drlogik 

I have an old Pinarello Montello with full Campy. It has Delta brakes and I've always run 23c tires on the old girl but got some 25c's to see if they'd work. They do, kinda. The bike rides a lot smoother with the larger tires so I'd like to keep them...if possible.

There's very little clearance from the tires to the caliper. So little that a small stone could get wedged and cause damage, or worse. I can move the caliper up so that there's enough clearance to the tire but the pad slot doesn't have enough room to move the pads down enough so they don't rub the tires.

I don't want to grind the brake pad slots or the hanger. These are Delta Brakes after all. Anyone have a suggestion? Is there a dropper bolt available that will still fit into the frame's caliper bar recess hole? Or am I destined to put the old 23c's back on?

FBinNY 

I've ridden for decades with less than 1mm clearance under my front caliper.

There's no problem. When the tire carries a stone up it compresses into the tire and is ejected forward with a sharp ping.

drlogik 

FB,

Yes, I've run low clearance tires over the years but if a stone goes under the Delta brake there's a better than likely chance that it's gonna scratch it or mess it up. I don't like dropper bolts but I really don't want to ruin the Delta's.

dedhed

https://bdopcycling.com/product/bdop...s-pair-silver/

​​​​​​https://www.amazon.com/Aican-Aluminu.../dp/B0788ZJZ7R

drlogik 

Ded,

Those Aican's look like they may work. Thanks for the link.

ThermionicScott 

How do you guys think dropper bolts or offset brake pad holders will magically add clearance under the calipers?

FBinNY 

Yes, but the damage will be where it can't be seen. But you might buy yourself some extra room by shaving the tops of the shoes.

That's what I do for my track bike's front brake. (track bike for road use). I use a Swiss rasp to shave a bevel, curve to follow the rim, so they're barely trimmed in the center.

Kontact

By putting them together with a brake caliper like the Delta that has a height adjustable mounting bolt.

But dropper bolts aren't going to help.

Kontact

You could also try putting a wedge shaped washer between the caliper and frame to make a small change to the angle of the caliper.

Get some of that clear frame protector tape and put it on the bottom of the caliper.

delbiker1 

I have 2 bikes that I place extra extra washers between the caliper and the mounting hole. That gives just a bit more clearance under the fork crown. It enables going from 25mm max to 28mm tires. Does not affect the braking.

KerryIrons

No offense, but is this a show bike or a bike to ride. When you ride a bike, things get scratched. The underside of the Deltas will get scratched but not damaged. Picture this scenario: you have 2 mm clearance so those small stones don't scratch the brakes, and then you find yourself on fresh seal coat and a much larger stone sticks to the tire and comes up and scratches the brakes. It's riding in the real world.

grumpus

That was going to be my suggestion, but I wonder if a stone is more likely to embed in the heli tape and cut the tyre.

icemilkcoffee 

Or get the kind of brake pads that have rounded cup washers which allows you to angle the brake pad- Typically in the toe-in direction, but in this case just angle it downwards.

79pmooney

A question and thought from someone who has never ridden or worked on Deltas. How far does the bottom of the brake under the bolt hang below the bike's brake bridge and fork crown? And how does this compare to a regular dual pivot?

And the thought - if the Delta is indeed lower, than perhaps this bike is best ridden with the smaller 23c tires or the brakes replaced with ones with more clearance. Perhaps running Deltas and 25c is a case of swimming upstream.

I have a Pro Miyata. 25c tires (measured) hit the Cyclone sidepulls and are very close elsewhere. 24s would give me your 1 mm. 23s fit comfortably. When I set it up it will be riding the best 23s I can get.

Kontact

Deltas are not particularly fussy. This is more of a brake bridge height issue.

So far my favorite solution is just adding spacers between the brake and bridge.

FBinNY 

If you can't raise the bridge lower the water.

If I under add tand the OP's problem, it's not that the shoes don't reach, but that the brake itself is too low.

Depending on what the OP cares about most, here are 2 options


1- use a rattail file or Dremel to raise the top of the brake hole 1 or 2mm. If you work carefully, you'll make a racetrack oval, so the brake can be moved up, but still kept on axis.

2- fashion a 1 o r 2mm shim for the top of the dropout so the wheel is pushed down. You can use something like copper tubing, or aluminum of the right thickness, and some glue to keep it in place. Once a wheel is there, th we axle will keep it home. The beauty of this is that it's easily reversed at any time.

BTW regarding the advice to space the brake out from the fork ---- that will only make things worse, because the tire rises forward of the fork.

delbiker1 

I can state as fact that putting the washers between the calipers and the mounting hole of the crown gave me enough space under the calipers to increase max tires from 25mm to 28mm. I do not remember what source that idea came from, but it surely worked on 2 different bikes.

Kontact

It is going to be more effective on the rear than the front. But it is easy enough to try and see.

SurferRosa

No smartphone? Where are the pics??