Disc or not?

Jon_1976

meanredspider wrote:

Jon_1976 wrote:

I wasn't that impressed with mechanical discs when I had a cross bike. In the dry, I found my road bike with 6800 rim brakes performed better and have adequate amounts of modulation. Obviously, in the wet the discs were better.

I found the mechanicals would constantly start rubbing after 10-15 miles even with regular maintenance/ adjust and precise setup (correctly torqueing bolts, etc). I dont plan on getting another cross bike (or road bike with discs) until hydraulics are more commonplace and affordable. So easy to set up, you can have decent pad to disc clearance, and less faffing about.

Something not right there - I've had none of this in 8-9,000 miles on the Volagi.

I'd agree. On the cross bike (Tricross), I noticed a design flaw. The brake pad 'tab' (the bit that sticks out to allow you to remove the pad) hit the calliper mount and forced the caliper to be too far inboard. . This meant the caliper couldnt be aligned properly. I cut the tab off, which solved the problem and allowed me to get the alignment and pad spacing correct. But after the mentioned (10-15 miles) the pads would start rubbing again, even in the dry. The rear, I set up once and it never needed adjusted again :roll:

I did take the time to bed the pads in. Guess I just had a bad/unlucky experience but it put me off mechanicals and I wasnt overly sad to see the bike go when I sold it

supersonic

Seen plenty of similar flaws on MTB bikes too. Rotor bolts catching parts. Bad alignments with some combos. On my bike I can't get the wheel out without removing the caliper! But with the 1000s of combos out there some is to be expected, though on a new bike it shouldn't happen.

antsmithmk

I don't think you can underestimate the importance of taking a new disk brake bike out and performing say 25-50 emergency stops in a safe environment. The whole system needs a little abuse before it will run smoothly.

Kieran_Burns

antsmithmk wrote:

I don't think you can underestimate the importance of taking a new disk brake bike out and performing say 25-50 emergency stops in a safe environment. The whole system needs a little abuse before it will run smoothly.

+1

antsmithmk

Thanks for the +1. The problem when buying bikes is that this sort of info is often not passed to the owner.

EKE_38BPM

The Kaffenback is the first bike I've had with disc brakes so I'm still learning about them. I didn't deliberately do 25 emergency stops, but I may have done them in the course of my work, part of which includes demonstrating good and bad emergency stops.

I'm very happy with my brakes, especially in the wet.

essex-commuter

meanredspider wrote:

Jon_1976 wrote:

I wasn't that impressed with mechanical discs when I had a cross bike. In the dry, I found my road bike with 6800 rim brakes performed better and have adequate amounts of modulation. Obviously, in the wet the discs were better.

I found the mechanicals would constantly start rubbing after 10-15 miles even with regular maintenance/ adjust and precise setup (correctly torqueing bolts, etc). I dont plan on getting another cross bike (or road bike with discs) until hydraulics are more commonplace and affordable. So easy to set up, you can have decent pad to disc clearance, and less faffing about.

Something not right there - I've had none of this in 8-9,000 miles on the Volagi.

+1. My BB7's have almost been a fit and forget I'm apart from a clockwisee pad turn every 1000 miles !

menthel

Apparently there is a disc ready fratello on the way. That might change my mind!

(Condor md on the bike show podcast.)

dhope

menthel wrote:

Apparently there is a disc ready fratello on the way. That might change my mind!

(Condor md on the bike show podcast.)

Hah, by the time I put the new fork and disc wheel on my Tempo (same frame as Fratello) they'll have released a version with it included. D'oh.

veronese68

dhope wrote:

menthel wrote:

Apparently there is a disc ready fratello on the way. That might change my mind!

(Condor md on the bike show podcast.)

Hah, by the time I put the new fork and disc wheel on my Tempo (same frame as Fratello) they'll have released a version with it included. D'oh.

I wondered if your post would be about the ongoing disc conversion.

essex-commuter

essex-commuter wrote:

I've pulled the plug on the Kinesis rim brake build.

Think I'm going to covert the CX to Campag and try it with an Ambrosio cassette. Meanwhile I'll get a new wheel built with a Campag disc hub.

Done. Campagnolo shifters and mechs, and an Ambrosio conversion cassette. Works sweet as.

My only issue was the rear shifter cable was only just long enough to reach the rear mech and the brake cable WASN'T long enough to reach the rear caliper. Need to source some good brake outers that are long enough and work with Campag Ultrashift.

Braking is even better with the Campag levers (BB7). I have no idea why.

Happy days.

ugo.santalucia

essex-commuter wrote:

essex-commuter wrote:

I've pulled the plug on the Kinesis rim brake build.

Think I'm going to covert the CX to Campag and try it with an Ambrosio cassette. Meanwhile I'll get a new wheel built with a Campag disc hub.

Done. Campagnolo shifters and mechs, and an Ambrosio conversion cassette. Works sweet as.

My only issue was the rear shifter cable was only just long enough to reach the rear mech and the brake cable WASN'T long enough to reach the rear caliper. Need to source some good brake outers that are long enough and work with Campag Ultrashift.

