Bicycle Mechanics - Stronglight headset assembly help

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View Full Version : Stronglight headset assembly help


tmh657
03-10-09, 10:23 PM
I have a 20 something year old Stronglight headset that came to me in pieces in a rag.

I can assume the correct way it would go together but want to make sure. Here's the pictures. There are 4 conical metal parts that would seem to have the bearings fit in between them. There are 2 smaller ones and 2 that are larger.
I placed them in the order I think with the top nut on the bottom right going to the left, then start back up at the top right going left to the end.
Thanks


jgedwa
03-10-09, 10:28 PM
That is a wonderful headset, by the way. You are lucky to have one.

I have one, and while I can't recall off-hand the order of assembly, I do recall that the right way is fairly obvious. I would think that if you stack them all together incorrectly it will just not fit together well. And the right way, all the parts will marry together like butter.

jim

JustChuck
03-10-09, 10:33 PM
As I recall the large race fits to the outside of each roller bearing and the smaller race fits to the inside. I am pretty sure about that becasue I have one of these on my fixed/commuter bike and have had to replaced cracked races three times.

This is a very cool headset, but I have not found it to be very durable. I have a vintage D/A waiting in the wings as my Stronglight feels like it has cracked a race yet again.


jgedwa
03-11-09, 06:28 AM
Any way to get spares for it? Are they prone to cracking the races? What about new needle bearings/cages?

jim

JohnDThompson
03-11-09, 06:47 AM
Any way to get spares for it? Are they prone to cracking the races? What about new needle bearings/cages?

jim
Replacement races and bearings are available and not terribly expensive. I've never had any problems with mine -- I have 4 of them in use here and all have lasted over 20 years without any problems. I even have one on my tandem.

jgedwa
03-11-09, 06:50 AM
(sorry for the complete hijack, but...) Where did you get the replacement parts? jim

JohnDThompson
03-11-09, 06:54 AM
As I recall the large race fits to the outside of each roller bearing and the smaller race fits to the inside. I am pretty sure about that becasue I have one of these on my fixed/commuter bike and have had to replaced cracked races three times.

This is a very cool headset, but I have not found it to be very durable. I have a vintage D/A waiting in the wings as my Stronglight feels like it has cracked a race yet again.
Have you checked your frame to ensure that the head tube is properly milled and faced and fork crown milled correctly? That's about the only reason I can think of why you've had so much trouble with the A9. I installed one on my commuter bike and as an experiment did *no* maintenance on it for over 20 years. In 2007 I opened it up to see how it fared:

http://os2.dhs.org/~john/A9.jpg

As you can see, there's a very mild amount of fretting damage on the inner race of the lower bearing. And that's it. I swapped upper and lower, repacked and will check again in another 20 years. :)

JohnDThompson
03-11-09, 07:01 AM
(sorry for the complete hijack, but...) Where did you get the replacement parts? jim
Ben's (http://shop.vendio.com/benscycle/item/914678743/index.html) in Milwaukee has replacement bearings and races:

http://imagehost.vendio.com/preview/be/benscycle/.mids/StronglightBearingRaces1.jpg

tmh657
03-11-09, 09:11 AM
After doing a thorough google search and trying to use the search function here,(is it broken or just me?) I couldn't find much on this headset so I thought, hmm, must be kind of an obscure component.

I shouldn't be surprised to find that you guys know everything there is about it. BF has to be the best place for info about my new hobby (addiction).

How did this kind of info get spread around 20 years ago? The library maybe, word of mouth. The 20 year old mechanic at my LBS could not be the source of this kind of knowledge.

Thanks for the help.

xB_Nutt
03-11-09, 10:08 AM
Looks like the right order to me. I have a Stronglight headset on my Cannondale that has been going strong since 91. I just serviced it and it still runs as smooth as butter. Mine has a one piece top nut with a bolt to cinch it down when it is adjusted correctly. Much easier to adjust.

JohnDThompson
03-11-09, 12:50 PM
After doing a thorough google search and trying to use the search function here,(is it broken or just me?) I couldn't find much on this headset so I thought, hmm, must be kind of an obscure component.
What search terms did you use? I get 6,170 hits on a google search for "Stronglight A9 (http://www.google.com/search?q=stronglight+a9&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a)".

Grand Bois
03-11-09, 04:32 PM
Just Chuck has the assembly order correct, but I suspect that he's over tightening.

The A-9 weighs 89 grams. Try to find a lighter headset.

JohnDThompson
03-11-09, 08:49 PM
Just Chuck has the assembly order correct, but I suspect that he's over tightening.

The A-9 weighs 89 grams. Try to find a lighter headset.
Stronglight B-10: 67grams. Just like the A-9, but with Delrin (plastic) cups.

Then there was the "single use only" Nylfor nylon headset -- under 30grams as I recall. Entirely nylon, including the balls. Not known for durability.

JustChuck
03-11-09, 09:57 PM
Just Chuck has the assembly order correct, but I suspect that he's over tightening.



Possibly, but a roller bearing should be a able to handle a higher load than a ball bearing(In a bearing set of similar size) and I have installed thousands and adjusted tens of thousands of headsets and never had one break a race.

I beleive the lower cup has a flaw in it and does not support the race properly, but I have never looked close because the races were cheap and easy to replace. I also figured it was the price paid for a super light headset made by the guys that make Stronglight cranks.

tmh657
03-11-09, 10:20 PM
FWIW I assembled the headset and fork today and it went together the way you guys said it would.
The bike isn't complete yet so it hasn't been ridden but the headset looks great.
Thanks

PGMikeT
03-12-09, 02:01 AM
I've had the A-9 on my Shogun since I bought it in 1979. My buddy's dad owned the shop and he says "I've got this sitting here, do you want it? It's lighter then the Tange that is on there stock." 30 years later, as all have said, like butter! PGMikeT

urodacus
03-12-09, 02:28 AM
I've had an A9 on my Saronni since new in 1984, apart from a year when i ran a replacement fork with a Scuzzy Pro-Logic headset. Rusty piece of....


the A9, OTOH, still "like butter" (thanks PGMikeT) after goodness knows how many 100,000.

JohnDThompson
03-12-09, 10:18 AM
Possibly, but a roller bearing should be a able to handle a higher load than a ball bearing(In a bearing set of similar size) and I have installed thousands and adjusted tens of thousands of headsets and never had one break a race.
Campy Super Record were famous for breaking races. I've never seen an A9 race break, though, and having worked as an assembly/warrenty inspector at Trek where we installed several hundred of them every day, that's saying something.

Are you certain that the head tube and fork crown race seat have been properly prepped?