Im looking at a Giant advance defy 3 bike and it has these brakes, someone said they are not adjustable heal to toe ??WHy not

They are just OEM Tektros, no reason why they can't be adjusted, by using the conical washer which all of that type of brake are fitted with, but how much toe in do you need with Dual Pivot brakes? normally with DP's you don't run any.

(To clarify, as per CACycling below with the adjustment, the conical washers I mentioned are on the pad fittings)

If you are looking the bike, budget to replace the pads (non-cartridge type), as this is the biggest weakness of Tektro brakes

The brake calipers don't adjust, the pads themselves will have a pivot to allow adjustment. Just loosen the screw that holds the pad onto the caliper and you should be able to set the angle where you need it.

so...how do the shimanos differ in adjustablity

Shimano and Tektro brake calipers hold the pads exactly the same way. The differences come in the type of pad used. Some (as mentioned) have conical washers to adjust toe, others don't.

They don't differ. It is the same.

I don't know of any road caliper shoes that have conical washers. The mounting post/bolt will pivot, giving you the toe in needed. Once the shoes are toed in, tighten the brake and it will be set.

Dual pivot brakes still need to be toed in.

We used to torque the toe into old center pull weinmann /etc calipers so much,
to toe them in, Park eventually stamped out a tool to do it with..

some of the cheaper ones lack the adjustable conical washers, actually.

No, if you have them set up correctly there is no need for toe in, same with V-type brakes, they have so little pad, and you run them so close to the rim there isn't any space or need for this, https://www.parktool.com/blog/repair-...-brake-service i

If they are set up correctly, they are toed. What do you mean by "need for this"? Brakes need to be toed. Dual caliper brakes need to be toed. Park Tools is saying if you are using the cheap pads that don't have that capability, then don't try to bend the calipers like was done with the old thin, single pivot calipers.

Not sure what you mean by not enough space. I run my pads very close to the rims. I like the pads to contact as soon as I start to pull on the levers. There is always enough space, you still place the pads however far way you like.

The only linear brake pads that don't get toed are the asymmetrical pads. Since the longer half can negate the twisting of the pads. But even then, I found a little bit of toe helps.

you don't need to toe in for V-brakes, but it does allow slightly better modulation if you do.

Kool Stop's pad holders for Shimano and Campy road dp brakes do come with conical washers and you can use them to set toe-in. However, I've found that most caliper brakes need little to no toe-in to work well and remain quiet. My Avid V-brakes do need toe-in to prevent squealing.