Trouble with a Triple on a 2006 Fierte Ti

[2manybikes]

I just purchased a 2006 Serotta Fierte Ti with all Dura-ace 7800 components except it has a 7900 BB. It has a 12-26 10 speed DA cassette and it has the standard 7803 crankset with the 52/39/30 chain rings. It has the 6.5mm spacer on the chain side and the 3mm on the other side.

Problem I'm having is that in either the large or middle chain ring with the chain on the largest rear cog, the chain wants to drop to the middle (if it was on the large) or the small (if it was on the middle) under heavy load such as a quick take off from a light. Also shifting from the small chainring to middle or middle to large when the rear cog is in the largest is difficult. I measured the chain line and it looks like it is somewhere between 50-52mm! Also it looks like the BB housing of the frame is wider than most other bikes I own. At least 2.8".

Has anyone one seen this problem and know how I can fix it? Maybe I can use the 3mm spacer on the chain side and throw away the 6.5mm spacer?

Thanks,
Mark

[AngryScientist]

cable tension, you dont have enough of it.

[chismog]

Hi Mark,

Assuming you have the stops set up correctly for high/low, I suspect trim is the problem.

You need to have some sort of cable tension adjuster inline. Adjusting trim for triples that drop to the lower ring is accomplished by increasing cable tension. You may need to adjust the low stop a bit after you tweak the trim.

Hope this helps,
C

[2manybikes]

Cable tension is not the issue. When the front derailleur has the chain on the middle ring there is plenty of tension or the derailleur would move to the inner ring. The tension is holding the derailleur in the middle position. The drop occurs after the chain is already on the middle ring and you can see that the chain is extremely angled ready to hop off. I'm nearly sure this is a chain line issue and need to know what combination of BB & spacers can help.

[2manybikes]

Hi Mark,

Assuming you have the stops set up correctly for high/low, I suspect trim is the problem.

You need to have some sort of cable tension adjuster inline. Adjusting trim for triples that drop to the lower ring is accomplished by increasing cable tension. You may need to adjust the low stop a bit after you tweak the trim.

Hope this helps,
C

I went down this path and got it adjusted where the derailleur was rubbing the inside of the chain and still the drop will occur. Again the chain angle is pretty extreme and I can see the side of the chain plate it is so bad.

[cp43]

Do you have a 6.5mm spacer between the drive side BB cup and the frame? If so, I'd guess that's your problem.

Do the Shimano docs suggest that you need this?

Check here:

Shimano Docs (http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Dura-Ace/FC-7800-7803/SI_1F30H_En_v1_m56577569830605111.pdf)

I see that it suggests a spacer on the non drive side for your cranks, but I don't see one on the drive side.

I would take the left crank arm off, and see if enough of the spindle is sticking out. If not, I would take the spacer off of the drive side.

Hope this helps.

Chris

[eddief]

I run hollow tech 10 speed triple cranks on all of my bikes. Now granted, I am running them with 9 speed cassettes. I run this set up on my long chainstay Rambouillet all the way down to the short stays on my new Cronus. No spacer on drive side of bb, spacer included with triple crankset on non-drive side is installed.

Now we may be mixing up spacer terminology as I recall when you look at the axle on a Hollow Tech crank, I think there is big black thing on the drive side of the axle, but does it come off? And there is definitely a spacer disk for triples that goes on just before you put on the crank arm.

For triple fronts with STI indexed shifting, cable tension and front d alignment are critical...and can be a pain the arse till you get em right. But maybe you have done this before and we are all a farting in the wind.

My guess is too much cable tension which prevents the front d and shifter from working together smootly; including not letting you take advantage of the trim stops available for when the chain is at rubby angles. My 7800 front triple shifter has two trim stops for getting down from the big ring to the middle.

What size frame is it?

[Mike748]

I agree with the spacer being the problem. Swap it and see if you can still adjust your FD inward enough to get the small chainring before the FD bottoms on the seat tube.

Even in good situations though running big-big or even middle-big with triple is going to result in some major chainline error and isn't a good idea.

[2manybikes]

Do you have a 6.5mm spacer between the drive side BB cup and the frame? If so, I'd guess that's your problem.

