Head tube angle/increased fork travel

Discussion in 'Mountain Bikes' started by Alan McClure, Jun 25, 2003.

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  1. Alan McClure

    Alan McClure Guest

    Alright, my bike currently has a 70mm head tube angle with 63 mm travel on the fork. I mentioned in
    another thread that I was thinking about getting a new fork like this one:

    http://makeashorterlink.com/?J2BC12E05

    or another 80mm travel fork (any suggestions for a nice price--marzocchi maybe). Anyway, someone
    mentioned that most people find 71 degrees to be about right for the head tube angle. Of course,
    mine is already off that mark by 1 degree. Does anyone know how much the above fork would throw off
    the angle even more? Is there any way at all to counteract that effect without having a frame
    builder replace the head tube. If not, then does anyone have any other suggestions?

    Thanks again,

    Alan McClure
     
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  2. Mark Hickey

    Mark Hickey Guest

    "Alan McClure" <[email protected]> wrote:

    >Alright, my bike currently has a 70mm head tube angle with 63 mm travel on the fork. I mentioned in
    >another thread that I was thinking about getting a new fork like this one:
    >
    >http://makeashorterlink.com/?J2BC12E05
    >
    >or another 80mm travel fork (any suggestions for a nice price--marzocchi maybe). Anyway, someone
    >mentioned that most people find 71 degrees to be about right for the head tube angle. Of course,
    >mine is already off that mark by 1 degree. Does anyone know how much the above fork would throw off
    >the angle even more? Is there any way at all to counteract that effect without having a frame
    >builder replace the head tube. If not, then does anyone have any other suggestions?

    The change from a 63 to 80mm shock (assuming the ride height will change by ~15mm once sag is
    factored in) will be between close to another degree (probably about 0.7-8 degrees, depending on a
    lot of minor things like wheelbase).

    That would put your head tube's effective angle at 69 degrees - pretty slack, but not horribly so. I
    doubt you'll find the difference all that drastic though. If it's a stiffer, better fork the result
    will be worth it.

    Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame
     
  3. Alan McClure

    Alan McClure Guest

    "Mark Hickey" <[email protected]> wrote in message
    news:[email protected]...
    > "Alan McClure" <[email protected]> wrote:
    > >or another 80mm travel fork (any suggestions for a nice price--marzocchi maybe). Anyway, someone
    > >mentioned that most people find 71 degrees to be about right for the head tube angle. Of course,
    > >mine is already off that mark by 1 degree. Does anyone know how much the above fork would throw
    off
    > >the angle even more? Is there any way at all to counteract that effect without having a frame
    > >builder replace the head tube. If not, then does anyone have any other suggestions?
    >
    > The change from a 63 to 80mm shock (assuming the ride height will change by ~15mm once sag is
    > factored in) will be between close to another degree (probably about 0.7-8 degrees, depending on a
    > lot of minor things like wheelbase).
    >
    > That would put your head tube's effective angle at 69 degrees - pretty slack, but not horribly so.
    > I doubt you'll find the difference all that drastic though. If it's a stiffer, better fork the
    > result will be worth it.
    >
    > Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame

    I think maybe I accidentally sent you an e-mail rather than replying to the group. So, here is
    what I wrote:

    Do you think there is any other reasonable option--including replacing the headtube at a frame
    machine shop? Would that cost an unreasonable amount of money? I am assuming that it would, but I
    don't really know. It seems like there would have to be some way around the loss of another degree,
    but maybe not.

    Alan
     
  4. Mark Hickey

    Mark Hickey Guest

    "Alan McClure" <[email protected]> wrote:

    >"Mark Hickey" <[email protected]> wrote

    >> The change from a 63 to 80mm shock (assuming the ride height will change by ~15mm once sag is
    >> factored in) will be between close to another degree (probably about 0.7-8 degrees, depending on
    >> a lot of minor things like wheelbase).
    >>
    >> That would put your head tube's effective angle at 69 degrees - pretty slack, but not horribly
    >> so. I doubt you'll find the difference all that drastic though. If it's a stiffer, better fork
    >> the result will be worth it.

    >I think maybe I accidentally sent you an e-mail rather than replying to the group. So, here is
    >what I wrote:
    >
    >Do you think there is any other reasonable option--including replacing the headtube at a frame
    >machine shop? Would that cost an unreasonable amount of money? I am assuming that it would, but I
    >don't really know. It seems like there would have to be some way around the loss of another degree,
    >but maybe not.

