K2 / Proflex Riders Group

General => Tech Forum => Topic started by: Swanny on October 09, 2004, 05:23:43 am

Title: Front Fork
Post by: Swanny on October 09, 2004, 05:23:43 am
Bought a new Pro Flex 856 in 1998 and promptly rode it a grand total of about 50 miles in the first 5 years of existence.  After blowing off the dust, this year, I've been riding it hard 3 times a week for the last 5 months - too bad I missed all of those years.

The front shock/spring are making some pretty nasty noises, so I'm thinking I want to purchase a new front fork - I'm looking at replacing the fork with a Manitou or other good fork/shock.  Question is - will that mess up the geometry?  Any sizing issues?  I see other bikes on the site that use other forks - I just have no idea what to look for....?  Thanks.
Title: Re: Front Fork
Post by: Scott on October 10, 2004, 04:32:51 am
Just keep to 100mm or under and you won't upset the angles too much.
Title: Re: Front Fork
Post by: Simon on October 10, 2004, 05:30:36 am
Agree with Scott,any quality fork not exceeding 100mm travel will be ideal.
Simon.
Title: Re: Front Fork
Post by: Kevins19 on October 10, 2004, 06:54:21 am
Just an FYI - every extra inch of travel from the original amount will slacken the head tube angle by 1 degree... roughly.

So if you felt you need like a 125mm  fork (Which also opens up your fork options even more) it wouldn't change the geometry too much.

Or, you could get a fork like the manitou black, or one of the Rock Shox w/ U-turn, which would let you switch your travel on the fly from 100mm (near stock, I think, I am not sure the actual stock travel) or if you need more for some rough stuff flip a lever and now you have it, then you can go back to 100mm after.
Title: Re: Front Fork
Post by: zulu on October 11, 2004, 03:42:22 am
 ;) I put a Fox 100rl on my 856 it is just amazing what a nice fork can due to a good bike. It allows me to climb really well and allows some great control in the rough stuff. A worthy upgrade if your going to replace the fork.
Also you may want to look into a Stratos shock replacement it would be a less expensive upgrade with good results.
keep on riding. 8) [smiley=beer.gif] [smiley=beer.gif] [smiley=beer.gif]
Title: Re: Front Fork
Post by: pmcnic856 on October 15, 2004, 06:19:00 am
What about the steer tube size. I believe that the steer tube on my 856-vector 2 fork is 1 inch. Will a 1.25-inch steer tube work? [smiley=worry.gif]

I checked it out this weekend. Very funky setup the steer tube is 1-1/8 at the bottom then immediately tapers to 1 inch and uses a cone shim for the top bearing of the 1-1/8” headset. Thus it uses a 1” stem and a 1-1/8” headset.
Title: Re: Front Fork
Post by: Simon on October 15, 2004, 06:29:59 am
Not sure about a 1.25" steerer but a 1-1/8 will fit fine,the vector fork is indeed a 1" steerer but it has a collar fitted to take it up to 1-1/8" you will find you are already running a suitable 1-1/8" headset but you will have to budget for a new stem.
Simon.
Title: Re: Front Fork
Post by: Swanny on October 17, 2004, 12:09:57 pm
Well, I borrowed a Manitu 80MM fork and compared it to my stock fork - it looks t be about an inch longer than stock.  Maybe I don't understand (likely :-) ) but wouldn't 63mm be closer to stock than 100mm?  Wouldn't 100mm be a few inches taller thus really changing the geometry?