|   Swapping a dual pivot from single pivot sidepull | NewTime
Jan 13, 2004 8:12 PM | | Is this a replacement one can make without any mods to the frame? I can't seem to get the single pivot to stay equilateral on both sides of the rim. Seems one side stays closer no matter how I adjust it. BTW the adjustment nut doesn't really do anything as far as the nut just inside the nutcap. It just seems to tighten the entire brake assembly. I had it completely disassembled and lubed, and it still favors one side. I am hoping a dual pivot will be a better solution and more maintenance-free for adjusting brake shoes. |
| You can likely make that change.... | alibi
Jan 14, 2004 12:13 PM | | without any mods to the frame. Dual pivot side pulls use the same single bolt attachment as single pivots. You will need to watch out for different kinds of nuts on that brake bolt though; older single pivot (pre ~1985) brakes used a regular external hex nut, whereas newer single pivots and most double pivots will use a recessed allen type bolt. Check that out first to make sure what you have. Recessed allen nuts require a different size hole in the frame.
What brakes do you have now, and on what frame?
But, you should be able to adjust those singles to eliminate your problem. The nuts on the front of the brake don't do anything as far as centering the assembly, but like you said, just tighten it together. You need to look for 2 flats on either side of the piece that the spring is attached to, right where it butts to the frame. Put a cone wrench on those flats, hold the assembly centered with the cone wrench, then tighten down the attachment nut on the back. Fine tune the position with the cone wrench. Another possibilty is that one side of the spring is either weaker, or it's movement is being obstructed in some way. Put a dab of grease on the spring where it catches the brake arm, or if need be, bend one arm of the spring so they apply more even pressure.
Having said all that, dual pivot brakes are worlds better than single pivot; much easier to obtain perfect, even pad movement as well as requiring much less hand pressure to activate. Even Shimano 105s, ~$40 a set, will work better than the best single pivot Campy Super Records. |
| You can likely make that change.... | New Time
Jan 14, 2004 6:44 PM | | The bike does have the external hex-nut. It's a very old Schwinn Varsity, something I inherited hahaha. Might be destines to rust instead of fixing up. I don;t want to give up on it yet though. |
| Ah, yeah.... | alibi
Jan 14, 2004 8:36 PM | | that's gonna be a problem you'll have live with. Those would be very old, long reach brakes of low quality. You will not find a dual pivot brakeset for that bike. I'd say keep working on making the spring pressure equal on both sides, check that everything is moving and well lubed, maybe invest in some new cables/housings.
Good luck. |
| Ah, yeah.... | NewTime
Jan 15, 2004 5:32 AM | | Do they sell replacement springs. After I cleaned and lubed the entire brake, it seemed that the spring wasn't as strong as it should be. Didn't want to bend it as the maintenance book recommended against this. Said it weakened the metal making it more prone to breaking. |
| |