Do the Shimano docs suggest that you need this?

Check here:

Shimano Docs (http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Dura-Ace/FC-7800-7803/SI_1F30H_En_v1_m56577569830605111.pdf)

I see that it suggests a spacer on the non drive side for your cranks, but I don't see one on the drive side.

I would take the left crank arm off, and see if enough of the spindle is sticking out. If not, I would take the spacer off of the drive side.

Hope this helps.

Chris

It is recommended and comes with the CS-7803. Item 11 in the shimano diagram is the spacer:

http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/FC/EV-FC-7803-2446A_v1_m56577569830608871.pdf

Mark

[2manybikes]

I run hollow tech 10 speed triple cranks on all of my bikes. Now granted, I am running them with 9 speed cassettes. I run this set up on my long chainstay Rambouillet all the way down to the short stays on my new Cronus. No spacer on drive side of bb, spacer included with triple crankset on non-drive side is installed.

Now we may be mixing up spacer terminology as I recall when you look at the axle on a Hollow Tech crank, I think there is big black thing on the drive side of the axle, but does it come off? And there is definitely a spacer disk for triples that goes on just before you put on the crank arm.

For triple fronts with STI indexed shifting, cable tension and front d alignment are critical...and can be a pain the arse till you get em right. But maybe you have done this before and we are all a farting in the wind.

My guess is too much cable tension which prevents the front d and shifter from working together smootly; including not letting you take advantage of the trim stops available for when the chain is at rubby angles. My 7800 front triple shifter has two trim stops for getting down from the big ring to the middle.

What size frame is it?

I am calling the black thing on the drive side the 6.5mm spacer. It is shown here:

http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/FC/EV-FC-7803-2446A_v1_m56577569830608871.pdf

I think it comes off, but I haven't pulled it apart yet. I'm able to find that spacer as a shimano part on some bike sights so I'm betting it comes off.

My bike frame is a 60cm

[2manybikes]

I agree with the spacer being the problem. Swap it and see if you can still adjust your FD inward enough to get the small chainring before the FD bottoms on the seat tube.

Even in good situations though running big-big or even middle-big with triple is going to result in some major chainline error and isn't a good idea.

I'll give it a shot tomorrow when I get the BB tool from my buddy. I realize it is a bad scenario and mainly only get in it when I come to a stop (easy to remember when stopping quickly to shift the back to the easiest gear and any front gear will allow me start again) or when I forget to get in the small ring on a tough hill and I try to not loose my momentum.

[oldpotatoe]

I am calling the black thing on the drive side the 6.5mm spacer. It is shown here:

http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/FC/EV-FC-7803-2446A_v1_m56577569830608871.pdf

I think it comes off, but I haven't pulled it apart yet. I'm able to find that spacer as a shimano part on some bike sights so I'm betting it comes off.

My bike frame is a 60cm

Take that off and you will have too much spindle protruding on the LH. With triples, gotta have that one and the other thinner one on the LH side. Not cable tension either as chainline is pulling the chain off the CR onto next smallest CR. The only thing I can think of is that you chainline is made worse by perhaps having the rear triangle bent to the left, making the chainline worse than it already is.

Also got the crank all the way on? CL should be about 47-50mm with that crank.

NO spacers under the BB cups against the frame? None required.

[oliver1850]

.

[eddief]

are you getting the trim stops when shifting from large ring to middle ring? if not, then ONE problem could be cable tension. i would be interested to hear the answer to that question.

[2manybikes]

Take that off and you will have too much spindle protruding on the LH. With triples, gotta have that one and the other thinner one on the LH side. Not cable tension either as chainline is pulling the chain off the CR onto next smallest CR. The only thing I can think of is that you chainline is made worse by perhaps having the rear triangle bent to the left, making the chainline worse than it already is.

Also got the crank all the way on? CL should be about 47-50mm with that crank.

I'm worried about that too, but if the shell is wider than it is supposed to be then I may be okay. We'll see when I get it apart.

[2manybikes]

are you getting the trim stops when shifting from large ring to middle ring? if not, then ONE problem could be cable tension. i would be intrested to hear the answer to that question.

I think I'm able to trim in all scenarios, but I'll double check.

