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


Go Back   > >

Recreational Cyclocross and Gravelbiking This has to be the most physically intense sport ever invented. It's high speed bicycle racing on a short off road course or riding the off pavement rides on gravel like :The Dirty Kanza". We also have a dedicated Racing forum for the Cyclocross Hard Core Racers.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 09-23-09, 06:38 PM   #1
brucegseidner
Newbie
Thread Starter
 
Join Date: Sep 2009
Bikes:
Posts: 1
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
insane stutter, Easton EC90, fork deflection, death

I just mounted an cross EC90 fork, FSA headset, and Cane Creek canti's with tons of toe in and soft shoes on my Raleigh (basically Kenisis cross frame).

At ten miles per hour, the application of the front brakes creates an insane stutter, fork deflection of several inches, and the feeling that certain death would accompany the application of the front brakes in normal riding.

I put 5 different people on the bike from the welter weight 150 LBS wrench to by 285 pant load and everybody had the same, "woa dude" experience of certain death.

What the heck is going on. Is the EC90 just so flexy that only sub 60 pound riders need apply or have a I missed something. I have never, ever, seen anything like it. It makes me think I need an all steel trials fork for my cyclocross bike.

Brucer
brucegseidner is offline   Reply With Quote
Old 09-23-09, 06:51 PM   #2
Jawn P
Senior Member
 
Jawn P's Avatar
 
Join Date: May 2008
Location: Kent, Ohio
Bikes: Waterford 1200, Redline Monocog, Redline Conquest Pro, Surly Long Haul Trucker, and a Sunday BMX bike!
Posts: 211
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I had the same problem with my EC90x and Raleigh RX1.

Heel in the pads like crazy. Like a really good amount, and it should stop the shudder.
Jawn P is offline   Reply With Quote
Old 09-23-09, 08:26 PM   #3
Cynikal
Team Beer
 
Cynikal's Avatar
 
Join Date: Apr 2004
Location: Sacramento CA
Bikes: Too Many
Posts: 5,920
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Funny, I have no problems with mine at all. Mine is attached to a Cannondale CX9 and I'm using tektro 720 calipers on it.
Cynikal is offline   Reply With Quote
Old 09-23-09, 09:57 PM   #4
jonestr
Senior Member
 
Join Date: Jul 2008
Location: ABQ, NM
Bikes: Neuvation F100, Surly Cross Check, Van Dessel Holeshot
Posts: 1,152
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I would try getting a straddle cable and yoke and varying the height of the yoke above the tire and see what happens

I am running the same fork, and I tried those brakes (went back to shorty 4s), with the bottom of the yoke 1.5" from the tire and maybe 2mm of toe in (folded piece of paper)

No shudder at all, but I am running a different frame
jonestr is offline   Reply With Quote
Old 09-24-09, 09:12 AM   #5
thefatkid
Junior Member
 
Join Date: Jul 2009
Location: Littleton, CO
Bikes:
Posts: 16
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I have a RX-1 with the EC90x fork, LX Deore brakes with Kool Stop pads. I have a pretty good amount of brake pad toe in and have no shudder. My Kool Stops have a mud sweeper that forces you to toe in the pads.

With my worn Ritchly (sp?) pads I was starting to get some shudder, due to the amount of wear I just replaced them rather then trying to adjust them.

I'd try new pads and more toe in like already stated.

edit: it should be heel the pads I guess. I'm an auto technician and it "looks like" toe in to me
thefatkid is offline   Reply With Quote
Old 09-24-09, 09:22 AM   #6
R900
Double Secret Probation
 
R900's Avatar
 
Join Date: Aug 2005
Location: Eastern Indiana
Bikes: Madone 6 series SSL, Cannondale CX9, Trek TTX, Trek 970, Trek T2000
Posts: 2,578
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Maybe try a brake booster/bridge and see if that helps.
__________________
Time to Ride...
R900 is offline   Reply With Quote
Old 09-24-09, 09:25 AM   #7
Cynikal
Team Beer
 
Cynikal's Avatar
 
Join Date: Apr 2004
Location: Sacramento CA
Bikes: Too Many
Posts: 5,920
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Also, keep in mind that as your pad wears you will lose your toe-in.
Cynikal is offline   Reply With Quote
Old 09-24-09, 09:43 AM   #8
Rejuvenator
Senior Member
 
