Disc Brake Noob – Tips Please!

hawkinspeter wrote:

ibr17xvii wrote:

hawkinspeter wrote:

ibr17xvii wrote:

hawkinspeter wrote:

I’ve just used the Shimano pads. I have heard from somewhere (probably this site) that you shouldn’t alternate metal and resin pads on the same rotor, but I have no idea how true that is or what the consequences are.

What I do recommend is either replace the shitty pad retaining pins or make sure you loosen/tighten them once in a while to stop them completely seizing. One of mine seized, so after my LBS rescued it, I replaced the pins with hex-head pins instead.

Good advice about the pin, hate spending ages fiddling with stuff like that.

I take it the pads are resin from the factory so best to stick with them?

My bike had metal pads originally, so I replaced like with like.

The part number will be printed on the pads, so if you take them out, you can figure out which ones to get e.g. L02A is resin and L04C is metal if you have the 805 brakes.

The reason you don’t want to use different pads is due to material transfer onto the rotor. That would cause poor braking performance unless you gave your rotor a good sandpapering.

Can I just undo the pin, take them out & put them back without faffing around taking the wheel off & potentially realigning the calipers etc?

If not I’ll wait for them to wear down a bit & buy some when they need replacing. The bike is brand new & hardly ridden so was just thinking ahead.

It should only take a few seconds to remove the retaining pin and then both the pads should just lift out and can go back in again easily enough. Removing the wheel might be needed for putting in new pads as they’ll be thicker than the worn pads, so you may need to carefully push the brake pistons in slightly to make enough room for them.

Cheers, sounds easy enough in theory………

Might just take them out to see what’s in there so I can make sure I get the same when they start wearing out.

Canyon48 wrote:

I’ve used the Shimano RS805 and Ultegra R8020 disc brake pads, really can’t fault them at all, I’d happily recommend them 🙂

Good to know the Shimano pads are up to scratch on discs. I’ve always replaced the stock rim brake pads straight away with Swissstop.

hawkinspeter wrote:

I’ve just used the Shimano pads. I have heard from somewhere (probably this site) that you shouldn’t alternate metal and resin pads on the same rotor, but I have no idea how true that is or what the consequences are.

What I do recommend is either replace the shitty pad retaining pins or make sure you loosen/tighten them once in a while to stop them completely seizing. One of mine seized, so after my LBS rescued it, I replaced the pins with hex-head pins instead.

Good advice about the pin, hate spending ages fiddling with stuff like that.

I take it the pads are resin from the factory so best to stick with them?

shutuplegz wrote:

I personally just prefer the feel, control and modulation all round, in all conditions, wet/gritty or dry/dusty….. plus the fact that I am not gradually trashing my rims. So on my disc braked bikes I have actually upgraded rims safe in the knowledge that they are going to last a long time without getting chewed each time I brake! I could never see the point on my rim braked bikes!

I still have a rim-braked bike, which is still my lightest bike (for now), but I don’t think I would ever go out and buy a new road/race bike that doesn’t have disc brakes now.

It will certainly be interesting to see how I feel when I go back to my rim barked bike. Discs just work whereas rims just don’t sometimes.

Will it be an excuse that I have to get a new best bike?!

shutuplegz wrote:

hawkinspeter wrote:

ibr17xvii wrote:

jterrier wrote:

Given that it is hydro with thru axles, its only down to caliper position. So its fixable by loosening the fixing bolts and making sure the gap either side of the rotor is the same. Put a piece of white paper behind it to help.

So stand at the front of the bike & place a white piece of paper behind the calipers to eyeball the gap & then tighten the bolts? Good idea, like the sound of that.

Thought maybe I was tightening the fixing bolts too much & pads were moving a little. Either way I must’ve loosened & tightened those bolts a dozen times before it stopped rubbing & not sure what I did differently when it worked all of a sudden.

It’s much easier to see the gap with a white background and you need to get your head in just the right place to easily see the gaps as they’re usually around 1mm or so.

I find it tricky to tighten up the bolts without the caliper moving, so I usually hold the caliper steady whilst putting just a little tension on the bolts. Once both bolts have a little tension, you can then tighten them up properly (don’t forget to tighten the bolts – I use a torque wrench to make sure they’re up to 5Nm).

