If metal must be removed to seat Crown Race (perennial issue)
Chad
This issue appears to be perennial at R.B.T.
I leave the specifics at the bottom*
Crown race will not seat on fork steerer
"widening" (at a loss for noun here but some call it "shoulder")
even with considerable force and bamming with
"slide hammer" tube at LBS. Strangely, CR
LOOKS just barely smaller than "shoulder"
Is it better to widen the crown race (and by what method?)
or mill down "shoulder" (method again?)
Just in case anyone doubts I didn't research
this enough without posting hastily, there were plenty,
of other posts, but no definitive best method
___if metal must be removed____:
http://makeashorterlink.com/?Y57121598
http://makeashorterlink.com/?H58115598
http://makeashorterlink.com/?I29132598
http://tinyurl.com/3a53z
*True Temper Alpha-Q fork,
Cane Creek ZS-2 Headset
Thanks,
Chad AT alumni DOT unh DOT edu
Weisse Luft
> This issue appears to be perennial at R.B.T. I leave the specifics at
> the bottom*
> Crown race will not seat on fork steerer "widening" (at a loss for noun
> here but some call it "shoulder") even with considerable force and
> bamming with "slide hammer" tube at LBS. Strangely, CR LOOKS just barely
> smaller than "shoulder"
> Is it better to widen the crown race (and by what method?) or mill down
> "shoulder" (method again?)
> Just in case anyone doubts I didn't research this enough without
> posting hastily, there were plenty, of other posts, but no definitive
> best method
> ___if metal must be removed____:
> 21598 http://makeashorterlink.com/?H58115598http://makeashorterlink.com-
> /?H58115598 http://makeashorterlink.com/?I29132598http://makeashorterli-
> nk.com/?I29132598 http://tinyurl.com/3a53zhttp://tinyurl.com/3a53z
> *True Temper Alpha-Q fork, Cane Creek ZS-2 Headset
> Thanks,
> Chad AT alumni DOT unh DOT edu
Measure the seat diameter at a few places and compare with the ID of the
crown race. You need 0.001-0.002" of INTERFERENCE. Machine the crown
race accordingly. Its hard so carbide tooling is required.
--
Chad
What is the correct 'machine' called to do this job?
Removing material on the outside of something that can
be fixed in a lathe is relatively easy, but what's
the technique for the inside? Perfect diameter boring
jig would be ideal but not likely to be found.
Decent-sized LBS wrenches- three were on hand-
all stumped-
Danny's Cycles in Scarsdale NY.
Chad
chad AT alumni DOT unh DOT edu
daveornee
> This issue appears to be perennial at R.B.T. I leave the specifics at
> the bottom*
> Crown race will not seat on fork steerer "widening" (at a loss for noun
> here but some call it "shoulder") even with considerable force and
> bamming with "slide hammer" tube at LBS. Strangely, CR LOOKS just barely
> smaller than "shoulder"
> Is it better to widen the crown race (and by what method?) or mill down
> "shoulder" (method again?)
> Just in case anyone doubts I didn't research this enough without
> posting hastily, there were plenty, of other posts, but no definitive
> best method
> ___if metal must be removed____:
> 21598 http://makeashorterlink.com/?H58115598http://makeashorterlink.com-
> /?H58115598 http://makeashorterlink.com/?I29132598http://makeashorterli-
> *True Temper Alpha-Q fork, Cane Creek ZS-2 Headset
> Thanks,
> Chad AT alumni DOT unh DOT edu
Make the meausrements to insure an interference fit. If the crown is too
large in diamenter use a Crown Racer Cutter:
<http://www.parktool.com/repair_help/howfix_forkmill.shtml>
--
Weisse Luft
> Thanks a lot for the reply.
> What is the correct 'machine' called to do this job? Removing material
> on the outside of something that can be fixed in a lathe is relatively
> easy, but what's the technique for the inside? Perfect diameter boring
> jig would be ideal but not likely to be found.
> Decent-sized LBS wrenches- three were on hand- all stumped- Danny's
> Cycles in Scarsdale NY.
> Chad
> chad AT alumni DOT unh DOT edu
> >
> >
Also done on a lathe. The problem will be chucking the crown race on the
OD as the section is quite thin and you need to index off the ID. Make
sure the ID is bored concentric to the original and shoot for a slight
interference fit.
I'm guessing just a bit of polishing work will get you where you need to
be. I had a problem with an Alpha Sub 3 1" and a Cane Creek C2. It was
tight but gentle persuasion from a bit of 1.125" ID tubing worked better
than a real crown race setting tool.
--
Werehatrack
said:
>
>This issue appears to be perennial at R.B.T.
>I leave the specifics at the bottom*
>
>Crown race will not seat on fork steerer
>"widening" (at a loss for noun here but some call it "shoulder")
>even with considerable force and bamming with
>"slide hammer" tube at LBS. Strangely, CR
>LOOKS just barely smaller than "shoulder"
Your eye is not calibrated accurately enough to tell if the fit is
potentially correct. Use a micrometer on the tube. Measuring the
bearing's ID precisely enough for this purpose is generally possible
with a good caliper.