Braking is even better with the Campag levers (BB7). I have no idea why.

Happy days.

Campagnolo is very stingy with their cables, I always use the Transfil stuff, which works just as well. The outer brake is a generic one, as Campagnolo only give you cuttings

Big_Paul

I took the cable BB5's off my Ute because they simply couldn't stop it when it was loaded, I put M596 Shimanos on it an it was much better, even if the pads lasted 400 miles.

My other lardy commuter bike on V's goes through a set of front pads every 1000 miles and the rears a bit longer, they're great in the dry but crap in the wet.

Initialised

My BB5s both seized up so the static pad couldn't move within a year, I can live with them needing regular adjustment so long as they can be adjusted. So not a big fan of BB5s they were OK at first.
I'm running a Parabox V2 now (calipers look like TRP Dash), they are much better.

ugo.santalucia

Initialised wrote:

My BB5s both seized up so the static pad couldn't move within a year,

if it's static, why would it move? :shock:

timothyw

It moves in/out when you turn it with the inboard adjuster knob. The point is that you only do this rarely, and it's right next to the brake pads... so loads of dust and shit gets into the threads, which sooner or later jam up the adjustment unless you take it to bits on a regular basis.

Pretty weak design really, hence why I changed to Spyres.

Initialised

TimothyW wrote:

It moves in/out when you turn it with the inboard adjuster knob. The point is that you only do this rarely, and it's right next to the brake pads... so loads of dust and shoot gets into the threads, which sooner or later jam up the adjustment unless you take it to bits on a regular basis.

Pretty weak design really, hence why I changed to Spyres.

Mine both jammed in under a year, maybe 7-8000 miles use.

I also suspect that a single piston design increases the chances of warping the discs under sustained heavy braking since you are applying an uneven sideways force to the rotor.

How are you finding the Spyres?

apreading

Were you both trying to adjust by hand or using a torx key? On my son's MTB they did get a bit stiff by hand but in 3 years of cycling through all sorts of crud they never stopped working with the proper tool.

timothyw

apreading wrote:

Were you both trying to adjust by hand or using a torx key? On my son's MTB they did get a bit stiff by hand but in 3 years of cycling through all sorts of crud they never stopped working with the proper tool.

Torx key - adjustment by hand proved pretty near impossible within a few weeks of use. On the rear I ended up stripping the head, although in fairness this might have been down to using a cheap/perhaps slightly mis-sized torx bit at work. I resorted to pliers for adjustment, then within a few more weeks got the spyres as it seemed clear to me that this was a potential issue with any disc with a static pad that required occasional adjustment.

To be fair my bike cleaning and maintenance regime do leave a lot to be desired, and the problem was no doubt compounded by commuting through a wet winter and storing the bike in a shed much of the time.

Initialised wrote:

How are you finding the Spyres?

Great. They still require a fettle to keep them braking at their sweetest, but they don't suffer from the performance fade that seems inherent with the static pad design (which is to say, if you go for a long ride with bb5/7s etc, sooner or later pad wear will mean that a large amount of your braking effort is going into bending the disc into contact with the static pad rather than actually slowing down the bike). In the most part, a tightening of the cable will make up for any wear.

There are two issues worth noting with the Spyres - one is that there isn't much float in the mount/pads so there's a fairly long break in period while you wait for the pads to be filed down to the same plane as the rotors, after which point the breaks work much better (100 miles or so of normal riding for me). The amount of time will depend on how off true the caliper mounts on your frame and fork are (for me my fork was fine but the rear took a fair while to properly bite in).

Second is that clearance can be a little close between the spyre and your spokes. Again this will depend on frame design, wheels, etc, but it does mean that I sometimes hear my spokes being strummed by the spyre when climbing out of the saddle - I might sooner or later move up a rotor size which should the problem.

Initialised

apreading wrote:

Were you both trying to adjust by hand or using a torx key? On my son's MTB they did get a bit stiff by hand but in 3 years of cycling through all sorts of crud they never stopped working with the proper tool.

Has your son put 8000 miles on them in a year through all weathers and all sorts of terrain?

Both ended up with chewed heads, rear went first, probably because it gets adjusted less as there's much less pad wear.

@TimothyW: Have you got them aligned?
Unscrew the mount bolts, pull the lever to bit, don't over do it, tighten bolts making sure the caliper doesn't move. Release brake, spin wheel and check for noise, repeat until silent. It usually takes me a few goes, but once it's done it's done. Avid brakes come with rounded washers, same as you get on V-brakes, you can add these for better alignment if your mounts aren't straight.

or do the pads just not sit parallel to the rotor?

You got a picture demonstrating how close the calipers are to the spokes?

Loving my Parabox R btw, took a while to get them mounted and aligned but now they're broken it they are great.

apreading

Initialised wrote:

apreading wrote:

Were you both trying to adjust by hand or using a torx key? On my son's MTB they did get a bit stiff by hand but in 3 years of cycling through all sorts of crud they never stopped working with the proper tool.

Has your son put 8000 miles on them in a year through all weathers and all sorts of terrain?