Once the caliper is aligned nicely, you shouldn’t have much of an issue with taking out the wheel and replacing it. I’m always removing the wheels when cleaning the bike and I don’t need to readjust the calipers for that.

 

I use the method mentioned by Jterrier and Hawkinspeter. With hydraulic calipers I’ve never had much success with the ‘insert-something-thin-between-the-pads-and-disc, pull-on-the-lever-and-then-nip-up-the-previously-loosened-caliper-bolts’ method and find that the calibrated eye is much better. I usually get myself into a darkish room or garage, so that the caliper and pads at least, are in shadow, then put a white piece of paper on the floor underneath the caliper or wherever you need to put it so you can look straight down through the caliper body and easily see the clearance between the pads and the disc. Then I shine a torch onto the paper so that the contrast is even greater. This way you can much more easily see the gap. I then tighten the bolts just enough (i.e. just using my fingers) to stop the caliper ‘rattling’ but enough so I can move it and it stays where I’ve moved it to. It usually takes a bit of playing around to get to this point. 

 

I normally then just nip up the two bolts when it looks right with equal clearance either side and pads aligned with disc also and usually they don’t budge any further once you fully tighten the bolts. However, I have had one where the caliper adaptor wasn’t perfectly machined and the whole thing moved slightly when fully tightened. Sometimes a thin washer under the caliper bolt head (if not already fitted) can reduce any tendency for the whole thing to move during final torque tightening.

 

With flat-mount and through-axles (as I think you have) I have found set up to be much easier as the mount/adaptor is usually less sensitive to movement when you tighten the bolts up and on my through axle bike I can take the wheel in and out numerous times with no need to realign the caliper whereas with my QR disc bikes (past and present) it seems you have to re-align almost every time you remove the wheel. On my commuting bike I have stuck with cable discs (Spyre SLC) so I can adjust each pad individually to give more or less clearance depending on the riding conditions – i.e. more clearance in the winter when there is more rain, dirt and grit getting stuck betwixt pad and disc! I also find cable discs need less maintaining than hydraulics as over time the fluid in a hydraulic system will absorb moisture (hydroscopic) and fill up the system eventually causing disc rub and zero clearance at which point you have to drain a bit of fluid out (or better still, flush/bleed the system with new fluid). I doubt you will be having this problem yet though as it is still new.

 

You can get any Shimano or SRAM hydraulic flat-mount/through-axle combination set up correctly so that you shouldn’t get any disc rub at all unless you are riding in really foul conditions or you are built like Chris Hoy and putting in some huge loads into the forks during out of the saddle accelerations! 

 

Hope you get it sorted!

That’s really detailed & helpful mate thanks for that.

Just a whole different ball game than rims but hopeful that I’ll get used to it in time.

Once they are set up the performance is outstanding especially in the wet when you’ve been used to rims. Although I don’t normally like getting wet I was itching to try them in damp conditions just to see if they really are any better.

Once they’d bedded in I was left in no doubt.

hawkinspeter wrote:

ibr17xvii wrote:

jterrier wrote:

Given that it is hydro with thru axles, its only down to caliper position. So its fixable by loosening the fixing bolts and making sure the gap either side of the rotor is the same. Put a piece of white paper behind it to help.

So stand at the front of the bike & place a white piece of paper behind the calipers to eyeball the gap & then tighten the bolts? Good idea, like the sound of that.

Thought maybe I was tightening the fixing bolts too much & pads were moving a little. Either way I must’ve loosened & tightened those bolts a dozen times before it stopped rubbing & not sure what I did differently when it worked all of a sudden.

It’s much easier to see the gap with a white background and you need to get your head in just the right place to easily see the gaps as they’re usually around 1mm or so.

I find it tricky to tighten up the bolts without the caliper moving, so I usually hold the caliper steady whilst putting just a little tension on the bolts. Once both bolts have a little tension, you can then tighten them up properly (don’t forget to tighten the bolts – I use a torque wrench to make sure they’re up to 5Nm).

Once the caliper is aligned nicely, you shouldn’t have much of an issue with taking out the wheel and replacing it. I’m always removing the wheels when cleaning the bike and I don’t need to readjust the calipers for that.

I think that’s what was happening to me & it was driving me nuts. I guess the trick is to tighten them alternately a little at a time to stop the caliper moving.