrow, shallow wheels. Open pro ish. Anything wide or deep it'll either not reach the spokes (unless they are spaced out or asymmetric) or it'll hit the deep section rim (and shred the stickers/finish)
I take the nubs out on bike with wide or deep rims.
And pads get inspected regularly anyway.
Those are "tyre guides" (little rubber nubs) presumably so you don't mar the finish of the fins :)).
See part number Y8FA16000.
How would they hit the spokes or rims? If they stuck out that far how would you get the wheel in?
No idea. I've ridden with people who let their pads get that worn and heard the ding ding ding (many years ago). I suspect it's something to do with the path of the caliper when you've got bugger all pad left.
Not something i've ever bothered looking at in detail.
And i guess when you've got nice thick fresh pads it does guide the tyre past the wing. Rather than having a massive aluminum wing that'll damage the spokes/rim when the pad is worn.
"wear indicator screw"
For deep section rims where the tyre guide could contact the rim when the pad is worn, the soft guide will contact first.
Some aero rims are wider than the brake track.