Two sets of brakes?

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mikeymo
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Joined: 27 Sep 2016, 6:23pm

Two sets of brakes?

Post by mikeymo »

Would that be weird?

I've noticed that Spa's latest disc-equiped tourer also has mounts for V/Canti brakes.

Quite a few people, including me, have cross-top levers on drop bars. Would it be bonkers to have both sets of brakes, the discs operated by the drop levers, and V/Canti's operated by levers on top?

Pros - backup for those apocryphal failures of discs. Cooling off opportunity for long downhills. Backup for long tours in out of the way places if one set breaks. Double the number of brake discussions to engage in on CUK.

Cons - weight. More cable. Double the number of brake discussions to engage in on CUK.
mattsccm
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Re: Two sets of brakes?

Post by mattsccm »

Could do I guess but I would have the discs (hydro) operated from the tops. Bog standard MTB brakes and thus no fuss and rim brakes from main lever. Also no fuss. The only limitation is that you would need older 25 ish mm bars and depending on your brakes maybe a touch with a file. Did this to create cable operated hydros before the big names brought them out.
This way you have two sets of well developed brakes. Bar top levers tend to have less efficiency that normal levers as the design splits the outer and really just compresses it and leverage isn't great. Usable not brilliant.
Brucey
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Re: Two sets of brakes?

Post by Brucey »

a third brake could make sense as a drag brake, on a heavily loaded bike, just as it does on a tandem. Otherwise it seems like overkill. Having bosses on the frame for cantis/Vs falls into the 'won't do any harm, might do some good' category, so why not...? There's very few situations where you can't get by with one brake for a day or two and you can pick up a V brake almost anywhere.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
mikeymo
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Re: Two sets of brakes?

Post by mikeymo »

Brucey wrote:a third brake could make sense as a drag brake, on a heavily loaded bike, just as it does on a tandem. Otherwise it seems like overkill. Having bosses on the frame for cantis/Vs falls into the 'won't do any harm, might do some good' category, so why not...? There's very few situations where you can't get by with one brake for a day or two and you can pick up a V brake almost anywhere.

cheers


That's what I thought. I don't know why more disc frame builders (at least for tourers) don't but canti bosses on. I don't suppose it makes that much difference (maybe cable stops on the top tube?). Whereas the opposite, a bike built for cantis, but with the "option" of discs would involve a strengthened fork.

Having been down a couple of long steep hills, unloaded, in Yorkshire and Scotland, the reassurance (if nothing else) of having an alternative way of stopping would have been nice. But probably only in my mind.
Vorpal
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Re: Two sets of brakes?

Post by Vorpal »

Are there rims that take both? I guess it should be feasible to put disk brakes on a rim designed for rim braking. Are rims for disk brakes only that way because they are lighter & don't need braking material? or is there something different in the spoking, as well?
“In some ways, it is easier to be a dissident, for then one is without responsibility.”
― Nelson Mandela, Long Walk to Freedom
mikeymo
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Re: Two sets of brakes?

Post by mikeymo »

Vorpal wrote:Are there rims that take both? I guess it should be feasible to put disk brakes on a rim designed for rim braking. Are rims for disk brakes only that way because they are lighter & don't need braking material? or is there something different in the spoking, as well?


I think that's what makes a "disc specific rim" disc specific. But any rim will work with discs, I think. It's the hubs that are different. My rims would take rim brakes, I think.
fastpedaller
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Re: Two sets of brakes?

Post by fastpedaller »

Vorpal wrote:Are there rims that take both? I guess it should be feasible to put disk brakes on a rim designed for rim braking. Are rims for disk brakes only that way because they are lighter & don't need braking material? or is there something different in the spoking, as well?

Surely just use 'rim brake' rims and the job's a good-un :D
Vorpal
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Re: Two sets of brakes?

