School me on road disc brake bikes

curium
curium Posts: 815
edited December 2014 in Road buying advice
Hi

I'm in the midst of considering a 2nd bike for commuting that will accept proper mudguards (if not for the remains of this winter then in time for next). I've decided I'll use this purchase to try a road disc setup since there seem to be a few out there.

Hydraulic setups are still very pricey so I'm looking at mechanical discs.

Its been ages since I've ridden a bike with disc brakes but I'm interested in finding out about any issues which specifically afflict road discs or mechanical discs. A quick google shows some people complaining about the need to continually adjust mechanical discs which seems odd since they are fairly standard on mountain bikes so I would of thought that would of been worked out fairly quickly or is this something that is tolerated? Is it a model specific issue.

The bikes I'm looking at seem to have either the Avid BB7 or the Promax Render R brakes. Is there much between these brakes? I notice that the Promax is not as widely sold in the UK as the Avid.

Is there a standard rotor size? I notice that some bikes have 160mm front & 140mm rear, similar to motorbikes really, but others have 160mm front & rear.

I know both SRAM and Shimano have recalled at least one version of their road disc brakes but don't know the exact reasons why. Are there problems matching existing shifters to mechanical discs?

What's the situation with hubs? Is there a good selection of quality road disc compatible hubs available to easily facilitate custom wheel building? What hubs are Shimano using on the systems they've built?
The bikes I'm considering are as follows:

The Tricross is £99 cheaper but comes with aluminium forks versus carbon forks on the Cannondales and is 9spd sora versus 10spd 105. 10spd would make it possible to share groupset components with my present bike.
The Cannondales have BB30 which I'm not massively sold on. There's a lot to be said for cartridge bottom brackets (like the UN-54) on a commute/winter bike.

Both the Synapse & the Tricross are available now while the CAADX is expected in April :cry: . Worth the wait?

I'm swaying towards the CAADX as it is genuinely different and my expectation is that Cannondale will have produced a good bike although I'd probably swap out the 46/34 gearing. The synapse looks a good bike too but is too similar to my existing road bike except for the discs. The Tricross is currently bottom of the list due to the fork and the 9 spd group although it does look good in the picture - I've not seen any of the bikes in the flesh, hopefully they'll be something to look at during the bicycle show at eXcel.

I'll finish up with some pictures:

Tricross
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Comments

  • cycleclinic
    cycleclinic Posts: 6,865
    rear disc size is not important as the rear brake only does 10% of the braking effort. Otherwise you have identified your choices try them out find the one that fits you best and buy that.

    Genesis do a number of disc brake CX frames that are worth a look as is the Tifosi CK6 when it finally arrives. The

    Tektro or Avid make good disc brake. I have an aversion to anything Promax they make far too much cheap tat found on £200 bikes.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • kajjal
    kajjal Posts: 3,380
    BB7 brakes are supposed to work well with good adjustment. Unless you are taking them off road in continual mud they would need little adjustment.

    160mm rotors front and rear will be fine. Road bikes while benefiting from disc brakes don't need the same power as a mountain bike would off road.

    My next road bike will definitely have disc brakes due to the controlled stopping power whatever the riding conditions. Especially if like me you are around 100kg in weight :)
  • curium
    curium Posts: 815
    I guess I could get the CAADX and see how the promax works out and replace them with BB7s if necessary...?
  • Hi,
    I know you don't need more suggestions to muddy your decision making. But, the Canyon Inflite al8s is in the same price area. I have had mine for a month now, bought primarily as a winter trainer. It comes with 105 throughout, carbon forks, Conti GP 4 season 28mm tyres and specially designed sks mudguards. It has shimano BR cx-77 disc brakes, I have not had to mess with them, since its delivery and they appear very good stoppers.
    I am like a young puppy with mine, 400 miles over the Cumbrian Fells, road only, in 4 weeks.
    Just a thought to help distract you.

