A cautionary tale

[Jameshow]

They are very good though.

Agreed...

 

[faster]

You can get offset pad holders which give a little extra drop to short drop calipers.

If it really is close, i'd be tempted to grind the slot in the calipers a little longer or/and grind the drop outs a little.

 

[Dogtrousers]

You can get offset pad holders which give a little extra drop to short drop calipers.

If it really is close, i'd be tempted to grind the slot in the calipers a little longer or/and grind the drop outs a little.

I considered Dremelling out the slots in the calipers for about a second and thought: "Me? The 13th duke of Hamfist attacking a safety-critical piece of equipment with a Dremel? With my reputation?"

So in the end I just decided to re-fit the old faithfuls that worked fine for many years.

 

[andrew_s]

The arms of the 105 callipers are too short for my bike.. Even with the brake blocks right at the end of the slot, the top of the brake block is juuust above the rim. I didn't notice this when fitting. Because I am an idiot. So as the brake blocks wore in they began to contact the tyre, wore it away ...

It may have been OK when you fitted the brakes.
On dual pivot brakes, the pads move up the rim towards the tyre as they wear.

 

[All uphill]

You can get offset pad holders which give a little extra drop to short drop calipers.

If it really is close, i'd be tempted to grind the slot in the calipers a little longer or/and grind the drop outs a little.

Could you/me/one trim a millimetre off the upper edge of the brake pads, do you think?

 

[Paulus]

I considered Dremelling out the slots in the calipers for about a second and thought: "Me? The 13th duke of Hamfist attacking a safety-critical piece of equipment with a Dremel? With my reputation?"

So in the end I just decided to re-fit the old faithfuls that worked fine for many years.

I have done a similar job with a rat tail file, I didn't have to take much off, but it did the job.

 

[Ming the Merciless]

I’m sure if you still have some Meccano then you could adapt your 105s to be true long drop 😂

 

[faster]

Could you/me/one trim a millimetre off the upper edge of the brake pads, do you think?

You/me/one could, yes, but for me, with the tools I have at my disposal, it would be a lot more work, would need to be repeated at each change of the pads, and give a less satisfactory result.

 

[Dogtrousers]

Could you/me/one trim a millimetre off the upper edge of the brake pads, do you think?

I think probably not. Because as the brake pad wears, the angle at which it meets the rim changes and it gets closer to the tyre (I'm struggling to envision this, so it might be cobblers) I think you'd have to be constantly checking and trimming your brake blocks as they wear. Anyway, if you know your brakes are too short, the thing to do is replace them, not bodge your way around the problem. My excuse was that, as I am an idiot, I didn't actually know.

 

[Ajax Bay]

You could trim the pads as described but:
a. all the risks and hassle @Dogtrousers mentions, and
b. less contact area on the rims (which limits the brake's effectiveness).
You could file the slot down to allow the blocks to be dropped a mill, but:
a. still touch and go, and
b. do you want to do that to calipers you've installed for their 'bling': once filed, bling reduced?
Both of us (idiots) went down the 'reduced bling: put the perfectly good old calipers back on' remedial measure: hazard eliminated.

 

[Dogtrousers]

I'm thinking of getting some silver Humbrol enamel and painting "105" on my old brakes to bling them up

 

[TheDoctor]

I'd be getting a round file to the calliper slots, personally. Mind you, I've managed to destroy three chainsets with a combination of mechanical mishaps and a great big hammer, so you may want to avoid my advice,

 

[LittleWheelsandBig]

There is another factor explaining why brake pad tyre interactions are more common on the front wheel.

Braking is a dynamic process and a fork flexes backwards relative to the fork crown. A caliper brake flexes forwards relative to the fork crown. Both actions effectively lift the brake pad relative to the rim, more so under hard braking and more so with a flexible fork. A brake adjustment that clears the tyre in the work stand might not do so on the road.

A rear caliper brake flexes downwards under heavy braking and there is little relatively change in pad/ rim alignment.

This isn’t just a theoretical issue. I have seen exactly this effect in action. Braking hard on the front brake, holding the front brake on and looking at the brake pad jutting above the rim when it was perfectly even in the workstand. I tend to keep the front edge of the front brake pads a millimetre or so below the top of the rim as a minimum.

 

[Jameshow]

I'm thinking of getting some silver Humbrol enamel and painting "105" on my old brakes to bling them up

Why not Dura ace instead?!

While your at it put HED on your ma2 wheels?!🤣🤣🤣

 

[Ming the Merciless]

What’s wrong with the old brakes?