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  1. #1
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    when will I.S. die?

    i keep seeing current frame made with IS mounts, what gives. low end to very high end frames. is anyone still making IS calipers. it seems like 99% of people on here with recent bikes are using an adapter. the advantages for post mount are very clear and should be an industry wide accepted standard.

  2. #2
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    the advantages for post mount are very clear and should be an industry wide accepted standard.
    Such as stripped PM threads in your frame?

    The proper way to do it on aluminum frames (-> using steel inserts) is more expensive than a simple threadless IS mount.
    I guess that is why frame manufacturers leave it up to the rider to install their brakes with an adapter.
    wanted: Cannondale Lefty w/ V-brake studs

  3. #3
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    Quote Originally Posted by lelebebbel
    Such as stripped PM threads in your frame?

    The proper way to do it on aluminum frames (-> using steel inserts) is more expensive than a simple threadless IS mount.
    I guess that is why frame manufacturers leave it up to the rider to install their brakes with an adapter.
    I agree. I have nothing against adapters because work without any problems besides those two extra bolts you have to install.

    I own a torque wrench and I think I'm a responsible enough mechanic that stripped threads shouldn't be a problem (it still happens to people though), but its nice to just not have to worry about that.

  4. #4
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    ive had both types on forks and never noticed any difference in anything. the adapters look different and thats about it.

    i dont see any very clear advantages either way. threaded aluminum to strip is a pretty big disadvantage though.

  5. #5
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    If you're stripping out threads, you deserve to ruin your frame. If you can't thread a bolt in straight, then I don't know how you can ride a bike. My neice's toy "workbench" has plastic screws and bolts that she is able to correctly assemble, she is 15 months.

  6. #6
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    Quote Originally Posted by ettore
    If you're stripping out threads, you deserve to ruin your frame. If you can't thread a bolt in straight, then I don't know how you can ride a bike. My neice's toy "workbench" has plastic screws and bolts that she is able to correctly assemble, she is 15 months.


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  7. #7
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    Quote Originally Posted by Riken
    the advantages for post mount are very clear and should be an industry wide accepted standard.
    But Post Mounts aren't and IS is Industry standard so you've sort of answered your own question

  8. #8
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    Is this a weight weenie thing? Do you not like using adapters? Even if post mount was standard, you'd still have to use adapters for any rotor other than 160mm. Personally for anyone who messes with their brakes on a regular basis, I'd think you'd prefer IS mounts. Given enough repeated unthreading and rethreading bolts in a given application, you still have a possibility for issues. I personally find my IS mount calipers pretty easy to setup and adjust. I like just moving the caliper without touching the adapter that's bolted to the frame. This way I'm just adjusting the brake, and not the brake where it attaches to the bike. I never have any problems with getting my brakes adjusted with 0 rubbing.

    I have 2 forks, 1 with IS and 1 with post mount. What's wrong with IS mount anyway?
    Last edited by BaeckerX1; 08-29-2010 at 06:56 AM.
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  9. #9
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    Quote Originally Posted by Riken
    i keep seeing current frame made with IS mounts, what gives. low end to very high end frames. is anyone still making IS calipers. it seems like 99% of people on here with recent bikes are using an adapter. the advantages for post mount are very clear and should be an industry wide accepted standard.
    IS is an industry wide standard, as is post mount. I have frames and forks with each, and they both work well. No advantage either way in actual use.

    I like that you can change mounting brackets for different rotor sizes and front vs rear with the "universal" calipers (ask the owners of IS only calipers about this). The brackets work well and are not very heavy.

    I have not seen any comparisons of weight differences between IS vs post mount on forks or frames.
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  10. #10
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    I would rather accidentaly strip a $6 adapter than a $600 fork, or a $1000 frame. That's how I see it.
    Quote Originally Posted by anthonys
    Its still just the push of a button away...
    I am no longer a hardtailkid. 2012 Trek Remedy 9!

  11. #11
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    Quote Originally Posted by hardtailkid
    I would rather accidentaly strip a $6 adapter than a $600 fork, or a $1000 frame. That's how I see it.
    Turners uses a replaceable dowel nut on their frames, don't know if anyone else has adopted this design but could/will catch on.

    I got to where i could eyeball shim an IS caliper and get it right the 95% of the time. But can see the advantages to PM calipers; 2 second alignments and not stuck with a 203mm caliper that you want use on a modern PM xc bike.

