4x frame fork ?

[Rockinthecasbah]

I just found a 100mm 4x world cup for for my jamis for a killer deal. It currently has a 130mm rock hard suntour fork on it. The head tube on the frame is 67 degrees it looks like most dj.4x frames are around 69 degrees The shorter fork is going to take some rake out of the front end. Is 130mm to 100mm going to be too much? I know its going to make it twitchier and the only real way to tell is to ride it but does anyone have any experience with puttin a shorter fork on a bike made for a longer one.

[tkblazer]

i believe the general rule of thumb is for every 20mm change in suspension travel, there is ~ 1* change in head angle. That said, to really know the difference, you will need to get the a/c heights of both forks and go from there.

[Rockinthecasbah]

so from 67 to 66

[BobBurnes]

Originally Posted by Rockinthecasbah

so from 67 to 66

I've gone frmo 140mm to 110 on the 4X WC fork. You'll notice a difference. What specific information are you looking for? Race? DJing?

[Chewyeti]

show me the geometry of your bike.... and i will calc the head angle change for your (real data + Diagram)

do the trig if you want to know

[Rockinthecasbah]

race djing im not really worried about I found the fork for a killer deal I could switch out the frame to somehting different if the geo if weird

[Chewyeti]

here is your frame specs


If i get bored... i will calc your head angle change

[BobBurnes]

Originally Posted by Chewyeti

here is your frame specs

wow.

[2wheel_lee]

Assuming the fork is 1 inch shorter (measure the axle to crown heights):

The head angle will be about 1 degree steeper (68 degrees). This will make the bike more responsive.

You'll also lower the bottom bracket, which will improve cornering.

The lower front end will make it more difficult to manual. How long are your chainstays?

My Azonic with the fork set at 140 mm had a head angle of about 66 degrees. With that same fork on my Black Market at 110 mm, the head angle is about 68 degrees (I need to measure it). The chainstays on the BM are much shorter so it's easier to manual. The quicker head angle is ok for me, considering my cruiser is 73 degrees. All of this makes it very hard to ride my DH bike at 64 degrees.

Originally Posted by Chewyeti

here is your frame specs


If i get bored... i will calc your head angle change

Unfortunately, without knowing the fork axle-to-crown height used to establish those specs, they aren't much use.

[Rockinthecasbah]

My chain stays are pretty short I can manual my7 point so I'm not really worried about it it looks like its going tobring the head tube angle down right where i want it

[Jman]

I played with the height of the fork on the Chameleon yesterday and I really prefered it down about half way in the travel as opposed to the full 140. It's a Tora so its a bit heavy but felt much better and quicker at probably closer to 100 (it's not marked so I'm just guessing here). This probably doesn't help since I think you already bought the fork but just thought I'd throw my 2 cents in.

[dirttorpeedo]

uh ricky.put the fork on it and change the gooseneck.

[Rockinthecasbah]

I have a 50mm easton stem I bought before the last Sr race and the fork is going to be going on lees old (brand freakin new) black market frame.
Jman 100mm is the standard for 4x bikes you should get used to riding it there it might be a little harder to get the front end up but it will handle better

[2wheel_lee]

Jman, you'll be amazed how much easier it'll be to get it up when you have a shorter stem.

A 50 mm stem is like viagra for a bike.





STOP THAT NOW!!!!

[Jman]

I think I've heard I need a shorter stem!

I spent so much time on the Chameleon the way it is I think I'm going to leave it for the race on Saturday and then change it for the last race of the series (the next time I'll be able to race) that way I'm not trying to get used to it at the last second.

Oh and there are going to be some other changed to the Chameleon 'cause I decided after last wednesday that it is going to be my 4x DJ bike, that way I can spend my incoming money on a new frame and replace the lg Heckler I have (I realized I prefer medium bikes) with a slightly burlier, tougher more freeride style bike.

[BobBurnes]

Originally Posted by Jman

I think I've heard I need a shorter stem!

I spent so much time on the Chameleon the way it is I think I'm going to leave it for the race on Saturday and then change it for the last race of the series (the next time I'll be able to race) that way I'm not trying to get used to it at the last second.

Oh and there are going to be some other changed to the Chameleon 'cause I decided after last wednesday that it is going to be my 4x DJ bike, that way I can spend my incoming money on a new frame and replace the lg Heckler I have (I realized I prefer medium bikes) with a slightly burlier, tougher more freeride style bike.

Lee's right.

Changing to the shorter stem will be easier than you think. It's not just a different feel, it's a better feel. You'll wonder what took you so long to switch up. Seriously-this will be a much improved upgrade that will effect your jumping, turning, and all around bike handling better and requires only you to ride it once to find out you've made a good choice.

In fact, I've got a like new (It's only a few months old) race face diablos 50mm stem for sale. 25 bucks for you JMAN.

C'mon....you know you want it.

[Jman]

PM headed your way! I have crumbled under the peer pressure!

[2wheel_lee]

Originally Posted by Jman

PM headed your way! I have crumbled under the peer pressure!

It's about time!

[Jman]

I know, I know...please hold the applause!

[dirttorpeedo]

that way I can spend my incoming money on a new frame and replace the lg Heckler I have (I realized I prefer medium bikes) with a slightly burlier, tougher more freeride style bike.[/quote]
ill sell you my cannondale gemini for a reel wammy price.