>Is it better to widen the crown race (and by what method?)
>or mill down "shoulder" (method again?)
If the headset's lower crown race is incorrectly sized, I would not
use it. If the steer tube is incorrectly sized, I would machine it.
There are tools specifically made for cutting the crown race seat to
the correct diameter, though apparently very few bike shops have one.
See http://tinyurl.com/32mko for examples.
Many general-purpose machine shops would have no problem turning the
steer tube to the correct diameter on a lathe.
--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.
Phil Brown
>Removing material on the outside of something that can
>be fixed in a lathe is relatively easy, but what's
>the technique for the inside? Perfect diameter boring
>jig would be ideal but not likely to be found.
>
>Decent-sized LBS wrenches- three were on hand-
>all stumped-
>Danny's Cycles in Scarsdale NY.
>
>
>Chad
>
>
seating can have many causes but one of the most common is trying to put an ISO
race on a JIS seat. Milling the crown race seat takes care of this problem. If
the "wrenches" don't know this take your business elsewhere. Typically crown
races are heavily chromed so trying to enlarge them is a loosing game. And a
boring machine won't do it either because the crown race is tapered and is
reamed, not bored.
>
Phil Brown
Qui si parla Campagnolo
even with considerable force and bamming with
<< Is it better to widen the crown race (and by what method?)
Too bad the LBS that is smashing the crap out of the crown race doesn't have
the knowledge to do what is proper. Use a fork crown race milling tool to get
the proper sizing for your crown race, assuming the fork is a steel one. If the
LBS gives you the 'thousand yard stare' when you suggest this, find a better
bike shop. The ineptitude of todays LBS amazes me.
Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"
Jay Beattie
"Qui si parla Campagnolo " <vecc...@aol.com> wrote in message
news:20040617091156...@mb-m18.aol.com...
> see-<< Crown race will not seat on fork steerer
> "widening" (at a loss for noun here but some call it
"shoulder")
> even with considerable force and bamming with
> "slide hammer" tube at LBS. >><BR><BR>
> << Is it better to widen the crown race (and by what method?)
> or mill down "shoulder" (method again?) >><BR><BR>
>
> Too bad the LBS that is smashing the crap out of the crown race
doesn't have
> the knowledge to do what is proper. Use a fork crown race
milling tool to get
> the proper sizing for your crown race, assuming the fork is a
steel one. If the
> LBS gives you the 'thousand yard stare' when you suggest this,
find a better
> bike shop. The ineptitude of todays LBS amazes me.
Wait until all of the ancients die off and we're left with the
plug-n-play mechanics I see populating most of the local shops.
One guy confided in me that he had not built a wheel in over a
year because all they sold were pre-fab wheels. At least he had
worked there a year. -- Jay Beattie.
Weisse Luft
fork is a carbon fiber Alpha. If its a Sub 3, the crown race seat is
only a shell and there is very little to machine.
Back in the old days when forks were brazed/welded affairs, milling the
seat was not a problem.
--
daveornee
Good point! A contact to the manufacturer before removing any material
in a structural element is necessary. There may be another choice of
headset that provides a suitable interference fit without removing any
material. I visited the FAQ for this manufacturer and they say nothing
on this issue.
--
John Everett
Campagnolo ) wrote:
>Too bad the LBS that is smashing the crap out of the crown race doesn't have
>the knowledge to do what is proper. Use a fork crown race milling tool to get
>the proper sizing for your crown race, assuming the fork is a steel one. If the
>LBS gives you the 'thousand yard stare' when you suggest this, find a better
>bike shop. The ineptitude of todays LBS amazes me.
Many years ago when I got back into "serious cycling" I bought a Trek
1400. It soon developed "indexed steering". Since I didn't then have
the proper tools I took it to an LBS and had them replace the Shimano
105 headset with an Ultegra.
This original bike was soon replaced by a better bike, becoming my
beater; a status it still enjoys. Some number of years later I cleaned
and repacked the headset and discovered that the crown race was split
radially, kind of like a piston ring. I can only assume this was done
by the LBS during installation. :-(
BTW, that split crown race is still in the bike, some ten or twelve
years later. I figure that since it seems to work, why replace it?
jeverett3<AT>earthlink<DOT>net http://home.earthlink.net/~jeverett3
Jim Adney
<usenet...@cyclingforums.com> wrote:
>Measure the seat diameter at a few places and compare with the ID of the
>crown race. You need 0.001-0.002" of INTERFERENCE. Machine the crown
>race accordingly. Its hard so carbide tooling is required.
In 30 plus years of working with bicycles, I have NEVER before heard
of anyone suggesting that it was appropriate, let alone practical, to
try to machine the ID of a crown race to fit a fork.
Cutters in standard sizes to trim the shoulder on the fork are
standard tools in any bike shop.
-
-----------------------------------------------
Jim Adney jad...@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------
Qui si parla Campagnolo
year because all they sold were pre-fab wheels >><BR><BR>
We LOVE the boxed wheelsets. We get to true/repair them all the time because
the bike shop that sold them cannot. And eventually, after these over priced,
over marketed crappola don't live up to the hype, we build the rider a set,
specifically for them.
