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Dual Pivot Rim Brakes Weak Power

plaketokofthsplaketokofths Posts: 4
edited August 2019 in Workshop
Hello,

I own a Trek Domane AL2 2018 which I bought it brand new. I like it very much but it lacks of braking power. These are the specs:

Brake set : Alloy dual-pivot (no further info but I guess are entry level tektro's - including tektro pads)
Shifters: Shimano Claris
Rims: Bontrager Tubeless Ready (Alloy)

I'm not exaggerating, these brakes have no power at all, from the first time since now that I ' ve already done about 1000km. When I'm on hoods it's almost impossible to stop, things getting better when cycling on drops. At the beginning I was thinkinkg that I have to wait a little bit for bed-in. I tried several times to clean both the rims and the pad with alcohol but there was no improvement at all. I checked the cables, alignment etc and everything seemed to be fine. I decided to change the pads with some Clarks that have good reviews but it was still the same. I have to mention that probably the calipers are long reach, I don't know how this affect the leverage.

Do you have an idea how to solve this? I'm thinking of changing one more set of pads, trying this time the SwissStop Flash Pro Brake Pads (the original black or the blue compound). I don't know how good are the OEM calipers and what options do I have if I want to replace them. I did a small search and many people propose the Shimano BR-R650 for long reach calipers.

Thanks in advance
Giannis

Posts

  • oxomanoxoman Posts: 11,172
    I've used various rim brakes from tektro and various shimano and I've found the the OEM blocks are usually pants. I've been using the swisstop box pro,s and found them to be brilliant. Don't try comparing them with disc brakes as its not a fair comparison. Recently did C2C with a few mates who all used disc brakes and they all struggled on the long descents with glazing pads brake fade which I had no issues with using the rim brakes with the swisstop,s
    Too many bikes according to Mrs O.
  • step83step83 Posts: 4,170
    Yep pads will be mainly plastic with most OEM brakes, that an they may not be lined up and toed in correctly.

    Swissstop BXP (Blues) an job done, need to make sure they are set up correctly though or you'll still struggle.

    Probably your best bet to start is line up the pads properly and sort the cable grab. Try a quick spin after it should have improved a great deal.
  • keef66keef66 Posts: 13,123
    For years I stuck with the stock all-in-one moulded Shimano blocks in the BR450 long reach calipers on my winter bike and the Tiagra calipers on the summer bike, and having nothing to compare them to, thought they were OK.

    Then I fitted some second-hand 5800 calipers on my summer bike and nearly put myself over the bars the first time I used them.

    All of a sudden I was less than happy with the braking on the winter bike. So I bought some 5800 cartridges / inserts and put them on the long drop calipers. Still nowhere near as good as the 5800 calipers, but a marked improvement. So if yours have the all-in-one blocks try replacing them with some metal holders / inserts. I'm guessing they flex less than the moulded ones. Makes swapping brake blocks easier too.
  • Many thanks for your replies.

    I bought the bike from an official Trek retailer which delivered the bike to me fully assembled and lined up. After 100km I went there for a fine tuning and I mentioned the issue with the brakes. He checked them carefully and told me that were fine. It's just the way they work and if I need a better brake he suggested to upgrade the calipers. I have also other bikes with entry level brake system and I never had such an issue with brakes. Therefore I was hesitant to believe him, sometimes sellers try to sell unnecessary things to customers.... So I think that's not a fine tuning problem.

    Step83 what do you mean "sort the cable grab" ?
    Below I posted some pictures from current setup. The white bike is a giant rapid with similar brakes with OEM calipers and pads but with different levers because it's a flatbar. The way is braking is far better than mine's.

    I' m thinking of giving a try to Swissstop BXP Blue, and maybe trying a better caliper? What options do I have for long reach calipers ?

