Disc Brakes on touring bikes

[Ajay]

I lurve my BB7s
I've long since had a small bee in my helmet with the fact that most cycling kit is designed with a 65kg Italian in mind, but the BB7s (on my Kona Sutra) actually feel and perform like they were made for me - a "fully grown" 108kg anglo saxon. The control and confidence I get from them is amazing. They really proved themselves on their first tour last summer, a French end to end which included some long long descents eg into the valleys of the Dordogne Lot and Tarn, plus the runs down Mt Aigoual and Le Ventoux.
Ive had a rim blow mid descent on tour before, so I would never go back to rim brakes on a tourer.
Plus discs have the added benefit of when you've finished your descent off the mountain you can use your rotors as hot plates to cook your dinner.

 

[snailracer]

Once they get adopted by the weight weenies they will get smaller. At present they are all crossovers from MTB technology where bigger rotors than stock are often better....

Hmmm I can't see why a road bike rotor should be smaller than a MTB rotor, unless a MTB rotor is over-engineered but why should it be?
The all-up mass of rider+bike is similar and while the MTB has wider tyres, they are wider knobbly tyres which presumably have less grip on tarmac. Off-road, grip is poor no matter how wide the MTB tyres are. You could even say a road bike usually goes faster, therefore needs bigger rotors than a MTB, no?

 

[jjb]

Off-road, grip is poor no matter how wide the MTB tyres are

I think this is the bit to question. On road you need fairly light braking to lock up and slide, so small discs are plenty. On some off road surfaces, grip is much better and the right knobbly tyres won't lock at all eg downhill on dry heather/bracken.

 

[john wood]

We've been riding a Cannondale road tandem fitted with BB7's and 203mm rotors for almost three years,its the only tandem we've ever owned that I can stop almost as quick as a solo with only two fingers(one on each lever) wet or dry.Truly awesome braking power.
I also have a Kona Dewdrop with BB7's and 160mm rotors,well powerful enough for any touring load IMO.
Discs and more specificly BB7 cable operated discs are the way forward for touring IMO,the main reasons are no rim wear and predictable very well modulated stopping whatever the weather even if the wheel is out of true.
Yes they're a bit heavier than other braking systems and you do need a substantial front fork to cope with extra loads imposed around the dropouts,its also better if the rear caliper is mounted within the rear triangle but if you want to see bikes made for the job take a look at Salsa Vaya or Fargo or Surly LHT disc.

PS I really can't see a need for hydraulic discs on a bicycle,especially with a caliper like the BB7 on the market.

 

[GrumpyGregry]

PS I really can't see a need for hydraulic discs on a bicycle,especially with a caliper like the BB7 on the market.

I have, and prefer hydraulic brakes on my mtb, Avid Elixir R as it happens. Off road on an MTB in the wet in the right 'wrong' terrain I've gone through a pair of pads in a day. Hydraulic disc systems are self adjusting. Cable ones aren't. I don't want to stop to fettle my brakes, with cold wet hands, once ever hour or so. I especially don't want to find out I need to adjust my brakes when travelling at some speed halfway down a mountain!

I have cable operated disc brakes on my drop bar tourer Avid BB7 Road as it happens. Upgrade from BB5's. Not sure what the point of BB5's are. Awful things. BB7's in the right 'wrong' conditions can eat pads at a similar rate. A wet weekends loaded touring on NCN7 last year saw me rip through a set of pads. Constantly having to stop and fiddle was a PITA but that is offset by the rarity of such events and the delight I take in touring on a drop barred bike.

 

[MacB]

Greg, I was reading some comments on bedding in of pads. Seemed to think that proper bedding in, whatever that is exactly, greatly extends pad life, especially if using sintered.

 

[GrumpyGregry]

Greg, I was reading some comments on bedding in of pads. Seemed to think that proper bedding in, whatever that is exactly, greatly extends pad life, especially if using sintered.

I've read similar. But could not find consistency as to what constitutes proper bedding in! Usual story, ask 10 cyclists get 13 opinions.

Also, does it not seem slightly counter-intuitive given pads are constantly wearing and all bedding in does is dress the original surface out of the packet.

 

[MacB]

I've read similar. But could not find consistency as to what constitutes proper bedding in! Usual story, ask 10 cyclists get 13 opinions.

Also, does it not seem slightly counter-intuitive given pads are constantly wearing and all bedding in does is dress the original surface out of the packet.

Ah, just thought you might have known more, I'm in the same boat as you, read this stuff then read a variety of opinion on what constitutes bedding in. I'm sure it would vary anyway depending on rotor and type of pad.

To be honest I've mainly seen it in terms of a response to a grumble about wearing through a set of pads really quickly. As in, you didn't bed them in right, followed by no detail or a vague anecdote. I'm sure there is some quality info lurking at the root of all this. But, as usual with the net, it's obfuscated by people just repeating what they think makes them sound knowledgeable. I still use that BB7 setup link you gave me, that's the level of quality I like

So far I've been able to glean that 'dragging' the brakes isn't a good way of bedding them in. You're better with a few well spaced out heavier braking activities. How many, for how long and at what speeds seems to be up in the air though. The logic being that the braking surface heats up and cools and somehow seals??? Whereas dragging them doesn't allow the cooling period and can somehow create a surface that will wear far more rapidly??? This is different to dragging them once they are properly bedded in apparently, then it's ok if you must.

