A Cycling & bikes forum. CycleBanter.com

Go Back   Home » CycleBanter.com forum » rec.bicycles » Techniques
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Rust in front fork



 
 
Thread Tools Display Modes
  #1  
Old August 15th 03, 01:47 AM
Ted Bennett
external usenet poster
 
Posts: n/a
Default Rust in front fork


So I recently acquired a 36-year old reynolds 531 raleigh frame and
when you shake the front fork you can hear what I presume are a few
flakes of rust jostling about. There are drain holes near the fork
tips. It does not sound like a lot of rust - perhaps one or two
flakes maybe 1/4" in size. Apparently, the pieces of rust are too
large to get down near the holes.

This is irritating and i was wondering if there is anything i can do
to remove the rust, and/or assess whether the fork has extensive
internal rust and might be unsafe?

- Don Gillies
San Diego, CA


I may not even be rust, Don. Your fork was certainly brazed together,
rather than welded, and those may be small bits of braze stuff rattling
around in there.

There is no way that I know to remove them, short of drilling a big
enough hole to shake them out. Do NOT do that. You could try injecting
some Framesaver or similar gunk into the fork and see if that makes the
flakes stick so that they don't rattle.

While it is possible, it's unlikely that the fork would be rusted enough
to be dangerous. You could tap the fork all over and judge by the sound
if there any areas that may be much thinner than the rest of it.

One of my bikes has an eighty-year-old (yes, 80) fork, never had any
anti-rust treatment and it's still OK.

--
Ted Bennett
Portland OR
Ads
  #2  
Old August 15th 03, 10:53 PM
andy borrows
external usenet poster
 
Posts: n/a
Default Rust in front fork

Be very, very wary of old forks. My bike has handbuilt 531 frameset
which is nearly as old as I am (48). Everything else has been replaced,
much of it several times, but the frame, and until last week the forks,
remained original.

Until last week... On my usual commute home from central London,
something felt amiss but I couldn't figure out what. I stopped to check
things over, couldn't find anything wrong, so pedalled off again. After
a few yards, one fork leg sheared off, the front wheel jammed in the
brakes and locked solid, bending the other fork leg back by six inches
and spitting me off the bike.

I fell to the left. If I'd fallen to the right I think my head have gone
under the car that was passing (roadspace was restricted due to
roadworks).

I was only doing a few mph. At normal speed, I'd have gone flying
straight over the handlebars and ended up in casualty, or worse, rather
than with just a few grazes and bruises.

The forks take a tremendous hammering and unlike the frame which is
triangulated they are simply cantilevered. I'd recommend getting a
magnifying glass out and inspecting yours very closely...



--
--------------------------

Posted via cyclingforums.com
http://www.cyclingforums.com
  #3  
Old August 17th 03, 01:11 AM
Chris Zacho The Wheelman
external usenet poster
 
Posts: n/a
Default Rust in front fork

Sheoot, the forks on my 87 Schwinn Voyager frameset jingled from the day
I walked out of the shop! My guess is what you're hearing is leftover
material from the brazing.

Peek into the frame tubes. They traveled the same roads under the same
conditions as the forks. If thet're not rusted away, the forks are
probaly just as good.

May you have the wind at your back.
And a really low gear for the hills!
Chris

Chris'Z Corner
"The Website for the Common Bicyclist":
http://www.geocities.com/czcorner

  #4  
Old August 17th 03, 03:35 AM
David L. Johnson
external usenet poster
 
Posts: n/a
Default Rust in front fork

On Thu, 14 Aug 2003 11:51:23 +0000, Donald Gillies wrote:

So I recently acquired a 36-year old reynolds 531 raleigh frame and when
you shake the front fork you can hear what I presume are a few flakes of
rust jostling about. There are drain holes near the fork tips. It does
not sound like a lot of rust - perhaps one or two flakes maybe 1/4" in
size. Apparently, the pieces of rust are too large to get down near the
holes.


Why do you assume it's rust? The brazing sometimes leaves bits of metal
rattling around loose in the tubes. I have these in one old bike. No big
deal.

This is irritating and i was wondering if there is anything i can do to
remove the rust, and/or assess whether the fork has extensive internal
rust and might be unsafe?


I*have two bikes of about the same vintage. While I was busy with young
children and an old house, and did not ride for several years, they hung
in my wet basement (it is a very old house). The paint was damaged, and
there was surface rust on the frames, but nothing serious.

--

David L. Johnson

__o | When you are up to your ass in alligators, it's hard to remember
_`\(,_ | that your initial objective was to drain the swamp. -- LBJ
(_)/ (_) |


  #6  
Old August 18th 03, 01:21 PM
Jim Adney
external usenet poster
 
Posts: n/a
Default Rust in front fork

On 18 Aug 2003 07:43:34 +0950 andy borrows
wrote:

Jim: These are (or were!) "traditional" style forks, with a separate
horizontal cross piece which joins the forks and the steerer tube,
rather than the more modern kind where the top of the fork legs are bent
inwards and join together. One leg cracked across the very top, where
the fork tube enters the cross piece (which undoubtedly has a name but
I'm afraid I don't know what). Interestingly, there's no sign of rusting
on the surfaces of the break, so I guess the crack remained at a
microscopic level and invisible under the paint until it finally decided
to give up.


Andy,

The word you're looking for is "crown."

To have a fork blade just crack off right under the crown is pretty
unusual, except for Jobst, who had this happen to him several times
with Cinelli crowns. In your case, were the fork blades brazed into a
socket in the crown, or was there a protrusion in the crown that stuck
into the top of the blade and was then brazed in place?

Usually, in cases like this there will be visible differences in the
texture of the broken metal which will let you differentiate places
that had been broken for some time and worn against each other, as
opposed to those which broke at the last moment.

If it really all broke at once, I wonder if your front hub/QR had come
loose, allowing the wheel to slip sideways and break off the fork
blade.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------
  #7  
Old August 19th 03, 05:47 AM
Jim Adney
external usenet poster
 
Posts: n/a
Default Rust in front fork

On 19 Aug 2003 05:53:37 +0950 andy borrows
wrote:

The forks that broke had the blades brazed into sockets in the crown.
The hub is conventional non-QR, and both blades were still attached
afterwards. For the last 4 years I've been doing a fairly high
mileage (4,000 miles a year) but before that nothing special. Just
bad luck I guess!


It's been years since i worked in a shop and saw bikes all day every
day, but I still think this is a pretty rare event.

Just a thought... A couple of years ago I hit a pot-hole at speed which
wrote off a pair of wheels (I managed to claim the cost back from the
local council though. Also went out and bought a decent twin halogen
light system!). That may have weakened the forks enough to start the
crack developing.


Certainly possible, but I've straightened forks where both blades had
been bent back like your other one and which then went on to live out
normal lives. OTOH, I don't think anyone wants to straighten forks
anymore, simply because of the liability issues.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------
 




Thread Tools
Display Modes

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Front Fork Clamps for Bike Carriers - Recommendations? David L. Johnson General 5 December 15th 03 07:24 PM
Off centre front fork Zoot Katz General 5 August 17th 03 07:57 PM
new front end - carbon fork ?'s dookie Techniques 2 August 1st 03 01:53 PM


All times are GMT +1. The time now is 05:50 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 CycleBanter.com.
The comments are property of their posters.