Both ended up with chewed heads, rear went first, probably because it gets adjusted less as there's much less pad wear.

No, admittedly not - only a couple of thousand. It is not a big shock that 8000 miles through all weathers and all sorts of terrain wore out some really cheap components though.

meanredspider

I'd recommend applying some copper-based anti-seize compound on the threads. It's not the greatest arrangement but properly protected, it should be ok.

timothyw

Initialised wrote:

@TimothyW: Have you got them aligned?
Unscrew the mount bolts, pull the lever to bit, don't over do it, tighten bolts making sure the caliper doesn't move. Release brake, spin wheel and check for noise, repeat until silent. It usually takes me a few goes, but once it's done it's done. Avid brakes come with rounded washers, same as you get on V-brakes, you can add these for better alignment if your mounts aren't straight.

or do the pads just not sit parallel to the rotor?

Yep, i did do the alignment when fitting, but because the spyres clamp directly to the frame (rather than via the conical washers) this only centres them, it doesn't align them - I would guess that Avid might have some kind of patent on the use of the washers as it does seem a fairly elegant solution. The problem if you fit them with the spyres is that it would result in the caliper sitting too far out on the rotor, so you might need a larger one. Brave souls can file down their frame a bit if the angle is way out.

I did consider fitting my rear Spyre with the conical washers from my bb5 and a 160mm rotor instead of the 140mm, and so kill two birds with that one stone, but it never seemed worth it as once the pads are bedded in it isn't even an issue, and the clearance is good enough 99% of the time.

Initialised wrote:

You got a picture demonstrating how close the calipers are to the spokes?

I'll try and take one to show you.

It did occur to me that the clearance could probably also be improved by putting washers between the rotor and hub when attaching it, so moving it slightly away from the wheels and towards the frame, which might be preferable to a larger rotor.

Initialised

I used conical washers from the BB5s, but most rim brake systems should have them and have done for years so no patent. I had to do it this way because the mounts for the BB5s were to long to get a good fit so I used a 160-180mm adapter designed for an Avid system.



I'd be wary of putting washers between the hub and rotor as you may end up with it out of parallel with the wheel and frame, increased stress on the bolts under heavy or prolonged braking. A safer way to do it would be to add the centre of an old rotor.

I had to do the opposite and install washers between the mount and frame to put the caliper in the right position on the rear:



PM me if you need my old 160mm front rotor.

jonny_trousers

I somehow accidentally managed to resurect this thread tonight and it's amazing to see how the industry has gone disc crazy in such a short space of time. Still a little gimmicky or the future? I don't know, but I do wish manufacturers would set a universal standard and that Campagnolo would hurry up and join the party. I still think discs look pretty ugly on a sleek road bike, but I'm sure we'll all be used to them soon enough.

meanredspider

Definitely not a gimmick and I happen to like the look of discs on a road bike - I think it makes the bike look purposeful and aggressive in the same way that deep rims do. If you're a fan of old school skinny steel frames and quill stems, I can see why they'd appear offensive though

Initialised

Disc brakes are the future, chances are they'll be UCI legal by 2016 but for the diversity of the MTB disc brake market there needs to be a separation of brake and shifter (there's a reason why integrated shifters & brakes never took off in MTB land). Electronic shifting could be the answer to this, instead of a big mechanism in the shifter it is reduced to a pair of buttons. So Campag don't need to join the party, they just need to add TRP, Magura, Hayes, Hope, Formula to the guest list with a standard port that any manufacturer can build into road levers.

jonny_trousers

I do accept that they're the future. I've read enough articles by people in the know to be convinced. It does seem a bit of a mess if systems at the moment, however. Maybe UCI sanctioning will solve that.

For me, rim brakes have always been fine, but then I've never tried braking on carbon rims in the wet. Nor have I ever thrown myself down an Alp.

If I had the money to buy a really nice new frame I think I'd be holding off to see what a year or two brings.

N0bodyOfTheGoat

I'm a little surprised we have not seen off the peg bikes come with a disc fork for say a front Hylex hydraulic, with an "old school" rim brake at the rear.

Part of me would love to mod my Tricross Singlecross while getting it road worthy again, by adding a Hylex front disc and a fork, albeit this would cost ~£275 plus labour. It needs a replacement front wheel anyway (additional cost) and a hydraulic front brake (where most of the braking comes from) would inspire confidence.
But by the time I've spent all that cash on the mod, it almost makes the £800 Pinnacle Singlespeed 2015 appealing, which will have two Hylex brakes and disc wheels, plus a rear hub spacing that could take the Saracen's Alfine if I really felt the need for more gears!

At least Shimano are now at the point where they are producing STI brake levers that can work with their own hydraulic system, as shown on the Pinnacle Arkose 4 2015...
http://www.evanscycles.com/products/pin ... e-ec071308

UndercoverElephant

So what we need is a pair of like-minded cyclists, one of whom likes euro braking, and the other who suffers the indignity of british brake routing. They could then buy a pair of 5800 hydraulic levers between them and both route their lever to a front brake.