sekaijin

What’s wrong with my Cyclone FD?

I’m just getting back on my road bike after a full winter overhaul and cleaning of everything.

My Cyclone FD now shifts perfectly on the bike stand, and when I’m riding on level ground or downhill.

But not when I’m going uphill. Then the cage just rubs against the chain and fails to push it onto the other ring. This is mainly a downshifting problem, since of course when going uphill you’re generally trying to downshift, but mechanically it’s happening with both upshifting and downshifting.

I don’t think this is a limit screws issue – I've tweaked those some, and the problem is occurring independent of how the limit screws are set.

Could this be related to the fact that I’ve switched to a narrower spindle, from a TA 374 triple spindle to a TA 344 double?

Any suggestions from the experts?

nlerner

I'm no FD expert, but I'd guess that under the load of climbing, you're getting enough flex (whether from the frame, or BB, or crankset) to screw up your FD shifting. I can't imagine the shorter spindle is a problem as the travel your FD needs to cover would still be the same. I'd check the orientation of your FD relative to the chainrings to make sure the cage is parallel to those rings. Perhaps also undo the derailleur cable to the FD and see with no cable tension at all how far the cage extends towards the frame.

Neal

Picchio Special

Also no expert, but I do know that some front derailleurs simply don't like to travel as far inboard as others. It may be that the shorter spindle is asking the front derailleur to travel further inboard than it wants to when the frame is flexing or the chain is aligned a certain way (have you tried shifting in the back prior to trying to shift in the front?) In any case, it seems to me that trying to downshift in the front while already climbing is always going to be a bit iffy. All of this is conjectural and could easily be disproven by the next (more knowledgeable) poster.

John E

If it works on the stand and on level ground, there is nothing wrong with the derailleur or its adjustment. The problem is pilot error, in the sense that derailleurs are not designed to be shifted under load, even though many riders abuse them in this manner. This is why it is so important to downshift early when starting a climb.

sekaijin

I take your point, but ...

As Shakespeare said, IIRC, some things are "more honored in the breach than the observance." I think downshifting under load is one of those things.

• I do it
• so do lots of (most?) others
• I can't quit - it's essential to keeping pace on my fast hilly group rides
• the equipment may not be designed for it, but it has worked OK up to now

Sorry but if I'm abusing the parts, I need a fix that will enable me to keep abusing.

sekaijin

... under load. I think you may have nailed it. On closer inspection, with the shorter spindle, the current inboard position has the FD maxed-out inward, without even touching the limit screw. I think it can't deal with the shorter spindle and I need to go back to the longer one.

I'm CERTAINLY no derailleur expert but maybe the FD spring tension does not pack enough push at the inner end of its flex range, where I have it now. I'm thinking he longer spindle should put it back in the middle of its flex range with more shifting power.

I think that's worth trying - still very open to opinions/thoughts/ideas, but I'm thinking I'll report back after swapping the longer spindle back in. Thanks all.

dannyg1 

Check your cable tension and the shift levers recoil under load. Tighten the mount bolts that hold the shifter to the frame. Sounds to me like you're running a higher tension and that the shifters slipping when you hammer. If I'm right, it'll do it n flat ground too, try standing out of the saddle and accelerating hard while to-and-fro'ing the bike under you (while on a flat stretch). My bet is that you'll get the same problem.

Danny

steelbikeguy

Troubleshooting from a distance is always tough, but my guess is that it's just that it's hard to downshift under load. I use a Cyclone FD on my commuter bike, and have to climb a 14% hill to get home. If I try to downshift from the middle to small ring while grunting up the hill, there is no way that the poor Cyclone can move the chain. The only solution is for me to turn around, go downhill, and downshift. Only then do I go back uphill.

I only own one modern front derailleur, a cheap Shimano Tiagra. When I tried to make it work with the old SunTour downtube levers, I was amazed at how strong the spring was! Maybe modern derailleurs can move the chain under load, especially if the chainrings have shaped teeth, but it sure doesn't happen with my 30 year old equipment.

good luck,

Steve K.

sekaijin

On re-reading my earlier comments I hope I did not come off sounding obnoxious in saying I wanted to “abuse” the equipment. The thing is, part of my love of riding C&V is in defying the expectations of modern riders, in a rather competitive group-ride culture.

Some people on rides seem to assume that the guy on the old-fashioned bike won’t be able to keep up. It’s fun to surprise them by doing just fine or even better than them on their ultra light, ultra expensive modern bikes.

I seem to do best on the hills by hammering in high gear at the base, then gradually downshifting my way up to the crest.