Anyone want to add to this party?

 

[jjb]

I read an hour or two on this subject and ended up not bothering with bedding in. I do suppose that if there were an advantage, there'd be a brand of brakes saying "pre-bedded", or there'd at least be instructions on the packaging for bedding them in.

 

[john wood]

I have, and prefer hydraulic brakes on my mtb, Avid Elixir R as it happens. Off road on an MTB in the wet in the right 'wrong' terrain I've gone through a pair of pads in a day. Hydraulic disc systems are self adjusting. Cable ones aren't. I don't want to stop to fettle my brakes, with cold wet hands, once ever hour or so. I especially don't want to find out I need to adjust my brakes when travelling at some speed halfway down a mountain!

I have cable operated disc brakes on my drop bar tourer Avid BB7 Road as it happens. Upgrade from BB5's. Not sure what the point of BB5's are. Awful things. BB7's in the right 'wrong' conditions can eat pads at a similar rate. A wet weekends loaded touring on NCN7 last year saw me rip through a set of pads. Constantly having to stop and fiddle was a PITA but that is offset by the rarity of such events and the delight I take in touring on a drop barred bike.

The C/dale,which is our winter tandem and so gets the worst of the weather,does see some mucky Cheshire lanes and towpaths and I've never yet needed to adjust pads on the road.In fact its only on its third set of pads since we bought the bike almost three years and 4 to 5,000miles ago.I can understend an MTB would see more muck than our tandem does but it seems very rapid pad wear.
What kind of pads are you using?

 

[GrumpyGregry]

^ Avids own, and a couple of other replacement brands whose name escapes me. I don't see 1000 miles from a set of pads.

NCN7 in mucky weather is a little more aggressive than lanes and towpaths, my companion shot his rim brakes over the same weekend.

Avid's published bedding in method

1. Accelerate the bike to a moderate speed
(approximately 19 kilometers or 12 miles per
hour), then firmly apply the brakes until you are
at walking speed. Repeat approximately twenty
times.
2. Accelerate the bike to a faster speed
(approximately 32 kilometers or 20 miles per
hour). Then very firmly and suddenly apply the
brakes until you are at walking speed. Repeat
approximately ten times.
important: do not lock up the wheels at any point
during the bed-in procedure.
3. Allow the brakes to cool prior to any additional
riding.
this concludes the disc brake pad and rotor bed-in
procedure. you did a great job! you are now ready to
ride. enjoy!

You are now ready to ride with badly glazed pads ime. Screeeeeeetch-tastic.

I'm of the bedding in = just ride normally school

 

[john wood]

Greg
When I asked what pads,I should've asked what compound?
I'm no expert on different pads as I only ever use Organic but I believe Sintered are harder than Organic so would/should(?) last longer.
Of course that only counts if you're using Organics
when I said the tandem was on its third set of pads,now I've checked the rear rear is on the third set (October last year) the front is still on its second.
I'm finding the pads from Superstar Components good kit and @ £18 for three sets good value too.

 

[jay clock]

I went from a Galaxy lookalike with cantis (terrible) to a Koga Miyata with v brakes. These are fantastic. But having an MTB with discs, I would definitely be keen to get these an my next tourer. If I ever get one.

It doesn't seem so long since the general word seemed to be that "the laws of science prove that disc brakes on dropped bar bikes mean they are impossible and in any case discs on tourers will cause the forks to snap off if you try and brake even at 1mph"

 

[MacB]

It doesn't seem so long since the general word seemed to be that "the laws of science prove that disc brakes on dropped bar bikes mean they are impossible and in any case discs on tourers will cause the forks to snap off if you try and brake even at 1mph"

It's quite funny to see the attitudes change as more and more manufacturers bring out options. Even the likes of Thorn have now specced disc brakes, though they still insist steel will combust if used as forks for disc brakes, so only offer carbon ones, a material they have been less than complimentary about in the past

 

[pkeenan]

I'm wondering if many people here have come across the Andra CSS (Carbide Super Sonic) rims? I have them on my tourer (Thorn Nomad), used with Swisstop Blue brake pad, Shimano XTR M970 V-brakes.
When I was in the market for my tourer (as some may recall), I was really heart-set on disc brakes. Eventually I decided the Nomad was the bike for me, though there was no disc brake option (or at least it was rear wheel only [can't recall] - I think this might have changed now). So I looked at their alternative - let's keep in mind that they designed this bike for hardcore expedition touring, so one would expect a pretty good substitute. I looked these Andras up, read what people thought of them in forums and such - they seemed very highly regarded. Multiple people claiming they've done up to 20000 miles on their original rims and pads.

My own personal verdict of them - they are absolutely brilliant. I have done about 4500/5000 miles since getting my bike in July (about 1500 of which was a very heavy loaded tour) and neither the rim nor the brake pads are showing any signs of wear. My wheels are also still perfectly true. (I've also not yet had a puncture, but that's for a different discussion!)

Of course, if one prefers disc brakes - that is a completely different matter. I would probably have gotten them, had I opted for a different bike. Though I think what my point is is that there *is* an alternative, and if it comes well built, it can (in many ways) be much more advantageous that discs, surprisingly so.

Whoever built my wheels is a very skilled craftsman - I can say that much.

Food for thought!