Horizontal Dropout Adjustm't Screws...

IXXI · #1 09-25-2004, 11:16 PM

I have an older Serotta with med. long horizontal Campy dropouts (and dropout screws). I've been riding it a lot this summer but lately have felt a little funny about something happening with the rear wheel: even though I have both adjust. screws exactly even (and I've done lots of experimenting), even though the hub and skewer are new ('03) DA with lots of serrations on all the faces that touch the drop, and even with the skewer *cranked*, after a long sprint or hard ride up a hill I can see that rear wheel has shifted in the drop a bit. Never quite touching the non-driveside chainstay, but clearly off center.

Have any of you all ever had this problem? Anything I can do? This was Ron Kiefel's old bike and I doubt I'm anywhere near as strong as he was/is.

What am I missing?

vaxn8r · #2 09-25-2004, 11:59 PM

I think there was a thread on this 6 months ago or so.

Seems you've thought of everything. I guess I'd try another rear skewer. I seem to recall that you may need teeth in the lock nut side. Yeah, that may be the problem...check it out.

amg · #3 09-26-2004, 07:37 AM

IXXI,

Check that the hub is far enough back in the drop outs so that it is making full contact with the face of the drop out. You want to ensure the hub serrated washers at the ends of the hub are fully covered by drop out.

In my experience I've found the Campagnolo Record and Chorus skewers to be the best and strongest skewers for this type of application. I personally wouldn't trust my rear wheel to any other skewer, that's not to say that there aren't other skewers out there that can do the job, but I've found the Campy skewers to work exceptionally well.

Hope this helps,

Antonio

keno · #4 09-26-2004, 07:54 AM

a while back with my Spectrum and Velomax wheels. In my case the wheel actually was pulled out of the drops. In my case there seemed to be a certain element at play, that was a stronger skewer was needed and amg actually gave me a Campy record skewer, I believe, that has worked flawlessly. There also was a possible second element at play, which I'll do my best to explain, not knowing the specific technical terms. The problem lies with the seating of the surface of the axle nut with the inside of the dropout. You want to have the ends of the axle body, represented by the axle nut, surfacing fully on the inside of the dropout just as the skewer surface meets the outside of the dropout. If the axle nut is not shaped properly, it is possible to have imperfect tightening of the wheel in the dropouts creating a false appearance of correct tightening. If I haven't explained the issue well, someone else might do it better or even provide a diagram. Important is what type of rear hub you are using so the more savvy would have a quicker answer.

Don't be casual with this problem, both for safety and potential repair problems. Good luck.

keno

christian · #5 09-26-2004, 08:29 AM

As others have said, in the case you're using an external cam skewer, definitely replace it with an internal cam model. I've been happy with Ultegra skewers, and my wife's Campy skewers have a lot of bite, as well.

Best of luck!

- Christian

IXXI · #6 09-26-2004, 10:47 AM

Thanks you everyone for your thoughts. This is my second wheelset on here; the first was a very cool set of Bontrager X Lites, but the hubs and skewers did not have enough serrations on all the surfaces-- so I switched to new DuraAce (DA) stuff with much more bit which helped, a lot, but I still have some movement.

I had a separate email off to Sheldon Brown who said in this instance DA is every bit as good as Campy; he suggested I take out the springs on the skewer to remove even that small amt of extra play. I'll try it and report back to you all.

(And Keno, you did explain it well! That's precisely what I've been looking at very closely.)

The safest course of action would be to pull the screws out so the hub is seated waaaaaay back in the dropout--and so the hub/skewer are biting into as much metal as possible. But this also puts the rear wheel waaaay back on the bike, vs. tucked up under, which I'm wondering how it will affect handling-- specifically climbing.

Anyway, the process continues...
Thanks all.

Ken Robb · #7 09-26-2004, 01:38 PM

I can't imagine how changing the position of the rear wheel in the dropouts on the same bike could affect climbing at all. Moving it back might make it slightly more stable descending.

IXXI · #8 09-26-2004, 02:50 PM

These are long dropouts; moving the wheel all the way back effectively lengthens the chainstay/wheelbase equation by several centimeters, or rather affects the effective geometry-- picture the difference between a real race bike with the wheel tucked up close to the seat tube and a more 'comfort' oriented bike with the wheel further back. I expect that moving it back will make it a great descender as you note and a pretty plush century bike; I suspect it will be a lot less 'snappier' a climber in this position though.

Ken Robb · #9 09-26-2004, 03:03 PM

I am of the opinion that this bike's suitability for climbing is not affect by where the rear wheel is in the dropout. I think that because many "snappy" race bikes that have short chainstays climb well because thay are very light and have light wheels and tires. I think some of us have extrapolated that into "shorter chainstays climb better". Also, when all else is equal, a bike with short chainstays is more likely to weave with every hard pedal stroke which can make me feel like I'm going faster. FWIW, I climb steep hills offroad a bit better on my longer wheelbase bike than on my short one because it's easier to keep the front wheel on the ground but this is never a factor on my road riding. I have bikes with chainstays from 40 to 45.5 cms. and 3 of them have long horizontal dropouts. I have done quite a bit of experimenting on them in regard to wheel positioning and I can't detect any difference in climbing on pavement.

IXXI · #10 09-26-2004, 03:15 PM

Ken, thanks for the insight. You've clearly had much more hands-on experience with long dropouts; this is my first bike with them and I'm going off theory in my head (scary) more than anything else. I'm anxious to experiment with this myself. (BTW- how do you have most of your wheels positioned on bikes with these dropouts-- toward middle, rear, front?)

Another question: what exactly is the purpose of such long dropouts and the adjusting screws? Was it indeed to have the flexibility of affecting ride by allowing dif't wheel positions? Just wondering...

Thanks all.

Ken Robb · #11 09-27-2004, 10:55 AM

I'm not sure about the reasons but I would guess that one is to adjust for misalignment in the frame or other "normal" variations in dropouts or other componentry. I have read about some riders who would use the range of movement to adjust their bikes for different handling in different events. I'll bet we cn get some real info from Classic Rendezvous.