    You did send me an email... here is/was my reply...

    Probably not worth it unless you have an emotional attachment to that frame that makes it worth
    spending much more than it's worth to upgrade it. I'd recommend trying the shock and see if you like
    the results. If that doesn't work out, there are plenty of frames out there that you could buy with
    appropriate angles (and that are probably lighter and stronger to boot).

    Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame
     
  5. In article <[email protected]>, [email protected] says...
    > Alright, my bike currently has a 70mm head tube angle with 63 mm travel on the fork. I mentioned
    > in another thread that I was thinking about getting a new fork like this one:
    >
    > http://makeashorterlink.com/?J2BC12E05
    >
    > or another 80mm travel fork (any suggestions for a nice price--marzocchi maybe). Anyway, someone
    > mentioned that most people find 71 degrees to be about right for the head tube angle. Of course,
    > mine is already off that mark by 1 degree. Does anyone know how much the above fork would throw
    > off the angle even more? Is there any way at all to counteract that effect without having a frame
    > builder replace the head tube. If not, then does anyone have any other suggestions?
    >
    > Thanks again,
    >
    > Alan McClure
    >
    >
    >
    >

    A lot of the 100mm Marzocchi forks can be converted to 80mm cheaply by cutting the springs or
    properly by buying new springs. Just FYI if you see a good deal on a MXC or soemthing.
    --
    _________________________
    Chris Phillipo - Cape Breton, Nova Scotia http://www.ramsays-online.com
     
  6. > > Home of the $695 ti frame
    >
    > I think maybe I accidentally sent you an e-mail rather than replying to the group. So, here is
    > what I wrote:
    >
    > Do you think there is any other reasonable option--including replacing the headtube at a frame
    > machine shop? Would that cost an unreasonable amount of money? I am assuming that it would, but I
    > don't really know. It seems like there would have to be some way around the loss of another
    > degree, but maybe not.
    >
    > Alan
    >
    >
    >
    >

    Are you talking about an expensive custom steel frame or just an old brand name hard tail frame?
    --
    _________________________
    Chris Phillipo - Cape Breton, Nova Scotia http://www.ramsays-online.com
     
  7. Alan McClure

    Alan McClure Guest

    "Mark Hickey" <[email protected]> wrote in message
    news:[email protected]...
    > "Alan McClure" <[email protected]> wrote:
    >
    > >"Mark Hickey" <[email protected]> wrote
    >
    > >> The change from a 63 to 80mm shock (assuming the ride height will change by ~15mm once sag is
    > >> factored in) will be between close to another degree (probably about 0.7-8 degrees, depending
    > >> on a lot of minor things like wheelbase).
    > >>
    > >> That would put your head tube's effective angle at 69 degrees - pretty slack, but not horribly
    > >> so. I doubt you'll find the difference all that drastic though. If it's a stiffer, better fork
    > >> the result will be worth it.
    >
    > >I think maybe I accidentally sent you an e-mail rather than replying to
    the
    > >group. So, here is what I wrote:
    > >
    > >Do you think there is any other reasonable option--including replacing
    the
    > >headtube at a frame machine shop? Would that cost an unreasonable amount
    of
    > >money? I am assuming that it would, but I don't really know. It seems
    like
    > >there would have to be some way around the loss of another degree, but
    maybe
    > >not.
    >
    > You did send me an email... here is/was my reply...
    >
    > Probably not worth it unless you have an emotional attachment to that frame that makes it worth
    > spending much more than it's worth to upgrade it. I'd recommend trying the shock and see if you
    > like the results. If that doesn't work out, there are plenty of frames out there that you could
    > buy with appropriate angles (and that are probably lighter and stronger to boot).
    >
    > Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame

    I guess I thought it just might be cheaper than buying a new frame. Now it looks like I have three
    options. 1) don't do anything and just ride with my crap fork(i've been doing it--but don't like
    it) 2) buy a new fork and see if I notice a negative slack steering difference (this one scares me)
    in which case I might do-- 3) buy a new frame too

    But I wonder.....aside from my hayes brake and front wheel/tires, my components are not that great.
    So....if I was already looking at about $300 on a fork, and then estimating at around $700 on a
    frame, maybe I should think about just doing 1) above, and then saving up $1000 for a bike with
    better components, and transferring my brake/front wheel over which actually adds another option 4)
    buy new bike, which is more of a long term choice.