    Steve H

    PS. Just noticed your question about hubs and wheels. I have just ordered some Archetype H Son Plus rims to fit to a pair of Hope Evo Pro 2 hubs. I think this may provide me with an even better riding experience.
  • FWIW I have the Synapse 105 Disc. Photo in my sig. I bought it for the same reason as the OP - Winter bike that will take full mudguards and has disc brakes. I've had it a few weeks now and really like it. I've ridden it in some pretty sh1tty weather and the brakes are fine.
    Shut up, knees!

    Various Boardmans, a Focus, a Cannondale and an ancient Trek.
  • mattsccm
    mattsccm Posts: 409
    BB7's are the "standard" . Other stuff may be fine but is less well accepted.
    I have gone to a second disc braked bike now, a On One Pickenflick as well as the Cotic x. When looking round I found 2 A4 lined pages worth of bikes at 1 bike per line! . None over 1500 quid and I didn't include anything below Shimano 105 or Sram Apex.
  • curium
    curium Posts: 815
    Hi,
    I know you don't need more suggestions to muddy your decision making. But, the Canyon Inflite al8s is in the same price area. I have had mine for a month now, bought primarily as a winter trainer. It comes with 105 throughout, carbon forks, Conti GP 4 season 28mm tyres and specially designed sks mudguards. It has shimano BR cx-77 disc brakes, I have not had to mess with them, since its delivery and they appear very good stoppers.
    I am like a young puppy with mine, 400 miles over the Cumbrian Fells, road only, in 4 weeks.
    Just a thought to help distract you.

    Steve H

    PS. Just noticed your question about hubs and wheels. I have just ordered some Archetype H Son Plus rims to fit to a pair of Hope Evo Pro 2 hubs. I think this may provide me with an even better riding experience.

    Would feel comfortable with the Shimano brakes as my first set of road disc brakes as they are a decent name.

    Are the mudguards customised to fit? Will standard mudguards fit?
  • The mudguards are a special design to fit around the discs. There are fitting points inside the front forks and inside the seat stays that are unique to the canyon. They have had sks design a special mudguard. I don't think any other mudguard would fit, not using the mounting points on the bike frame. Check out their website, the bike looks (and is) fantastic and you can see how the mudguards fit, simple but efficient.
    Good luck.
  • curium
    curium Posts: 815
    Hi,
    I know you don't need more suggestions to muddy your decision making. But, the Canyon Inflite al8s is in the same price area. I have had mine for a month now, bought primarily as a winter trainer. It comes with 105 throughout, carbon forks, Conti GP 4 season 28mm tyres and specially designed sks mudguards. It has shimano BR cx-77 disc brakes, I have not had to mess with them, since its delivery and they appear very good stoppers.
    I am like a young puppy with mine, 400 miles over the Cumbrian Fells, road only, in 4 weeks.
    Just a thought to help distract you.

    Steve H

    PS. Just noticed your question about hubs and wheels. I have just ordered some Archetype H Son Plus rims to fit to a pair of Hope Evo Pro 2 hubs. I think this may provide me with an even better riding experience.

    No mention on the site of the size of the front chainrings. Is the big ring 50 or 46? Do they allow customisation?

    Also, are the wheels mountbike wheels (26") or normal road wheels (700c)?
  • At the bottom of this link http://www.canyon.com/_en/roadbikes/bik ... ab-reiter2 it shows the equipment. 50/34 compact chainring and it runs standard road 700c Continental 4 season tyres.

    Steve
  • Anonymous
    Anonymous Posts: 79,667
    Think the caadx is 46/36.

    Not sure if this is good or bad as a commuting bike (might be an advantage for the same reason it is in cyclocross) but guess it depends what (if any) other things the bike is used for.

    The other problem with getting an actual CX bike (or any bike called a CX bike) is that you will need to change the tyres.
  • monkimark
    monkimark Posts: 1,793
    I have Avid BB7 up front and Shimano CX77 at the back, the avid seem a bit sharper but that's probably just because they're new (the rear brake is about 5 years old).

    Aside from never really having heard of promax, I much prefer having screw adjusters on both sides to set up the brakes and the Promax only seem to have inboard adjustment
  • monkimark wrote:
    I have Avid BB7 up front and Shimano CX77 at the back, the avid seem a bit sharper but that's probably just because they're new (the rear brake is about 5 years old).

