Advertise on Bikeforums.net



User Tag List

Page 1 of 2 12 LastLast
Results 1 to 25 of 35
  1. #1
    Sub10 Rider sub-atom's Avatar
    Join Date
    Mar 2008
    Location
    Finland
    My Bikes
    Scott Sub10 2004
    Posts
    20
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Replace v-brakes by u-brakes on a frame designed for 28'' wheels.

    Hi guys,

    is it reasonable to exchange v-brakes for u-brakes in order to adapt a 26'' wheelset to a frame that was made for 28'' wheels? I would like to make a touring bike.

    thanks.

  2. #2
    bike whisperer Kimmo's Avatar
    Join Date
    Dec 2009
    Location
    Melbourne, Oz
    My Bikes
    - - - - - - - - - - - - - - http://velospace.org/node/36949 http://velospace.org/node/47746 http://velospace.org/node/47747
    Posts
    6,529
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Good question; NFI.

  3. #3
    Mad bike riding scientist cyccommute's Avatar
    Join Date
    Nov 2004
    Location
    Denver, CO
    My Bikes
    Some silver ones, a black one, a red one, an orange one and a couple of titanium ones
    Posts
    15,028
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by sub-atom View Post
    Hi guys,

    is it reasonable to exchange v-brakes for u-brakes in order to adapt a 26'' wheelset to a frame that was made for 28'' wheels? I would like to make a touring bike.

    thanks.
    U-brakes don't use the same brake studs as linear/cantilever brakes. The diameter of the stud is different and the location of studs is wrong.
    Stuart Black
    Solo Without Pie. The search for pie in the Midwest.
    Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
    Days of Wineless Roads. Bed and Breakfasting along the KATY
    Twisting Down the Alley. Misadventures in tornado alley.
    An Good Ol' Fashion Appalachian Butt Whoopin'.

  4. #4
    bike whisperer Kimmo's Avatar
    Join Date
    Dec 2009
    Location
    Melbourne, Oz
    My Bikes
    - - - - - - - - - - - - - - http://velospace.org/node/36949 http://velospace.org/node/47746 http://velospace.org/node/47747
    Posts
    6,529
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by cyccommute View Post
    The diameter of the stud is different and the location of studs is wrong.
    Wrong for the same wheel size, or what's proposed here?

    Which uses the larger stud? Any idea by how much? Maybe it could be sleeved.

    I like a challenge

  5. #5
    Senior Member himespau's Avatar
    Join Date
    Jun 2008
    Location
    Louisville, KY
    Posts
    7,186
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    There was a thread here not too long ago where someone was able to use the hole in the fork and bridge to mount dual pivot (I think) brakes and go from 26" to 700c wheels, but he said he had a big drawer of brake calipers to choose from and he had to try most of them to find some that'd fit.
    Punctuation is important. It's the difference between "I helped my uncle, Jack, off a horse" and "I helped my uncle Jack off a horse"


  6. #6
    bike whisperer Kimmo's Avatar
    Join Date
    Dec 2009
    Location
    Melbourne, Oz
    My Bikes
    - - - - - - - - - - - - - - http://velospace.org/node/36949 http://velospace.org/node/47746 http://velospace.org/node/47747
    Posts
    6,529
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    There's always hub brakes...

  7. #7
    Sub10 Rider sub-atom's Avatar
    Join Date
    Mar 2008
    Location
    Finland
    My Bikes
    Scott Sub10 2004
    Posts
    20
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I see... maybe I need to try to find a place from where to try several models until I have a match. But looking at the placement of the studs and their diameters... it looked feasible to me. I will get back if I succeed...

  8. #8
    Mad bike riding scientist cyccommute's Avatar
    Join Date
    Nov 2004
    Location
    Denver, CO
    My Bikes
    Some silver ones, a black one, a red one, an orange one and a couple of titanium ones
    Posts
    15,028
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Kimmo View Post
    Wrong for the same wheel size, or what's proposed here?

    Which uses the larger stud? Any idea by how much? Maybe it could be sleeved.

    I like a challenge
    The U-brake stud is larger in diameter.
    Stuart Black
    Solo Without Pie. The search for pie in the Midwest.
    Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
    Days of Wineless Roads. Bed and Breakfasting along the KATY
    Twisting Down the Alley. Misadventures in tornado alley.
    An Good Ol' Fashion Appalachian Butt Whoopin'.

  9. #9
    Mister Bleak! mconlonx's Avatar
    Join Date
    Jun 2007
    Posts
    4,689
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by cyccommute View Post
    The U-brake stud is larger in diameter.
    I believe 9mm vs 8mm stud for regular cantis/v-brakes. Not an easy mod. Suggest OP looks into Sturmey Archer drum brake options...
    Quote Originally Posted by Six jours View Post
    Bottom line: everyone here should listen to Mconlonx... he has it figured out and the rest of you, well, don't.
    I know next to nothing. I am frequently wrong.