[roydyates]

I just purchased a 2006 Serotta Fierte Ti with all Dura-ace 7800 components except it has a 7900 BB. It has a 12-26 10 speed DA cassette and it has the standard 7803 crankset with the 52/39/30 chain rings. It has the 6.5mm spacer on the chain side and the 3mm on the other side.

Problem I'm having is that in either the large or middle chain ring with the chain on the largest rear cog, the chain wants to drop to the middle (if it was on the large) or the small (if it was on the middle) under heavy load such as a quick take off from a light. Also shifting from the small chainring to middle or middle to large when the rear cog is in the largest is difficult. I measured the chain line and it looks like it is somewhere between 50-52mm! Also it looks like the BB housing of the frame is wider than most other bikes I own. At least 2.8".

Has anyone one seen this problem and know how I can fix it? Maybe I can use the 3mm spacer on the chain side and throw away the 6.5mm spacer?

Thanks,
Mark
I wish I had some DA triple cranks. I do have two 6600 triple cranks and a 6700 triple crank. They all have a thin spacer on the non-drive side. If you flip it to the other side, won't you get assymmetry in your Q factors, ie your pedals will not be the same distance from the centerline? That's got to be bad for your pedaling. My 6700 crank has the black spacer (just like item 11 on your schematic) on the drive side. I thought that it was needed for clearance from the chain stay. In short, my guess is that any major deviation from the techdocs recommendation for crank setup will be obviously wrong.

I'm betting on the guys who pointed to chain tension.

[2manybikes]

I wish I had some DA triple cranks. I do have two 6600 triple cranks and a 6700 triple crank. They all have a thin spacer on the non-drive side. If you flip it to the other side, won't you get assymmetry in your Q factors, ie your pedals will not be the same distance from the centerline? That's got to be bad for your pedaling. My 6700 crank has the black spacer (just like item 11 on your schematic) on the drive side. I thought that it was needed for clearance from the chain stay. In short, my guess is that any major deviation from the techdocs recommendation for crank setup will be obviously wrong.

I'm betting on the guys who pointed to chain tension.

Symmetry is off by about 2mmm, so I think I could pull the 6.5mm spacer out and move the 3mm spacer to the drive side and be pretty close.

I am pursing the tension theory before the spacers. I noticed last night that the FD was angled outward to the back. If I get it more parallel it will allow more tension before rubbing. Also looks like I could lower it some more and still be in the 1-3mm spec. Also measured chain wear and just barely fitting the .75 on the park tool, so I'll swap the chain as well to see if it helps.

[2manybikes]

Latest update:

Front derailleur is now about 1-2mm above the large chainring and is parallel to the chain ring. I adjusted the tension so that when in the middle or large chainring the inside rubs hard when in the large cog and continues to rub until I move to the 3rd largest cog. This seemed to put enough pressur on the chain when on the middle chainring or large chainring to keep the drop from happening even under heavy pressure on the pedals. Then I replaced the chain to a new DA 7801 with nothing else changed and now the chain has trouble getting onto the big chain ring and when it does, several links rid on top of the teeth. Put more tension on the cable but still isn't great. I'm pretty sure I still need to get a couple mm off the chainline to make this run smooth. Thoughts?

[eddief]

but all of your machinations sound like you'd benefit by spending some money with a very experienced mechanic. chances that chainline is off on a serotta makes me have my doubts. chances you could use a good mechanic seem more likely. just a guess.

[2manybikes]

but all of your machinations sound like you'd benefit by spending some money with a very experienced mechanic. chances that chainline is off on a serotta makes me have my doubts. chances you could use a good mechanic seem more likely. just a guess.

If I knew where to find one that wouldn't be guessing and charge me for their guessing, I'd do that. Plus I learn more from experiencing than from having someone else do it.

[eddief]

can you adjust the front d outer screw counter clock wise so the front d can move further to the outside? Have you determined whether your cable tension allows you to use the 2 trim stops available when down shifting from the big ring to the middle ring?

