Advertise on Bikeforums.net



User Tag List

Results 1 to 21 of 21

Thread: please be kind

  1. #1
    Junior Member
    Join Date
    Sep 2010
    Location
    Quebec
    My Bikes
    Masi and clunker
    Posts
    21
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    please be kind

    For a trained mechanic this is probably a no brainer, but here it is anyway. I adjusted my stem yesterday and reinstalled it by eye. I went for a ride and after 30 minutes it was evident that my 'bars were not lined up correctly. Is there a precise method for doing this?

  2. #2
    surly old man jgedwa's Avatar
    Join Date
    Sep 2006
    Location
    Carlisle, PA
    My Bikes
    IRO Mark V, Karate Monkey half fat, Trek 620 IGH, Cannondale 26/24 MTB, Amp Research B3, and more.
    Posts
    3,268
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Precise method? Probably not.

    I find that when I turn the wheel to one side I am less distracted/confused by the overall bike and can focus more on the stem and fork relationship. Even so, I often have to tweak it a bit after riding it around the block.

    jim
    Cross Check Nexus7, IRO Mark V, Trek 620 Nexus7, Karate Monkey half fat, IRO Model 19 fixed, Amp Research B3, Surly 1x1 half fat fixed, and more...
    --------------------------
    SB forever

  3. #3
    Senior Member
    Join Date
    Apr 2009
    Location
    New Rochelle, NY
    My Bikes
    too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
    Posts
    18,048
    Mentioned
    20 Post(s)
    Tagged
    1 Thread(s)
    There's no super precise method because none is required, eyeball alignment is accurate enough. Years ago someone marketed a tool to help, but most mechanics found it not to be worth the effort.

    Loosen the stem slightly so the bars can rotate, but keep it tight enough to stay in place. Eyeball the stem against the front tire looking from both sides and try for perfect symmetry. If you have a very short stem try this trick; put your front wheel squarely against a wall, and looking from the top align the bars to the joint betwen the wall and floor.
    FB
    Chain-L site

    An ounce of diagnosis is worth a pound of cure.

    “Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

    “One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

    WARNING, I'm from New York. Thin skinned people should maintain safe distance.

  4. #4
    Senior Member
    Join Date
    Jun 2010
    Posts
    817
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Years ago my Dad taught me this method - though I no longer use it.

    Tie/tape a piece of string long enough to go from one end of the handlebars around the seat post to the other end of the handlebars - mark the center with a Sharpie/piece of ribbon. Now turn the handlebars until the mark/ribbon cannot be seen - should be centered within a couple millimeters this way.
    -----------------------------------------
    While others have labelled me antisocial at various times, it's actually not true. I just don't like people.

  5. #5
    Senior Member
    Join Date
    Jun 2010
    Location
    Pearland, Texas
    My Bikes
    Cannondale, Trek, Raleigh, Santana
    Posts
    5,104
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    ayceejay, Compare the handlebars to the front axle by looking down while straddling the bike. This is as close to a measuring tool that I can think of.

    Brad

  6. #6
    Senior Member peripatetic's Avatar
    Join Date
    Oct 2004
    Location
    NYC
    My Bikes
    All 70s and 80s, only steel.
    Posts
    2,125
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    As mentioned before, turning the fork and wheel so it's at an angle to the frame can help you to see the alignment between only the stem and wheel. And then eyeball that sucker.

  7. #7
    Senior Member
    Join Date
    Feb 2010
    Posts
    397
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I straddle the front wheelm holding the wheel with my knees, line up the wheel with the frame, then eyeball the handlebars in line with the frame. As said before, i have the headset tight but still able to me twisted. Then I screw down the bolt so it doesn't move and finish the bolt off with a torque wrench.

  8. #8
    Senior Member Bent In El Paso's Avatar
    Join Date
    Nov 2009
    Location
    El Paso, TX
    My Bikes
    Co-Motion Speedster Co-Pilot
    Posts
    187
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Have my wife do it. I can never get the bars/saddles straight but she hits it perfect every time.

