TobinHatesYou wrote: ↑
Sun May 12, 2019 12:53 am
There was a brief moment in the late 90s when Magura's hydro rim brakes were top spec on MTBs. Disc brakes quickly dethroned them.
Hmmm... were you even riding bicycles in the 90's, I mean other than a tricycle.
The whole hydro rim brakes deserves a revisit, if for no other reason than to ponder it as another braking option. I was advocating for this option years ago. It's a nobrainer that hydro discs replaced hydro rim brakes in the mountain bike world. When your rims are buried in mud a good percentage (or any percentage) of the time it only makes sense. So, no one questions why discs are more appropriate for mountain bikes, that's a given, they are. But road, here's where it gets more interesting, especially at the highest level of road racing bicycles where weight and simplicity are king.
First let's clear up the history a bit, by going back to the late 80's. Magura had hdyro rim brakes quite successfully established in the mountain bike world. So, why not the road bike world. They actually came out with the HS77 hydraulic rim brakes for road bikes. It was just very bad timing back then. Why?... well guess what else was introduced around the same time.... integrated shift/brake levers. And that, was a no brainer in the road world... there was no delay in adpoting STI/Ergo shift levers... that change happened as soon as people could afford to make the switch. Despite what some people like to say about how adoption of this technology was slow (trying to compare it to the road disc brake scenario), it wasn't. Again, a no brainer... give me shifting and braking all in the same place, and no one mourned the death of downtube shifters for anything but nostalgic reasons. But where did that leave the budding hydro rim brakes that Magura just introduced. Well, without being able to integrate the shifting with braking, meaning you would still have to use downtube shifters, the Magura hydro rim brakes for road just never even got off the ground. End of story.
But damn... it wasn't a bad idea. Here's my own personal account of hydraulic rim brakes. I was doing a fair amount of loaded self contained bike touring back then, and had a custom touring bike built for me. It was very specific to loaded touring... and had mountain bike rear spaciing (135mm), long 44cm chainstays so my heels wouldn't hit my paniers etc. It was a touring bike to end all touring bikes back then... here it is in New Zealand, with Mount Cook in the backdrop...
Now, that bike originally had cable pull cantilevers on it, and it was during a trip from Lands End to John O'Groats (why not), that I found myself loaded up and heading down a very very steep section of road to a little town on the coast that I just thought I should go to (cuz why not). I really was afraid of a brake cable snapping at that point, and the pressure I had to exert by squeezing the brake levers with all that weight was a lot, while at the same time trying not to apply so much pressure that my tires would lose it on the damp roads. That was the moment that made me consider hydraulics in the first place. Leaving that town on the coast I was treated to a 30% uphill grade (accoring to the warning sign posted), and while I thought I might make it, some chugging car was coming up buring the clutch and I had to stop to let it go by. Needless to say I couldn't get started again on that grade with all that weight on the super narrow lane so ended up pushing to the top. All that is just preamble for what happened when I returned home about a month or so later.
Finding myself in a bike shop, I noticed a set of Magura HS77 levers collecting dust and thought... why not throw those on my touring bike along with the mountain calipers on the bosses and at least do away with the brake cables. I didn't care about the integrated shifting as I had reliable bar end shifters which were easy to service and fix in the event of a mishap on the road. So that's what I did. Hydrualic rim brakes on my touring bike. And this touring bike saw a lot of duty in the French Alps, Swiss Alps, Germany, Austria, West Coast of America, South Island of New Zealand, and all through the UK, among other shorter trips. The hydraulic brakes worked great... light action at the hands, and great braking.
Here's the setup... HS77 levers...
And the rather cumbersome mounatin bike (at the time) calipers... but boy did they work...
People shouldn't confuse the action of hydraulics with the action of the brakes themselves. Whether the bike is being stopped at the rim, or a rotor down by the hub, hydraulics makes that process very easy. And it is true, that a rim is in fact a huge disc in itself. So, if they say you need 160mm rotors over 140mm for the road, then it seems a no brainer that the 622m or whatever it is of a big road wheel would be the ultimate disc.
So... fast forward to the last decade or so.... why not now? The original problem of integrating shifting with hydraulics has been overcome by all three of the major manufacturers. Why not just slap on a set of relatively lightweight (unlike the mountain monstrosities I have on the touring bike) calipers on existing road bikes and voila... hydro rim brakes. No need to beef up forks and stays to account for the assymetric forces of disc braking on only one side of the hub. No need to add spokes to the wheels (the extra reinforcement is required due to all the braking action at the hub rather than the rim, and the resulting transfer of force through the spokes to the rim). No need to widen the rear dropouts, or alter existing chainlines, etc. etc., Basically, no need to essentially redesign the road frame from the ground up. Basically, no need to turn the road bike into a mountain bike. It's beautiful the way it was. Why uglify it.
Anyway, such a simple solution might have been quite nice for those that wanted the light action of hydraulics, but what would that do for the ultimate business model. Well, not much really. Whereas by adding mountain bike discs to road bikes... well now there's a business model that pays off. No need for the development and production of different braking technologies for both road and mountain, so there's a huge cost savings right there. The manufacturers just needed to convince everyone that discs are the only way forward, for everyone! Even when maybe the simple, effective rim brake may still be the best option for some disciplines... namely... that damn stubborn pro peloton. Why can't they just jump on board so the manufacturers don't have to explain why at the very highest level of road racing, the lowly rim brake is still the brake of choice. Damn those pros.
Anyway, just something to think about... hydro rim brakes are a very valid option, especially now that we have integrated shifting and hydraulics and rim braking is very very good. I'm going to use Campagnolo Bora as my gold standard, because I realize there are some very poor rim braking options out there as well. But if Campagnolo can make such a superb rim brake/pad combo, I'm sure others could too if they tried. Now, for economic reasons, there's little chance in hell that the manufacturers would get behind this while the push to discs is almost complete (damn those pros with their fancy light efficent bikes that they don't want to give up). At least not right now. Perhaps when they've got everyone switched over to discs, and new sales have died, and they need something to refresh the industry once again, then someone will pop up out of nowhere with this novel new idea, except it's not new. But don't hold your breath. Of course, the proper marketing can change everything.
Anyway, not trying to convince anyone that discs are bad, and rim brakes are good, but I do believe that there are disciplines where each has very distinct advantages.
Happy Mothers Day everyone!