Gravel / Gravé / Gnarmac / Groad / ATB

These days I generally get shops to build 'new' bikes and then I don't touch the hydros again until it's time to replace the bike or swap groupsets or something equally dramatic. I don't even have any bleed kits now.

And for good reason, the average prommuter rides more than I do. I'm a scumbag anyway, I ride mechanical discs off road and rim on road. Hydraulic on the hire bike on Tenerife was scary, the modulation was either go forward or stop right now thank you very much

We had the opposite in Tenerife with hired rim braked road bikes.

It was partly my fault for just stealing someone's DEATH ROUTE and riding it without checking it

Put it this way, I made it around the corners but if there was anything coming up the hill I'd probably not be writing this and my missus used a rock wall to stop with and walked down. FUN FOR THE WHOLE FAMILY! :D

These days I generally get shops to build 'new' bikes and then I don't touch the hydros again until it's time to replace the bike or swap groupsets or something equally dramatic. I don't even have any bleed kits now.

As a pathetic apartment-dwelling millennial, fixing bikes is one of my few tastes of self-sufficiency and I'll be damned if I give that up.

I bought some lovely new handlebars 3 months ago and keep putting installation off because of the dreaded bleed.

Were you cycling off cliffs?

I was surprised also

hydro disc di2 is the least maintenance I’ve ever had to do.

Wait…why would new handlebars need a brake bleed?!

Don't get me wrong, I still seem to spend half my life working on the bastard things, it's just that big initial builds without a workstand and Madison account = no thanks.

May as well have been. Nah, they were roads or sort of roads - concreted camis. Dunno what the descent in question was but I definitely remember my missus having a minor breakdown on a 28% climb up somewhere else on the route, all the while looking over at the, say, 9% hairpinned road next to us.

Exactly. I'd have had less Di2 work to do too if I'd put the batteries in nicely (as I've been mentioning in the Di2 thread).

People of Gravel. I have a problem, and as forward thinking bike riders I need your opinion.

My Hope RX4+ Flat Mounts are the +20 variety, which looks pretty and does away with an adapter. Now this wasn't an issue on my SL7 which was obviously 140 standard. But the issue is my Crux is already +20 and thus 160 standard.

So what do I do? both options will cost the same.

1. 180mm disc? This would involve changing the rear one also to both be CL mountain bike as they don't do the road one in 160mm.
   
2. New RX4 calliper and adapter. This would not be pretty like the current solution.
   
   

For reference: I'm a little fat and it's hilly round here, so a 180mm disc would not be insane and I don't think it would be too out of place on a 61cm frame either.

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Yeah do the big disc if it works

You can’t do enough stopping

Don't they usually spec a max size? Could the bigger disc create more bang crash explosion?

I have some standard 160mm black rx4+ Shimano calipers for sale if anyone’s interested.

By +20, do you mean that you bought too 'front' RX4+ callipers? I have the non+ versions, one front flat mount (longer), one rear flat mount (shorter) - neither need an adapter as it's built in - and was running 160mm rotors on my Diverge.

Hope have a rotor size to rider weight + bike chart, and for gravel they suggest 180 front and 160 rear for the well fed chaps and defo shouldn't look out of place.

Perfect timing.

I ride my rim brake road bike to work mainly because it’s nicer to ride SPD-SLs with trainers than MTB pedals.

The Crux frame is compatible with 140 or 160 mm rear rotors and uses the flat-mount standard. The Crux fork is designed for 160 or 180 mm rotors. It uses the normal flat-mount bracket, which is set in the "low" position for 160 mm rotors.

The Hopes have the adapter built in, and default +20 (high) so when combined with a fork mount that is designed to be low by default it equals 180 rotors.

@snoops PM inbound.

@infmz believe the + simply denotes a few tweaks vs the original RX4, with the main one being the angle which the hoses exit the calliper after feedback from the masses.
I have a ‘normal’ flat mount which required adapter and a front flat mount which includes adapter built in but in the ‘high’ setting - they are obviously designed for 140mm forks to be run in a 160 config.
I’m fat, but I’m on the cusp of the 180 recommendation. Humph.

I never thought about putting 180 on the gravel bike. I guess with the bigger tyres we can run these days (MTB tyres will fit now, ie. 27.5x2.1) you're less likely to find traction the limiter. I guess you'd get used to it on the road although if I've managed with 160 all this time, is it overkill or is there a noticeable difference for us fatties?

Oh I see, I can sort've picture it in my head (despite no sleep from being on-call). My weight shifts between 80-90kg depending on the season and would totally get 180mm for myself. Assuming your bigger (sorry dude), 180 up front defo makes sense.

Did you reach out to Hope to see if a 180mm RX rotor is coming? Might save you having to buy a set of 180s, which for Centerlock especially is not exactly cheap.

@yeahdext whoops forgot to tag

Four piston is very nice. Noticeable difference.

180mm rotors on the mtb is noticeable, so can’t see why it wouldn’t be on the road bike.

https://peak-torque.com/products/180mm-flat-mount-adaptor-for-road-gravel-bikes

I have Rx4 180mm in the front and Shimano 160 mm something on the rear.
My main drivers were

1. The Hope caliper was cheap 2nd hand and looks pretty.
   
2. Overheating on long descents bike packing with a system weight of 115kg.
   Not sure they are any more “powerful” than the 160mm SRAM on my road bike.
   Nobody has noticed the large disc yet so it must look fairly normal.
   
   

+1 on every point made - was gonna share Peak Torque's link earlier.

My SRAM Rival (new AXS) and Force calipers (old AXS) feel very on/off. The Hope RX4 4 pots are a dream in comparison, but a nightmare to setup. Power and modulation are great. On my mtb I have some Tektro/TRP 4 pot brakes made for e-bikes paired with 180mm rotors. Not experienced such good braking before, and I can only imagine that the higher tier stuff from Hope, Shimano and Magura is even better.