Rear Derailleur Issue
 

I just picked up a Lotus 3000R. It wasn't shifting well and I identified the issue. The adjustment screw that keeps the pulleys from pulling up into the freewheel does not fit against the frame nub (see pictures). It looks like the derailleur seems to be in fair shape but I cannot see how the standoff screw could possibly match. I also believe the RD is original equipment.
Does anyone have any suggestions as to missing parts or other installation issues that would fix the issue? I suspect a different RD is in order (though I only have one non-index friendly one on hand). These thumbnails expand to larger pics.

http://img691.imageshack.us/img691/286/1003750.th.jpg
http://img693.imageshack.us/img693/4672/1003749.th.jpg
http://img109.imageshack.us/img109/9615/1003753.th.jpg

Not sure but it looks like the spring behind the main fixing bolt is not working correctly, broken or needs to be reset. Pull the derailleur off the frame and check out the spring. When you push the upper half of the derailleur forward you should be pushing against chain tension. Take a look at some derailleurs that are working correctly.

Al

Suntour derailleurs may utilize the B-tension screw differently than shimano derailleurs. But it looks like the der is not threaded into the hanger all the way, or there may be some 'key' that is part of the der that is not properly resting on the B-tension stop on the dropout.

The derailleur would not fit differently or tigher to the frame. I replaced it with an earlier Suntour RD that I had on hand - that doesn't have an adjustment for the cable (i.e. friction only type). [does anyone know of a inline adjustment that'd mate to where the cable housing fits the derailleur?] The accushift levers seem to be 7 speed index only but I got the indexing working. Hopefully that'll work for now.

The Blase derailleur is still perplexing. It appears the stop screw sets against the integrated cam plate. The cam plate has two stop areas. I'm wondering if the frame dropout is supposed to have a ridge that one of the stop area mates against. This bike frame does not.

Many frames I've worked on have such a ridge. I'd be surprised at a mismatch if that was the original derailleur. Hmm.

Looks like there is a part of a claw hanger still attached to the backside of that derailleur. It is not attaching correctly for some reason.

I have a Blaze on a bike right now, I'll have to look at it.

Assuming that the RD is correctly attached then I've had a similar problem. In my case the B screw was not making full contact with the platform provided by the hanger which itself was part of the steel frame. In one instance I solved the problem by adding a new surface to the platform by welding and in another, I replaced the adjusting screw with a longer Allen headed one. In both cases this moved the pulley further away from the sprockets.

The cranskset is clearly marked "Blaze" so the RD is probably original. It was fully seated, however, and could not be oriented differently. The stop also has paint worn off where the adjustment screw evidently hit it at some earlier time. I suspect a missing adapter. The other Suntour RD, without the cam/spring, mated perfectly to the dropout. It holds the chain off the freewheel.

The poor shifting performance probably caused the discounted price I paid for the Lotus.

there looks to be a little blip of metal in front of the rear derailleur mounting bolt. I don't think that should be there- it may need to be rotated or held in place as you thread the der into the frame.

Would it be too much trouble to bring it to a bike shop and have someone with more experience look at it? It shouldn't cost more than $10-15 for them to monkey with it for a bit, adjust it and have it functional.

With the chain on the smallest cog and smallest chainring does the chain go slack? Maybe the chain is too long and/or stretched?

Al

:)

Checked the hanger alignment?

All the SunTour RD's that I've come across do not have a top spring (the one that attaches to the dropout). The adjusting setscrew is supposed to set against either the dropout or the #4 mounting bushing pictured below. That bushing is keyed to fit over the dropout. You have to orient that bushing before screwing the derailleur onto the dropout. I saw something to the right of the dropout on your first picture that looked like the tab the setscrew is supposed to move against. My first supposition is that you need to re-orient the bushing.

Another possibility is that the bushing is screws onto the #2 mounting bolt pictured below. It's possible that it's positioned too far out.

http://www.velo-pages.com/main.php?g...serialNumber=2

If that RD is original, the b-screw should bear against the b-screw surface on the hanger. In the second photo, there's a wear spot on the integrated hanger, just where the screw should be touching it, but it's obviously not touching it. instead, the screw is pointing at the the piece of metal that's between the derailleur body and the bike's integrated hanger. Looking at photo#1, it kinda looks like that piece of metal is part of a broken-off claw hanger--the kind of bolt-on hanger that's use on bikes without integrated hangers (part #5 in SBinNYC's exploded-view diagram). It looks to me like this is not the original derailleur, though it could be the same model as was originally mounted (without the broken claw hanger). Assuming I'm right that that's a part of a broken bolt-on hanger, can you take it off? You should be able to do that, then screw it directly back into the integrated hanger, adjust the b-screw, etcetera.

Another bit of circumstantial evidence that this bike has been modified/repaired: I'd expect to see quick-release axles, rather than bolt-on.

If you're still scratching your head, then probably Tom Velo Orange's suggestion to take it to a bike shop is the best advice, though.

EDIT:

Tom Velo Orange mentions there might be a "key". Looking at photos 1 & 2 again, what looked to me at first in photo 2 like the broken-off top of a bolt-on hanger, might actually be such a key, rotated the wrong way.

If that's true, then this can't be the original derailleur. The original derailleur's b-screw obviously bore against the integrated hanger (what you call the "nub").

Hard to be sure, based on these photos, I guess.

It looks like you have to remove a spacer similar to part #4 in the Suntour Cyclone exploded diagram posted on this thread shows.
The derailleur upper body at the upper pivot should mount up very close against the dropout with just enough space to still let it freely swing back as most, if not all derailleurs i have used/encountered do, as the placement of your derailleur stop screw seem to also confirm.

Chombi

No, the chain length is good.

The extra metal is a cam attached to derailleur complete with a spring mechanism and lock ring. I'm going with the theory this RD was originally off a bike w/o an integrated hanger and bolted on in a manner that secured the cam. Another clue is it turns out the bolt-on rear wheel is 27" and the front is 700c. Perhaps the previous owner damaged the rear wheel / RD.

I installed a different RD so the bike is up and running until I get a replacement 700c wheel.

Thanks all!

If the replacement der works, leave it on there (or get another like it, if you can't leave it).