eschlwc

Ever bent a crank arm on purpose in order to clear the fd? Is it possible? How did you do it? What else did you try before bending it?

My story is long and sad. I'm still trying to put the finishing touches on an '80 pkn10. The Simplex derailleur on it could not upshift at all. So I replaced it and the rear with Campy Record, and at least now it's shifting decently. But after trying all sorts of minute fd placement, I can't get the fd to clear both the chain and arm. I think I need 2-3mm more from the arm for it to rotate without rub when in its highest gear.

The crank is a stronglight after-market (I assume) triple that came with the bike as found. I've removed the granny ring. The fd is the three-hole variety, not wide, much narrower than the Simplex it replaced, and just like the Campy fd on my Moto.

I've never run into this kind of problem before with a build. A quiet bike is so important to me. When I can't hear any chain rub, my heart soars like a hawk. What to do? Bend the arm somehow? Make it a 6-speed?

lord_athlon

Is the derailleur straight? An old Record FD should work fine with a low-q stronglight

Velognome 

Sounds like a longer BB spindle is in order. Bending the crank arm sounds like a bad idea.

eschlwc

I think I've tried every possible fd adjustment. Oh, man, what a pain when the anchor bolt is giving you fits to boot!

I've never run into this problem before ... but this is only my ninth build.

A longer spindle will just move the big ring out too! That's the real issue: the narrow gap between big ring and arm.

repechage

I read this as the new Campagnolo front derailleur is of the later type with the CPSC lip to prevent you from cutting yourself on that dangerous original version.
If that is the case then look for an earlier Campagnolo front unit sans CPSC lip and know you are living dangerously.
When Campagnolo introduced it they had to redesign the crank arm to clear the extra width, more room between the spider and arm.

The other old bike shop mechanic trick is to slightly bent the inside leading edge of the cage to pick up the chain faster. Not very much, just a tad.
Works wonders.

cyclotoine

my thoughts exactly.

jacksbike

I sold a Motobecane, perhaps a Grand Jubilee model from the mid 70's that had a similar problem that drove me nuts. It came with Huret Jubilee derailleurs and no matter how I moved the front derailleur , it would hit the right hand crank arm. I finally, and with much regret, ended up squishing the derailleur cage together with a pair of channel locks, in order for the problem to cease. Rarely had ever come across a problem like this. Yes, the Stronglite crank and derailleurs were original.

rhm

I straightened a crank arm not long ago. It was an SR Maxy left arm that was, well, bent. I put it on the anvil, put a piece of plywood over it, pounded on it three times with a three pound hammer, and figured it was much improved. Haven't tried riding it.

Bending a right side crank arm would be more difficult. Bending it twice, in opposite directions, exactly the same amount, very tricky indeed. I suggest you go for it! But realize that when you're done you're going to buy a new crank. Better yet, save some time and aggravation and just buy a new crank now.

eschlwc

^ interesting.

I had tried to bend the Simplex fd to upshift, and that turned out even worse, with no resolution to the problem. So I was hoping I wouldn't need to do anything to the beautiful Campy replacement.

Here's a pic.

repechage

The Simplex cage is of a different design and it won't work as well, the Campagnolo has an open leading portion, give that a very small bend in (at an angle, basically the bend "line" parallel to the down tube and it will catch fast and guide up. Beyond that, the expected lip is there. Stronglight and TA cranks were designed before and do not have the distance between the backside of the arm and the chainring necessary for this Campagnolo later derailleur.

There was a reason Camagnolo was the standard of excellence before the CPSC became involved.

eschlwc

ok, that's it! Just checked the campy fd on my '73 Falcon, and, not only is the cage more narrow, but, sans front lip, the older fd will give me the 2-3mm I need.

Brilliant! Why couldn't I have figured this out myself? Well, because I have this same 3-hole fd on my '76 Moto and it works great. Of course, I have a Sugino crank on that bike...

rootboy 

Lawyer lips sink ships.

David Newton

Don't bend the arm, grind some clearance into it, polish it up, no one will ever know.

Velognome 

Perfect...need to store that one away for future recall!

eschlwc

root, we need more poetry around here.

david, i was thinking about that as well. i'll try to find an early '70s campy nr fd, and if that still doesn't work, i'll get out the file and grind a mm or two out of the back of the arm. it would be a 15mm section of the arm that would need to be shaved.

i thought about switching this fd with my '73 falcon fd. that bike has a sugino crank (like my moto), so i assume it could clear the fd with the lip. but the falcon's fd is original to the bike, and something tells me that would just be wrong to remove it (even though it would look better with this 3-hole version).

repechage and everyone, thanks for all the helpful info. merry bike building.

frantik

my bike polo bike has a BB which is too short for the frame.. the current crankset just barely clears the chainstay. one night at polo something happened so the arm wouldnt clear the stay any more. i tried to bend the crank arm using a lot of brute force but in the end i just borrowed a file and ground it down until it cleared again

16Victor

I'm glad you didn't bend the arm. My right knee cried in sympathy with the idea...getting the crank and pedal axes to be collinear after bending would be pretty near impossible. Guess it may not be so bad with these modern clipless pedals and the play they allow your foot but in the good ole' clip & strap days, it'd be painfully damaging to the knee.

big chainring 

I ran into a similar problem once and it was indeed the BB spindle length. Check your chainline. Check the chainring/chainstay clearance.

smontanaro 

If you need a pre-CPSC Record front derailleur, I have one on Ebay that's missing the clamp bolt and has the front clamp drilled out. Search for smontanaro. Happy to cancel the auction and make a deal...

Reynolds 

Your story is long and sad, but it will be sadder if you bend the crank arm IMO.

rootboy 

I remember the old bend the front lip trick. We used to do it with a small Crescent wrench. Just a wee bit. It helped some.

Homebrew01

Yup.

Modern pedals don't have play in that direction. Just left-right pivot as far as I know.

eschlwc

i saw that one. many thanks for the offer, but i'm looking for a stock, standard band, campy 1052/1 'no-hole' fd from the mid-'70s with all its fittings.

cheers, all!

gerv 

+1 This thread has me confused. Has anyone adjusted the angle of a quill stem?

Catnap 

this finally explains why i kept seeing Campy FD's with the inner cage slightly bent. i had no idea it was intentional.