CHOP CULT HOME
Email Password
Search
  1. #1
    Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2011
    Posts
    44

    Default measuring trail on a girder......?

    Hey guys, Brand new member.

    I'm Planning out a build I'm currently working on funding, And have stumbled across a problem. It's going to be a kz1000 police engine with a fully custom rigid frame by cycleone manufacturing, and a spitfire girder front end.

    My problem is with the girder and how to measure trail on it. typically you follow the wheel straight down and the neck at it's angle and factor in the offset. But with a girder it's got the area that would typically be called the triple trees/steering yoke, and then across the link bar there are the actual ends of the forks. Which to I measure to for m y offset?

    I figure it's the top of the fork/girder section it's self and not the yoke connection points but I'm not certain. Also being that the height changes differently with a girder than a springer or glide front end, Will I need someone sitting on it to even out the ride height to factor in a rider?

    Anyone have experience with the skateboard wheel type chain tensioners? I like em but don 't want to be on a long ride (like the stampede) and have to buy a skateboard at some walmart for a replacement. How long do they last

  2. #2
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2010
    Posts
    599

    Default

    As far as the skateboard wheel tensioner your better off getting one from bitwell or lowbrow, the wheels you get from walmart will not hold up, they are a hard plastic and by the time you go to an actual skate shop and buy a high quality urethane wheel and then make a bracket and buy a nut and bolt and the roller bearings your better off buying one already mad and will come out just a little cheaper, been there done that.

  3. #3
    Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2011
    Posts
    44

    Default

    yea those are the ones i was asking about. I just meant I dont want to have to buy a cheap wheel to replace it on a ride. So i wanted to make sure that the wheels last well from a person who's used em, and if the tensioner works well or not.

  4. #4
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2010
    Posts
    599

    Default

    Yeah they work and hold up pretty well, the cheapest high quality wheel I could find was like 60 bucks, so they are definitely worth it.

  5. #5
    Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2011
    Posts
    44

    Default

    cool I just wanted to make sure I wasn't going to shell out cash for it and have it chewed up in a couple hundred miles wishing I'd just stuck with the frame adjusters. But since they seem to work well I'll have both.

  6. #6
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Dec 2009
    Posts
    1,361

    Default

    good question...I too am interested in what some people with some real experience say.

    for mine it was measuring straight threw the neck to where the tire meets the ground...the distance between was my trail....I know it can get ALOT more complicated than that but that is what I went with

  7. #7
    Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2011
    Posts
    44

    Default

    That's one question down. anyone know on the girder?

  8. #8
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Aug 2009
    Posts
    362

    Default

    http://rbracing-rsr.com/rakeandtrail.html

    Heres a great page on this subject.... Im no expert either, but Ive used to get a little more educated...

  9. #9
    Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2011
    Posts
    44

    Default

    Quote Originally Posted by oildevil13 View Post
    http://rbracing-rsr.com/rakeandtrail.html

    Heres a great page on this subject.... Im no expert either, but Ive used to get a little more educated...
    That and another one with mainly the same text (rewrittin enough to claim difference), were what I was reading on it. So I guess the offset distance for me is the neck center to the front upper link bolt, while someone is seated on it (to adjust for the rotational throw of the link bars). the rotation of those link bars will be the real x factor and only on bumps.

    IT's kinda sad that I didn't understand how trail worked until a couple days ago, when I used to build for American Performance Choppers. But I was an auto mechanic only when I started with them, and had only worked on my own honda magna when it came to bikes. Plus all my parts were ordered before I even got the work order. I was more of an assembler/diagnostician with them than a builder I guess. But that's the life of a tech at a mass produced chopper company I guess. 2-3 models and their planned out once and never really deviate as far as the geometry goes.

    How should I set the ride height? all for link bars level, or do they need to point slightly up/down when sitting with a rider on it?

  10. #10
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2010
    Posts
    1,580

    Default

    if i'm not mistaken, you still draw a line through the steering stem and drop a plumb bob from the axle. the offset on a girder helps correct the trail on a raked out bike which is one of the reasons they're popular, it works the same way the raked trees do on the wcc/occ style bikes.

  11. #11
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Aug 2009
    Posts
    542

    Default

    Have you called CycleOne? Red is a good guy and has been building frames and bikes for a Loooooong time. I'm sure if you sent in some pics of you girder and some measurements you guys can figure it out.

  12. #12
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Feb 2010
    Posts
    329

    Default

    Quote Originally Posted by hellbilly1932 View Post
    Have you called CycleOne? Red is a good guy and has been building frames and bikes for a Loooooong time. I'm sure if you sent in some pics of you girder and some measurements you guys can figure it out.
    id have to disagree. I got a frame from cycleone and it's was all jacked-up.. kate and red are very nice but the frame looks like it was built in a garage. I sent it over to acme choppers for fixing as the motor was crooked as hell and the motor plates were horrible. cycleone then got it from acme where they are trying to fix it. acme advised me against using the frame.

  13. #13
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Dec 2010
    Posts
    206

    Default

    Turbonate is correct on trail, all that matters in neck angle and tire placement, doesnt matter what shape the forks are. You need at least a couple inches, but too much can make it steer real slow. The RB racing link is great.

Share This



Tags for this Thread

Posting Permissions

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

Log in

Log in