|ugly shifting on Trek 5200 (triple)||bludoggy|
May 21, 2002 9:18 PM
|In my middle chainring and easiest cog, the chain drops down into the small ring when I stand and start to hammer. Very frustrating on big climbs. The front der. is adjusted so that there is not contacting the chain when this happens. Anybody have any suggestions? It almost seems like the bb is too long, pushing the chainline out of whack...
Thanks in advance
|re: ugly shifting on Trek 5200 (triple)||Paul|
May 22, 2002 4:47 AM
|I imagine you have the Ultegra triple. I put this system on my wife's bike, works great with hardly any adjustment in three years. Sounds like nothing more then adjustment. Do you have the instructions? If you have about two mm (chain to derailleur inner/outer cage plate) when in the biggest chain ring/smallest cog, and smallest chain ring/largest cog), then when in the middle should be no problem. BB is 118 mm if i remember correctly. Does it drop off when in the smallest chain ring? |
On the Ultegra triple, the barrel adjust is real important. If you're in the smallest chain ring, and largest cog, and the distance from the chain to the inner plate is greater then 2 mm, adjust the barrel to bring the plate closer to the chain (CCW). This sort of thing also happens with the rear derailleur.
Also, make sure your chain is parallel with the derailleur when in the big chain ring/small cog. The outer cage should be directly over and in-line with the chain when looking down.
You can try a quickie fix by just adjusting the inner stop (one closest to the seat tube) by about 1/2 turn CW, though this might affect shifting to the smallest chain ring. Try it, and if no change, go back to the original position.
Triples are more difficult to set up.
|STI triples can be tricky to set up.||Spoke Wrench|
May 22, 2002 5:48 AM
|It sounds to me like you have some bottom bracket movement that makes your derailleur work differently when hammering uphill than it does on the workstand. Assuming the position of your derailleur is right (and I'm betting it is), you need a little more cable tension. If it's set up right, your shifters should give you two middle chain ring positions.
To eyeball your chainline, shift into the middle/middle combination and look down on the chain from above. The chain should appear to be parallel to the top tube. If you think the crank really is too far out, first check for clearance between the chainrings and the chainstays. You might be able to gerry-rig a closer chain alignment using an XTR bottom bracket and some combination of spacers, but you really would be voiding the warranty on your carbon fiber frame. I wouldn't do it.
|It really seems to be a bad chainline... any other ideas?||bludoggy|
May 22, 2002 2:06 PM
|It really seems to be the chainline. The front derailleur is set up so that i have two clicks for the middle chainring, and i have adjusted it now so that I have only about 1 mm between the chain and der. cage while in this problematic gear combo. So the der. doesn't seem to be the issue. The chainline looks kind of drastic when I look down the chain while in middle chainring, big cog combo. Also, I can see the chain sort of ride up on the teeth of the chainring when I pedal. My LBS from which I bought the bike 3 weeks ago, claims that this gear combo is probably just unusable. I am having a tough time accepting this since this is one of the most important gears for tough climbing. I can't imagine having to drop into the little ring mid climb...
Your idea of an XTR bottom bracket is intriguing, but why would it void my warranty?
|The chain is supposed to be askew in the middle/big combo.||Spoke Wrench|
May 22, 2002 8:39 PM
|How's it look in the middle/middle combination?
Most bikes don't have much room to move the right crank closer to the frame. My concern is that any bottom bracket movement under load might ding the chainstay with the chain or small chainring. On a steel or aluminum bike that usually just musses the paint. Titanium is so hard that it might even take a chunk out of your chainring. On a carbon bike, however, you just might nick a few fibers in a row and cause the chainstay to fail. If that happens, I doubt Trek would honor their warranty because you made the change that contributed to the failure.
|Disagree with the LBS. When in the middle chainring, you||Paul|
May 23, 2002 3:33 AM
|can be on any cog. That's what a triple is all about. It's radical to be on the big chain ring, big cog, or small chain ring, smallest cog. Upon your description of 1mm when in the middle chain ring, you have a set up problem. When in the middle chain ring, fifth cog up, the chain should be just about dead center between the cages. If you don't have this, you have a set up problem. Don't know why you think you have chainline problems. I saw a picture one time on how to check chain line, bare with me on this, but I believe they were in the middle chain ring (double set up, should be the same for a triple), and the fourth or fifth cog. They put a long straight bar between the two chainrings, and ran it straight back over the cog in front of the chain. Should be perfectly straight. Someone on this board might know the exact setup. |
My wife's triple has worked perfectly over the years. Do you have the correct lenght BB? What cassette combo do you have? How many links in the chain? My setup is a 12-27, 107 links, and the Ultegra triple crank and BB.
