Results 1 to 41 of 41
  1. #1
    mtbr member
    Reputation:
    Join Date
    May 2008
    Posts
    164

    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
    Look at the time!
    Reputation: lelebebbel's Avatar
    Join Date
    Jan 2005
    Posts
    1,137
    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
    mtbr member
    Reputation: boomn's Avatar
    Join Date
    Jul 2007
    Posts
    9,647
    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
    mtbr member
    Reputation: One Pivot's Avatar
    Join Date
    Nov 2009
    Posts
    5,944
    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
    Legend
    Reputation:
    Join Date
    Nov 2004
    Posts
    1,287
    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
    AZ
    AZ is offline
    banned
    Reputation: AZ's Avatar
    Join Date
    Apr 2009
    Posts
    19,201
    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.


    It must be hard to be as awesome as you are .

  7. #7
    Sheffield,South Yorkshire
    Reputation: ibbo's Avatar
    Join Date
    Feb 2009
    Posts
    424
    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
    mtbr member
    Reputation: BaeckerX1's Avatar
    Join Date
    Oct 2007
    Posts
    2,228
    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 07:56 AM.
    Gotta get up to get down.
    LMB

  9. #9
    Nouveau Retrogrouch SuperModerator
    Reputation: shiggy's Avatar
    Join Date
    Dec 1998
    Posts
    48,307
    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.
    mtbtires.com
    The trouble with common sense is it is no longer common

  10. #10
    No longer a hardtailkid.
    Reputation: hardtailkid's Avatar
    Join Date
    Jan 2010
    Posts
    1,830
    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
    mtbr member
    Reputation:
    Join Date
    Dec 2003
    Posts
    2,889
    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
    No longer a hardtailkid.
    Reputation: hardtailkid's Avatar
    Join Date
    Jan 2010
    Posts
    1,830
    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
    No longer a hardtailkid.
    Reputation: hardtailkid's Avatar
    Join Date
    Jan 2010
    Posts
    1,830
    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
    NWS is offline
    mtbr member
    Reputation:
    Join Date
    Jun 2010
    Posts
    1,391
    Quote Originally Posted by AZ.MTNS
    It must be hard to be as awesome as you are .
    Bravo.

  15. #15
    AZ
    AZ is offline
    banned
    Reputation: AZ's Avatar
    Join Date
    Apr 2009
    Posts
    19,201
    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
    No longer a hardtailkid.
    Reputation: hardtailkid's Avatar
    Join Date
    Jan 2010
    Posts
    1,830
    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
    Look at the time!
    Reputation: lelebebbel's Avatar
    Join Date
    Jan 2005
    Posts
    1,137
    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
    mtbr member
    Reputation:
    Join Date
    Sep 2007
    Posts
    752
    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
    bi-winning
    Reputation: rkj__'s Avatar
    Join Date
    Feb 2004
    Posts
    11,121
    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.
    When under pressure, your level of performance will sink to your level of preparation.

  20. #20
    mtbr member
    Reputation: gticlay's Avatar
    Join Date
    Dec 2007
    Posts
    6,632
    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
    mtbr member
    Reputation:
    Join Date
    May 2006
    Posts
    11,942
    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
    mtbr member
    Reputation:
    Join Date
    Oct 2009
    Posts
    587
    The 2011 Trances have PM for the back brakes now as well

  23. #23
    mtbr member
    Reputation:
    Join Date
    May 2007
    Posts
    5,220
    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
    Curmudgeon
    Reputation: shif's Avatar
    Join Date
    May 2008
    Posts
    158
    Ibis Mojo HD also has PM brake mounts on the rear:



    -S

  25. #25
    mtbr member
    Reputation: k1lluaA's Avatar
    Join Date
    Oct 2008
    Posts
    332
    why would you even want to risk stripping your frame or fork? +1 to the arguement that ruining a 1$ adapter is preferable...
    2008 Kona Caldera

    "Today I saw my own son use a bicycle as a weapon....
    I seriously thought he was going to rape me"

  26. #26
    ride hard take risks
    Reputation: dogonfr's Avatar
    Join Date
    Jan 2005
    Posts
    25,418
    PM rules
    Formotion Products
    http://www.formot

  27. #27
    mtbr member
    Reputation: boomn's Avatar
    Join Date
    Jul 2007
    Posts
    9,647
    I wish I could find the older thread where a guy got a bike with rear PM mounts that were skewed and there were no tools to easily correct it like an IS mount. The bolts themselves end up at an angle so you have to start using CPS style washers even on non-Avid brakes

  28. #28
    mtbr member
    Reputation: subydoo's Avatar
    Join Date
    Feb 2005
    Posts
    236
    Quote Originally Posted by k1lluaA
    why would you even want to risk stripping your frame or fork? +1 to the arguement that ruining a 1$ adapter is preferable...
    If you might ruin your frame, cuz you cant run a bolt in straight, buy a cheap frame. Or don't work on it yourself. I like my fancy high end bikes, and covet expensive lightweight sh*t.

    Adapters are like the whole lipstick on a pig thing.

    I would love a fork with PM 7" and Frame with PM 7" combo...... I am however, over 6 foot tall, and cannot imagine running smaller rotors. The wife on the other hand will never need a larger than 6" rotor on the rear of her rig.

    So, I guess what I am saying is, we need a new standard.