So, guilty as charged of downshifting under load, and with a brazen lack of remorse. But I hope this would please and not offend the gods of C&V!

Charles Wahl

I still think that JohnE's advice, given early, and seconded by several others, is what you need to focus on: Don't do that! (or get a different derailer). Be on the small chainring before you get into a position to have to shift under load. I have this problem too, and it's when I have omitted forward thinking, or been jammed up by someone slowing/stopping in front of me in a group on a hill.

sekaijin

To update: I switched the longer TA 374 spindle back in, and took the bike on a fast 26 mile group ride on hilly farm roads. The FD downshifted nicely, both on level ground and when going uphill. The spring tension must be higher in the more outward part of the FD's range of motion, as a couple of you suggested.

Several of you pointed out that FD downshifting under load is a no-no. I did not realize that. Sorry if it offends some, but downshifting my way to the crest is a very helpful way to maintain speed on the hilly terrain around here. I never thought about it before, but today I noticed that before downshifting in a climb, I generally pedal standing up to build up some speed, then sit and shift while coasting off that momentum a little.

I take care of my 70s racer with a lot of TLC, but I'm a rider, not a collector. The bike is a rare high-end model, but probably damaged goods from a collector's perspective given its history (with a prior owner) of major frame damage, repairs and repaint.

But it loves to go fast, sprint up hills, and show the club riders that old steel, friction shifting and tubulars can still get it done.

Thanks for the help and peace all!

stronglight

A whole lot of stuff could be happening here.

I'm curious what crankset you are using on the TA BB which would allow you to alternate between a "double" and a "triple" crank axle. You didn't mention changing cranksets or chainrings, so it sounds like there may be a simple chainline issue here rather than anything to do with the derailleur at all.

Assuming the rear spacing relative to the frame is centered and in alignment, the chain should be in essentially a straight line with the center cog of the freewheel and the center between the chainrings (assuming there are two).

If the rear wheel was built at an unusual dish to accommodate a rear triangle which was canted farther out to the right - rather than centered to the frame, this could be pushing the freewheel outboard more than normal (I have seen this done before)... If this is the case, even if the chainline "appears correct", it may not be correct for the derailleur in it's normal intended setting for a reasonable inward movement with a modest length axle.

Make sure the rear derailleur hanger is straight on the bike too.

Both the rear and the front derailleurs were intended to shift a chain across a 5 or 6 speed freewheel. If you're using something wider in the rear and have spread the rear spacing (like I often do), it may be straining the limits of the preferred movement of the derailleur.

Also, the spring on my (early model) Cyclone is enclosed inside an drum open at one end which can get gunked up and sticky or gritty inside which could impair the free movement of the spring. Unfortunately, there is no easy way to clean it out since the cage is riveted (rather than bolted) through the center of the spring and the outer cover.

The return spring just could be weakening with age.

And, as always, the Forces of Evil could be at work, trying to slowly drive you mad by throwing obstacles in your path which simply defy logical explanations or solutions.

sekaijin

Stronglight, thanks for all this brainstorming. My hunch is to along with your 2nd-to-last idea – return spring weakening with age.

The crankset is a TA Cyclotouriste, and I have changed it around some. When I got the bike in 2006, it was a triple, and it would not upshift from the granny up to the middle ring. For 2007 I got different TA rings and bolts off ebay, rebuilt it as a double (but did not change the spindle), and it shifted fine for all of 2007 as a double crankset on a triple spindle.

Interesting that you raise the issue of chainline, because that’s why I tried switching to the shorter spindle for 2008, to improve the chainline as a double. But that brought back the FD shifting issue. That’s why I think your “return spring weakening with age” theory is correct: all the shifting problems occur in the inward part of the FD’s range of motion. But the shifting is fine in the more outward part of the FD's range of motion, where the spring is coiled under higher tension.

Maybe I need to replace the FD (preferably with another 1st-gen Cyclone, but one with a livelier spring). That could go on my winter project list for 2009. At this point I hope the bike is done being overhauled for 2008, and ready to be ridden all season as is.

BTW I tried my best to clean the FD spring drum, which as you point out is rivet sealed. I used WD-40 and compressed air – and before the WD-40 cops book me, I followed that up with applications of Panef lubricating oil (same stuff I lube my chain with).

Also, it’s the original 120mm rear spacing with 5-speed freewheel, so hopefully the chainline is as intended.

Of course, the Forces of Evil are always a big concern. May the gods of C&V find favor in my care of the exquisite machine they have entrusted to me, and bestow their protection upon it.