soonerbills

I can't seem to get the original light action derail to quit acting up on shifts. I replaced the chain with a Hg50 and new cable yet when shifting to a lower gear the chain jumps.
I'm wondering if the derail is the issue or would a chain one link too short cause this? Am I missing something on the derail adjustment?
But I would like to know if it is compatible to use a 1st gen Cyclone with Shimano 6 speed index DT shifters. Failing all this I may just look to replace the whole thing with something new.. if so what would you recommend that is not expensive. I know that is subjective. I would not be opposed to going to a 7 or 8 speed on the bike. I do intend to put some real mileage on this bike.

ColonelJLloyd 

I've used both the Light Action long cage and the 1st gen Cyclone GT. Both shifted great. Does your freewheel need replacing? Certainly you need to have your chain at the proper length. Are your shifters adjusted tightly enough?

Doohickie

I had an early SIS Light Action system on a Schwinn Prelude. Never got it to shift quite right, until.... I replaced the little pigtail of housing at the derailleur with SIS housing. The housing was very stiff so I zip tied it to the dropout to force it to the the shape I wanted it to be. After that it shifted great. I assume it still is, but you'd have to ask brockd15 since he now has that bike.

gabewill

+1 for using SIS housing. It also might be worth checking the alignment of the derailleur hanger and rear dropouts. My beater wasn't shifting well and taking in to the shop to get the hanger bent back into place did the trick.

Zaphod Beeblebrox 

You mean like you shift to a lower gear (larger Cog) and then it jumps back down to the next smaller?

What cogs does this happen in? Just the Largest? All of em?

If your chain is one link short that will only become a problem when you're in the Big Chainring and attempt to shift to the Lowest Gear (biggest cog). If that's the case, then yes. Add a link or two.

You *might* be able to get a 1st Gen Cyclone RD to index. Stranger things happen. If you're gonna try it be sure you put a Barrel Adjuster somewhere between the shifter and the Derailleur as 1st gen Cyclones don't have one on the derailleur body like the Light Action derailleur does.

And like everyone else has already said. Make sure you are using SIS housing and wires.

auchencrow

+1 to what the Colonel said.
The problem you described is more commonly associated with the FW rather than the DR.

BTW - The Shimano Light Action is an excellent DR if you are running friction.

Iowegian

Thanks for the tip, I need to try this. I have a couple of Light Action RD's and one of them is just a bit 'too light', ie it's sluggish shifting down into a smaller cog unless I over-adjust it in that direction. The springs still feel fine but I think I have good ol' brake housing on the pigtail, will have to try the SIS housing.

top506

I have three Light Action RDs in the fleet. All run and index perfectly with the Shimano 7-speed drivetrains they are set up with.

Top

Grand Bois

The solution to shifting problems with an indexed derailer is definitely not to replace it with a friction derailer if you want index shifting. You don't want to mix Suntour and Shimano, either.

3speed

I'm going to go ahead and back up the idea of checking out the freewheel. In my experience, a worn freewheel is a bigger problem for shifting than anything else. And I've used a Shimano Light Action and it shifted perfectly, so I have a bit of trouble believing it's the derailer without Knowing the freewheel is in good condition.

wrk101

To your original question, for the current problem? No. But because a G1 Cyclone looks way cool (and the Light Action RD looks pretty pedestrian)?

Absolutely. G1 Cyclone is my favorite derailleur.

Alan Edwards

Look at your pully wheels too as they can also be a problem.

Captain Blight

Should I replace a Shimano light action with a 1st gen Cyclone?



Yes, absolutely! And at the first opportunity: Immediately, if not sooner. Replace your brifters with bar-ends and never, ever look back.


Or is that, Never look 'forward?'

soonerbills

The chain is not jumping to another cog... it seems to be jumping on the cog that I shift to when shifting to a taller(lower) gear. It does not happen when shifting uo to a higher gear.
I see now that the derail climbs into the cluster when in the large/large combo, not that I would really ever use that combo but it does tell me the chain is too short .I am using regular cable and housing... is SIS just lined or is it a special for some reason? I checked the hanger and that's not the issue but the freewheel does have quite a few miles on it. If I need to swap it out I might as well bump up to the 8 speed and change out the system. Using the Cyclone was just a wild thought. I will ty the SIS cable,fix the chain and a readjust and hopefully it cures the issue.

wrk101

SIS housing is totally, completely different. Cut a piece and you will see. It does not compress. Its a must for SIS shifting.

divineAndbright

A brand new chain on an older freewheel could be a nightmare unless you're sure that freewheel only has seen minor use in its life.
For chain length I set it in small/small, the derailleur should just have enough stretch so the top of the chain isn't touching scraping the pulley cage coming off the derailleur (or into it, depending which way you're turning the crank to check).

I don't think chain length could cause skipping like you are describing though, I think something is specifically wrong with that certain cog in the freewheel, like its too worn for the new chain, or a tooth problem.

also check your new chain for a stiff link (though you would probably see the jump in other cogs too)

auchencrow

This is definitely a FW-chain issue:
Get a new KMC chain ($5) and 6spd FW ($11) from Niagara.

SIS housing is uncompressible for use with Shimano indexed shifters.

3speed

SIS is obviously better suited to the job, being designed for it and all, but I say replace the freewheel before spending money on the housing. Personally, I've only come across one situation where the bike wouldn't shift properly due to not having SIS housing. Other times regular housing has worked fine.

Zaphod Beeblebrox 

I can't follow your logic. A freewheel is 15-20 bux or more. Housing is a buck a foot. A buck fifty If you buy the expensive Jagwire stuff. Its DT Shifters on the OP's bike so he won't likely even need a whole foot of housing.

Doohickie

My guess is that when everything was brand new, it probably worked fine, but as it wears in and the pivots get a little sloppy, the reduction of lost motion from the SIS cable makes up for the slop.

Doohickie

And yet, I think for the first year or two of production, some bikes at least came with standard friction shifter cable as stock. I suspect that the SIS cable housing was developed as a response to problems shifting that occurred when the systems wore in a bit.

Doohickie

1 foot of SIS housing costs less than a freewheel. Do the cheapest thing first.

auchencrow

The chain will still skip if he only replaces the housing. It may be necessary for optimal performance, but not sufficient.

Zaphod Beeblebrox 

Fair enough point, if the Freewheel is, in fact the issue.

Personally I think it sounds like an effed up link in the chain but that's JMO.

3speed

This was my logic. If he just replaces the housing, it's still going to skip. If he replaces the freewheel, it May skip, but I really think it probably won't. I personally think the housing won't make a big difference at all. Maybe slightly faster shifts, but not a big deal.
I think a stiff link would show itself in multiple gears, and more likely on the smaller gears rather than the larger as the OP is experiencing. I've been wrong before, though.