i'm building up my Gios Super Record using parts off a donor Gios Professional (too big for me after all).

i'm using the Super Record crank set and italian thread bottom bracket off the donor and a spare Super Record braze-on front derailleur (the Gios Pro used a clamp-on FD). All parts are in like-new condition.

the problem i'm running into occurs when i shift to the inside/small chain ring. the derailleur pushes the chain off the large ring and the chain fall onto the small ring, BUT the chain lands with the inside edge, ON TOP of the small ring's teeth, and will not engage. this really only happens when i'm on the 2-3 smallest cogs of a 7speed cassette, so not entirely unavoidable, but something i wouldn't assume i'd HAVE to live with.








my first assumption was that the derailleur needed to be adjusted to move inward a bit more. only problem is, even with the limit screw backed all the way out, the derailleur will not move inward anymore.




i tried rotating/twisting/raising/lowering the FD and got it to work but it was then in the way of the crank arm or would not shift properly. after tinkering with it for a few hours yesterday, i took it to my trusted LBS where myself and 2 mechs basically determined that the only solution would be a spindle that would put the drive side crank arm more outboard.

1. is there such a spindle, from campagnolo, that would place the crank arm out 1mm or 2?

2. is there another option to solve my problem? spacing the fixed cup possible?

3. were there newer and later front derailleurs that provide a wider/different range?

4. anyone else ever run into an issue like this?


the current splindle is 115.33mm on my calipers, so i'm assuming it's the 115.5mm spindle from '77-'87, and i would assume matching crankset as everything else on the bike was original. what year would a <4> inside a diamond be, 1974?



i know this seems like more of a mechanics forum question but i'm looking for a vintage spindle

Is the spindle asymmetrical? If so, maybe try flipping it?

it is installed correctly, already checked that.

was doing some more searching and came accross this: https://www.bicycleclassics.com/bottom.html

"Use of pre-78 cranks on post-77 spindles will result in cranks sitting 1.0 (LH) and 1.5 (RH) millimeters too far outboard. If crank arm tapers are well used, this may actually not be bad."

i might have a pre-'78 crank on a post-'77 spindle which would put me 1.5mm outboard, which would help in this situation, i'm even more confused.

I thought you want to be outboard. My other thought is that your taper holes are worn, or you really torqued the bejeezus out of the crank on installation. But if everything is original and in good condition...?

Is the inside plate of the FD actually preventing the chain from dropping? The only obvious difference I can see is that you have a different chain than would have been originally equipped.

you're correct, i edited my last post, brain fart. the crank sitting outboard is what i want.

no, the inside plate of the cage is not interfering with the chain, the chain is actually still resting against the outside plate.

this issue is not 100% of the time. some of the time it will shift over, drop down on the edge but within a half rotation of the crank, drop down in the teeth and engage.

i previously had a NOS regina chain installed that had slightly wider pins that would not fit the inside cogs of the Suntour Winner Pro freewheel, but that chain had this same problem and worse.

I just had the same problem on my Trek TX900; small ring would sometimes not engage, The inner ring was also too close to the chainstay (1mm or so clearance). I think it's possible to put a spacer on the fixed cup. I used a Phil Wood BB since I had one at hand, seems to have fixed it.

What chain do you have on there now? Could it be that the derailleur needs to be positioned up/down or angled inward or outward slightly to get a better push on the chain as it moves down to the small ring. Can't say I have had this exact problem, but I do find it strange that the chain would ride in that position for any amount of time without seating into the chainring teeth.

I have a Regina chain, and this is the first time I have seen the problem.

not blaming the regina, wouldn't work with my cassette choice anyway.

new chain is a KMC Z-72 3/32, 6/7/8 speed chain.

it actually would spin and spin seemingly indefinitely on top of the teeth.

i tried raising/lowering/twisting/angling the derailleur, when i worked, it would strike the crank arm, when placed just out of the way of the crank arm, this issue would return.

maybe i'll break down and get a phil wood

As long as you have enough exposed threads on the adjustable cup, try a spacer first (it's only 95 cents on LooseScrews). They also have 1mm and 1.5mm versions.

Are narrow chains supposed to be used with that Super Record chain ring set up? I see the links marked "Narrow". That could be your problem, the chain should float over to the next chain ring, not fall between the two. I would try a different chain. I don't think it's the position of the crank that's causing the problems. Do you have a modern Campagnolo crankset to try out? I bet it would work flawlessly.

