Jim -- Would you lease elaborate no this paragraph that you just posted? I'd like to understand this issue, also. Here's the graph:
"Take a look at the thickness of the hanger - if it's a less expensive stamped piece, you might try a thicker part. Also, pay attention to the fit of the ferrule on the cable end. If there's movement there, that will tend to exacerbate it." ________________________________ From: CycloFiend <cyclofi...@earthlink.net> To: rbw-owners-bunch@googlegroups.com Sent: Fri, February 18, 2011 11:56:27 PM Subject: Re: [RBW] AR front brake shudder and fork flex on 2/18/11 7:09 PM, rw1911 at rw1...@gmail.com wrote: > I've recently installed Paul brakes (neo-retro front, touring rear) on > my relatively new to me 700c All-Rounder. The rears are wonderful, if > not too powerful... I can skid at will. However, I'm experiencing > extreme shudder and fork flex on the front. > > The headset is tight and the pads are toe'd to contact forward. Under > low to medium speed braking, I can see/feel the fork flex (a lot!) > and shudder. The straddle cable is set at about the top third of the > lower headset cup. I've cleaned the rim and while it has gotten > slightly better with use, is this a matter of adjustment or is the neo- > retro too powerful? This has cropped up on CX boards (and maybe iBob - too late to skim the archives there). The working theory (which seems pretty salient) is that flex in the hanger tends causing the shuddering. There's really two separate issues going on - the fork flex you are seeing and the shuddering of the brakes. With averagely strong brakes, you will generally see some flexing of the blades. More than likely, you don't notice it until the shuddering starts, but the two aren't necessarily linked. Take a look at the thickness of the hanger - if it's a less expensive stamped piece, you might try a thicker part. Also, pay attention to the fit of the ferrule on the cable end. If there's movement there, that will tend to exacerbate it. As you clamp down and the pads clench, if the hanger flexes, it will lessen the pressure on the brake pads. Less pressure on the pad causes the hanger to straighten applying more pressure to the pad, which causes the hanger to flex again... kind of similar to the anti-lock brake shudder you get on an auto. The neo-retros are pretty powerful, so you are probably getting a bit more oomph from the system. You might try adjusting the brakes so you get a bit less leverage on them. Sheldon shows the variables - http://sheldonbrown.com/cantilever-adjustment.html hope that helps. -- Jim Edgar cyclofi...@earthlink.net ³Velvet pillows, safari parks, sunglasses: people have become woolly mice. They still have bodies that can walk for five days and four nights through a desert of snow, without food, but they accept praise for having taken a one-hour bicycle ride.² - Tim Krabbe, "The Rider" Cyclofiend Bicycle Photo Galleries - http://www.cyclofiend.com Current Classics - Cross Bikes Singlespeed - Working Bikes Send In Your Photos! - Here's how: http://www.cyclofiend.com/guidelines -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en. -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