  12. #12
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    What frames use a post mount? I've only ever seen frames with the 51mm IS.
    Quote Originally Posted by anthonys
    Its still just the push of a button away...
    I am no longer a hardtailkid. 2012 Trek Remedy 9!

  13. #13
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    I just looked the Turner post mount design, and it's really cool. I found pictures on this page (http://redstonecyclery.blogspot.com/...nk-style.html). The welds on that frame are absolutely amazing.
    Quote Originally Posted by anthonys
    Its still just the push of a button away...
    I am no longer a hardtailkid. 2012 Trek Remedy 9!

  14. #14
    NWS
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    Quote Originally Posted by AZ.MTNS
    It must be hard to be as awesome as you are .
    Bravo.

  15. #15
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    Quote Originally Posted by hardtailkid
    I just looked the Turner post mount design, and it's really cool. I found pictures on this page (http://redstonecyclery.blogspot.com/...nk-style.html). The welds on that frame are absolutely amazing.



    Sorry, the page you were looking for in the blog redstone underground does not exist.

  16. #16
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    Quote Originally Posted by AZ.MTNS
    Sorry, the page you were looking for in the blog redstone underground does not exist.
    Ooops. It took the end parenthesis and put it as part of the link. Just copy the link and take out the end parenthesis
    Quote Originally Posted by anthonys
    Its still just the push of a button away...
    I am no longer a hardtailkid. 2012 Trek Remedy 9!

  17. #17
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    Turner DHR DW

    (sorry, I could't find a larger pic )

    I wish they did the same thing on forks.
    wanted: Cannondale Lefty w/ V-brake studs

  18. #18
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    I think I will continue to see both posts and IS for a long time to come.
    As a shop wrench I like IS because when, not if they are not totally parallel, flush and all that, practically every shop and even some home mechanics have a facing tool. On some cheap bikes i have had to face as much as 2mm off of one ear of the IS tab to make it flush. The thought of entry level aluminum hard tails having posts is scary, its already nearly imposable to set up a tektro IO or BB5 brake with out some rubbing. On the other hand if good builders, pivot, santa cruz, ibis, yeti, ect, ect, want to do posts and do them well then there is no drawback on high end frames. Oh you dont have to cross thread, or over torque a post mount to strip it out, I have seen a slightly too short bolt, which was included with an avid elixir caliper strip out the post on a brand new fox F29. The person thought the fork was defective because they used a torque wrench and torqued to the spec. My salsa fargo has posts and they are not the straightest but since I use avid brakes the hard ware corrects for it.

  19. #19
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    I really like Turner's approach with the replaceable dowels. I could get on board with that. But, I still don't see it as a huge improvement over IS.

    I think there are enough people who are inexperienced, unskilled, or accident prone when it comes to working on bikes, that having non-replaceable threads in the post mount is a bit of a risk.
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  20. #20
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    There is no real improvement with PM. I still have 4 bolts and still need an adaptor front and rear. What difference does it make?
    "It looks flexy"

  21. #21
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    Quote Originally Posted by shiggy
    IS is an industry wide standard, as is post mount. I have frames and forks with each, and they both work well. No advantage either way in actual use.

    I like that you can change mounting brackets for different rotor sizes and front vs rear with the "universal" calipers (ask the owners of IS only calipers about this). The brackets work well and are not very heavy.

    I have not seen any comparisons of weight differences between IS vs post mount on forks or frames.

    In most cases IS will result in somewhat less weight.

    IS provides a very solid connection for caliper alingment.

    I have seen IS shims fall out....but just tighten and continue riding.

    I would prefer to avoid adapters, but with various rotor sizes this is not always possible.

  22. #22
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    The 2011 Trances have PM for the back brakes now as well

  23. #23
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    Quote Originally Posted by ettore
    If you're stripping out threads, you deserve to ruin your frame. If you can't thread a bolt in straight, then I don't know how you can ride a bike. My neice's toy "workbench" has plastic screws and bolts that she is able to correctly assemble, she is 15 months.
    I'm so impressed with your mech skills and humble attitude.
    Lead by my Lefty............... right down the trail, no brakes.

  24. #24
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    Ibis Mojo HD also has PM brake mounts on the rear:



    -S

  25. #25
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    why would you even want to risk stripping your frame or fork? +1 to the arguement that ruining a 1$ adapter is preferable...
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