Brakes Dual disc brake hubs and forks

Discussion in 'Bicycle Repair' started by Fabian, Jun 18, 2010.

  1. Fabian

    Fabian Well-Known Member

    Ok, i'm having issues at the moment (some in here may say all the time) and can't seem to find any manufacturers of front QR hubs with dual disc brake carriers and forks with mounting lugs to carry the right hand side brake caliper.

    I have been making enquiries about getting a custom made 12 inch disc and caliper extension bracket but the two shops that i've been to are reluctant to take on the job as they've never made anything for a bicycle application and in such thin gauge stainless.
    One shop has said he will do it, but it could be upwards of $600 for a custom floating disc and caliper hanger.
    At this point in time, i don't care how much it costs, because i just damm well want the biggest, class leading bicycle disc brake on the planet, for my particular application.

    Having said that, it would look even more cool to have a dual 8 inch disc brake setup on the front forks and hub.

    What are my options in dual carrier disc brake hubs and forks?

    Last edited: Jun 18, 2010

  2. ocscully

    ocscully Member

  3. Erik James

    Erik James Guest

    Hey everyone
    I had the same problem and I decided to do something about it !
    I now make my own and they are available for sale.
    Theres more information here:

    We use them in our Motorized Bicycle Builds but they can also be used on any bicycle.
    And also take special orders & oddball sizes


  4. FurryOnTheInside

    FurryOnTheInside Well-Known Member

    Ouch $130 for the ghettobike one although it seems to be aluminum, and only $20 for the choppersus with the steel body (not in stock right now).
    I really like the idea of aluminum body like every other decent hub out there, but it seems a bit too much for a front hub, considering that it doesn't take a QR skewer, isn't the standard 9mm, won't adapt to 20mm bolt through, or 15mm QR, and twin disks are actually unnecessary anyway if you have a decent modern brake with either vented floating rotor (Hope Tech 4) or aluminium sandwich floating rotor (Shimano Ice Tech), with finned and sintered pads.
    It does look like fun though. I like the idea of having two independent front brakes. Four levers on the bars. It'll look rad! :D
    You could have a different pad compound for each brake too. Metal (sintered) for power and consistent performance in wet conditions for the off road riding, and resin for quietness and better modulation on the road. :)

    Read this!

    And this!

    This year is the 20th anniversary of the Marzocchi Z1, the fork that changed the world of mountain biking. (Some of) these came with the twin disc brake caliper mounts, since brakes on mountain bikes in 1997 were not as good as they are now.
    The Z1 has other advantages besides the fact that it (can) has twin disc brake caliper mounts. It was a giant leap forward in bicycle technology at the time, but even today the performance of the motocross style open oil bath suspension system is far better than a great many modern mountain bike forks.. As long as you don't require any lock out system for climbing and you aren't bothered by the extra weight of all that oil and two springs.. but I don't think anyone on this forum is bothered about stuff like that! ;)
    The anodizing used on the stanchions of these early forks were not bad either. In fact they seem to hold up better than a lot of modern forks.
    As long as they have been looked after / stored in a dry place there really isn't any reason why an original 1997 Marzocchi Z1 shouldn't be just fine today. Change the oil maybe. I like to top it up a little bit higher than standard. Some people say use 10wt instead of the standard 7.5wt to slow them down.
    I'm not sure tbh. I have had a set of 1997 Z2/Z3 forks since 2001 and I can barely remember when I got them. I think they came on
    a Brooklyn hardtail that I bought used. I had had other Marzocchi forks, new ones, but the open oil bath suspension felt better than anything I had tried. I definitely changed the oil but I think I just put the standard 7.5wt in, to a slightly higher level so they would ramp up nicely for jumping.
    So I got a Z1 fork this morning. The paint is a bit scuffed up and the stickers have mostly come off. Otherwise it seems to be pretty much as it was when new. You can see in the pictures there is no visible wear to the anodizing on the stanchions, I can find no oil leaks, and the action of the fork- well you'll have to take my word for it but just gave these a quick bounce pressing them on the floor and they feel smoother than any of my newer air or coil&air forks. I'm definitely putting it on my not-yet motored bike today! :)

    This is only slightly a gloating post. It's relevant, honestly, because of the twin disc mounts. ;)


    _20170307_104134.JPG _20170307_104306.JPG _20170307_104241.JPG
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    Last edited: Mar 7, 2017
    Coyoteloven likes this.
  5. Frankenstein

    Frankenstein Well-Known Member

    Oh the best part is they make double pull cables as well, litteraly a single cable with 2 individual cables comming off it. With a double pull lever and 2 double cables one lever could operate both front disk brakes and the front rim brakes AND the rear brake all at once. Talk about the perfect overkill.

