Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Mountain Biking Mountain biking is one of the fastest growing sports in the world. Check out this forum to discuss the latest tips, tricks, gear and equipment in the world of mountain biking.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 08-24-04, 02:57 AM   #1
Hopper
Ride bike or bike ride?
Thread Starter
 
Hopper's Avatar
 
Join Date: Oct 2003
Location: Adelaide, Australia
Bikes: MongoosePro DH, Dart custom road bike, .243 Racing FR street bike
Posts: 1,447
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Fork bob while braking

You know how when you brake, your fork uses some of it's travel. Well a friend said that some company is trying to devise a way to get rid of this. Is there any point and also, how the f*** would anyone stop this? Because when you brake your weight gets shifted to the front, so I don't see how it's possible.
Hopper is offline   Reply With Quote
Old 08-24-04, 03:32 AM   #2
JohnnyTheFox
Senior Member
 
Join Date: May 2004
Bikes:
Posts: 138
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I find it useful under hard braking, on my old bike a ridgid fork, braking too hard would throw me over the front. With some suspension it takes some of your body weight and allows you more control when stopping quickly. Of course you can still endo but theres a smoother transition.
JohnnyTheFox is offline   Reply With Quote
Old 08-24-04, 04:36 AM   #3
Aus_MTB
Brisbane Rider
 
Aus_MTB's Avatar
 
Join Date: Jul 2004
Location: Brisbane
Bikes: 2005 Giant XTC 2 LE
Posts: 216
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Only thing i can think of would just lower the sensitivity of the shock so that it doesnt respond to braking like that but would still absorb hard and fast shocks.
Aus_MTB is offline   Reply With Quote
Old 08-24-04, 08:37 AM   #4
a2psyklnut
NCAA - DUAL CHAMPIONS!
 
a2psyklnut's Avatar
 
Join Date: Mar 2000
Location: From Sarasota, FL sitting in front of a computer spewing random thoughts!
Bikes: Intense Uzzi SL, Masi Speciale, Trek 3700 Nashbar Single Speed, Old Cilo Road frame
Posts: 7,964
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
A lot of the new technology in suspension design is toward inertia valved shocks or SPV (Speed Positioning Valving). The inertia valve activates when the suspension is activated from the bottom pushing up. (like from a bump) When the weight is applied from the top (rider pushing down) it locks out.

Carnutt is the leader in this, but Fox Suspension and Progressive and all the others are following suit. It's still pretty expensive, (figure $650 range for forks), but in the next couple years you'll see the trickle down effect.

L8R
__________________
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming, "WOW, What a Ride!" - unknown
"Your Bike Sucks" - Sky Yaeger
a2psyklnut is offline   Reply With Quote
Old 08-24-04, 08:42 AM   #5
chris_krueger
Member
 
Join Date: Aug 2004
Bikes:
Posts: 42
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
if the fork was only operated properly from bottom up, when you do a drop would it go rigid and break your wrist, or am i understanding this wrong??
chris_krueger is offline   Reply With Quote
Old 08-24-04, 08:47 AM   #6
a2psyklnut
NCAA - DUAL CHAMPIONS!
 
a2psyklnut's Avatar
 
Join Date: Mar 2000
Location: From Sarasota, FL sitting in front of a computer spewing random thoughts!
Bikes: Intense Uzzi SL, Masi Speciale, Trek 3700 Nashbar Single Speed, Old Cilo Road frame
Posts: 7,964
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
When you drop, the impact is on the wheel first which activates the suspension.

it's very technical and hard to explain, but the oil in suspension moves from one chamber to another. The oil flow through a piston with holes in it. Adjusting the rate of flow affects the suspension. An inertia valve has a brass plug that blocks the hole(s) and keeps the oil from flowing into the other chamber. When the piston is activated from the bottom the brass plug moves upwards and opens the hole(s). When the suspension is activated from the top (pushing down on the handlebars on flat ground), the plug remains in place.

L8R
__________________
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming, "WOW, What a Ride!" - unknown
"Your Bike Sucks" - Sky Yaeger
a2psyklnut is offline   Reply With Quote
Old 08-24-04, 08:53 AM   #7
nepaMTBer
Senior Member
 
nepaMTBer's Avatar
 
Join Date: Aug 2004
Bikes:
Posts: 146
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
But if the rider pushed down on his handle bars and the shox locked out than that force would go to the wheel wich than would hit the ground realying the force back up the fork the opisite way. We learned that in science class last year.
nepaMTBer is offline   Reply With Quote
Old 08-24-04, 09:18 AM   #8
Maelstrom 
Wood Licker
 
Maelstrom's Avatar
 
Join Date: Apr 2002
Location: Whistler,BC
Bikes: Transition Dirtbag, Kona Roast 2002 and specialized BMX
Posts: 16,885
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
ITs really technical. But it does realize which way is which (I can't fully explain except that it does work) however there have been complaints on the rear shock of it not working on small bumps, removing some of the sensativity of having a shock. Either that or it seem late to engage while the ball bearing moves out of the way.

I just bought a manitou SPV Evolve (3 or 4th generation SPV from manitou) and am anxious to test it out. Some complaints in 04 about a stiction feeling but it will be neat to see if they fixed it with an spv revamp.
Maelstrom is offline   Reply With Quote
Old 08-24-04, 08:24 PM   #9
seely
The Rabbi
 
seely's Avatar
 
Join Date: Apr 2004
Bikes:
Posts: 5,088
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
I have an F80x on my XC ride and its like butter. No bob uphill or on braking (esp. not on braking), but at $775 its pretty pricey. Stiff as heck and very tunable.
seely is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 07:48 AM.