Clacking front end noise when crossing RR tracks

Hoping others might participate and possibly also benefit, this topic responds to the following inquiry:

[PM'er] wrote:

You wrote: Re:New Discs and pads 3 Months ago
Seems odd that both front calipers are doing the same thing.
Any unusual clacking noise from the front end when crossing railroad tracks while riding?...I'm having that problem in exactly same situation, crossing railroads, what could be wrong in my calipers?

A caliper that's excessively loose in its floating movement area may emit a clacking sound when shaken, such as when riding over railroad tracks. But the noise stops during brake application, even while crossing the rough surface, while the caliper is held tightly in position regardless of slop in the floating action.

Depending on particular make and model, a floating caliper's movement area is typically protected by rubber seals against foreign matter from getting inside and abrading the bolt and caliper hole and wearing out the supposedly smooth clean slightly lubricated area of interplay between caliper and bolt shaft, which may include o-rings. The rubber seals rot and deteriorate over time, which allows dust, road crud, grit, etc. into the supposedly pristine floating area, eventually allowing slop in the floating movement due to worn rubber dampers and o-rings, or metal part wear.

The factory service manual (FSM) for the particular make and model involved should have a detailed cutaway diagram with full information about the front caliper. A caliper overhaul kit may be available from Z1 Enterprises.

Good Fortune!

If no one caught the jest of this post, it is; Don't ride over railroad tracks if you don't want your brake pads to "clack" :laugh:

I though it was:

Don't ride over railroad tracks when you forgot to tighten the caliper bolts.

And here's a related tip for safer riding.

Cross railroad tracks by approaching at an angle as close to 90 degrees as possible under the circumstances.

This is to minimize possibility of front wheel being trapped, resulting in unexpected sudden loss of control and tip-over.

Good Fortune!

Crossing tracks the wrong way slowly works better than coffee in the morning hours!

:laugh: :laugh: :laugh:

And wet tracks are even more treacherous than dry tracks.

Similar danger is encountered when traversing different pavement levels, such as changing lanes in a construction area where the lanes are being resurfaced.

Easier to move from higher to lower lane (for instance, from the already resurfaced lane to the yet unresurfaced lane).

It's often dangerous to attempt crossing over from lower level lane to higher level lane. And should in any event strive to approach the cross-over as perpendicular as possible, and with bike perfectly erect (not leaned over).

Good Fortune!

otakar wrote:

If no one caught the jest of this post, it is; Don't ride over railroad tracks if you don't want your brake pads to "clack" :laugh:

bountyhunter wrote:

I though it was:
Don't ride over railroad tracks when you forgot to tighten the caliper bolts.

:ohmy: :lol: :laugh: :laugh: :kiss:


The noise emitted from the caliper (a rattle or clack from the front end when crossing a rough surface such as a railroad track, which noise disappears while brake is applied) typically has no relation to the pads or tightness of caliper bolts. Or to style, condition or tightness of steering head bearings. Or to condition of front wheel or wheel bearings. Or maybe even a loosely attached handlebar. Or loose fender. Or any other loose whatever.

In the issue as presented, it's presupposed that everything else about the bike's front end is perfect (except for the clacking, as described).

Such clacking front end noise typically persists as a mystery to the rider after brake pads and caliper bolts and other components have already been checked. And may result from interplay between the caliper and caliper shaft, where slop or excessive looseness has developed due to worn or deteriorated soft parts such as rubber dust seals or o-rings or bushings. In more extreme cases, the caliper and/or shaft itself may be abraded and worn along their interface, this being where the caliper moves (floats) back and forth along the caliper shaft as the brake is applied and released.

The caliper movement, or floating, is what keeps the pressures equalized between opposing brake pads, whereby each pad imposes same pressure against the disc.

Good Fortune!

Might also want to check out these former threads:

Click here > Clackity

Click here > Clack

Good Fortune!

I am not sure if this is relevant or not but I once had a clack when crossing railroad tracks. I tracked (no pun intended) it down to the headlight ears being loose and clacking on the fork tubes.

Clickety-clack,clickety-clack,
Train acomin down the track.
Clickety-clack,clickety-clunk,
KZ 1000 is now junk.bj

Train Tracks

TY Patton for answeering, i've PM'd you because i saw an old thread where you wrote about this topic and didn't want to post on an old topic.

I'll check my front calipers mounting bolts asap. What confuse me is that i restored the bike in 2004 and it has done 4000km. since then and i remember that all was fine... nevertheless will check again. They sound very loudly and i have to admit that i use to cross the RRs aplying a little bit of pressure over the front brake lever and a little bit of throttle in order of avoiding that noise... not very safe manouver...

Hugs all,

Sebastian