Cycling UK Forum

When I got my last bike I popped an Avid Elixir hydraulic disc on the front, and I've had over 2000 miles of literally flawless use (no adjustments or anything!)

Now after about 2200 miles, I'm thinking about new pads, and the other week I did have to bleed the fluid (a new experience for me but I bought the Avid bleed kit and it took about half an hour inclusive of opening the box and finding the instructions!)

So, personally, my first on-road bike with discs has been an overwhelming success. I paid £80 I think, VS say £30 for a rim brake, lever & cables, but if I priced my maintainance time I think it's broken even already! (All the moreso when you consider that this time last year, I was building a new wheel because I'd worn through the rim in a single winter's commute)

I've ridden it in all weather and have no complaints. The quick release has never faltered, the extra weight (if any) hasn't been noticeable, etc. etc.

Fashion / tradition / inertia is the only real reason I can see behind the surprising persistance of rim brakes on new bikes. (Can understand why you wouldn't bother converting your bike, but less so why you'd set out to buy a rim braked frame)

You've said everything I would expect about disc brakes vs rim brakes. I cannot see any disadvantage whatsoever. Disc brake technology has come on in leaps and bounds over the last few years, and I think that the rim brake has had its day. Disc brakes are even on cheapo bikes now, not just the high-price end of the market.

If, and it's a big if, I were to buy a new bike of any persuasion or use, it would be a disc brake bike. I am yet to be convinced about hydraulic vs mechanical.

Interesting! I've run Magura hydraulic rim brakes for 13 years now. I've never done anything more than snap in new pads.
I now have Maguras on two tandems, an MTB and a Tourer. However, I'm still not convinced about discs. For a road-based machine then it strikes me as a solution for a problem that doesn't exist for me. The Maguras can pull up a tandem and child trailer on a 1 in 4 in torrential rain in Devon - the limitation is still grip.

There are theoretical advantages both ways, and lots of this needs to be compared properly on a like-for-like basis. There is a world of difference between a light tourer doing B&Bs in France, a loaded tandem and a bike touring in remote areas with zero spares availability. Trite statements like "ZZZ is better" don't cut it. It is (and will remain) always a trade-off and there are no cut-and-dried answers.

In the context of motor cars many of the developments we enjoy as normal now originated from motor sport. This does not seem as clearcut in cycling, the pro road racing teams have not began to use disc brakes although I'm sure the off-roaders do (I'm watching electronic gear shifting with interest). I suspect the answer is that for the road racers there is no need - their existing brakes do the job well. If Wiggins et al began to use disc brakes they would become fashionable and every young club racer would want them too.

As it is, the systems which are available seem to be well developed, effective and reliable. I have cable operated discs on the tandem, backed up with a third rim brake. They work very well and can stop some heavy weights when we are fully laden.

Like MickF above. I'd be looking for discs on a new bike should I be buying one (and also hub gears) ..... no darling I'm not wanting yet another bike!!!

mw3230 wrote:I suspect the answer is that for the road racers there is no need - their existing brakes do the job well.

Well?
It depends on the weather!

We live on a 1in4 hill - near the bottom - and one day last year I was caught in TORRENTIAL rain on my way home. I would normally fly down the long Gunnislake Hill and turn off in the village. A short way along, then strain up the 1in4 for a hundred yards. Simple, but the rain put me off from going down the main road.

I turned off at the top of the main hill, and took our lane. It was like a river! Even though I was pulling on the brake levers as hard as I could, I couldn't have actually stopped! All I could do, was to hold back from careering out of control.

I have good quality rims - Rigida Chrina - and Campagnolo Chorus brakes. They work faultlessly and progressively, but on that day in that rain, they didn't!

Disc brakes would have been perfect.

I believe discs are banned from national level cyclocross; the reason given as "too dangerous, they stop too quickly". This is clearly ridiculous at face value, the only danger of "too efficient" brakes is that a rider goes over the bars and that should be mitigated by the excellent modulation possible with many disc brakes. The real reason must be that they could represent an obstacle to riders without them and so are a safety risk. One day, as older bikes are replaced, discs will become universal.