  29. #29
    ride hard take risks
    Reputation: dogonfr's Avatar
    Join Date
    Jan 2005
    Posts
    25,418
    Quote Originally Posted by boomn
    I wish I could find the older thread where a guy got a bike with rear PM mounts that were skewed and there were no tools to easily correct it like an IS mount. The bolts themselves end up at an angle so you have to start using CPS style washers even on non-Avid brakes
    New swingarm
    Formotion Products
    http://www.formot

  30. #30
    mtbr member
    Reputation: gticlay's Avatar
    Join Date
    Dec 2007
    Posts
    6,632
    Quote Originally Posted by subydoo
    If you might ruin your frame, cuz you cant run a bolt in straight, buy a cheap frame. Or don't work on it yourself. I like my fancy high end bikes, and covet expensive lightweight sh*t.

    Adapters are like the whole lipstick on a pig thing.

    I would love a fork with PM 7" and Frame with PM 7" combo...... I am however, over 6 foot tall, and cannot imagine running smaller rotors. The wife on the other hand will never need a larger than 6" rotor on the rear of her rig.

    So, I guess what I am saying is, we need a new standard.
    You might, but how does that address those that want a 7" front, 6" rear... or those running 8" front and rear, or 6" both ends... PM doesn't do ANYTHING to get rid of adapters. I think you got that while you were typing....
    "It looks flexy"

  31. #31
    ride hard take risks
    Reputation: dogonfr's Avatar
    Join Date
    Jan 2005
    Posts
    25,418
    The PM design can handle more load than IS which why PM is IS on motos for quite a few years now.
    Formotion Products
    http://www.formot

  32. #32
    mtbr member
    Reputation:
    Join Date
    Apr 2009
    Posts
    2,431
    Good side of IS - no stripped threads (but you really shouldn't be stripping them out anyhow - use a longer bolt)

    Bad side - on some brakes with poor tolerances you need to face the mounts (due to paint) to get the caliper to sit square and plumb. I found this, and do you think I could locate a shop with the proper facing tool - no!

    PM for the win for me
    Rimmer - "There's an old human saying - if you talk garbage, expect pain"

  33. #33
    mtbr member
    Reputation:
    Join Date
    Sep 2007
    Posts
    169
    For those of you who are worried about stripping threads did you ever hear of a helicoil?

    And where do you get a $1 adapter from? I cant find one for less then $20 hear in Australia

  34. #34
    g3h6o3
    Reputation: PissedOffCil's Avatar
    Join Date
    Oct 2007
    Posts
    3,707
    As far as I'm concerned, I prefer IS to be able to remove my brake without losing my adjustment (remove the adapter from mount, not the brake from adapter)
    Check out my SportTracks plugins for some training aid software.

  35. #35
    mtbr member
    Reputation:
    Join Date
    Jan 2004
    Posts
    6,487
    Quote Originally Posted by gticlay
    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?
    For the vast majority of XC/Trail bikes running 160mm rear rotors, no adapter would be needed, and for different rotor sizes, some PM adapters are effectively spacers, with no extra bolts required.

  36. #36
    mtbr member
    Reputation: subydoo's Avatar
    Join Date
    Feb 2005
    Posts
    236

    Good job!

    Quote Originally Posted by edzwa
    For those of you who are worried about stripping threads did you ever hear of a helicoil?
    Yeah, what he said....


    An adapter is an adapter, how bout only one type?

    PM sho nuff!

  37. #37
    mtbr member
    Reputation: k1lluaA's Avatar
    Join Date
    Oct 2008
    Posts
    332
    i love all you super mechs in here, who have never in your life accidentally stripped a bolt. classic...

    Its not a matter of it happening often, its about the risk of one time doing it...

    imo adapters dont look that bad, i have them on my bike and i dont notice them, besides i have a bike to ride it, not stand next to it like some kind of car show model...
    2008 Kona Caldera

    "Today I saw my own son use a bicycle as a weapon....
    I seriously thought he was going to rape me"

  38. #38
    mtbr member
    Reputation: subydoo's Avatar
    Join Date
    Feb 2005
    Posts
    236
    Quote Originally Posted by k1lluaA
    i love all you super mechs in here, who have never in your life accidentally stripped a bolt. classic...

    Its not a matter of it happening often, its about the risk of one time doing it...

    imo adapters dont look that bad, i have them on my bike and i dont notice them, besides i have a bike to ride it, not stand next to it like some kind of car show model...

    Super mech....hah! I strip bolts all the time, wife calls me Tommy the Torquer.
    That being said, there are bolts to be extra careful with. You know those that thread into your jewel.

    I just want a single type of adapter, I have not used an IS mount caliper in a while. Lets get up to date here.


    Oh, and my bikes are expensive, dirty and beatup. Just like my women, er wife, ridden hard and put away wet.

  39. #39
    mtbr member
    Reputation: subydoo's Avatar
    Join Date
    Feb 2005
    Posts
    236
    AND, did anyone see that Turner setup, thats a thing of beauty.

    Imagine that, a post mount caliper with a post mount. Genius!

  40. #40
    mtbr member
    Reputation:
    Join Date
    May 2008
    Posts
    164
    is that mount replaceable on the HD? i like the hanger too.

  41. #41
    Bicyclochondriac.
    Reputation:
    Join Date
    Jan 2004
    Posts
    13,388
    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.
    I came into this thread thinking I could not possibly care less about whether a frame or fork is PM or IS.

    I was wrong.

    I now care even less than I did before reading this thread.
    15mm is a second-best solution to a problem that was already solved.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •