Anyone know anything about disc brakes?

Merlin are selling the tektro Gemini m535 for 53.95 delivered. Not bad for a 4 piston set up.

My daughter has moved up to a 20" bike with cable discs. She cycles to school, but the front wheel gets removed daily for her return trip in the car (separate issue). 2/2 days of this routine and the disc rubs the pads big style when replacing the wheel (QR). Other than cycling home, any rules of thumb to avoid this? It's not like I'm clamping the QR with wildly different force, fork is alloy and not noticeably flexy

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Bent rotor?

It's probably just clamping the wheel in a slightly different position each time, meaning calliper alignment is out a bit.

Might be teaching you to suck eggs and kinda don't expect it to be a perfect fix but, put weight on the bars to try and center the wheel as far into the dropout as it'll go for more consistent positioning?

Thanks both, not a bent rotor thankfully as I got the calliper aligned nicely this morning (and the bike has barely been used!) @M_V not at all, will persevere this evening and see if I can get the wheel back in the same place twice! Failing that, work out how to wedge it in the boot in one!

Roof rack?

Can't see a world where you'll get your technique so good that you install and remove a disc brake wheel every single day without rubbing

Cheaper option engaged! Thanks for pointing out it's a total folly, thought as much. Will get the caliper aligned then leave it!

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Banjos. Do I need to care about them?

Current plan is to get a full m6120 set from Merlin (because it's more economical than buying hoses separately) and swap levers to GRX. brakes are going on IS adapters.

I know I need BH90 olive and barb, what's the nut for in this set, and do I need it?

Nut is for the shifter, deore use a straight hose so no banjos to worry about.

If they're going on flat to IS adapters I'd stick with flat mount brakes, but if it's a POST/IS frame then the 4pot brakes work well.

If you're buying the full set from merlin (levers and callipers), you shouldn't need to buy any extra parts like that.

There's now an "easy install system" whereby if you don't need to cut the hose you literally take a cap off, shove it in the hole, and then do up the flare nut on the lever. The nut in the set you linked to is a flare nut for where the hose goes into the lever. The olive is pre-installed in the lever and the flare nut.

Even if you do need to cut the hose, the brake set I bought around February had extra barbs in it.

Check out the installation manual for brake set you are buying, it will describe the process.

Banjos. Do I need to care about them?

Only if you like bluegrass.

nice, cheers for the info guys, will study the installation docs, hopefully Shimano's site is back up now.

GRX levers do need the special flange nut that you linked to, meaning you will need to re-terminate the Deore hoses and may need extra barbs and olives depending on exactly which parts you use from what set.

Stupid question about hydraulic disc brakes - I need to disconnect hoses from caliper and/or lever in order to install my brakes on a different bike. Can you disconnect the hoses without fluid going everywhere? I'm getting the bike shop to set up the brakes, but want to just give them the bike plus brakes.

Drain the fluid out of the system before you remove the hoses, I don't think you can't seal the hoses. You would need to bleed the brakes on the different bike anyway. If it's clean you could keep the fluid to use for bleeding the brakes at home.

If you don't squeeze the lever while it's disconnected the fluid will stay where it is due to surface tension on the tiny surface area at the end of the hose. Try not to disconnect both ends of the hose at the same time.

It's definitely not going to squirt everywhere though.

I need to bleed my SRAM level T disc brakes (circa 2016). I have no clue, should I just read the SRAM manual? Do I need a 'bleed kit', can anyone recommend a particular one?

"DOT 5.1 DOT 4 ONLY" What's the difference in those two oils?

Look at a YouTube videos. But if you are near me can bring fluid and syringe to do it for you.

But it is easy as for dot 5.1 or 4 not much different for a cycle and 500ml automotive is cheaper than 125ml cycle.

The SRAM original kit is pretty good but not that cheap for home mechanics

I'm looking at the cheaper kits as it seems like I don't need to do it often. This is the first bleed I've had to do. I think I might have let air get into the system by pushing the pistons too far out when trying to clean them.

Any thoughts on this idea?

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Are bleeding the air out or replacing the fluid?

Look up how to do a reverse bleed, basically you push fluid up for the brake caliper till clean fluid comes out the top.

https://youtu.be/4KCjs21lyQ8?si=wq-w2FD9Nf75T5X9

Silly question but okay for sram dot rubbish?

My spares box Ultegra (front) R8070 caliper pisses oil when you pull the brake hard. Can't seem to locate them online for a reasonable price. Is there a shimano alternative before I buy another set of RX4?

Any Shimano caliper will work.