I suspect the issue with road racers is more that if one rider has discs, all must otherwise differential stopping ates will lead to collisions. At that level the weight penalty of discs might be seen as significant and "out braking" an opponent is not as important in cycling as in motorsport, so discs don't necessarily give an immediate competitive advantage. Again, I find it hard to believe that discs will not become universal in due course.

From the point of view of a lesser mortal, I can see no advantage of rim brakes over discs. The BB7s on my tandem are fantastic. Whenever I ride a rim braked tandem I have a nasty feeling that at any moment I will run out of brakes, or rims.

my 2p worth....

in recent decades tourists have been the poor-man of road riding in terms of kit. What we used was often dribbled down from race bike technology. Racers, quite understandably, have little time or discs until they get much lighter. Thus touring road bikes haven't been built with discs. Racers also have little time for cantis - but cantis became popular back when touring bikes were popular and so didn't have to come via the race scene.

More recently, tourers have realised that some MTB kit can be very good for them. So we are starting to see more tourers with V brakes, and a few with discs.

But discs do present problems:
- you need a different fork design, the traditional tourer fork with it's springy ends isn't ideal. This leads to two issues - firstly people think that the stiffer disc fork will be less comfortable (views vary on this - with many claiming that the importance fork rigidity is dwarfed by the difference that tyre swapping can make), and second, for all those bikes already in production you'd probably have to have a change to the production process that might cost money.
- cost. You can get a reasonable set of Vs or cantis for very much less than the equivalent discs. So, if you are happy that your brakes work why splash out on the extra. Also, until recently, low cost Vs work much better than low cost discs, in comparison to the higher end ones....so if kitting out a 'budget' bike it can be better to avoid discs.
- maintenance. people are familiar with Vs/cantis and their workings seem more obvious. hydraulic discs are certainly more of an effort to maintain. cable discs are getting better.
- spares. canti and V pads are pretty universal, whereas disc pads are much more specific. Fine if there is a good bike shop nearby, but more of a pain if you nadger a pad while out on a tour, in the back of beyond.
- racks. there are a few racks that fit disc frames/forks, but not many. so if you want to continue to use your existing expensive racks then some bodgery is called for. if you break a rack while on tour then it's harder to find a replacement that will fit the disc frame/fork.
- hydraulic brakes and drop bars. hydraulic, in my experience, are head and shoulders above cable discs in the stoppability stakes. but if you want to use drop bars then hydraulic are out.
- is there a problem? many people are perfectly happy with cantis or Vs, so why go to the cost and effort of changing something that works fine? If you are after a new bike and it happens to come with discs at no extra cost then no probs, but retro fitting can seem pointless to those who have no probs with their brakes.

That last one applies to me. I have nothing against discs on a tourer if all works well together. But my cantis do the job, even in hilly country with camping kit on board, so why should I change something that's not broke?

531colin wrote:I'm pants at computering, but if you work at my post of last night, you can see pictures of my current project, which is self fitting cheap discs to a cheap non disc frame to make a rough stuff bike. I have been using rim brakes for half a century, but I like to think I am open to new ideas, like SPD. Mucky rims and rim wear are a problem off road, and I want to know if discs will deliver the improvements they promise. But I wouldn't go all out and fit discs to my treasured made to measure Bob Jackson!

I will type more eg. mechanical specifics, when I get time, and try to port more/better pics. If you click the pics, you can get them bigger.