  9. #9
    Senior Member
    Join Date
    Aug 2005
    Location
    Pittsburgh, PA
    My Bikes
    '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
    Posts
    24,768
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    I place a metal yardstick edge on so it is centered on the stem bolt and over the handle bar clamp (these points are pretty easy to find accurately) and extends forward over the front tire. If the bars are centered, the straight edge will exactly bisect the tire.

    You must be straddling the bike to make this or any other eyeball centering method work.

  10. #10
    Applying for Membership.. grandjeanius's Avatar
    Join Date
    Dec 2009
    Location
    Ashburn, Virginia
    My Bikes
    Lynskey Cooper Ti, Surly CrossCheck, Motobecane Fantom Pro Ti, StumpJumper Xtra-cycle
    Posts
    41
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I've always used the stand over/trial and error method.. but thinking about the problem led me to:
    What if you used a Plumb Line (String with weight attached) and held it from the center of the handlebars so it hangs above the front tire? Then it would dangle a line straight down that you could use to line up with the center of the wheel.
    The only variable then would be making sure that the bike was standing straight up and down.. that could be accomplished with a level across the top of the handlebars. Maybe that would do the trick. Or did I just way "overgeek" this?
    Lynskey Cooper Ti, Surly CrossCheck, Motobecane Fantom Pro Ti, '97 StumpJumper Pro Xtra cycle.

  11. #11
    Bikaholic blamp28's Avatar
    Join Date
    Dec 2006
    Location
    Western, Michigan
    My Bikes
    Trek Fuel 90, Giant OCR, Rans Screamer Tandem
    Posts
    1,465
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by grandjeanius View Post
    did I just way "overgeek" this?
    Yes. Good plan for perfection but a simple trial and error would be quicker and work just fine.
    Trek Fuel XC MTB, Giant OCR Road Bike, Rans Screamer - Tandem

  12. #12
    Senior Member Retro Grouch's Avatar
    Join Date
    Feb 2004
    Location
    St Peters, Missouri
    My Bikes
    Rans Enduro Sport, Hase Kettweisel Tandem, Merin Bear Valley beater bike
    Posts
    23,099
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    When I do it for a customer I ask them to tell me when the bars are aligned so I can tighten it. That way I don't get any repeats.

    When I do it by myself, I close 1 eye.

  13. #13
    Senior Member MudPie's Avatar
    Join Date
    May 2004
    Location
    Southern California
    Posts
    1,874
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I've been riding/working on my own bikes for 30+ years and still no precise, engineered method.

    I once tried to make an aligning gauge. Imagine a 36" long threaded rod that is secured to the front dropouts with wing nut and washers, then the rod is centered by measuring the distance from the fork dropouts to the end of the rod (this was by trial and error). Then I would make measurements from the ends of the rod to the center of the stem (like a bolt feature on the stem's faceplate). Theoretically, the bars are centered when the distance from the rod end to the common center point are equal (like an isosceles triangle). There was always uncertainty in the process (is the threaded rod exactly centered, am I measuring from the same points...) and took a lot of fiddling and adjusting Bottom line, the threaded rod went to serve another garage project and I went back to the above forementioned eyeball methods.

  14. #14
    Senior Member DannoXYZ's Avatar
    Join Date
    Jul 2005
    Location
    Saratoga, CA
    Posts
    11,496
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    There's a method using two lasers and an alignment chart on a wall about 10m away.

  15. #15
    I'm Carbon Curious 531phile's Avatar
    Join Date
    Aug 2005
    Location
    Earthquake Central
    My Bikes
    Enough
    Posts
    2,196
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I just standover the bike and eyeball it. But for the perfectionist, couldn't Park come out with a tool similar to their rear derailleur alignment tool that does this? Fasten it to the handlebar and have two rods with feelers to see if the distance between the forks are equidistant.

