Advertise on Bikeforums.net



User Tag List

Results 1 to 12 of 12
  1. #1
    Senior Member Bicycle Addict's Avatar
    Join Date
    Sep 2012
    Location
    Auckland NZ
    My Bikes
    Marin Bolinas Ridge, Carlton Corsa 5, Falcon Olympic 12, Gary Fisher Marlin, Gary Fisher Aquila
    Posts
    443
    Mentioned
    8 Post(s)
    Tagged
    1 Thread(s)

    Trek Multitrack 750 Seat post size?

    Hey all, Paul here I have just got a Trek 750 frame, which came with no seatpost, can someone check theirs for me? Thanks
    Where are the Bikeaholic meetings? . . . . . I need help!? I just don't think I can do this alone.

    Behold the humble bicycle . . .the oldest form of mechanical transport for the individual person.
    It will be the last too.

    Re-Cycle that Bicycle. Fix it, Ride it, Give it away.

  2. #2
    Senior Member
    Join Date
    Apr 2006
    Posts
    2,321
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    I believe it is 26.6 but a cheap caliper is a better answer. Roger

  3. #3
    Senior Member rumrunn6's Avatar
    Join Date
    Jul 2008
    Location
    25 miles northwest of Boston
    My Bikes
    Bottecchia Sprint
    Posts
    13,178
    Mentioned
    9 Post(s)
    Tagged
    0 Thread(s)
    I don't have a caliper but I think my son's multitrack is a 750. if I remember I'd be happy to eyeball it with a standard ruler, if that would help. but then you can kinda do that with the frame ... there must be a Trek Spec web site out there, no?
    cycling is like baseball ~ it doesn't take much to make it interesting

  4. #4
    Senior Member surreal's Avatar
    Join Date
    Mar 2002
    Location
    NJ
    Posts
    3,084
    Mentioned
    10 Post(s)
    Tagged
    0 Thread(s)
    What year? Googling has suggested 27.2, but it wouldn't surprise me if earlier examples were narrower....

  5. #5
    Gouge Away kaliayev's Avatar
    Join Date
    Nov 2008
    Location
    BFOH
    Posts
    975
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    I have a 1990 750 and it uses a 26.8 sp. Congrats on the find, pretty sweet frames. 90-93 the 750 used TT lugged steel. After 93 the frames were tigged so might have changed sp sizing.
    Last edited by kaliayev; 01-03-14 at 09:44 AM.
    2003 Stevenson Custom Cycles Sportive
    1978 Trek TX700
    1990 Trek 750
    All are frame/frame set builds.

  6. #6
    Senior Member
    Join Date
    Apr 2006
    Posts
    2,321
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Surreal that site lists the seatpost for the earlier road bike from the 1970s called 750 not the newer 1990s hybrid 750s which this is. Roger

  7. #7
    Senior Member Lascauxcaveman's Avatar
    Join Date
    Nov 2011
    Location
    Pacific Northwest
    My Bikes
    A green one, "Ragleigh," or something.
    Posts
    2,655
    Mentioned
    35 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by rhenning View Post
    I believe it is 26.6 but a cheap caliper is a better answer. Roger
    +1

    Seriously, OP, go to the big online auction house and invest $5 on a cheap caliper. You'll use it on all your oddball seat post, quill, spacer etc, questions.
    ● 1971 Grandis SL ● 1972 Lambert Grand Prix frankenbike ● 1972 Raleigh Super Course fixie ● 1972 Peugeot UE-18 Mixte ● 1982 Motobecane Jubile Sport ● 1983 Nishiki Landau ● 1985 Peugeot Vagabond ● 1985 Trek 600 ● 1985 Shogun Prairie Breaker ● 1985 Raleigh Elkhorn ● 1986 Univega Nuovo Sport ● 1986 DeRosa Professional ● 1987 Schwinn Tempo ● 1996 Kona Lava Dome ● And a Bike to Be Named Later ●

  8. #8
    Gouge Away kaliayev's Avatar
    Join Date
    Nov 2008
    Location
    BFOH
    Posts
    975
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Personally I think the caliper idea is not very good. Unless the caliper is calibrated and you are very proficient at measuring inside diameters, being off by just .2mm means the difference in a sp working and not working. Best to go to your LBS if you are unsure and let them determine the sp size.
    2003 Stevenson Custom Cycles Sportive
    1978 Trek TX700
    1990 Trek 750
    All are frame/frame set builds.

  9. #9
    Senior Member
    Join Date
    Apr 2006
    Posts
    2,321
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    For $10 your can buy a digital caliper from Harbor Freight (most of the time it is on sale for that) that will be accurate enough for your needs. It can be set for for both inches and metric measurement. I have high end calipers but use that one the most because I don't worry about breaking it

  10. #10
    Senior Member surreal's Avatar
    Join Date
    Mar 2002
    Location
    NJ
    Posts
    3,084
    Mentioned
    10 Post(s)
    Tagged
    0 Thread(s)
    I saw info on 750s' seatposts on a few sites, including this one. Google is awesome that way; buncha results. The 27.2 was for late 90s models...

    Many shops have a tapered rod that they can insert into your frame to determine the size.

    If the OP tells us the year, or hits up his LBS, we'll be closer to solving this, although even at this point, we can prolly narrow it down to 3 different sizes....

  11. #11
    Senior Member Hummer's Avatar
    Join Date
    Sep 2010
    My Bikes
    1981 Raleigh GP, 1985 Norco Bush Pilot, . . .
    Posts
    303
    Mentioned
    17 Post(s)
    Tagged
    0 Thread(s)
    The seatpost diameter varies from year to year for this trek model. 1991: 27.2; 1993: 26.8.

    My advice, if you do not know the year of your bike, or you do know the year but not the diameter for that year, then you will need to use trial and error. Start with 27.2.

  12. #12
    Newbie
    Join Date
    Mar 2009
    Posts
    2
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Bicycle Addict View Post
    Hey all, Paul here I have just got a Trek 750 frame, which came with no seatpost, can someone check theirs for me? Thanks
    I'm sure by now you've already found the right seat post but if it helps anyone else, I found these pretty specs pretty detailed:
    Trek, Fisher, Klein, Lemond bike catalogs, bicycle brochures
    I recently came across a 1993 Trek Multitrack 720 with a wrong seat post size (using a dodgy shim), the manual/spec says it should be 26.8mm. Although I found that trying to fit a smaller 26.6mm was way too hard. The seat tube doesn't look too dirty or distorted but going to try to clean it out so see if that helps or just stick with whatever works I guess.

Posting Permissions

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