Advertise on Bikeforums.net



User Tag List

Results 1 to 9 of 9
  1. #1
    Senior Member
    Join Date
    Nov 2004
    My Bikes
    A few
    Posts
    896
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)

    Why the wide disparity in trail of touring bikes

    In comparing the trail of various touring bikes I have noticed they vary widely in the amount of trail based on the steering geometry. The difference in trail also means there is a great difference in the amount of wheel flop. Isn't there any agreement on what amount of trail provides for the best handling when loaded and with a front load being carried in low riders?
    Be the person your dog thinks you are.
    T.J.

  2. #2
    Senior Member
    Join Date
    Jul 2011
    Posts
    1,557
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    You have obviously got some numbers, but for the most part I have seen73/45. There are some lower steering angles, and that would change a lot, since the forks seem to be made to the same numbers.

  3. #3
    Senior Member
    Join Date
    Nov 2004
    My Bikes
    A few
    Posts
    896
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Thanks MassiveD. Trucker Deluxe for example is 71/45. You answered my question though; I was just wondering about what is considered the accepted norm.
    Be the person your dog thinks you are.
    T.J.

  4. #4
    Sprinter linus's Avatar
    Join Date
    Apr 2005
    Location
    Toronto, Ontario
    Posts
    1,068
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    It has more to do with company's philosophy on weight distribution of the riders. In general, road bike geo. is designed to be 40Front 60rear ratio but touring bikes' long chainstays messes up the weight distribution and the position of the riders. Therefore, they increase the front centre by slacker head angle and more fork rake. Hence the 18wheeler wheelbase.

  5. #5
    Senior Member
    Join Date
    Nov 2004
    My Bikes
    A few
    Posts
    896
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Thanks linus. I just picked up a bike to add to my collection that has 48.5 cm chain stays, but it only has a 71/45 HT angle/fork offset and I was comparing it to many other bikes to try and figure this all out. Steering geometry is actually identical to the Trucker Deluxe. I found the trail computes to being identical or close to several other very good bikes, depending on tire width. The seat tube on the bike I acquired is also very slack at 71.5 degrees. May not be a lively ride, but will sure be stable when descending.
    Be the person your dog thinks you are.
    T.J.

  6. #6
    coprolite fietsbob's Avatar
    Join Date
    Jun 2010
    Location
    NW,Oregon Coast
    My Bikes
    7
    Posts
    3,207
    Mentioned
    47 Post(s)
    Tagged
    0 Thread(s)
    No, different builders have different ideas./.

    components are mass produced, bike frames to mount them on
    can be made by an individual.

    then there is wheel size .. and contact patch size, of chosen tire.

    but I don't see trail stated.. only implied .. ['71/45']

    Trail, that is the distance laid out on the ground plane. in MM.

    measure that and get back..
    Last edited by fietsbob; 05-02-12 at 12:28 PM.

  7. #7
    coprolite fietsbob's Avatar
    Join Date
    Jun 2010
    Location
    NW,Oregon Coast
    My Bikes
    7
    Posts
    3,207
    Mentioned
    47 Post(s)
    Tagged
    0 Thread(s)
    front loads, like the Porteur's bikes, shuttling Parisian newspaper bundles
    to the Sellers stands from the Printer.

    have different needs than someone wanting to look at the scenery on a stable bike
    that does not need their full attention.

  8. #8
    Senior Member
    Join Date
    Nov 2004
    My Bikes
    A few
    Posts
    896
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Thanks fietsbob, that makes sense. The bike in question is an old 26" wheeled mtn bike. I made a spread sheet comparing the trail to several other bikes - some with 26" wheels, some with 650b, and some with 700c. I also compared different size tires for each. The bike I bought has quite a lot of trail, it ranges from 67 mm with 1.9" tires to 71 mm with 2.35" tires. Mechanical trail shows a little less for each. The bike will probably be fine for commuting/townie purposes and touring as described by your last sentence, and that is what I bought it for.

    Perhaps low trail is more important for Porteur's carrying heavy loads up high? My other road touring bikes have very low trail and seem stable and comfortable to "look at the scenery." Guess I will see how this one rides when it arrives in a few days.
    Be the person your dog thinks you are.
    T.J.

  9. #9
    Senior Member
    Join Date
    Nov 2004
    My Bikes
    A few
    Posts
    896
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    fietsbob, I did not measure the trail but used the online trail calculator here to compare different bikes based on their head tube angle, fork offset/rake, and different tire widths. Based on tire width, the trail ranges from 62 mm to 71 mm for the bike I got. Seems like a lot to me, but it compares favorably to some other good bikes like the Atlantis, A. Homer Hilson, Hunqapilar, SOMA San Marco, LHT Deluxe; even the Bridgestone XO-1 if I run 35 mm tires. The bike in question is an old 1983 Trek 850 that is on its way to me.

    I have wanted a 26" wheeled bike to make into an all-around/townie/tourer and the Trek is what I got.
    Last edited by Ciufalon; 05-05-12 at 01:32 AM.
    Be the person your dog thinks you are.
    T.J.

Posting Permissions

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