Bicycle Mechanics - Mystery screw..

I have just been checking the wear and cleaning my road bike brakes.

The small round headed screw above the blocks, on the Ultegra brakes has me puzzled , I removed them and replaced them, but they just seem totaly redundant, serving no purpose, can anyone tell me otherwise......?

Is that the brake balence screw ???
When it´s in place and you tighten it does it move one side of the caliper closer to the rim ?

Hi Et-Ingles. No! I`m familiar to the one you are refering to,

The screw I mean is the one located on the actual brake block shoe. It just seems to have no function at all, but surely it would not be there without a purpose.

They are supposed to hold the brake shoes in their holders.

They are supposed to hold the brake shoes in their holders.

Mostly as a legal butt-covering measure. I suppose they're there in case you're rolling backwards and apply the brakes... trackstanding for example.

Those little screws aren't going to hold for long if you install the brake shoe backwards.

Its part SFA I600 , according to Shimano`s exploding diagram of components which I have researched with the aid of Acrobatic reader .
Titled a tyre guide? Huh....what the hell is a tyre guide ,no explination on the brake diagram. Still seems a superfluace rounded headed screw to me.... Ah well!!!

Its part SFA I600 , according to Shimano`s exploding diagram of components which I have researched with the aid of Acrobatic reader .
Titled a tyre guide? Huh....what the hell is a tyre guide ,no explination on the brake diagram. Still seems a superfluace rounded headed screw to me.... Ah well!!!

Here is a link to what willic is talking about. It's item 13 in the drawing. I'm puzzled.

http://bike.shimano.com/product_images/BR/ev_images/BR_6500_EV.pdf


I'll move this to the Mechanics forum (which is where it should be :rolleyes: . Maybe a shop wrench knows the answer.

I presume it is to push the tyre inwards so it doesn't catch on the hard edge of the block when installing the wheel.

According to this, http://www.paul-lange.de/nl/2002/TT_1_02.PDF, we are suppose to remove them prior to riding.

Only thing I can figure out is that they are spacers to keep the levers from coming to close to the tire during setup. Of course, if removed and you adjust the brakes...............

Guess I should remove mine, as I've apparently been "Riding With Death" all these years.



>>>Opps, suppose to have gone into the Mystery Screw thread

According to this, http://www.paul-lange.de/nl/2002/TT_1_02.PDF, we are suppose to remove them prior to riding.

Only thing I can figure out is that they are spacers to keep the levers from coming to close to the tire during setup. Of course, if removed and you adjust the brakes...............

Guess I should remove mine, as I've apparently been "Riding With Death" all these years.



>>>Opps, suppose to have gone into the Mystery Screw thread


Thanks for the link Dobber..

A very informative site. And yeh you are it does say remove before riding!

Well now... How many bike shop mech`s would Know that one?.
Guess its an old saying....., but we learn something new everyday .

So do think I should ask the wrench working on my bike ,when I take in tomorrow for its Pre-season service to remove the screw/s It should be interesting to hear his reply....

I thought you were talking about #15. The screws you are referring to, #13, allow you to easily set proper toe-in of the pads.

I thought you were talking about #15. The screws you are referring to, #13, allow you to easily set proper toe-in of the pads.

How........do you use them to space the pads off the rim, at which point you adjust the toe? It looks like they'd be to low to contact the rim.

I always thought of them as a stupid brake pad wear indicator. If your brake pads are worn out enough and you have semi deep dish wheels, they will eventually start rubbing on them, leading to some really scratched rims. :( Needless to say, I've taken them off on my bike, just when I use my Sun Venus rims which have a moderate dish too them.

If they have another function, like for toe-in, I did not know that.

Jay

Well I am going to remove them at the first opportunity,

I did not like the way they unscrewed rather easily with a slotted screw driver. My thoughts are with the potential for a nasty accident if they happen to unscrew themselves owing to vibration.

They have a long enough thread to eventually jam against the Rim. Any one with wheel rims of the side spoke mountings would do well to check post-haste to make sure they are removed as that could spell disaster, clearing out their spokes in a single wheel revolution......