    Also very stylish, take them and make them your front fork on your bike.
  6. FurryOnTheInside

    FurryOnTheInside Well-Known Member

    Yeah they are awesome retro coolness factor if you like that kind of thing. The tall red adjusters at the top and orange lowers are very recognisable.
    I do wonder though if I could swap the lowers for the Z3QR20 lowers that I have on my other open oil bath fork (which I think might be a Z2 upper and insides) because I have to mess around with the converter to mount the brake:

    The Z1 mounts are Formula Standard (FS) and everything made after 2000 is either International Standard 2000 (IS) or post mount (PM).
    The FS holes are 5mm and 48.55mm apart centre-to-centre, where as the IS holes are 6mm and 51mm apart.
    The mount is slightly further from the centre line of the hub too, but that is okay if there is some adjustment in the PM holes on the top of the converter.
    What is going to take some thought is the problem of axle-to-mount distance and the angle. This is what I have to look at next, after I have had my lunch. :)

    I can't remember the exact figures because I was in the kitchen texting and cooking for the last half-an-hour, but I think the IS lower hole is 49mm from the axle and the FS is 57mm, so I will try measuring again carefully and then I will try a 180mm rotor with the 160mm converter see where that gets me.

    As for combining more than one caliper into the same lever, I have my own opinion on that and I don't think it is a good idea really because it divides the effort and lowers the pressure on the rotor. I can't anyway because I have already committed to using a hydraulic brake on my build.
    Last edited: Mar 12, 2017
  7. Frankenstein

    Frankenstein Well-Known Member

    Are you using a centrifugal clutch then?
  8. FurryOnTheInside

    FurryOnTheInside Well-Known Member

    No, and I just ordered my third clutch lever yesterday actually haha but I'm gradually figuring out what I want to use.
    I sent a2z an email to see if they have any ideas about this FS mount to PM caliper issue. They replied with one line that they don't do that anymore.
    Last edited: Mar 10, 2017
  9. KCvale

    KCvale Motorized Bicycle Vendor

    Can I ask what you are building that requires more front brake than a 1,000cc 150mph motorcycle needs?

    Hey, I am all for good brakes, the more the merrier, I am just curious as to what you are up to hehehe ;-}
    Last edited: Mar 8, 2017
  10. FurryOnTheInside

    FurryOnTheInside Well-Known Member

    Since Fabian hasn't been seen for a while I'll say that AFAIK he was just looking for better cooling. He rides with a trailer and a heavily built bike in the dryest continent (so probably has some water in the trailer) and was experiencing brake fade.

    I also have a similar trailer and a lot of heav;y equipment to carry but I don't think joining two calipers to a single lever is the way forward. I think that a SINGLE modern 203mm rotor either the aluminium core floating Shimano IceTech or the very expensive (and can clog in muddy conditions) vented floating Hope rotor would be better. Finned pads are available for the Shimano STX/XT/XTR calipers too and they reduce heat build up even further.
    The Hope vented floating rotor can only be used in the Hope Tech V4 Evo caliper, if I remember correctly, because it is about 4mm thick.

    Two front calipers could still be used but on different levers so you alternate between them, or perhaps you can have a simple cable disc on the right side for a spare or for those infrequent moments when even the left rotor and pads overheat.

    Personally I'm still solving the issue of mounting a left hand PM standard caliper to an old formula standard (FS) mount, though. The right side will likely be for someone else to do. I just put it in this thread because the 1997 Bomber Z1 fork is about as close to what Fabian's original post was about than anything else I have seen. There isn't much info on the interwebs about how to mount a left side IS caliper to this fork and as far as I can see nothing at all on how to mount the right hand side. I think you have to make your own adapter for that.
    Last edited: Mar 9, 2017
  11. KCvale

    KCvale Motorized Bicycle Vendor

    That makes sense, if you have to stop a heavy load going down hill sure, you want REALLY GOOD brakes.