    Hmmmm.........

    Looks like there is not an easy answer.

    Thanks,

    Alan
     
  8. In article <[email protected]>, [email protected] says...
    >
    > "Mark Hickey" <[email protected]> wrote in message
    > news:[email protected]...
    > > "Alan McClure" <[email protected]> wrote:
    > >
    > > >"Mark Hickey" <[email protected]> wrote
    > >
    > > >> The change from a 63 to 80mm shock (assuming the ride height will change by ~15mm once sag is
    > > >> factored in) will be between close to another degree (probably about 0.7-8 degrees, depending
    > > >> on a lot of minor things like wheelbase).
    > > >>
    > > >> That would put your head tube's effective angle at 69 degrees - pretty slack, but not
    > > >> horribly so. I doubt you'll find the difference all that drastic though. If it's a stiffer,
    > > >> better fork the result will be worth it.
    > >
    > > >I think maybe I accidentally sent you an e-mail rather than replying to
    > the
    > > >group. So, here is what I wrote:
    > > >
    > > >Do you think there is any other reasonable option--including replacing
    > the
    > > >headtube at a frame machine shop? Would that cost an unreasonable amount
    > of
    > > >money? I am assuming that it would, but I don't really know. It seems
    > like
    > > >there would have to be some way around the loss of another degree, but
    > maybe
    > > >not.
    > >
    > > You did send me an email... here is/was my reply...
    > >
    > > Probably not worth it unless you have an emotional attachment to that frame that makes it worth
    > > spending much more than it's worth to upgrade it. I'd recommend trying the shock and see if you
    > > like the results. If that doesn't work out, there are plenty of frames out there that you could
    > > buy with appropriate angles (and that are probably lighter and stronger to boot).
    > >
    > > Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame
    >
    > I guess I thought it just might be cheaper than buying a new frame. Now it looks like I have
    > three options. 1) don't do anything and just ride with my crap fork(i've been doing it--but don't
    > like it) 2) buy a new fork and see if I notice a negative slack steering difference (this one
    > scares me) in which case I

    By the sounds of it you could get a bike for a lot less than $1000 and still be ahead of what you
    have now, especially if you get one with v- brakes and transfer that disc you have already. Put the
    regular wheel on the old bike to sell or have as a spare.
    --
    _________________________
    Chris Phillipo - Cape Breton, Nova Scotia http://www.ramsays-online.com
     
  9. Superslinky

    Superslinky Guest

    Alan McClure said...

    > Alright, my bike currently has a 70mm head tube angle with 63 mm travel on the fork. I mentioned
    > in another thread that I was thinking about getting a new fork like this one:
    >
    > http://makeashorterlink.com/?J2BC12E05
    >
    > or another 80mm travel fork (any suggestions for a nice price--marzocchi maybe). Anyway, someone
    > mentioned that most people find 71 degrees to be about right for the head tube angle. Of course,
    > mine is already off that mark by 1 degree. Does anyone know how much the above fork would throw
    > off the angle even more? Is there any way at all to counteract that effect without having a frame
    > builder replace the head tube. If not, then does anyone have any other suggestions?
    >
    > Thanks again,
    >
    > Alan McClure

    I just went from 80mm travel to 125mm travel when I installed my Fox Vanilla fork and I love the
    geometry change. One reason I bought the Fox was that it converts between 80, 100, and 125mm travel.
    I figured that I would have to knock it down to 80 to get good handling, but now I see no reason to
    bother with it. When I was having problems with my stock 80mm fork, I talked with the guy who
    designed the bike and he said that they run them at 105mm all the time and they feel great. This
    conversation came up when I arranged to trade up my defective 80mm fork for a Duke SL U-Turn which
    has a travel range of 63-105mm. My experience agrees with his. I do have the sag set to the maximum
    recommended, and I may find out that there may be times when less travel would be better, like on
    challenging uphills, but there are advantages and disadvantages to everything. It's all a matter of
    taste, and the differences can be subtle. I don't think you should lose any sleep over the
    difference between a 63 and 80mm fork.
     
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