    Aside from never really having heard of promax, I much prefer having screw adjusters on both sides to set up the brakes and the Promax only seem to have inboard adjustment


    Most disc calipers have an inboard adjustment and a barrel adjuster (much like the one in rim calipers) to adjust the outboard pad... it is basically the same thing
    left the forum March 2023
  • curium
    curium Posts: 815
    Most disc calipers have an inboard adjustment and a barrel adjuster (much like the one in rim calipers) to adjust the outboard pad... it is basically the same thing
    Good to know as I'm new to road disc brakes.
    monkimark wrote:
    I have Avid BB7 up front and Shimano CX77 at the back, the avid seem a bit sharper but that's probably just because they're new (the rear brake is about 5 years old).

    Aside from never really having heard of promax, I much prefer having screw adjusters on both sides to set up the brakes and the Promax only seem to have inboard adjustment
    I thought the CX77 is new? You said you've had it 5 years

    I leaning away from the Cannondale as I too have never heard of Promax and I've never been sold on BB30.

    Heading to the Bicycle Show on Saturday where I'm hoping to try a Canyon for size. If I like it I'll order straight away as the full Shimano (including crankset) is something I prefer. So if anyone has anything bad to say about Canyon please speak up now!
  • I've just built a new winter road/CX bike with disc brakes. Some photos below.

    After doing a bit of research I went for 160mm discs front and rear. I could have got away with 140mm on the rear but having the same front and rear makes the discs interchangeable without needing to move the calipers.

    I went for Deore XT centrelock hubs - they seemed the best balance between price, weight, durability and easy of service. The centrelock fitment does limit the range of rotors available to you but they take seconds to change. I have them built into H Plus Son Archetype rims for road and then have another set built into Mavic Open Pro CD rims for CX to save having to change tyres etc (thanks to Ugo/Paolo :D ).

    I never really considered hydraulic. I have them on my mountain bike and they are a pain in the ars* to adjust at times. Mechanical are a lot cheaper, are easy to adjust at home and on the road and work with regular levers so no need for fancy kit. I went with the Shimano CX77 calipers to match the Ultegra kit on the bike and they must have taken all of 10 mins to fit and set up due to the fact that both pads are adjustable.

    IMG_2383_zps058fd2b6.jpg

    IMG_2414_zps85b4afc9.jpg

    IMG_2420_zps1c4ef064.jpg

    IMG_2423_zpsdd68564b.jpg
  • rafletcher
    rafletcher Posts: 1,235
    Well I built up my "jack of all traddes" bike initially with BB7's, but recently changed to TRP Hy/Rd's - these use standard levers, but the hydraulic reservoir is housed in the (surprisingly small) caliper. So you get the advantages of the standard cable lever with the lack of manual adjustment of pads that you get from a hydraulic set-up. An occasional twist of an inline cable adjuster to keep the lever travel to my liking is all I need to do.
  • boydster76 wrote:
    I've just built a new winter road/CX bike with disc brakes. Some photos below.

    After doing a bit of research I went for 160mm discs front and rear. I could have got away with 140mm on the rear but having the same front and rear makes the discs interchangeable without needing to move the calipers.

    I went for Deore XT centrelock hubs - they seemed the best balance between price, weight, durability and easy of service. The centrelock fitment does limit the range of rotors available to you but they take seconds to change. I have them built into H Plus Son Archetype rims for road and then have another set built into Mavic Open Pro CD rims for CX to save having to change tyres etc (thanks to Ugo/Paolo :D ).

    I never really considered hydraulic. I have them on my mountain bike and they are a pain in the ars* to adjust at times. Mechanical are a lot cheaper, are easy to adjust at home and on the road and work with regular levers so no need for fancy kit. I went with the Shimano CX77 calipers to match the Ultegra kit on the bike and they must have taken all of 10 mins to fit and set up due to the fact that both pads are adjustable.

