Jul 24, 2001 6:14 AM
|I recently purchased a Zeppelin with an Ultegra group and opted for the triple chainrings. I've had to adjust the barrel on the rear derailleur to get things lined up quite a bit in the 500 or so miles that I've had the bike. I would think that a few times in the first 100 miles or so and that should take care of it for the season. I sold a bike with a 105 triple (8 speed), and I never had to fuss with it. Could it be because of the 9 speed cassette or is there a better cable I could buy to eliminate tweeking it so much.|
|Couple Thoughts||grzy mnky|
Jul 24, 2001 9:02 AM
|First, you're right after the initial break-in and stretching of the cables it should be a done deal. I'm not familiar with the Zeplin, but there are a couple common problem areas. First, verify that you are hitting every gear and that you're properly synched up. shft all the way down, then go up one gear you should be in cog #8. If not adjust until you are. Next, verify that the limit screws are adjusted correctly. Limit screws and barrel adjusters each have their own function and one shouldn't be used to compensate for the other. This is a common error. Next, verify that the rear der. hanger is aligned and that it's parallel with the rear wheel (Park DAG-1 or your LBS). If this isn't right it will never shift correctly. Make sure that the der. is snug and that the front is properly aligned for height (1 mm or so) and parallel to the CR's. Finally check your cable housings for correct lenght - if the housing is too short then it's like having a cable with a changing length. This is very subtle and less common, but can happen. Another area to investigate is the chainline. Sometimes the wrong BB will be used (double and triple Ultegra BB's are not the same length) and this can really raise hell with dialing in a bike. Make sure that the front and rear der. do not have any play in the pivots - unlikely on new stuff, but a real factor on used components. |
I've setup many triples and done lots of conversions and always get it dialed in, but sometimes it takes a while and you have to play detective. If all the parts are correct and straight and the frame is not tweaked then it can be done. If all else fails go to a good LBS and get their best wrench on it. Hope this helps - it pays to be persistent, but if you're not too expereinced it can drive you nuts while you're learning the tricks.
Jul 24, 2001 1:14 PM
|Hi Grz: |
Your technical tips are welcome. Please could you elaborate:
1) How do you know the correct housing length?
2) If your hanger is not aligned parallel, how can one adjust this?
|Couple Thoughts||grzy mnky|
Jul 24, 2001 5:03 PM
|Correct housing length is a subtle thing. You want narural looking bends through the normal range of motion with both ends of all housing lengths firmly nested in their sockets/bosses. Had a Dean MTB wiht an XTR rapid rise rear der. recently drive me nuts until I found that one end was coming unseated during certain motions. Plucking an exposed section of the cable, like a guitar string, while going through all the gearing combos will usually give it away - look for the housing to move a little bit. the tollerances on the drive train components are very tight so a little play or a bent component can really raise hell. Also check the housing ends and any feruels (cable end thingys). |
Hanger parallelism is checked and adjusted with a thing Park Tools calls the Der. Alignment Gauge (DAG-1). You need a fairly true rear wheel (but can be done with a tweaked one also), then the DAG-1 is inserted in place of the rear der. and you swing the end through an arc looking for constant spacing from the rear wheel. If it's off you *carefully* tweak it back into place. Obviously not something you want to mess up or do too many times with aluminum. A good LBS will be all over this and will charge something like $5 or $10 for the service - the tool is around $50 and only really worth it if you do a lot of work on MTBs that get crashed a lot. Sometimes the hanger is obviously out, other times you can only tell by using the tool.
|What he said...plus||Spoke Wrench|
Jul 29, 2001 1:42 PM
|Just for fun, check to be sure your cassette is on tight. If it's sliding back and forth the tiniest amount, it will have you readjusting cable tension till you puke.|| |