  10. #10
    bike whisperer Kimmo's Avatar
    Join Date
    Dec 2009
    Location
    Melbourne, Oz
    My Bikes
    - - - - - - - - - - - - - - http://velospace.org/node/36949 http://velospace.org/node/47746 http://velospace.org/node/47747
    Posts
    6,529
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    0.5mm sleeve sounds possible... what about the other aspect; the height?

  11. #11
    Mad bike riding scientist cyccommute's Avatar
    Join Date
    Nov 2004
    Location
    Denver, CO
    My Bikes
    Some silver ones, a black one, a red one, an orange one and a couple of titanium ones
    Posts
    15,028
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Kimmo View Post
    0.5mm sleeve sounds possible... what about the other aspect; the height?
    You are going the wrong way. The U-brake stud is 9mm. The cantilever stud is 8 mm. You'd have to drill out the brakes to make them fit.
    Stuart Black
    Solo Without Pie. The search for pie in the Midwest.
    Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
    Days of Wineless Roads. Bed and Breakfasting along the KATY
    Twisting Down the Alley. Misadventures in tornado alley.
    An Good Ol' Fashion Appalachian Butt Whoopin'.

  12. #12
    bike whisperer Kimmo's Avatar
    Join Date
    Dec 2009
    Location
    Melbourne, Oz
    My Bikes
    - - - - - - - - - - - - - - http://velospace.org/node/36949 http://velospace.org/node/47746 http://velospace.org/node/47747
    Posts
    6,529
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Um...
    Quote Originally Posted by sub-atom View Post
    exchange v-brakes for u-brakes
    Anyway, drilling out the brake would be easier, if the brass bushing was thick enough.

  13. #13
    Mister Bleak! mconlonx's Avatar
    Join Date
    Jun 2007
    Posts
    4,689
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Kimmo View Post
    Anyway, drilling out the brake would be easier, if the brass bushing was thick enough.
    It's not.

    However, OP should see if the studs are removable and if they can be replaced with appropriate studs. There, of course, still might be rim alignment issues...
    Quote Originally Posted by Six jours View Post
    Bottom line: everyone here should listen to Mconlonx... he has it figured out and the rest of you, well, don't.
    I know next to nothing. I am frequently wrong.

  14. #14
    Sub10 Rider sub-atom's Avatar
    Join Date
    Mar 2008
    Location
    Finland
    My Bikes
    Scott Sub10 2004
    Posts
    20
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by cyccommute View Post
    You are going the wrong way. The U-brake stud is 9mm. The cantilever stud is 8 mm. You'd have to drill out the brakes to make them fit.

    i've tried out an old shimano and the stud is actually larger, so the U-brake would fit with an adapter althought not an ideal solution...

  15. #15
    Sub10 Rider sub-atom's Avatar
    Join Date
    Mar 2008
    Location
    Finland
    My Bikes
    Scott Sub10 2004
    Posts
    20
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Kimmo View Post
    There's always hub brakes...
    hub brakes would indeed be awesome. Just a rather expensive mod... need to change the entire gear system as well...

  16. #16
    Senior Member
    Join Date
    Mar 2008
    Posts
    3,932
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Why can't you tour on 28" wheels?
    And why would you need to change the entire gear system if you went to hub brakes?
    And what would the difference be, as you're already considering getting new 26" wheels?

  17. #17
    Sub10 Rider sub-atom's Avatar
    Join Date
    Mar 2008
    Location
    Finland
    My Bikes
    Scott Sub10 2004
    Posts
    20
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I didn't say I couldn't tour on 28'' wheels. They are actually totally awesome. I'm just worried about not being able to mount tougher tyres (wider, buffier). The hub brakes I have checked have in-hub gears, so I would need to dump the whole shimano business, no? I didn't say I was going to get new 26''... more like second hand. But as my first sentence suggest, I would like to see if it's reasonable to switch brakes (the main issue), and since the studs ain't the same size, it probably ain't reasonable.