    64238538-397602817604502-716886340133715968-n.jpg 67733287-954784988189349-461443929003261952-n.jpg 67735425-399891390644170-3982483114973724672-n.jpg 67832999-464637957419669-2471079497831546880-n.jpg 67909811-2273681402942824-3731874990182629376-n.jpg
  • keef66keef66 Posts: 13,123
    Shimano R451 or the dearer / better R650

    By the time you've replaced the all-in-one blocks on the former you may have spent as much as the latter which comes with metal holders / inserts
  • paulbnixpaulbnix Posts: 584
    I had Tektro long drop brakes on my Boardman bike.
    Tried Swisstop and still not brilliant.
    Bought the Shimano 650 brakes and it definitely improved - not as good as short drop but good enough.
  • Even the cheapest tektro's should have some stopping power with standard pads. Trek can design bikes.

    Mechanic may be right but do the pads clamp onto the rim solidly with levers halted, or do the levers continue to compress and pull more cable with no power? If so then you may have a cabling problem. Check outers have ferrules either end and that the outer cable is not being pulled through the stops and that there is not cable slack somewhere. If the problem is at shifter then will require replacement of cables and bar tape which will cost £20 DIY but may be worth it before blaming pads.
  • oxomanoxoman Posts: 11,172
    Obviously you will never get full braking off the hoods unless there hydraulic, stands to reason that being on the drops you have extra leverage. I suspect when cable grab was mentioned he meant the distance from pulling the levers and the blocks starting to touch the rims. I normally leave approx 3mm between my blocks and rims, if you get a buckle or rim deflection you can always have a slightly bigger gap.
    Too many bikes according to Mrs O.
  • AlejandrosdogAlejandrosdog Posts: 1,975
    I rode down some 20% + descents at the weekend. On the hoods, braking was good.

    Stock Shimano pads Dura ace callipers no problem. I find cable routing, and set up account for most braking issues, once you’re beyond flexy levers and callipers.

    As above before spending lots
    On new callipers check that the cables are installed properly.
  • step83step83 Posts: 4,170
    Cable grab as in how much you need to pull the brake lever before it comes in contact with the pad as Oxo said, if you run the pads close to the rim you have a minimal grab/lever pull before it starts slowing you down. I run mine very close for this reason, more so on the back as a snappy front brake can lead to close up floor inspections.

    I'd go with what Veryslowtitch said it seems plausible. If the caliper is not clamping tightly down then it will explain the poor braking, a quick test would be wind the barrel adaptor in so its nearly touching the rim then see what it stops like, you should be able to get an idea just doing a quick ride round the block or up the street an back.
  • Cable grab was ok
    I checked the front cable/wire and it was also OK end properly lubed.
    Both front and rear breaks perform the same.
    You helped me a lot and I appreciate this.

    I tried two other set of pads that a friend had in spare, for the first one I don't know the specs, and the other set was shimano R50T2 brand new and the compound seems to be soft. Unfortunately no improvement at all.

    I m gonna change both the pads and the calipers.
    For pads, I' m thinking of using the Koolstop Salmon or the Swissstop Flash Pro Brake Pads Blue.
    For calipers I will give a go to the R451. R451 look identical to the R650 except the finish quality and a Ball Retainer Unit reduce pivot friction. I don't know if the R650 worth the extra money.

    I will keep you posted.
  • AlejandrosdogAlejandrosdog Posts: 1,975
    Jesus Christ spend spend spend
  • keef66keef66 Posts: 13,123
    You do realise the R451 come with the all-in one moulded blocks so if you want to fit Koolstop or Swisstop inserts you need to buy the cartridge holders too?
  • MatthewfalleMatthewfalle Posts: 17,380
    lifeline from wiggle are inexpensive and very good. you'll need the holders but just ask your mate who had the spare blocks or your lbs if they have any - normally the sort of thing that is just lying around

    #thrifty
    #skids
    #251
    Postby team47b » Sun Jun 28, 2015 11:53 am

    De Sisti wrote:
    This is one of the silliest threads I've come across. :lol:

    Recognition at last Matthew, well done!, a justified honour :D
    smithy21 wrote:

    He's right you know.
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