Post by Vorpal »

fastpedaller wrote:
Vorpal wrote:Are there rims that take both? I guess it should be feasible to put disk brakes on a rim designed for rim braking. Are rims for disk brakes only that way because they are lighter & don't need braking material? or is there something different in the spoking, as well?

Surely just use 'rim brake' rims and the job's a good-un :D

That was my first thought. But I'm not a wheel builder, and most of my bikes do not have disk brakes, so I don't know as much about them.
“In some ways, it is easier to be a dissident, for then one is without responsibility.”
― Nelson Mandela, Long Walk to Freedom
9494arnold
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Re: Two sets of brakes?

Post by 9494arnold »

Quite a few of the "Cross top" levers actually interrupt the outer cable, and rely in the return spring in the Brake r in the "Main" Lever. So to do what you suggest might involve finding cross top levers with a return spring (Old School brakes had springs in the brakes, more modern ones in the levers) . (I spent 2 days trying to get Shimano sidepulls to work with Old School Campag Levers . :oops: )"
pwa
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Re: Two sets of brakes?

Post by pwa »

We have a tandem in the garage with two rear brakes (rim and disc in this case) and it is easy to alternate between them on long descents, reducing the risk of overheating, so it does work as a concept. And the weight of a single vee brake set-up isn't much.

Many years ago the Missus and me did a tour that took us down this little hill. https://www.google.com/maps/@46.5293259 ... 6?hl=en-GB
With camping gear we had to stop numerous times on the way down to allow our sizzlingly hot wheel rims to cool. An extra rear brake would have been worth the extra weight.
mikeymo
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Re: Two sets of brakes?

Post by mikeymo »

9494arnold wrote:Quite a few of the "Cross top" levers actually interrupt the outer cable, and rely in the return spring in the Brake r in the "Main" Lever. So to do what you suggest might involve finding cross top levers with a return spring (Old School brakes had springs in the brakes, more modern ones in the levers) . (I spent 2 days trying to get Shimano sidepulls to work with Old School Campag Levers . :oops: )"


I'm not thinking of actual 'cross top' levers. Just ordinary straight bar brake levers, but in the 'cross top' position. Two completely independent brake systems, in other words.
Jamesh
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Re: Two sets of brakes?

Post by Jamesh »

On a similar function
Why not have a regenerative braking as modern hybrid cars do.
All that energy wasted going down hill could charge a lipo battery and a small motor in the front wheel.
So long as the net gain is zero it's not really cheating?!!!
I shall patent if in the morning!!

Cheers James
Mike_Ayling
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Re: Two sets of brakes?

Post by Mike_Ayling »

Another consideration:
Rims designed for disc brakes have less metal and are not always machined on the surface where rim brake pads apply the friction to operate.
Rims designed for rim brakes have more metal than disc brake rims because the rim brakes wear the rim away over time.
This is a real disadvantage in the rim brakes versus disc brakes debate.
(I still prefer rim brakes over discs but I suspect that I am becoming part of a small minority here.)

Mike
Brucey
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Re: Two sets of brakes?

Post by Brucey »

Mike_Ayling wrote:Another consideration:
Rims designed for disc brakes have less metal and are not always machined on the surface where rim brake pads apply the friction to operate.
Rims designed for rim brakes have more metal than disc brake rims because the rim brakes wear the rim away over time.
This is an imaginary disadvantage in the rim brakes versus disc brakes debate.....


FTFY

-unless folk suppose that having rims about 30g heavier (and stronger to boot) is a big deal on a touring bike?

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
Vorpal
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Re: Two sets of brakes?

Post by Vorpal »

Jamesh wrote:On a similar function
Why not have a regenerative braking as modern hybrid cars do.
All that energy wasted going down hill could charge a lipo battery and a small motor in the front wheel.
So long as the net gain is zero it's not really cheating?!!!
I shall patent if in the morning!!

Cheers James

There are already electric bikes with regenerative braking. 8)
“In some ways, it is easier to be a dissident, for then one is without responsibility.”
― Nelson Mandela, Long Walk to Freedom
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