Chain jumping off big-ring. Campy problems

[toosahn]

So I have an eclectic build going on here with my Eisentraut.

I decided to upgrade some of my drive-train to Campy 10:

-Record 10 crankset 53/39. Square taper
-Record 10 Ultra-narrow chain
-10-sp Chorus rear cassette

BUT, I'm using these parts as well:
-Suntour Cyclone front and rear derailleurs

Anyways, the problem I'm having is that when I have the bike on the stand and I do a very quick upshift from the small ring to the big ring, the chain sometimes just comes right off the big ring and onto the crank-arm.

I tried changing the front derailleur to a Dura-Ace 7700 unit I had lying around and I had the same problem.

Is this a trim problem or a front derailleur problem?

Also, as a side note, is there anything wrong with running such old derailleurs with newer Campy 10sp stuff as long as I'm running friction?

Thanks!

[vqdriver]

recheck your limit screw and cage alignment. the fd can move a bit farther to facilitate the shift and then "spring" back once you release the lever, but it shouldn't open up a gap large enough for the chain to drop thru. if you can't reduce that gap enough without chain rub it's probably not aligned correctly.

i wouldn't think it a matters much which FD you have on there but it doesn't hurt to try a campy one if nothing else works.

[Jaq]

What VQ said. Limit screws and alignment sounds the most likely culprit (and simplest fix)

Don’t know if FSA (or others) makes a carbon chainring guard in 135 BCD, but if they do, you could toss on one of those. Mix/match stuff shouldn’t matter, especially with friction. I’ve got a Frankenshimagnolo set-up in front: 8-Speed ergo shifters, 8-speed Campy DR, 9-speed chain, 130 BCD Topline cranks, 53a/43b 105 10-speed rings. It all works flawlessly.

[buldogge]

The cage width on the Cyclone is gonna be much larger than a Campy 10s as well. Careful adjustment of the limit screws and attention to cage angle in relation to the big ring should work.

-Mark in St. Louis

[toosahn]

recheck your limit screw and cage alignment. the fd can move a bit farther to facilitate the shift and then "spring" back once you release the lever, but it shouldn't open up a gap large enough for the chain to drop thru. if you can't reduce that gap enough without chain rub it's probably not aligned correctly.

i wouldn't think it a matters much which FD you have on there but it doesn't hurt to try a campy one if nothing else works.

So I think you are right about the alignment. I did a bit of aligning and it doesn't jump off as much when I shift it slowly (I'm using bar-end shifters).

But how do you incorporate that spring-back action with friction bar-ends?

[vqdriver]

don't know with friction shifting. it's been a looong while since i've used those but i don't think you can really.

one note, i assume the frame has a braze on FD mount. make sure you have a concave washer in between the mounting bolt and braze on tab so that it doesn't just straighten out when you tighten it.

[toosahn]

The frame is clamp-on.

[Hindmost]

But how do you incorporate that spring-back action with friction bar-ends?

I am thinking that spring-back is what used to be called trimming the derailer. It is manual.

[Ralph]

Drop the FD as close as you can to big ring. Almost touching. It can't throw it off this way. Then limit travel of FD. Chain in middle of FD cage is too far. Set it up so chain almost touches outer cage when on big ring in front and small rear cog. Check angle of FD. If fhrow is too fierce, then angle cage so it doesn't throw it so hard (kick FD cage tail out....but not so much it rubs crank arm). You don't have a Campy problem.

[oldpotatoe]

So I have an eclectic build going on here with my Eisentraut.

I decided to upgrade some of my drive-train to Campy 10:

-Record 10 crankset 53/39. Square taper
-Record 10 Ultra-narrow chain
-10-sp Chorus rear cassette

BUT, I'm using these parts as well:
-Suntour Cyclone front and rear derailleurs

Anyways, the problem I'm having is that when I have the bike on the stand and I do a very quick upshift from the small ring to the big ring, the chain sometimes just comes right off the big ring and onto the crank-arm.

I tried changing the front derailleur to a Dura-Ace 7700 unit I had lying around and I had the same problem.

Is this a trim problem or a front derailleur problem?

Also, as a side note, is there anything wrong with running such old derailleurs with newer Campy 10sp stuff as long as I'm running friction?

Thanks!

FD problem, probably either height or distance out. If ya got adjust it quite a ways out to get the chain up to the big ring, so it then spits it off...why not just get a Campagnolo FD? It has the 'bump' in the correct place to encourage the chain to get to the big ring w/o spitting it off. about 2mm above the big ring, aligned with the chain when in big ring and small cog.

[AngryScientist]

FD problem, probably either height or distance out. If ya got adjust it quite a ways out to get the chain up to the big ring, so it then spits it off...why not just get a Campagnolo FD? It has the 'bump' in the correct place to encourage the chain to get to the big ring w/o spitting it off. about 2mm above the big ring, aligned with the chain when in big ring and small cog.

this is good advice. you see campy FDs all over the classifieds for <$40, why not just get one?