My advise is to see a good mechanic if you can't figure it out. The LBS you go to don't know what they are talking about.
|Disagree with the LBS. When in the middle chainring, you||pa rider|
May 23, 2002 4:53 AM
|I agree with Paul about going to another LBS. I just put a new bottom bracket on my triple (118mm) and the shop didn't adjust my front derailer right.
I found one LBS mechanic is a perfectness about adjusting derailers. I had my derailer adjusted three time last year (had to get new front derailer because the winter riding wore out the cheap derailer that came on my c-dale), and found this guy did the adjustments the best.
If one of the other LBS do the work and I'm not satisfied with the adjustments, I'll pay the $5 or $10 to have the other LBS adjust it correctly for me. When you're riding the bike alot money to fix it correctly is well spent.
Just my 2 cents.
May 23, 2002 4:43 AM
|I have a new 5200 triple as well, and I think you have an adjustment issue. My bike shifts like a champ, and I can use ALL the gears in my middle chainring. Take it elsewhere and pay for a front shifter adjustment.
On a side issue, as far as the chainrings "taking a chunk" out of the frame, there should be a nice aluminum plate stuck on where this might happen, right behing the BB.
May 23, 2002 3:20 PM
|A wiley wrench can dial that thing in as sweet as buttah - you just haven't found him/her yet. It's a finnese thing - either you have it or you don't. Ain't nothing strange about a 5200 with an Ultegra triple. It's common that a lot of people don't get them set up correctly.|
|Nope, here's the deal||bludoggy|
May 23, 2002 8:14 PM
|Here's the deal. The front derailleur can not be the issue. In fact let's - for argument's sake - remove the front derailleur altogether. Then, after putting the chain in the middle chainring, shift through all nine cogs on the rear cluster. We shouldn't see any problems on the front, true? Therefore, it stands to reason that no amount of front derailleur fiddling will fix this problem if it isn't in contact with the chain in the first place.
The only counter to this argument would be that I have to have the chain rubbing the front derailleur to keep it from dropping into the small, but I can't imagine that that is standard set up.
I have a very similar setup on my mountain bike--xtr nine speed with triple chains. I have that baby wired perfectly and it takes me about five minutes to get the adjustments made after I change the cables out.
Any other ideas? It has been great to hear everybody's opinions on this because it is really helping to clarify the problem.
|Nope, here's the deal||grzy|
May 24, 2002 8:35 AM
|Look at it this way - you're not ghost shifting until you stomp on it. For this reason I'd lean towards the idea that something is moving under load related to the crank. There is a slight possibilty that something related to the rear wheel cogset is moving. Could be the BB, the crank arm to BB connection or the CR to crank. You should also keep in mind that you really are running crossed and if this were a 2x9 setup then you would infact be as crossed as you can get. Remove, disassemble and inspect the components and don't ride crossed. |
You never said what kind of hub you're running or the cogset. ?If you run a MTB cogset it wil fit, BUT without the required 1.1 mm spacer it floats around on the cassette body. It's a part of humna nature to look for complex and unlikely explanations when often times it's a simple one. FWIW - A major difference with MTB's are that the chainstays tend to be longer so the deflection angles aren't as severe and the CR's are smaller and have more shaped teeth.
|re: ugly shifting on Trek 5200 (triple)||curlybike|
May 24, 2002 7:34 AM
|It would seem that the force of pedaling would hold the chain to the middle ring. Look for a damaged chainring that allows the chain to get oof the ring. Chain line would have more effect if you were back pedaling and therefore unloaded. Seems that chainline would cause a lot of noise before a derailling problem. Check for lateral play in the BB with no chain on the rings or a loose crank. If a bearing is failing in the bb this would happen.|
May 24, 2002 9:52 AM
|Someone posted a similar problem once and reported back that the frame was cracked, through the chain stay I think.|
|re: ugly shifting on Trek 5200 (triple)||bludoggy|
May 27, 2002 2:00 PM
|At this point, it looks like it is a bad chainline. My LBS is going to try to shim out the cassette with a .5 mm spacer and remove a .5 mm spacer in the bottom bracket. We are hoping that this extra mil will give a better shift. At least the owner of the LBS is agreeing that I should have all 9 gears with the middle chainring. For the time being i am avoiding that gear... man does it hurt on the hills.
Thank all you for all of your thoughtful input -- I marvel at the collective knowledge in this forum.