[RPS]

Problem I'm having is that in either the large or middle chain ring with the chain on the largest rear cog, the chain wants to drop to the middle (if it was on the large) or the small (if it was on the middle) under heavy load such as a quick take off from a light.
Mark, Shimano clearly recommends that the drive system not be used with these combinations; particularly large ring to large cog. Even if your system was set up perfectly you shouldn't be using these combinations.

If it were me, before I'd spend a lot of time on chainline worries I'd first look at the inner chain ring to see how close it misses the driveside chainstay; and also how close the driveside crank arm misses the driveside chainstay. On most normal bikes you should have a little clearance but not huge. Unless you have a lot of excess clearance that would suggest you can move the chainline inside I'd stop worrying about that as the source of your problems.

[2manybikes]

Mark, Shimano clearly recommends that the drive system not be used with these combinations; particularly large ring to large cog. Even if your system was set up perfectly you shouldn't be using these combinations.

If it were me, before I'd spend a lot of time on chainline worries I'd first look at the inner chain ring to see how close it misses the driveside chainstay; and also how close the driveside crank arm misses the driveside chainstay. On most normal bikes you should have a little clearance but not huge. Unless you have a lot of excess clearance that would suggest you can move the chainline inside I'd stop worrying about that as the source of your problems.

Where does Shimano clearly state this for the 7803 triple set up? I know it is not the best thing to do and I only do it when I have to and don't want it to drop, but I can't find Shimano saying stay out those gearing combinations only to trim if there is noise when there.

I have enough clearance to play with it a few mm.

[oldpotatoe]

Where does Shimano clearly state this for the 7803 triple set up? I know it is not the best thing to do and I only do it when I have to and don't want it to drop, but I can't find Shimano saying stay out those gearing combinations only to trim if there is noise when there.

I have enough clearance to play with it a few mm.

You should be able to go from big-big to small-small and any other combo w/o the chain coming off a chainring when you pedal with force. I gather this happens w/o the chain contacting the front der at all...so it's gotta be a chainline issue, not a FD issue, since this would happen w/o the FD being on the bike.

[Ralph]

It's not difficult to measure if chain line is OK, if crankset is centered in frame, etc. It would take me less than minute.

[nahtnoj]

2.8" = 71.12mm

Are you sure that is right? I find it hard to believe that Serotta let a bike out the door with a BB shell that is 3mm too wide. Have you been able to ascertain whether or not the shell is symmetrical? I think your problem comes down to the shell, if it is really 71mm.

I have a bike with a 6600 triple that shifts perfectly. I have the exact spacers shown in the diagram - 6.5mm DS and 3mm NDS.

How is the interface of the spindle and NDS crank arm? I would think you are not getting the arm all the way onto the spindle with the extra width you have.

[jischr]

My chain never jumped but it was angled pretty severely on my old steel road frame using a 105 triple. I took the triple BB off and put on a double BB, added a 3 mm spacer on the drive side and got about 4 mm of space between the small ring and the chain stay. Works better, looks better, and have yet to contact the chain stay.

[2manybikes]

Here is the latest update. Brought it to the LBS that sold the bike. Mechanic measured chain line between 48 & 49. Width of bottom bracket housing is correct at 68mm. He was stumped on the issue, but said it is not cable tension. He spoke to Shimano but they didn't have any suggestions. He will be calling Serotta on Monday to see what they say about it.

[eddief]

to hear the outcome. a lot of variables, but your parts sound normal, your bike sounds normal. makes me wonder about the humans in the equation. i have often found myself to be the weakest link. i hope you get satisfaction soon.

[2manybikes]

According the the mechanic, Serotta is saying that the chain stay angle is too accute to meet Shimano's recommendations for a triple. Got this from a voice-mail, so I'll follow up tomorrow when he is back at the shop to get clarification. In the mean time I decide to put a 6650 ultegra compact crank and change out the left shifter and front derailleur to a 7800.


Thanks for all the input!

[roydyates]

According the the mechanic, Serotta is saying that the chain stay angle is too accute to meet Shimano's recommendations for a triple. Got this from a voice-mail, so I'll follow up tomorrow when he is back at the shop to get clarification. ...
Just out of curiosity, how short is your chainstay? 40cm? Less than 40cm?

[eddief]

still interested in the outcome of this mystery. but maybe if you are installing a double, we will never know what became of the triple issue.