We still build many wheels, about 400 or so per year, many more than any bike
shop sells of wheels outta boxes here in the 'Republic'. I can count on one
hand decent wheel builders in Boulder, and three of them are at Vecchio's.
Qui si parla Campagnolo
the
fork is a carbon fiber Alpha. If its a Sub 3, the crown race seat is
If the HS is a standard one, then something is amiss with the fork, not the
crown race.
Weisse Luft
> weisse-<< The reason I sggested machining the crown race and not the
> seat is the fork is a carbon fiber Alpha. If its a Sub 3, the crown race
> seat is only a shell and there is very little to machine. >>
> the crown race.
> Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
> convenzionali costruite eccezionalmente bene"
Could be but since the fork is made in the US, its highly unlikely its
a JIS crown race seat (27mm). Both parts are machined and I would
place my bets on the HS being off spec. Regardless, machining the fork
would void the warranty. See True Temper about this problem BEFORE
milling the fork.
--
Chad
all the posts, thanks much.
It is an Alpha-Q sub 3, the steerer is all carbon with just the
little ring of metal at the bottom as a seat.
I've had helpful conversations with Cane Creek;
efforts to contact True Temper have yielded two observations-
their phone system is a hall of mirrors, and their is only
one email address listed on their site, tubing (at sign)
truetemper.com - I emailed them a careful and polite
letter on Monday and have not heard back. Any other
ideas on how to contact them are appreciated.
As I don't have a micrometer or caliper I'm still
in the dark, I've been calling the larger bike shops
in the area, and patiently explaining the situation.
"Yeah? sounds like a drag, no we don't do that"
is the average response.
Does anyone have a more intelligent approach to
this than the shoot-in-the dark approach I'm using?
For serious machining, how does one find a machine
shop that is willing to take on such a tiny job?
very best
Chad
chad AT alumni DOT unh DOT edu
ps- frameset came with fork at fire sale prices.
Headset is an upgrade from earlier CC one with
no lower seal.
> Qui Si Parla Ca wrote:
> > weisse-<< The reason I sggested machining the crown race and not
> > the seat is the fork is a carbon fiber Alpha. If its a Sub 3, the
> > crown race seat is only a shell and there is very little to
> > machine. >> If the HS is a standard one, then something is amiss
> > with the fork, not the crown race.
> > Peter Chisholm Vecchio's Bicicletteria
>
>
>
j_erhardt
Does anyone have a more intelligent approach to this than the shoot-in-
the dark approach I'm using? For serious machining, how does one find a
machine shop that is willing to take on such a tiny job?
well, if you're really worried about warranty on the fork AND can't find
a bike shop to mill the steerer tube, try to find an automotive machine
shop. They do small jobs all the time. Just look in the phone book.
There are fewer and fewer of them as cars also become more disposable.
But the ones I know stay alive because they do work for drag racing
teams/people. Ask them to first measure the fork and race to see how far
they're off. You could also buy a cheap pair of calipers from Sears to
find out for yourself. If you lived in Denver or Boulder, I'd offer to
measure it for you.
JohnE
--
Qui si parla Campagnolo
its
a JIS crown race seat (27mm). >><BR><BR>
Not saying it is JIS. But if the HS crown race won't fit, something is amiss. I
would bet that the HS crown race is more likely to be correct than the fork.
I would doubt you need to take .6mm of the crown race seat, maybe just a wee
bit of emery paper.
Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
Benjamin Weiner
> As I don't have a micrometer or caliper I'm still
> in the dark, I've been calling the larger bike shops
> in the area, and patiently explaining the situation.
> "Yeah? sounds like a drag, no we don't do that"
> is the average response.
> Does anyone have a more intelligent approach to
> this than the shoot-in-the dark approach I'm using?
> For serious machining, how does one find a machine
> shop that is willing to take on such a tiny job?
Calipers are inexpensive, and available at a good hardware
store. Or find some friendly person who will measure both
parts for you. This is really a situation where you want
to measure before cutting metal. Better bike shops will
probably have some gauges that slip over the crown race
and seat to tell if they are in spec. Are these part of
the Campy toolkit? I think Campy makes such gauges anyway.
You may not want the largest bike shop, but the bike shop
with the oldest most experienced codger. Not that anyone
in rbr meets such a description of course.
Chad
this kind of situation, I am posting the info
that came in today from True Temper:
I think 26.5mm is the "crown race seat" OD
Quoted Text below:
>For 1" the headset race ID is 26.4 mm
>The crown race on the fork should measure 26.5 mm
>
>Thanks,
>
>Bert
>
>Bert Hull
>Performance Sports
>True Temper Sports, Inc.
daveornee
Yes, if it is a 1", Burt's numbers are correct. You need the OD to be
.1 mm larger than the ID of the Crown Race Bearing. The .1 mm provides
and interference fit. If it is a 1 - 1/8" the numbers are 30.1 mm OD
and 30.0 mm ID. You don't really need to caliper it or "mic" it; you
just need to find a shop that has the right tools and understands how
to use them. The Park Tool or Hozan Tool is made to insure this
dimension is correct and that the shape is perfectly round.... without
any eliptical shape.
--