    I have seen Fabians 'Train Bike', it did what it needed to do at the time for him.
  12. FurryOnTheInside

    FurryOnTheInside Well-Known Member

  13. Frankenstein

    Frankenstein Well-Known Member

    A brake caliper would be mounted turned around on the right side, so the actuator was on the outside of the rotor. This just lifts that caliper system to the proper hight so the pads bed in the rotor correctly and at the right angle.
  14. FurryOnTheInside

    FurryOnTheInside Well-Known Member

  15. FurryOnTheInside

    FurryOnTheInside Well-Known Member

    Yeah that's what I thought, with the caliper flipped over it would require a different shape adapter, and this is it. Still needs the right right side IS mount on the fork of course and there's not many of them around.
  16. Frankenstein

    Frankenstein Well-Known Member

    I see them all the time, they look like nuts and welding rods at the hardware store.
  17. Frankenstein

    Frankenstein Well-Known Member

    Or grab some high grade silver solder/braze and make a very very excellent fit on the parts, the thinner the solder and the closer the 2 parts joined the stronger the joint.

    Careful planning would do the job.
  18. FurryOnTheInside

    FurryOnTheInside Well-Known Member

    I only meant there's not many forks with a right hand side International Standard 2000 (IS) disc brake caliper mount!

    So you mean that you can just make one from nuts and weld it to any fork? I don't think it's quite as simple as you suggest.

    Even just measuring can be a PITA. :rolleyes:
    I'm trying to work from the caliper back to the fork but it isn't easy keeping the caliper still because of the stiff hose. I don't want to remove the hose at the caliper end (this often turns out badly). I have taped it on now but really it is hard to know exactly where it wants to be. There's only supposed to be a knat's hair clearance inside so the rotor edge doesn't scrape the caliper body. I might try again with paper wrapped around it. Perhaps I should have stuck with the old Hope C2 #3 that had much more clearance than the Shimano XT m785.
    I am using a 3mm steel plate brake mount from an old scooter, modifying it to bolt to the FS mount. Work has stopped until tomorrow so I can make loud grinding noise.
    I should be able to get at least one brake on this fork. It won't look pretty but I think it can work. :)
    Then it should be simple to get the same thing on the right side.. for those who want to.

    Attached Files:

    Last edited: Mar 9, 2017
  19. Frankenstein

    Frankenstein Well-Known Member

    Squeeze the brake onto the rotor with a brake lever and it will be centered on the rotor correctly, turn the wheel until the brake assembly comes to the frame. Level it out carefully and adjust its seat. Once it's set get a friend to continue squeezing the lever. You mark and measure so if you mess up its not their fault.

    Put it together and ride.
  20. FurryOnTheInside

    FurryOnTheInside Well-Known Member

    Well, it's on there but I'll probably be doing it again because there is actually some flex in the 3mm thick steel plate. I will have to drill new IS mount holes and use the appropriate IS-PM 203 Shimano adapter, instead of this concoction of homemade IS+43 plate and IS-PM 160 adapter.
    I also found (even without braking force applied) that the 3mm plate brings the caliper slightly too close to the spokes and there isn't enough outward adjustment in the PM slots to centre the caliper over the rotor, so I did a lot of grinding and filing to get it "perfectly" lined up.

    Do NOT use Stupid Shimano XT precision engineered bloody racing brakes haha, there's no clearance for doing the build by hand. Be sensible and use Hope C2 #3 if you're going to mess around with a homemade adapter plate. :confused:
    (Hope C2 #4 I think is the one that actually mounts direct but that limits you to I think a 165mm rotor.)

    I'm Definitely leaving the right hand side for someone else.
    Anyway here are the pictures of my LEFT side +43 mount for the dual disc mount Marzocchi Z1 1997 that I already know isn't the final version. :rolleyes:

    Sorry the photos are sideways and I have no idea why.