    Quote Originally Posted by avner View Post
    I loled. Twice. Then I cried. Then I rubbed one out and cried again, but thanks for sharing.

  16. #16
    Senior Member MudPie's Avatar
    Join Date
    May 2004
    Location
    Southern California
    Posts
    1,874
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by 531phile View Post
    I just standover the bike and eyeball it. But for the perfectionist, couldn't Park come out with a tool similar to their rear derailleur alignment tool that does this? Fasten it to the handlebar and have two rods with feelers to see if the distance between the forks are equidistant.
    My alignment gauge (see #13 above) tried to replicate said. As I found, there were too many variables using tape measures. I thought about measuring from the handlebar, but that assumes the handlebar is centered. I tried to reference a "fixed" spot, like the center of the stem's faceplate.

    I always thought the fork manufacturer can put a scribed mark (or notch) on the steer tube that is points straight ahead. Then align a "straight ahead" feature on the stem to the one on the steer tube. It's easier to place these marks in a controlled, manufacturing environment. (For example, after the steer tube is pressed into the fork crown, the assembly is placed in a precision jig and marked. The stem and fork manufacturers would need to stanardize, and I wouldn't consider it "proprietary", so it should be relatively easy to implement. Of course, this only would work with threadless systems.

  17. #17
    Junior Member
    Join Date
    Sep 2010
    Location
    Quebec
    My Bikes
    Masi and clunker
    Posts
    21
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thanks to everyone for their input, I thought it was just me! It seems that a jig of some sort would be the definitive answer but I don't intend doing this very often so I had my wife help me, at least if it is still wonky I know who to blame!

  18. #18
    Senior Member rishardh's Avatar
    Join Date
    Jun 2008
    Location
    North Texas
    My Bikes
    Kestrel Talon; Giant NRS Air; Litespeed Tuscany; Burley Rivazza; Cerverlo RS; BMC SLX01; Litespeed C1r
    Posts
    364
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Yeah, eyeballing is good enough but I make adjustments after the first ride cos it irritates me knowing its not dead straight. The same problem applies to saddles too, but since I don't see it while riding it does not bother me.

  19. #19
    Senior Member
    Join Date
    Mar 2009
    Location
    Boise, ID.
    Posts
    1,253
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I've had good luck with this method.

    Stand in front of the bike, facing the handlebars. Lock the front wheel between your knees/legs. Line the stem up by eye with the center of the wheel and tighten.

    That method has gotten me "close enough" that I haven't noticed it being off. YMMV
    1993 Cannondale T700 - 1994 Specialized Rockhopper - Actionbent T1 (Electrification in progress!)

  20. #20
    Senior Member
    Join Date
    Feb 2001
    Location
    England
    Posts
    12,073
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    A lot of cheap bikes have mis-aligned forks that are visually way off centre. Assuming you have a proper bike and correctly aligned forks, you can centre the stem :
    Loosen the stem binder bolt(s), depending on the headset style these are at the side or the top. You need some resistance to maintain the position.
    Stradle the bike and hold the wheel in place with a foot.
    Centre your head by aligning the tyre midway with respect to the hub.
    Rotate the stem so the bar clamp part centres on the tyre.
    Tighten stem.

  21. #21
    Don from Austin Texas
    Join Date
    Jul 2009
    Location
    Austin, Texas
    My Bikes
    Schwinn S25 "department store crap" FS MTB, home-made CF 26" hybrid, CF road bike with straight bar, various wierd frankenbikes
    Posts
    1,139
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by rishardh View Post
    Yeah, eyeballing is good enough but I make adjustments after the first ride cos it irritates me knowing its not dead straight. The same problem applies to saddles too, but since I don't see it while riding it does not bother me.
    Even though you can't see the saddle skewed to one side while you are riding: http://www.bikeforums.net/showthread...n-and-solution!

    Don in Austin

Posting Permissions

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