Mike

Did you loosen the cable first ? Based on your picture, with cable clamped tight, of course it won't move inward.

Michael Angelo- it's a 6/7/8 speed chain. I have a wider chain (a Regina) on there previously and the problem was worse.

Homebrew01- yeah, the inside plate of the derailleur is contacting the limit screw stopper area.

Ex pres- I will measure chain line when I get home from work. How do you do that?

For the front, measure the from the edge of the seat tube to the midpoint between the rings, then add 14.3mm (I think most ST are 28.6).
For the rear measure from the mid cog to the inside face of the dropout. Subtract that number from half of your frame dropout spacing dimension (126, 128, etc.)

Consider a Phil Wood BB, they're adjustable in chainline, mounting rings,
and you can buy a variety of spindle lengths,
and further adjust them by pressing the axle thru the bearings to change the offsets.

If that is a '74 crank, I think a 112mm spindle (70-SS-120) is what you should have. 114.5 for post '77 (70-SS), at least from here (chart 4)

https://www.minortriad.com/campagbb.html

I don't understand how spacing the crank away from the frame could help. It seems very likely the chain is too narrow for the spacing between the rings. I just laid an 8 speed chain on an SR crank with 42/52 chainrings and sure enough, it hangs on the tips of the teeth on the inner ring. A 5 speed chain doesn't do this: it just drops right in.

Hope this helps!

Nothing a little Dremel action won't fix !
Skim .020" off the inside plate of the derailleur and you'll be good to go.

Some newer chains are prone to crankset chainskate on cranksets with 4mm spacing; the Campagnolo Nuovo/Super Record arms included, ditto for Stronglight and others.

That said, KMC may call that particular Z chain a "6/7/8-speed chain," but it is technically a Shimano design for 7 and 8 speed.

Prior to the introduction of narrow chains, 6-speed 3/32" chains (Reginas, Sedis, etc) were slightly wider and less prone to skating, but - as you note - they have their own set of problems (won't work on a 7-speed, Shimano-spaced freewheel; chain rub on FD, etc).

Though a current 7/8-speed chain - such as the KMC - will work on a classic or modern 6-speed freewheel and crankset without issue (and are spec'ed on modern bikes w/6-speed freewheels), they often chainskate on C&V cranksets. If you can find another 7/8 speed chain with wider outer plates, you might be able to work around the issue. Set the FD as you would for any other chain.

-Kurt

I'm going to guess, being in the highest gears on the freewheel and shifting to the inner ring, there is not enough tension on the chain once it leaves the large ring to hold it "rigid" enough to complete the shift. That position is certainly cross-chaining on these old bikes! Otherwise, worth trying a spacer under the fixed cup.

Brings a couple other possibilities to mind: 1) spring tension on RD is weak, or 2) chain is too long

Its a chainring/chain issue NOT a spindle length issue.

In my years of wrenching I've found there to 2 primary reasons for this:

1: Chainring are too far apart due to either too many spacers or the rings being bent out. In this particular instance its not a spacer isue but the large ring could be uniformly bent out or flared so to speak. Its unlikely the small ring is unifirmly bent towards the seat tube. As Kurt mentioned its spinning because its not engaging due to the wide space between rings.

2: The chain. Just because a chain says 6/7 whatever on the box doesnt mean it'll work. 6/7/8/9 whatever simply refers to chain dimensions not neccessarly compatibility.

Changing the spidle will NOT fix this. How many of you have seen a chain ride on top and spin on a freewheel cog? It happens.....

PROBLEM SOLVED!

thanks for all the advice everyone! i swapped the crank for another record crank, now it shifts like a dream!

i took a measurement of the chain line at the front and i was getting about 40mm with the "problem" crank, after installing the new crank, chain line is now ~44mm.

within minutes i was able to dial in the front and rear derailleurs to shift up and down through all gears on both front rings, everything shifts smoothly in all possible combination.

strange thing is the new crank is stamped <3>, making it a year older and still falling within the range of '73-'79.

Questionable fix over the long run (I'd like to see what the new setup does under load), but I'm curious what condition the taper is on the old crank, if the difference in mounting position was an entire 4mm. Even 3mm would raise my eyebrows.

If you have a spare Campagnolo spindle, could you install it into the "problem" crankset and photograph at the crank bolt area, so the taper is visible?

-Kurt

i suspect that the square taper on the bad crank arm is worn a bit, only logical explanation when going from one crank to another solving the problem.

how much taper on the spindle should be showing? i'd say there's between 1-2mm tops on the bad crank.