philbob57

I just switched from a Shimano (Tourney?) 14-28 7-speed freewheel to a Sunrace 13-28. The attachment bolt of a Suntour V-GT is too long to permit using that; besides the chain sags on my 28T granny gear on all rear cogs.
I
f I use a Microshift R10, the low limit screw doesn't move the cage out far enough to prevent the chain from falling between the cogs and spokes, so if I make a mistake shifting, I could be in trouble.

The FW appears to be installed correctly. I took it off to re-adjust the bearings (I packed the bearings a couple of days ago when I switched the FW but the adjustment was a little off) and the threads weren't crossed. It's screwed on pretty tight, so I don't think the inner cog will move further toward to hub flange.

How do I fix this? Spacer between hub and FW? Between the R10 der and hanger (Campy 1010)? New der? Shorter bolt or spacer for the V-GT? Something else?

Thanks in advance.

79pmooney

Is the bolt extending through the hanger and hitting the 13 tooth cog?

So the SunRace FW sits further out than the Shimano? Still, I am surprised the low limit screw won't bring the RD cage a lot (like several cogs).

If I understand what you are saying, spacing out the RD with a washer should work fine to bring the cage closer and prevent dropping the chain - but - first look long and hard at the derailleur cage from the rear. Is it vertical and in line with the chainrings or is it closer to the wheel at the bottom? This sounds like a bent derailleur hanger - common on older bikes from ordinary fall overs where the RD hits the ground or garage floor. That hanger should be perfectly vertical and so should the RD cage. (Both also should be straight fore and aft.) Bikes shops have a $100 tool that both measures the hanger for alignment and is used to straighten it (if we are talking of a steel framed bikes). If aluminum or carbon fiber, the hanger will be a detachable aluminum piece which must be replaced.

Take a look at the alignment and tell us what you see. (Quote me so I get the email.)

Duragrouch

Fit a spoke protector too, clear plastic and tasteful. Not as a solution to your problem, but just as... wait for it... spoke protection, if you drop the chain between the low cog and the spokes, because otherwise it does damage spokes. But sometimes the protector is close enough to the low cog, that the chain doesn't touch in normal operation, but is close enough that it prevents the chain dropping inboard.

Kontact

This all makes no sense.

What bike has '80s derailleurs and Shimano 7 speed freewheels? Are you aware that current 7 speed Shimano freewheels are only for department store mountain bikes and use different spacing than everything else. What kind of bike is this?

An R10 derailleur limit screw won't screw in far enough to limit the Low side? Get a longer screw for it.

Why is the mounting bolt rubbing the chain? Which freewheel does it do that with? How far is it sticking past the inside of the dropout?

bboy314

I agree your description is kind of confusing.

Is the mounting bolt for the Suntour derailleur hitting the freewheel cog? I’d fix this with a washer between the derailleur and hanger.

On the Microshift, with the low limit screw all the way in, the derailleur still moves past the low cog into the spokes? This indeed doesn’t make sense. Pictures of the setup might help determine what’s going on.

Kai Winters

seems a lot more wrong than what the person describes though his descriptions are very confusing and likely caused by user error

Crankycrank

A few photos would help. A side shot of the bike drivetrain in big chainring and big rear sprocket and also small-small so we can see if your chain is the correct length for one.

philbob57

I agree that user error is a high probability - my first thought was a mistake in installing the FW.

The V-GT's bolt does extend past the dropout and hits the 13T cog, which keeps the FW from turning. On the Microshift, with the low limit screw all the way in, the derailleur indeed moves past the low cog into the spokes. Thanks for the clear statements of the problems. I apologize for the confusing description I gave. Alas, it was the best I could do.

The dropout looks good. The der's cage looks perpendicular. The bike hasn't fallen on its DS in the years since the frame was cold set to 126 mm.

BTW, I'd be unhappy using a modern wheel. FWs provide gearing that works for me, with only one cog I'll never need - 13 or 14. Available cassettes have multiple cogs I'll never use. A modern bike with gearing designed to work with available cassettes is not likely to be a prudent purchase at my age.

Thanks for the help.

BTW, I've never had a spoke protector on this bike (frame is from 1973, and I've owned it since 1981), but it's a good idea. I hope to pick one up on my ride today.

soyabean

I always verify with a DAG-3 first step before I do any RD trubbleshooting.

Groupsets are always straightforward to fix with zero guessing.

Either deraillerus are wrongly installed, deformed, or dropout not aligned.

Kontact

FWs are fine. Again, what kind of bike is this? Is the derailleur hanger built in or a hook type?

Can you put a washer between the Suntour derailleur and hanger to move the bolt to the right so it doesn't hit the 13t cog?

Can you use a longer screw in the R10 Low? I had to do that years ago on a Campy Athena derailleur.

Aubergine 

I'd just add that putting a washer between the derailleur and dropout may solve the low limit screw issue as well.

philbob57

Thanks for confirming that a washer between frame and der is likely to be a solution.

It's a 1973 MKM frame. DOs are Campagnolo 1010s. The der hangs perpendicular to the floor and isn't twisted either toward the DS or NDS. Shifting with Suntour Power Shifters is very reliable, but I just went back to friction a few rides ago, so not a lot of history. The chain isn't supposed to go into the spokes, of course, but it does so only when the der moves it to the wrong place.

grumpus

I recently had to fit spacers to stop a derailleur mounting bolt from hitting the chain on the smallest sprocket - 10 x 16 x 1 mm stainless washers from Amazon made a neat job of it, and would also work as axle spacers if you wanted to increase the derailleur to hub body distance.

KCT1986

Could you have changed the hub spacing when rebuilding?

Shimano's spec below. Suntour stated 37mm for the same spec for 7 speed, back in the Accushift days, (7 sp ultra FW).




Also, about the RD hanger, does the horizontal alignment also look good?

Bill Kapaun

Just what gears on say a 14-25 9 speed cassette wouldn't you use?

You have enough posts to add a few pictures to better describe what the heck you are talking about.

philbob57

Solved by a longer screw for the R10's low limit. Shifts great, and the low limit works right. Thanks for mentioning the option, Kontakt. I certainly didn't think of it myself.

Mine is a classic bike with half-step + granny gearing via 45/42/28 chainrings, so it's not a good match for a close ratio cassette. The 14-25 9-speed gives, in essence, 11 speeds with those chainwheels, and I'd need a new wheel to use a cassette. Besides, if I forced a 130 mm hub into my 126 mm DOs, I probably would obsess over DO alignment. In any case, I'm pretty sure major mods to my bike are not good financial choices.