Something disc brakes need
 

Hi guys. I recently bought a bike with disc brakes. In my case, I have to remove the front wheel to get it in my car. The little plastic piece that I have to put in between the calipers when I do is a terrible solution IMHO. Surely, with all those brilliant engineers designing all this amazing technology these days, they could come up with a way to lock them when there is no disc inserted, no? I sure wish they would, even if it did add a couple of grams. It's just a matter of time before I loose that little plastic thing.

??? plastic? I'm thinking the things between the calipers are brake pads, which are not plastic. regardless, yeah you have to keep aye on a cpl things when putting the wheel back on ...

No, I'm talking about the thing you have to put between the brake pads to keep the brakes from seizing if you accidentally hit the brake lever with no disc in there.

Another solution, at least for Shimano, are the yellow lever locks that many (all?) levers ship with; they keep you from shifting and from actuating the brakes. That's what I use when I travel with the bike. If you go down to your local bike shop and ask for some, they probably have dozens that they throw away every week. They are left and right specific, though, so be sure to get a pair. They may also be model-specific, I don't know.

Edit: these are what I'm talking about -

https://cimg1.ibsrv.net/gimg/bikefor...1a5f4c5ad4.jpg

I've never used a pad spacer/block when transporting my bike and this has never been a problem. Just don't squeeze the brake lever with the wheel removed and it'll be fine.

Even if you do squeeze the brake lever for some reason, all you have to do is use a plastic tire lever to push the pads back into the caliper before re-inserting the wheel.

The problem with having some kind of lockout on the brakes is... what happens if you re-insert the wheel and go riding off and forget to unlock it?

I didn't know this was a thing. I've been putting disc braked mtb's in the car since 2008 and never had a problem.

I got a couple of those thingies, in a bag, along with sundry hydraulic parts, with one of my bikes. I don't use them and if I did squeeze my pads together inadvertently, I'd just pry them apart with a tire lever or something, as mentioned above.

Yeah, I think that it's mostly a non-issue, but I could see how it might be problematic as pads near end-of-life. When I travel with the bike, it's 1500 miles on the road, so I'll take the 30 seconds of popping on the lever locks as insurance.

Old business cards are good for that purpose - fold one in half and shove it between the pads. If you lose one, just grab another from the old box of cards you never give out anymore.

What CAN happen is if the lever gets squeezed you can pop the pistons out of the calipers and it's just about impossible to put them back in.

and it's a mess

I know some "expert mechanics" will claim this is no problem but then you are faced with the prospect of re-bleeding the brakes.

so I use the blocks, mostly in the stand, to prevent such an occurrence

/markp

Just jam a piece of cardboard in there. You have some cardboard lying around in your trunk or truck, right? Improvise my man.

Once you have a few bikes with disc brakes you soon accumulate a stock of the plastic spacers. I have at least half a dozen of them in my toolbox. Can’t say I lose them very easily. I just keep one in the car and one next to my direct drive trainer.

It's not a requirement. Just don't squeeze the lever.

I think it would have to only be able to work if the disc was not between the calipers. In other words, only operable when the wheel was not on the bike.

The pads will hit each other so that wouldn't happen.

Like others said. It's not a thing.

My first gen Campy Ergo brifters had a button which when pushed would open the brakes to ease tire/wheel removal. They would stay locked open until the button was pushed again. Thought it was a cool feature which could be applicable here.

With my first disc bike (MTB) removing the bike from the back of the car, I inadvertently pressed the front brake lever which caused some scrambling to figure out how to move the pistons back. A screwdriver took care of it, but accidents do happen. Learned my lesson the hard way and am now super cautious.

How much lever squeezing are we talking about here?

With pads installed, I don’t see how the pistons would extend far enough to come out. This definitely can’t happen on my Shimano GRX brakes.

If I were boxing/bagging up a bike for a flight I’d probably use the blocks. I frequently load my bike on a fork mounted roof rack with the front wheel off, and don’t do anything- and have never had a problem even on multi-state drives.

I think this is a non-issue

I’m on board, but how would you do it? Rim brakes put them in the caliper, which you could do with cable disks but maybe not hydraulic. Perhaps a latch or safety in the lever. It would not be automatic. The hydraulic system basically can’t “know” if the disc is present. Anything that actuated or sensed that would interfere with the free spinning of the wheel. I can imagine some kind of interlock with the axle but those components don’t normally talk to one another

it would be nice if they were all the same, wouldn’t it?

7 bikes in my garage. Mix of Shimano and SRAM brakes. On every bike...At one time or another I've loaded them up with the front wheel off and have accidentally hit the brake lever. Pistons never popped out.

You are are right. It's a non-issue.

I have several different types but they all work fine on any of my bikes. I have a mix of SRAM, Shimano road and mtb brakes. They are all basically just plastic wedges.

That’s only ever going to happen with the brake pads removed and several pumps of the lever. So not an issue for wheel off transport.

I'm pretty much with the OP here. It's not terrible. It's just a nuisance we could do without. I put the plastic tab in when I remove the wheel just to prevent something bad from happening. It's recommended. The last time I traveled, I forgot to put the tab in. Nothing bad happened. But I'm still going to use the tab as a preventive measure. It's not that much trouble, but it is some trouble, and it's recommended to prevent more trouble.

Would new business cards work? :D

I got 250 business cards.

Then they changed one digit of the phone number. So I got 250 NEW business cards.

Now we've moved.

I'll be able to center my calipers for the rest of my natural life.