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Headset stack height 
PostPosted: Wed Sep 15, 2010 9:58 am Reply with quote
scozim
Joined: 26 Sep 2008
Posts: 629
Location: Ellensburg, WA
There's been a lot of discussion on the differences between the Stronglight vs. Campagnolo headset stack height here. Forigve my ignorance but what's the best way to measure/determine stack height needed when replacing a headset.

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Measuring Stack Height 
PostPosted: Wed Sep 15, 2010 11:03 am Reply with quote
verktyg
Joined: 14 Jan 2007
Posts: 2813
Location: SF Bay Area
Measuring Stack Height...

That's easy, at least for a bare frame:




The easiest way to measure the stack height of a headset is use caged ball bearings and "assemble" the top and bottom portions of the headset on a flat surface.

Measure the distance from the shoulder of the race where it goes into the the top or bottom of the head tube to the top or bottom of the headset section. Don't forget the lock washers (and brake cable hangers if used). Add the two dimensions.




(Note: not many classic headsets had seals shown in this picture)


Gitane Gran Sport and similar entry level French headsets = 30mm -33mm

Stronglight P3 headsets = 33mm

Stronglight V4 Competition headsets = 38mm

Stronglight S5 Super Competition headset = 41mm

Stronglight A9 alloy headset used in the 1980s = 39mm

Campagnolo Nuovo Record Road = 41mm

Campagnolo Nuovo Record Track = 34mm

Note: these dimensions are approximate. Every spec I've seen plus my own measurements have differed from the "non-standard" dimensions.

Rule of thumb for the locknut is that it must have a minimum of three full turns of engagement.

You can add 1mm-2mm in spacers under the locknut with a headset that has a "slightly" shorter stack height as long as the bottom height is close to the original headset.

It the bottom height is too thin or too thick, it can change the head tube angle which will affect the bike's handling.

If the steerer is to short by a few millimeters, in the worst case scenario someone with the PROPER tools and WHO KNOWS WHAT THEY ARE DOING can face off the top and bottom of the head tube plus the fork crown to pick up a few millimeters.

Also note: Many French bikes used 27mm inside diameter fork crown races. A lot of replacement headsets came with 26.4mm ID crown races.

Remember, that changes to the frame are forever and can affect the head tube angle. Because of this, I highly recommend finding a headset with the proper stack height!


Last edited by verktyg on Sun Sep 18, 2011 9:07 pm; edited 1 time in total

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Chas.
SF Bay Area, CA USA
==============
1984 Criterium
1969 TdF
1971 TdF
1974 TdF
1984 TdF x 2 Bikes
1970 SC
1971 SC
1972 SC
1984 SC
1984 Team Pro
1985 Professional
1990s Team Replica
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PostPosted: Fri Apr 29, 2011 2:06 pm Reply with quote
LeicaLad
Joined: 12 Jun 2010
Posts: 142
Location: Northern Virginia
Okay. I've spent hours searching for more information about the quality of the Stronglight headset options. Obviously, stack height is crucial. So I use this thread to ask: What are the quality differences, if one is looking to replace a beat headset?

If comparing to a Campy NR, as a sort of baseline: What would be your best or first choice of Stronglight headsets on a 70s TdF or SC?

I'm not eager to go back to a P3, so let's move up the chain, please.

Is the V4 a solid performer?

What about the D8, if one is available to you?

The D9 is among the most easily available. Anyone like them?

Some qualitative comments would be appreciated.

Thank you.

Owen
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Stronglight Headsets 
PostPosted: Sat Apr 30, 2011 2:36 pm Reply with quote
verktyg
Joined: 14 Jan 2007
Posts: 2813
Location: SF Bay Area
The top of the line Stronglight headset up through the 1970s was the D6 Extra Légere that came out about 1978. This was the alloy version of the venerable Stronglight S5 Super Competition headset.

The Stronglight S5 was made in both polished and satin finish chrome plated finish.

S5 Satin Chrome


D6 Alloy


1980 Stronglight Catalog


The S5 and D6 had the same dimensions as Campagnolo Nuovo Record and Super Record headsets with a 41mm Stack Height.

The S5 headsets were considerably harder than some Campy NR headsets and were far less likely to pit or "Index" in the lower cup and crown race.

I have several bikes with D6 headsets. One pitted after very little use.


The 1982 Stronglight catalog shows S7 and D8 headsets. I've never seen either as far as I know but they look the same as the S5 and D6 models.

S7 headset


D8 headset


1982 catalog



The V4 was a very reliable headset. I think I may have only seen one that had gone bad over 35+ years. they use the same toothed washer for adjustment as the P3.

V4 headset


V4 parts showing the V shaped bearing races.


1980 Stronglight catalog


The V4 headsets have a 38mm stack height which is 5mm TOO high for a TdF and 3mm too short for a SC.

ALL 1st generation Super Corsas and Olympics were built with Campagnolo NR headsets.


In 1984 Stronglight introduced the A9 alloy headset with tapered roller bearings. They look ugly IMHO but they work well. An A9 or later model Stronglight headset would look hooky (and I don't mean the UofV Hokies) on a classic 70s Gitane frame. Also they have about a 39mm - 40mm stack height.