Colin, Well done! I think its great and hope to see many more road bikes altered like this. I think you should try putting one of those links in your post using the Img button to get the pictures directly in

I note that you have a rising stem and the drops well canted - as an old, less flexible bloke I have given up on drops and use flat or riser bars with bar ends, they are much more comfortable. I still have the original drops with the Dawes engraving on my old Dawes. They will be fitted when I sell it

Al

Al

Si wrote:- hydraulic brakes and drop bars. hydraulic, in my experience, are head and shoulders above cable discs in the stoppability stakes. but if you want to use drop bars then hydraulic are out

Yes, as a tandemist, this is a particular source of disgruntlement. It shouldn't be so. Afew years ago there were a couple of types of remote cable operated cylinders available, so that you could operate hydraulics off drop bar cable levers. These don't seem to be around any more; presumably they weren't very good but the idea seems perfectly sound and not terribly hard. Also hydraulic flat bar levers look pretty similar to cable ones, so surely it is pretty simple to fit a master cylinder in a drop bar lever?

Thi, of course, is linked into the ridiculous difference in cable pull between MTB and road levers. The only advantage I can see of this product differentiation is that it allows manufacturers to sell two sets of kit, dependant upon what shaped bars you want (similarly 130 vs. 135 oln hubs, etc, etc.)

I think 2500 miles from a set of pads sounds about right.............. BUT! I took my drums apart to check for wear at 4400 miles and they were like new. I use them on 20" wheels and descend fast relying on the brakes to pull me up if/when the need arises, So in theory I should be hard on the brakes. Drum brakes are virtually fit and forget for most cyclists, my Avid BB5 were a pain and ate a set of pads in under 1000 miles (20" wheels again.) the BB7s I upgraded to from the BB5s have done 1500 miles and still are fine, but I bet they won't make 4400 miles, never mind look brand new when they get there!

I still can't do this image posting thing, this is my best shot
http://s786.photobucket.com/albums/yy145/colin531thomson/?action=view&current=DSC00009.jpg&newest=1

If you scroll through and blow up the rear disc image, you see there is no interference with the carrier if you put the disc caliper in a sensible place. Similarly, I have a conventional front mudguard, but low riders might be a problem. i will try to answer some of "Horizon's" points from a bit back.
All bike hub brakes are anchored on a single fork leg. Would we know by now if this was a problem?
Rim brakes work on the periphery of the wheel, so have better leverage than hub brakes. True, but these disc brakes i recently fitted will out-brake any rim brake i have had in 50 years.
The old questions about cable pull. Cable pull divides into 2 groups.
ROAD is short pull for sidepulls, dual pivot sidepulls, centrepulls, cantilevers that stick out the side. And AVID at least make a cable disc for road pull levers. Levers are drop levers including "brifters", or "road" straight levers.
V BRAKE is long pull for V brakes and most (mountain bike )disc calipers. Levers are mountain bike levers, or specific drop bar levers for v brakes, which are on my bike - but not "brifters".
Helpfully, "low profile" cantis which point up not out are somewhere in between, their cable pull requirements are met by old mountain bike levers, but road levers dont pull quite enough cable, so you have to set the brake blocks very close to the rim.
I originally put road levers on my bike, and was accidently locking up the wheels. the long pull levers have calmed it all down.

For rough stuff, which is this bikes purpose, there are problems with rim brakes, including rapid rim and pad wear, dodgy braking when rims are wet and slimy, and mud packing up round the brakes and stopping the wheels. And occasionally "dinged"rims.

I cant wait to find out if discs will live up to their promise.

However, if i had known Salsa were going to produce their Fargo, I could have saved myself lots of work!

uploading an image

1) click reply to the thread
2) click the tab Upload attachment
3) click Choose, and select the image file you want from your computer
4) click Add the file
5) click Place inline

done.

anyway, nice metal-work!

You seem to get a lot more life out of pads than I do. On my MTB I go through 6 to 8 sets of (sintered) pads a year! I have mountains of worn out pads

DougieB wrote:uploading an image

1) click reply to the thread
2) click the tab Upload attachment
3) click Choose, and select the image file you want from your computer
4) click Add the file
5) click Place inline

done.

anyway, nice metal-work!

Photo file size has to be less than 256kb, so most images need re-sizing before you can upload them.

Thanks for the photo hints, guys, I will try it when I'm not falling asleep.

I have just"edited" my last post to about twice its original size!