    IMG_2383_zps058fd2b6.jpg

    IMG_2414_zps85b4afc9.jpg

    IMG_2420_zps1c4ef064.jpg

    IMG_2423_zpsdd68564b.jpg

    Is this the stainless CdF? How is it?
    left the forum March 2023
  • monkimark
    monkimark Posts: 1,793
    curium wrote:
    monkimark wrote:
    I have Avid BB7 up front and Shimano CX77 at the back, the avid seem a bit sharper but that's probably just because they're new (the rear brake is about 5 years old).

    Aside from never really having heard of promax, I much prefer having screw adjusters on both sides to set up the brakes and the Promax only seem to have inboard adjustment
    I thought the CX77 is new? You said you've had it 5 years

    Quite right, I meant BR505 (road version) - I was reading & typing at the same time and ended up just typing what I'd read.
  • comsense
    comsense Posts: 245
    Specifically on the BB7 and Promax Render R - I have both brakes. I only went for BB7 as the Promax were good but not great. I ended up getting the wrong replacement and had to reinstall the Promax. In between taking them off and reinstalling I had read a good bit about setting mechanical discs up. I followed the instructions to the letter and the Promax , although one of the cheapest brakes around, worked perfectly after the reinstall. You could control, slow and stop with absolute confidence in any situation. There are plenty of reviews about the bb7's and I agree they very good if you follow online discussions about how to set them up. Book mark this for when you need it
    http://www.cxmagazine.com/mechanical-mo ... rake-setup

    On the bike itself, I have the CaadX. I've upgraded a few things - but only because I had them to hand. it now has Ultegra levers and hong fu carbon bars and my personal favourite saddle, but it was good out of the box. When I got the knack for the brakes it became even better. Fantastic all day riding bike and I am as quick (or rather slow) as I am on my carbon race bike
  • earth
    earth Posts: 934
    I have BB5's and am not impressed. They have improved over a couple of months but they still judder and screech. The rear has a lot of lever pull before it bites. Adjusting them further only results in the pads dragging on the rotor. Some rotor drag is unavoidable or the lever pull before they bite is too much to give proper leverage when they do bite. The front wheel rotates slightly when pushing the bike forward while the front brake is applied. Initially thought it was the headset but I've ruled that out now. The movement in the front wheel makes me suspect the caliper and it might explain the juddering.

    I wouldn't bother with mechanical discs again unless someone explains the improvements to the design over BB5s.
  • curium
    curium Posts: 815
    Excellent info guys! :D
    boydster76 wrote:
    I went for Deore XT centrelock hubs - they seemed the best balance between price, weight, durability and easy of service. The centrelock fitment does limit the range of rotors available to you but they take seconds to change. I have them built into H Plus Son Archetype rims for road and then have another set built into Mavic Open Pro CD rims for CX to save having to change tyres etc (thanks to Ugo/Paolo :D ).
    Can you elaborate please or point me to a suitable source of info?

    What is the centre lock fitment? Are there different standards for fitting rotors to hubs? If so what is the standard that gives widest choice?

    I may also look at getting a set of wheels built for my new bike so anything that affects hub choice for discs I'd like to know.

    Cheers!
  • earth wrote:
    I have BB5's and am not impressed. They have improved over a couple of months but they still judder and screech. The rear has a lot of lever pull before it bites. Adjusting them further only results in the pads dragging on the rotor. Some rotor drag is unavoidable or the lever pull before they bite is too much to give proper leverage when they do bite. The front wheel rotates slightly when pushing the bike forward while the front brake is applied. Initially thought it was the headset but I've ruled that out now. The movement in the front wheel makes me suspect the caliper and it might explain the juddering.

    I wouldn't bother with mechanical discs again unless someone explains the improvements to the design over BB5s.

    Judder is a sign of bad installation and so is the lack of response. Screeching can be due to the type of pad you use and when it's wet all discs screech like hell
    Basically don't rule them off until you have learnt to fit them properly... and don't worry I had all the same issues before I did learn to fit them properly
    left the forum March 2023
  • Centrelock is Shimano's own design and involves the rotor disc being attached to the hub and secured with a lockring in the same way a cassette is attached and it uses the same cassette tool (which is handy). One twist and it's off. The other (more common) system is a 6-bolt fixing which is a little more labour intensive to change the rotor and people report shearing bolts through over tightening without a torque wrench. Shimano's Deore XT 6 bolt hub is a lot heavier than their newer centrelock hub but this may just be old v new rather than centrelock v 6-bolt.

