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"B" adjustment screw on Record rear derailleur?(15 posts)

"B" adjustment screw on Record rear derailleur?DougSloan
Aug 22, 2002 5:55 AM
How does the little adjustment screw on the Record derailleur work, the one on the housing of the main spring? Does it work the same as the former B adjustment screw? Does it pre-load the spring? I can't figure it out. There is nothing on Campy's otherwise complete website or the printed instructions. Thanks.

same i thinkColnagoFE
Aug 22, 2002 6:06 AM
but if nobody else can answer this you can always email peter the campy dude at vecchios. he seems to know everything campy.
re: "B" adjustment screw on Record rear derailleur?JohnG
Aug 22, 2002 10:14 AM
The little screw acts as a worm drive on the tiny plate that fixes the spring for the lower cage. You get around 60-90 degrees of spring rotation out of the adjustment. I suspect the action from this screw is slightly different than the old b-screw since the location is different..... but for all practical purposes it probably does the same thing.

Also, don't overlook chain length (and subtle variations on the recommended value) when setting up a C10 drivetrain. The factory recommended chain length is not always the best setup........ will even cause significant problems (cog to jockey wheel interference) when using a casette with a 29 tooth cog.

you know, I have this problem...Stinky Hippie
Aug 22, 2002 10:56 AM
...with my 29 tooth cog when I bring the wheel all the way forward in the dropouts. would a longer chain solve this problem?
you know, I have this problem...JohnG
Aug 22, 2002 12:22 PM
*** Contrary to intuitive logic you actually have to shorten the chain. ***

**** The reason the jockey wheel is rubbing when you move the wheel forward in the dropouts is because you are effectively lengthening the chain when you move the axle forward.

That makes alot of sense...Stinky Hippie
Aug 22, 2002 1:57 PM
...I think I've avoided learning this for myself because I can't afford to replace 50 dollar chains should I screw something up.


Feel the gin

By the way, where did you get those Zipp 303s for $825? My fiance just bought me a Breitling Chronomat so I was going to put the fancy wheelset thing off for a while, but your post below got me reconsidering those 303s .
a Breitling?DougSloan
Aug 22, 2002 2:33 PM
If she can buy you a Breitling, the wheels are chump change; have her get the wheels, too. Or, return the watch and buy a nice set of wheels; get your priorities straight, man! :-)

a Breitling?JohnG
Aug 22, 2002 2:56 PM
LOL............ Yeah, let's get our priorities straight!!!

FWIW: it's really quite simple to remove a couple of links from a C10 chain. A good chain tool (Park shop type) is what I use to assemble/disassemble the C10 chains. I've done this literally dozens of times with absolutely no problems. On the other hand I've seen numerous PL failures (including my own which caused disasterous consequences ) so I KNOW that's a real liability issue. You could also use one of the several master links that's available for the C10 chain.

I was going to buy the AC carbon wheelset (they use the same Zipp rims as the 303's) until I got this killer deal. At that price it was hard to resist......... even though the Zipps do have a reputation for being a little fragile. I'm just hoping I can get at least a couple of seasons out of them before they 'break'.

You can contact me at for the wheel info.
Now guys, my priorities are more than straight....Stinky Hippie
Aug 23, 2002 5:32 AM
....I mean, the watch perfectly matches my stainless lugged frame. And you know, I wasn't the one to notice it first -- the future wife was...It's why she insisted I have it!!!

yeah, I've got me a good one --- good enough that she will probably let me get the 303s. I'll email ya, John. And by the way, I took a link out and the pulley doesn't rub the 29 tooth cog anymore with the wheel all the way forward.

And while we're on the subject, what exactly does bringing the wheel forward accomplish? will I get better climbing, or just quicker handling?


Feel the gin
Now guys, my priorities are more than straight....JohnG
Aug 23, 2002 6:12 AM
Hey, you do have a "good one" there! :)

Bringing the rear wheel forward will make a very small change in the handling and climbing characterists of a bike. However, unless you are talking about > 1cm I doubt you would ever "feel" the difference. Let us know..... curious minds.

FWIW: My LOOK 281 has adjustable dropouts and I've heard people say that they can't feel any difference when the wheel is adjusted forward and aft. It has a little less than 1cm of adjustment though.

In theory, a shorter effective rear stay length would stiffen the bike and should be better for climbing. I still think the change would be "in the noise" though.

well you know, the henry james dropouts....Stinky Hippie
Aug 23, 2002 6:45 AM
...are at a slight angle, so it seems like I'm also slightly raising the chainstays (and with them, the whole bike) as I move the wheel forward AND downward. I have a feel the bike might feel stiffer in the rear (looks like I've subtracted 1 1/8 cms from the wheelbase), but I won't know til tomorrow, cuz I ain't riding in a 108 degree heat index before tonight's trip to the martini bar :)
Nice combination, but a warningDMoore
Aug 26, 2002 8:02 AM
I've had a Chronomat for about 8 years - just got the Zipp 303's (sewups)as my race wheels at the start of this season. But I can't use the Breitling to time my improvement with the faster wheels, as I wouldn't dare wear the watch on a bike ride. The thought of crashing with it is just too painful.

Your fiancee has saddled you with a heavy burden. I just got my watch back from service. After 8 years things were sticking and the stem wouldn't screw down. The service took 2 months and cost $750!!!
I've been thinking about that....Stinky Hippie
Aug 26, 2002 2:15 PM
...I couldn't bear the thought of crashing while wearing that watch. Oh, and thanks for the advance warning regarding service costs. :)

And hey, did Breitling ever send you any surprise gifts?
re: "B" adjustment screw on Record rear derailleur?B2
Aug 23, 2002 5:01 AM
I assume you're after how the screw makes the RD move.

However if you're after the adjustment procedure, here you go - screw "H" is what you are referring to I believe.

Aug 23, 2002 7:32 AM
Thanks; for some reason I did not find that at the Campy site. Perfectly clear, now.