Callipers don’t quite have enough drop.

[GOATever]

I was testing a bike out that I fitted with an R7000 groupset yesterday. I found a couple of minor snags. I hadn’t ensured that the shifters were at exactly the same level before I wrapped up the bars ( my bad ) which I sorted today. The other issue is massively annoying. With the pads that were supplied, toed and pitched correctly, at the maximum drop ( 51mm ) I’m about 1 mm ( a bit less actually ) shy of having the pads comfortably on the braking track, and they are just catching the tyre at the rim interface. Is there a solution to this, or am I going to have to fit long drop callipers?

[gazza285]

I think you know the answer, you need some long drop callipers...

[Paul Drawmer]

I've had this and just used a round file to extend the slots in the calipers (I think I needed almost 3mm).

[GOATever]

Paul Drawmer said:

I've had this and just used a round file to extend the slots in the calipers (I think I needed almost 3mm).

Good thinking batman. I might do that very thing. I’ve got a dremel, that should sort it.

[gazza285]

GOATever said:

Paul Drawmer said:

I've had this and just used a round file to extend the slots in the calipers (I think I needed almost 3mm).

Good thinking batman. I might do that very thing. I’ve got a dremel, that should sort it.

Bodge.

[GOATever]

gazza285 said:

Bodge.

True, but Shimano don’t do a long drop R7000 calliper, the Tektro numbers are very different.

[Shuttle Cock]

How do the new ones measure compared to the old ones?

[anonymous-user]

gazza285 said:

Bodge.

Fettling - quite acceptable !

[gazza285]

Jimboka said:

gazza285 said:

Bodge.

Fettling - quite acceptable !

On pre-unit British motorcycles maybe...

[GOATever]

Shuttle Cock said:

How do the new ones measure compared to the old ones?

They have a max drop of 51mm, and will take a 28mm tyre clearance wise. They are very like the Ultegra 6800 type, so the centring adjustments is via a little grub screw in the arms of the callipers. Like I’ve discovered, the max drop is a bit tight for most rims, that I’ve used, so a file / dremel may come in handy.

[gazza285]

I'd go get some R451 or R650 long drops, and sell the R7000 ones on, rather than butchering them. Having the blocks right at the bottom of the caliper also reduces the leverage.

[GOATever]

The filed down calliper.



The un filed one.

There’s quite a lot of filing required to get the pads comfortably onto the braking track, however, they don’t feel any different, so the bodge works.

[gazza285]

The horror! The horror!

[TwistingMyMelon]

I had this on an old single speed

About 2mm too short

Bought some long drops and then they were too long !

I'd just dremmal it

[TheTardis]

Yeah bodge it, it's only brakes, what's the worst that can happen?

[GOATever]

TheTardis said:

Yeah bodge it, it's only brakes, what's the worst that can happen?

It’s the rear brakes, so the absolute worst that can happen is that I lose the rear brakes temporarily, that’s not a massive problem, as you should slow using the fronts mostly. So far they work just fine anyway.

[yellowjack]

GOATever said:

TheTardis said:

Yeah bodge it, it's only brakes, what's the worst that can happen?

It’s the rear brakes, so the absolute worst that can happen is that I lose the rear brakes temporarily, that’s not a massive problem, as you should slow using the fronts mostly. So far they work just fine anyway.

I've done it both ways in the past. I took a needle file to the slot in a set of normal drop calipers because they were but a few millimetres out, and the solution was invisible once the cartridge pads were bolted in.

On another bike, I needed the long drop calipers to get around a mudguard fouling issue, and I bought some Shimano long drop calipers which were the equivalent standard/finish to go with an Ultegra 6700 groupset. Lovely things, aesthetically, and nice to "do the job right" (for a change). But if it's only a couple of mm then file 'em. There's probably plenty of leeway in the amount of material in the caliper, and in real life use you'll probably not get near to imparting the type of force into them that is needed to exceed their limits.

Just think of all the weight-weenie stuff from t'olden days - drilling out excess material from gear levers, brake levers, handlebars, seatposts, etc... http://www.classiclightweights.co.uk/extras/drilli...

[GOATever]

yellowjack said:

I've done it both ways in the past. I took a needle file to the slot in a set of normal drop calipers because they were but a few millimetres out, and the solution was invisible once the cartridge pads were bolted in.

On another bike, I needed the long drop calipers to get around a mudguard fouling issue, and I bought some Shimano long drop calipers which were the equivalent standard/finish to go with an Ultegra 6700 groupset. Lovely things, aesthetically, and nice to "do the job right" (for a change). But if it's only a couple of mm then file 'em. There's probably plenty of leeway in the amount of material in the caliper, and in real life use you'll probably not get near to imparting the type of force into them that is needed to exceed their limits.

Just think of all the weight-weenie stuff from t'olden days - drilling out excess material from gear levers, brake levers, handlebars, seatposts, etc... http://www.classiclightweights.co.uk/extras/drilli...

I’ve sorted it now. The dremel worked a treat, and everything still works.