Join Date: Aug 2008
Bikes:
Posts: 58
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The shudder comes from the long distance between the brake hanger and the brakes. Try to jimmy a hanger that fits right above the fork--it can be done, and I think you can buy one now. Think of the old mountain forks--they did the same thing.
Rejuvenator is offline   Reply With Quote
Old 09-24-09, 09:58 AM   #9
cerewa
put our Heads Together
 
cerewa's Avatar
 
Join Date: Jun 2003
Location: southeast pennsylvania
Bikes: a mountain bike with a cargo box on the back and aero bars on the front. an old well-worn dahon folding bike
Posts: 3,155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Quote:
tons of toe in and soft shoes on my Raleigh
From my perspective, this is probably the problem. Jawn P says to try setting the pads "heel in". My thinking is that harder brake pads are likely to help - they are less "sticky" and the force between pad and rim is stronger whenever you brake hard. (when the force between pad and rim is stronger, there should be more resistance to 'bouncing' motion or vibration). I also think that having your pads set with lots of "toe in" is problematic, and that you'll get less shudder if you try lots of heel in, a little heel in, or a little toe in. (see what seems to work best for you.)


Quote:
The shudder comes from the long distance between the brake hanger and the brakes. Try to jimmy a hanger that fits right above the fork
With cantilever brakes, I don't think this is where the problem lies.
cerewa is offline   Reply With Quote
Old 09-24-09, 03:20 PM   #10
nubcake
Senior Member
 
nubcake's Avatar
 
Join Date: Feb 2008
Location: Colorado Springs
Bikes: Gunnar Crosshairs, Giant Trance, Felt Breed, Marin SS MTB, Felt Pyre BMX bike, oldschool GT trials bike
Posts: 700
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
BRUCE!!!!!! This is Chris from the shop...

What he is saying is spot on, We have tried all levels of toe in, out, flat, different pads, everything. Have you tried the brake booster yet? Also if you have them try some v-brakes and that might save you from buying that new fork.
nubcake is offline   Reply With Quote
Old 09-28-09, 08:43 AM   #11
Rejuvenator
Senior Member
 
Join Date: Aug 2008
Bikes:
Posts: 58
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
With cantilever brakes, I don't think this is where the problem lies.[/QUOTE]

Actually, I'm quite sure this is where it lies, as I have dealt with this a few times. Old mountain bikes used canti brakes, and they had a cable hanger built into the fork--suspension forks used to have these. When everyone switched to V-brakes, they disappeared. The problem is the long run of cable from the stack down the head tube to the straddle. Trust me on this one. Install a cable hanger down there somewhere and you will have shudder free love with the flimsiest of carbon forks.
Rejuvenator is offline   Reply With Quote
Old 09-28-09, 08:58 AM   #12
late
Senior Member
 
late's Avatar
 
Join Date: Oct 2002
Location: Southern Maine
Bikes:
Posts: 8,377
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Quote:
Originally Posted by R900 View Post
Maybe try a brake booster/bridge and see if that helps.
I used to use one of those around the time shocks first came out. The shocks back then had a number of limitations. It definitely helped.
late is offline   Reply With Quote
Old 09-28-09, 11:04 AM   #13
isotopesope
shoot up or shut up.
 
isotopesope's Avatar
 
Join Date: Nov 2003
Location: colorado springs, co
Bikes: yes please.
Posts: 1,961
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
regardless of pad alignment, my front hub has been slightly loose before and caused shuddering. have you checked it?

fwiw, i run avid v brakes on my mountain bike and recently starting running brake boosters. it has made a huge improvement in my braking. i can one finger most things now.

Last edited by isotopesope; 09-28-09 at 11:08 AM.
isotopesope is offline   Reply With Quote
Old 09-28-09, 01:11 PM   #14
OnTheRivet
Senior Member
 
Join Date: May 2008
Bikes:
Posts: 135
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
"Actually, I'm quite sure this is where it lies, as I have dealt with this a few times. Old mountain bikes used canti brakes, and they had a cable hanger built into the fork--suspension forks used to have these. When everyone switched to V-brakes, they disappeared. The problem is the long run of cable from the stack down the head tube to the straddle. Trust me on this one. Install a cable hanger down there somewhere and you will have shudder free love with the flimsiest of carbon forks."


This is exactly it, as an experiment and I could stop my fork from shuddering by simply putting pressure on the cable with my finger when braking. It's also the reason Specialized is now using a hanger bolted to the fork on the 2010 tricross. I eventually went to Mini-v's...way better.
OnTheRivet 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 02:26 AM.