  18. #18
    Sub10 Rider sub-atom's Avatar
    Join Date
    Mar 2008
    Location
    Finland
    My Bikes
    Scott Sub10 2004
    Posts
    20
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by himespau View Post
    There was a thread here not too long ago where someone was able to use the hole in the fork and bridge to mount dual pivot (I think) brakes and go from 26" to 700c wheels, but he said he had a big drawer of brake calipers to choose from and he had to try most of them to find some that'd fit.
    Well, given that I would like to fit a smaller wheel, that would place the rim even farther from any hypothetical hole in the fork/bridge than with a 28'' wheel. So it goes one way,not the other ;-)

  19. #19
    Senior Member himespau's Avatar
    Join Date
    Jun 2008
    Location
    Louisville, KY
    Posts
    7,186
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Ah, I must have misread your first post. I thought it said you wanted to go to 28" from 26" with cantilever brakes. Guess a couple of us thought that.
    Punctuation is important. It's the difference between "I helped my uncle, Jack, off a horse" and "I helped my uncle Jack off a horse"


  20. #20
    Sub10 Rider sub-atom's Avatar
    Join Date
    Mar 2008
    Location
    Finland
    My Bikes
    Scott Sub10 2004
    Posts
    20
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by himespau View Post
    Ah, I must have misread your first post. I thought it said you wanted to go to 28" from 26" with cantilever brakes. Guess a couple of us thought that.
    oops. Sorry if that wasn't clear enough! Indeed. I want to replace 28'' wheels with 26''!

  21. #21
    Senior Member DannoXYZ's Avatar
    Join Date
    Jul 2005
    Location
    Saratoga, CA
    Posts
    11,496
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The other issue with this conversion is the 31.5mm drop in the radius from the axle to ground will decrease trail by a significant amount. The bike will be very twitchy and hunt/dart around after hitting bumps in the road. It gets tiring riding such a thing because you have to keep your hands on the bars all the time and keep it on track.

  22. #22
    bike whisperer Kimmo's Avatar
    Join Date
    Dec 2009
    Location
    Melbourne, Oz
    My Bikes
    - - - - - - - - - - - - - - http://velospace.org/node/36949 http://velospace.org/node/47746 http://velospace.org/node/47747
    Posts
    6,529
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Not to mention BB height...

    But I'm tipping it's nowhere near as much as 31.5mm, since the OP said the point is to fit bigger tyres.

  23. #23
    Senior Member
    Join Date
    Oct 2009
    Location
    England, currently dividing my time between university in Guildford and home just outside Reading
    My Bikes
    Too many to list here!
    Posts
    1,769
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by sub-atom View Post
    The hub brakes I have checked have in-hub gears, so I would need to dump the whole shimano business, no?
    Sturmey-Archer make a drum brake hub with a freehub, and also one that's threaded for a freewheel.

    As for the u-brake thing, I've done it while trying to put a 20" wheel on a 26" fork to make a chopper. I can confirm that, with a sleeve (I used brass stock I had lying about), a u-brake will fit a cantilever brake boss. The different wheel size didn't work out on that bike, so I never actually used the brake. To be honest, it's not enough of a decrease in diameter going from 28" to 26", you'll probably put the cantilever boss about level with the rim, when it needs to be above it for a U-brake.

  24. #24
    Senior Member LesterOfPuppets's Avatar
    Join Date
    Sep 2008
    Location
    Vancouver, USA
    My Bikes
    My War
    Posts
    18,440
    Mentioned
    16 Post(s)
    Tagged
    6 Thread(s)
    BB and axle height will be about the same if 2" tires are going to be used and 23mm tires were being used.

    Seems like long reach BMX calipers would be an easier swap.
    1980ish Free Spirit Sunbird fixed * 1996 Mongoose IBOC Zero-G * 1997 KHS Comp * 1990-ish Scapin * Olde Western Auto Cruiser.

  25. #25
    Senior Member
    Join Date
    Mar 2008
    Posts
    3,932
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by sub-atom View Post
    I didn't say I couldn't tour on 28'' wheels. They are actually totally awesome. I'm just worried about not being able to mount tougher tyres (wider, buffier).
    For tire availability, check out cyclocross tires and 29er MTB tires. They'll both fit a 28" / ETRTO 622 mm rim. Might be something there that'll give you an acceptable tread pattern as well as clearing your fork/frame.

    Quote Originally Posted by sub-atom View Post
    The hub brakes I have checked have in-hub gears, so I would need to dump the whole shimano business, no?
    Well, if you're running external (shimano) gears now, and is considering going to IGH, then you will need a new shifter.
    If the current setup is brake and shifter lever in one assembly, I'd advise replacing that one too.
    You might get away with using the brake lever, but it'll probably steal the space where you'd otherwise would have liked the shifter to go.

    There might be chainline issues when going from EGH to IGH. Nothing that can't be fixed, just don't expect stuff to play nice at first assembly.

    Quote Originally Posted by sub-atom View Post
    The hub brakes...
    I'd be a bit wary about touring on hub brakes if you're heading into truly mountainous areas. There is a risk of overheating.

Page 1 of 2 12 LastLast

Posting Permissions

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