One problem that you need to watch out for is the diameter of the fork crown race. The races came in 26.4mm and 27mm IDs. Many French bikes used 27mm races. SCs came with Campy headsets with a 26.4mm race.


P3s aren't that bad, I've seen far more indexing failures in Campy NR headsets. Also. I posted the work around for using a metric threaded P3 top end with a Tange bottom race and crown race a number of times, so check the Forum archives.

Good luck.


Last edited by verktyg on Sun May 01, 2011 2:28 am; edited 1 time in total

_________________
Chas.
SF Bay Area, CA USA
==============
1984 Criterium
1969 TdF
1971 TdF
1974 TdF
1984 TdF x 2 Bikes
1970 SC
1971 SC
1972 SC
1984 SC
1984 Team Pro
1985 Professional
1990s Team Replica
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PostPosted: Sat Apr 30, 2011 7:20 pm Reply with quote
LeicaLad
Joined: 12 Jun 2010
Posts: 142
Location: Northern Virginia
Chas,

As always, you're a font of fabulous knowledge.

What's the going price for a fine/NOS V4? Should one pay more than $50? More than $70?

Do I assume correctly that spacers will allow for matching up the stack height? My '71 TdF has a Campy NR, so has that much height available (it may be minus a spacer). SO, I can hope/presume a V4 can be made to work?

Owen
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PostPosted: Sun May 01, 2011 11:17 am Reply with quote
verktyg
Joined: 14 Jan 2007
Posts: 2813
Location: SF Bay Area
LeicaLad wrote:
What's the going price for a fine/NOS V4? Should one pay more than $50? More than $70?
Owen


V4 headsets go from $50 to $100 on eBay depending on what the Japanese bingo card collectors are looking for at the time.

Many of the Japanese French bike component collectors aren't even into cycling. Collecting old French components is like stamp collecting for them. Some of them have websites with pages of all of specific manufacturer's products in blocks. As they acquire the missing components in their collections they post pictures in the blocks thus the bingo card reference.

Some of the collectors have lots of money and prices can become exorbitant. They frequently employ 2nd party buying agents in Japan to locate the item they want and to do their acquiring. That's why Ideale saddles can go for over $300 on eBay!

Sadly, most of those components will never see the light of day again much less be installed on a bike and used! Evil or Very Mad

LeicaLad wrote:
Do I assume correctly that spacers will allow for matching up the stack height? My '71 TdF has a Campy NR, so has that much height available (it may be minus a spacer). SO, I can hope/presume a V4 can be made to work?
Owen


Do you have a steering tube stretcher? Laughing

TdF head tubes and steerers were machined to fit the 33mm stack height of a Stronglight P3 headset.

V4 headsets have a 39mm+ stack height.

The bottom pressed in race plus the crown race with bearings on a P3 are 11mm high. The V4 is 14mm high. That's 3mm difference.

The top races and lock nut on a P3 are 23mm high while the V4 is 26mm, another 3mm to make up.

TdF steerers tended to be short. Measure the length of the steerer as in the picture in my post above. It's easiest with the crown race removed.

Butt the faced off area of the crown against the bottom of the head tube and measure how much is sticking out of the top. That's how much room you have for the headset.

You can remove a millimeter or so off of the crown race with the special tool designed for doing that. You will probably need to find one with a 27mm crown race cutter, not very common.

File off any chrome plating on the faced off area as it tears up cutters.

You can also remove a millimeter or so off of the top and bottom of the head tube. That's about 3mm so you will still be about 3mm shy.

The front brake cable hanger is about 1.5mm to 2mm thick and any spacers are 1mm to 2mm thick.


If you have a P3 headset you can get an inexpensive Tange headset with a 33mm stack height and only use the bottom bearing parts as they are the ones that wear out.

A headset is a thrust bearing with very little rotational travel. Under load the bottom races take all of the forces. You can get by with lot lower quality parts in that area as long as the races are through hardened.

Tange headset are decent quality, they are available with 26.4mm and 27mm crown races, they look correct plus they are cheap.

You only need the top parts of the P3 because they are metric threaded.

_________________
Chas.
SF Bay Area, CA USA
==============
1984 Criterium
1969 TdF
1971 TdF
1974 TdF
1984 TdF x 2 Bikes
1970 SC
1971 SC
1972 SC
1984 SC
1984 Team Pro
1985 Professional
1990s Team Replica
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PostPosted: Sun May 01, 2011 1:09 pm Reply with quote
LeicaLad
Joined: 12 Jun 2010
Posts: 142
Location: Northern Virginia
The system won't accept my response. Hmm. This is a test. I'll try to edit.

Frustrating system. I've spent more than an hour trying to post a simple response. THIS works, but not what I've typed. Grrrrr.

Make that TWO hours. This system is a serious pain. I have no idea what is stopping the post. I've removed every dash, apostrophe, colon or whatever.

Yet, I can send this...

4th edit: Screw it! I'm sending Chas an email. Sorry. I know this info can be useful to others. But this has been tooo much.
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PostPosted: Wed Mar 02, 2016 11:55 pm Reply with quote
rasha
Joined: 02 Mar 2016
Posts: 1
yes i like D9

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Headset stack height 
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