increasing rake

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

  1. kjparker

    kjparker Member


    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?

  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
    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