Weberish

Hello.

I have a 2 part question. I am replacing my freewheel on my 1985 Fuji League. The current one is a 6 speed Suntour Mighty, standard spaced. I believe the new one is the same, (I am getting it from someone else). Anyway, if it is a tighter spacing, do I need to add washers somewhere to keep the chain alignment proper?

Also, recently, after a sand blasted ride, I cleaned out my cogs, derailleur and chain; however, recently, I've been getting a strange somewhat grinding sound from the backside with my chain (freewheel or derailleur). Anyway, it occurs more often on hard cycling and happens between too many turns to be a particular link in the chain. Is there some common problem this could be?

Is there a good chance after replacing the freewheel and the chain, I will be free of this problem?

Sorry to be not direct or specific, but it is confusing me with my minor knowledge.

Thanks.

CACycling

No need for spacers. You might need to adjust the RD limit screws a bit and, if you have indexed shifters, may need to tweek the adjustment there as well.

The grinding could be the chain or freewheel but also might be the hub bearings. This would be a good time to disassemble, clean or replace the bearings and grease it all up.

operator

Doublecheck that your cogs aren't running close to the frame at any point first - that's a game over deal.

SJX426 

Not to hyjack this thread but maybe enhance it? I have had a problem with index shifting a 6spd. I measured the spacing between cogs and found one that was significantly less. This is the cog I am haveing issues with. it is the distance between the second smallest to the next largest. I can't effectively upshift from the third to the second but can downshift to the second cog from the first (smallest). All distances measre 5.51 +.ox. The one in question is 5.3+.

I then started measuring other freewheels, 5, 6, and 7 speed all of which have some variance. Are they all suppose to be the consistant distance for each cog space on a freewheel + or - a couple of thou?

FBinNY 

If you're running 6 speed, odds are you don't have index shifting, so small variances in spacing are immaterial.

You didn't give details of the sprocket sizes, but I suspect you may have a wide range freewheel, ie. 13-28 or larger. Also that the step from the 2nd (from outside) to the 3rd is larger than the step from the small to the 2nd.

What may be happening, especially if the chain is a bit older and/or the derailleur is sitting a bit father away is that the chain flexes over and touches on the 3rd sprocket before it touches the 2nd. You can often observe this on a repair stand, if you start a shift and stop at the first sound of tooth contact.

There's no easy cure, but bringing the RD up as far as possible (check for clearance on larger sprockets). Also, since chain wear is a factor take a moment to measure your chain for stretch (wear), and if it's near the end of it's life, consider replacing it.

Little Darwin

It is hardly hijacking when you resurrect a 5 year old thread.

As I recall there were two different 6 speed "standards" back in the day. Maybe one was called ultra??? Anyway, as I recall reading, one version of the 6 speed was developed to be the same overall width as 5 speed, so the cogs were closer together than the typical 6 speed, which retained the 5 speed width overall... the other (the majority as I recall) retained the 5 speed spacing so was wider overall, so was wider overall. 7 speed did reduce spacing across the board as I recall.

If you want more info and don't get a definitive answer here, you could ask in the Classic & Vintage section.

{edited to correct logic error]

Andrew R Stewart 

Sun Tour freewheel cog spacing was not always consistent WRT the smaller cogs and the larger cogs. Close to the same C-c spacing but not exactly the same. This is but one aspect of the Shimano/Sun Tour non compatibility when indexed. Shimano cog spacing is consistent across all the cogs.

Cleaning a chain can cause it to run with more noise. The presence of grime acts as a damper for noise. If the freewheel internal bearings were cleaned and not relubed some noise can come from the dry ratchet bits/bearings acting on each other. (To give a possible answer to the OP, I hope his problem was cleared up since ) Andy.