increasing rake

Discussion in 'Bicycle Repair' started by kjparker, Jun 15, 2008.

  1. kjparker

    kjparker Member

    hi,

    I am toying with the idea of having the steerer tube changed on my frame from one that accepts a 1 inch steerer to one that takes a 1 1/18 steerer.

    the removing and re-welding part isnt too much of a problem. However wondering what the effect of increasing the rake slightly would be on the handling of the bike?

    If it understand correctly, it should slow the handling. Is this correct?
     

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  2. eljefino

    eljefino Member

    you'd increase caster which will make it fight harder to track straight or in your words handle more slowly. Good for a road bike, bad for quick city darting about.
     
  3. stude13

    stude13 Active Member

    i was behind a sportster today. he had kicked it out just a little. we came off the of a bridge that sent him into a 65mph tank slapper, he made it.
     
  4. frameteam2003

    frameteam2003 Member

    unless you really start changing the head tube angles a lot it shouldn't make much difference.You really would want to stay with the same angles of your frame.You'll need a frame jig.
     
  5. bucvoss

    bucvoss Member

    I just did that to my trike that Im building. i secured the frame so it could not move. recorded the tube angle and cut the sucka off. the new tube was no big deal i tack welded it into place with the increased angle i wanted. I then took a string from a a point off the back in two places that i had previously measured before the cut and slightly tapped the new tube till it was exact. will it work , i sure hope so. I put the extended fork in and seems to be ok when i pedal it. I don't know how it will be when the etek is installed and 200 lbs of battery's. I did add an plate in the diamond at the tube to help reinforce the welded tube. I recommend a very good mig for bike tube welding as it can be sort of difficult if you not use to welding light guage metal

    I have two trikes that are front wheel hub drive with an extended frame. I dont like the quick steering at all above 30 mph. Here is a link to one of the battery trikes. Dont look at the mess in the garage lol
    [​IMG]
     
    Last edited: Jun 20, 2008
  6. crabdance

    crabdance Member

    Nice Trike! I really love it! Why don't you put some more pictures up in the picture gallery so we can all have a good look. :cool:
     
  7. lennyharp

    lennyharp Member

    Most bicycles that are ridden very far are between 69 and 74 degrees head tube angle with from 1 to 3 inches of fork rake. You would not believe the amount 2 degrees will change handling characteristics. I am sure you can go shallower say to 65 and steeper say to 80 degrees.

    A frames geometry effects its stability and handling and how well it rides over bumps. I would think 71 degrees is a good compromise. That is a generally accepted angle for mountain bikes. I will be building my next frame with 72 or 73 degrees to have a predictable handling bike that goes where I point it when I point it there. It is easier to change direction and if well balanced will ride hands free just by shifting balance.

    Trikes work a little different and I have not built them so can't say about them. That is a great looking trike you have bucvoss. Another way to do a bike modification is to braze using brazing rod and what is called fillet brazing. Here is a link that explaines about Schwinn frames and what made them so strong. Part was the Fillet Brazing used. Doesn't this 4130 Cro-Moly rack look stronger and lighter than a bolt together mild steel rack most motor kits use?
     

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    Last edited: Jun 20, 2008
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