    As far as I know there are only the two fitment systems.
  • curium
    curium Posts: 815
    Cheers for that!
  • andy_s_t
    andy_s_t Posts: 106
    boydster76 wrote:

    IMG_2383_zps058fd2b6.jpg

    IMG_2414_zps85b4afc9.jpg

    IMG_2420_zps1c4ef064.jpg

    IMG_2423_zpsdd68564b.jpg

    That is one beautiful looking bike.

    Love my Croix de Fer and TRP HY/RDs. I have just put some EBC Gold pads in as the TRP pads didn't last very long in our current weather. Really impressed with the sintered pads, really surprised at the difference a set of pads makes, maybe not quite as much grab in the dry, but they feel identical when they are absolutely soaked which is very nice.
  • earth
    earth Posts: 934
    earth wrote:
    I have BB5's and am not impressed. They have improved over a couple of months but they still judder and screech. The rear has a lot of lever pull before it bites. Adjusting them further only results in the pads dragging on the rotor. Some rotor drag is unavoidable or the lever pull before they bite is too much to give proper leverage when they do bite. The front wheel rotates slightly when pushing the bike forward while the front brake is applied. Initially thought it was the headset but I've ruled that out now. The movement in the front wheel makes me suspect the caliper and it might explain the juddering.

    I wouldn't bother with mechanical discs again unless someone explains the improvements to the design over BB5s.

    Judder is a sign of bad installation and so is the lack of response. Screeching can be due to the type of pad you use and when it's wet all discs screech like hell
    Basically don't rule them off until you have learnt to fit them properly... and don't worry I had all the same issues before I did learn to fit them properly


    I didn't fit them.
  • earth wrote:
    earth wrote:
    I have BB5's and am not impressed. They have improved over a couple of months but they still judder and screech. The rear has a lot of lever pull before it bites. Adjusting them further only results in the pads dragging on the rotor. Some rotor drag is unavoidable or the lever pull before they bite is too much to give proper leverage when they do bite. The front wheel rotates slightly when pushing the bike forward while the front brake is applied. Initially thought it was the headset but I've ruled that out now. The movement in the front wheel makes me suspect the caliper and it might explain the juddering.

    I wouldn't bother with mechanical discs again unless someone explains the improvements to the design over BB5s.

    Judder is a sign of bad installation and so is the lack of response. Screeching can be due to the type of pad you use and when it's wet all discs screech like hell
    Basically don't rule them off until you have learnt to fit them properly... and don't worry I had all the same issues before I did learn to fit them properly


    I didn't fit them.

    WHoever fitted them didn't do a good job... it's not easy and it takes tim to get them just right
    left the forum March 2023
  • monkimark
    monkimark Posts: 1,793
    I had similar problems with the BB7 on the front of my bike, I don't think the crosstop levers helped.

    Crosstop levers removed and inline barrel adjuster added instead, a good 50 mile weekend ride to bed them in and they were fine - the dragging on the disc is no longer a problem and they can be set up to bite right at the start of the lever pull.

    They do screech a bit in the wet but that's a thousand times better than rim brakes, which make no noise in the rain but also don't stop you.
  • meesterbond
    meesterbond Posts: 1,240
    What do you guys do to bed the pads in?

    On the mountain bike I've always done 10 or so accelerations and hard stops to get the pads sitting properly, a bit of heat in the pads and some material on the rotors, seems to prevent glazing them too. Never used discs on road but I'd assume the same sort of approach would be advisable?
  • monkimark
    monkimark Posts: 1,793
    I rode up and down the hill at the end of my road a couple of times, hard braking a few times on the way down and the braking improved a lot so I thought they were bedded in.

    They seemed to improve a lot more after a proper ride just using the brakes normally, it was around Biggin hill with some pretty quick descents so maybe it needed a bit more heat to really bed them in.