1. The most important thing about buying a new bike is to make sure it fits. The only way you'll know if the bike is right for you is to size up the bike and make sure that the bike's geometry matches your body's geometry. Ask questions and do some research.
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2. If possible, try to find a shop that will let you demo the bike on real dirt. Five minutes in a parking lot won't cut it. You wouldn't buy a car without a real world test drive, and a bike should be no different.
3. Don't belive the hype. Just because your favorite rider or best friend rides a certain bike, that doesn't mean that's the best one for you. Have an open mind and be realistic about your needs and ability.
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  1. #1
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    Caution;  Merge;  Workers Ahead! What fork? For GT Avalanche 1998

    Any feedback with regards to what fork would fit my Avalanche 1998. Not sure about the measurements that need to be taken or how, or weather this frame is modern enough to be compatible with most forks.
    Cheers!

  2. #2
    No good in rock gardens..
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    It will have the current 1 1/8" threadless headset system, so any modern 1 1/8" threadless fork will fit (this is what most forks are). I'm assuming it has V brakes. All you will need to ensure is you get a fork with studs for cantilever brakes (some forks are now disc only) and it would probably be best to limit your new fork to 80mm travel, as that was about maximum back then. A 100mm would most likely make it handle a bit slow.
    My Cannondale Lefty keeps failing....

  3. #3
    Former Bike Wrench
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    As mentioned above
    -1998 Avalanche uses the standard 1.125" steer tube fork
    -Stick with an 80mm fork as the original fork was 63mm as I recall (I worked on and sold GT in 1998). Anything longer will alter the handling significantly
    -Make double sure the replacement fork has canti studs, many forks are disc specific these days

  4. #4
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    Listen! Thanks guys! next Question: Steerer length

    Thanks I would have made a complete balls-up, was heading for a 100mm fork!

    I'm considering a Spinner Aeris Sport with 80mm travel but the steerer has been cut to 170mm, I know the stem and the headset used also plays a part, but would a 170mm steerer be sufficient? Or is it impossible to calculate without the headset and stem and the headtube length?

  5. #5
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    Yepper, added travel will increase the leverage on the head tube as well and you will greatly increase the stresses there. I used a longer travel fork for just over a year on an older bike and stressed it to where it cracked....
    Just be careful with choices, no one can argue with physics!
    KIN
    Yes its retro but IT WORKS!

    8 Speed is great and V-Brakes rock!

    Ex-wrench...have a Question just ask!

  6. #6
    No good in rock gardens..
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    Quote Originally Posted by leepreto
    Thanks I would have made a complete balls-up, was heading for a 100mm fork!

    I'm considering a Spinner Aeris Sport with 80mm travel but the steerer has been cut to 170mm, I know the stem and the headset used also plays a part, but would a 170mm steerer be sufficient? Or is it impossible to calculate without the headset and stem and the headtube length?

    The bigger the frame size, the longer the head tube, as a rule of thumb.

    If the bike has a rigid or other fork already fitted, measure from the top of the fork crown (where it goes into the head tube) to the top of the stem. That will give you an idea of the length you need - you may or may not want / need another 1/2 to 3/4 of an inch to put spacers under the stem to allow you to adjust height.

    If it's justa bare frame, you'll need a fork steerer about 2 3/4 to 3" longer than the actual head tube length, to factor in a headset stack and stem.
    My Cannondale Lefty keeps failing....

  7. #7
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    Well damn. I put a 140mm Fox Vanilla RLC on my 98-99 Cannondale F400. First bike, so im not sure what the handling should feel like. I guess i'll ride it until i can afford a new frame.

    J

  8. #8
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    Keep an eye on that headtube

    Quote Originally Posted by JayDial
    Well damn. I put a 140mm Fox Vanilla RLC on my 98-99 Cannondale F400. First bike, so im not sure what the handling should feel like. I guess i'll ride it until i can afford a new frame.

    J
    Cannondale's are not know for their durability (I know, I warrantied quite a few)...though an F-400 will have thicker tubes than their higher end stuff. That said, an '98-'99 F-400 was designed for a 70mm fork so you have doubled the travel. Not only will that greatly affect the handling, but put a huge amount of extra stress on the headtube welds...something that frame was never designed for.

    Good luck...if it were me, I'd be looking for a new frame ASAP

  9. #9
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    Quote Originally Posted by mtnbiker72
    Cannondale's are not know for their durability (I know, I warrantied quite a few)...though an F-400 will have thicker tubes than their higher end stuff. That said, an '98-'99 F-400 was designed for a 70mm fork so you have doubled the travel. Not only will that greatly affect the handling, but put a huge amount of extra stress on the headtube welds...something that frame was never designed for.

    Good luck...if it were me, I'd be looking for a new frame ASAP

    Thanks for the info! I'll start looking, and not ride so hard!

    OP: Sorry to hijack this!

  10. #10
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    Cool, I am learning shed loads!
    BTW, the spinner fork went for a song on ebay, I think 80, but who ever sold it cut the steerer too short, I did some rough math, and depending on whether you have frame with an integrated or zero stack headset, which I didn't, you would have had a tad too little material to work with, so I'm so glad I didn't jump for it.

    Thanks for all the advice,
    a lot more questions coming at the Ex-wrenches here, some a bit daft from my side!

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