Will I ever get proper shifting from this combo?

Johan Bornman said:

I have a persistent shifting problem on my 7-speed downtube shifter
bike.

The shifter is Shimano, the sprockets are Sachs Mailard on a freewheel.
The rear deraileur is a modern Shimano Tiagra. I use index mode when on
the shifter.

The problem is many-fold: in the higher gears, the shifter starts to
creep, eventually causing a half downshift so that the chain rides on
top of the sprocket. If I shift quickly fast up and down, I find that
the chain rides on top of the sprocket - again on the downshift only.
With a bit of maneuvering of the shifter, I can get it to drop into the
cogs.

Then, when shifting up, the highest two or three gears produce perfect
shifting, but the higher I go, the noisier the chain gets, to a point
where it seems as if it wants to shift up by itself.

The shifter is new, with only a thousand or so kms behind it. However,
it feels as if there is quite a bit of play in each click setting,
enough play to force it a gear up without it clicking into the next
gear shift. I never had the opportunity to familiarise myself with its
play when it was new, since I then had a Suntour Superbe Pro rear
deraileur on there, working with friction shift.

I'm confident that the cable runs smoothly and that the noodle at the
back doesn't have too much friction.

1) Are you sure the particular freewheel you're using is index
compatible?

2) If it is, realize that some older "index compatible" freewheels have
tooth patterns that make them fussy to set up (I've had problems with
some Regina FWs, for example).

3) Your derailluer hanger may be slightly bent, have a properly
equipped shop check it. Not a big issue with friction shifting, but
noticable when indexed.

Johan Bornman said:

The problem is many-fold: in the higher gears, the shifter starts to
creep, eventually causing a half downshift so that the chain rides on
top of the sprocket. If I shift quickly fast up and down, I find that
the chain rides on top of the sprocket - again on the downshift only.
With a bit of maneuvering of the shifter, I can get it to drop into the
cogs.

Then, when shifting up, the highest two or three gears produce perfect
shifting, but the higher I go, the noisier the chain gets, to a point
where it seems as if it wants to shift up by itself.

The shifter is new, with only a thousand or so kms behind it. However,
it feels as if there is quite a bit of play in each click setting,
enough play to force it a gear up without it clicking into the next
gear shift. I never had the opportunity to familiarise myself with its
play when it was new, since I then had a Suntour Superbe Pro rear
deraileur on there, working with friction shift.

I'm confident that the cable runs smoothly and that the noodle at the
back doesn't have too much friction.

Johan Bornman

I had similar issues with my first set of 7-speed Shimano bar-end
shifters, many, many years ago (1991-ish). I fixed it by tightening the
hold-down screw to about twice Shimano's recommeded torque. After that,
shifting was flawless. Use a big screwdriver that fits the slot
closely.

Jeff

Quoted message said:

1) Are you sure the particular freewheel you're using is index
compatible?

No, I'm not sure. All I know is that it's a Sachs-Mailard and has seven
sprockets.

Quoted message said:

2) If it is, realize that some older "index compatible" freewheels have
tooth patterns that make them fussy to set up (I've had problems with
some Regina FWs, for example).

Where does the fussiness come in to play? Do they really work with the
Shimano components I listed?

Quoted message said:

3) Your derailluer hanger may be slightly bent, have a properly
equipped shop check it. Not a big issue with friction shifting, but
noticable when indexed.

How does a bent hanger affect shifting?

JB

Johan Bornman said:

Quoted message said:

1) Are you sure the particular freewheel you're using is index
compatible?

No, I'm not sure. All I know is that it's a Sachs-Mailard and has seven
sprockets.

I believe that all S-M 7SP freewheels were index compatible, but I'm
not absolutely certain. Do you know when it was made?

Also, make sure the cogs are on the freewheel body in the proper
orientation. Some designs (e.g., Reginas) allow you to put a cog on
"backwards". I'm not sure if this is true of a 7SP Sachs.

Quoted message said:

Quoted message said:

2) If it is, realize that some older "index compatible" freewheels have
tooth patterns that make them fussy to set up (I've had problems with
some Regina FWs, for example).

Where does the fussiness come in to play?

The tooth designs of some older freewheel sprockets shift less
precisely than things like Shimano Hyperglide or even the older
Uniglide.

Quoted message said:

Do they really work with the
Shimano components I listed?

Yes, but they may be much less tolerant of small amounts of
mis-adjustment/mis-alignment. I have some early 90s 7 and 8SP
freewheels that I occasionally use, and everything needs to be "just
so" to get good shifting quality.

Quoted message said:

Quoted message said:

3) Your derailluer hanger may be slightly bent, have a properly
equipped shop check it. Not a big issue with friction shifting, but
noticable when indexed.

How does a bent hanger affect shifting?

It changes the position/alignment of the jockey pulley relative to the
sprockets. One symptom of this is that you may be able get the bike to
shift fine in the small ring, but not the large ring. Or vice versa.

If possible, try putting on a different freewheel, one with modern
tooth design and see what happens. If the symptoms persist, have the
derailleur hanger alignment checked.

Oh, one last thing: try putting a new piece of "compressionless"
derailleur cable housing on the bike. Some older housings that work
fine in friction mode can cause problems with indaxed shifting.

Let us know how it goes.

Quoted message said:

It changes the position/alignment of the jockey pulley relative to the
sprockets. One symptom of this is that you may be able get the bike to
shift fine in the small ring, but not the large ring. Or vice versa.

That mirrors my experience. It shifts fine in the higher gears but
going up to the lower gears causes problems, even skipping.

Quoted message said:

If possible, try putting on a different freewheel, one with modern
tooth design and see what happens. If the symptoms persist, have the
derailleur hanger alignment checked.

Hmmm...easier said than done. I may have to build a new wheel to do
this.

Quoted message said:

Oh, one last thing: try putting a new piece of "compressionless"
derailleur cable housing on the bike. Some older housings that work
fine in friction mode can cause problems with indaxed shifting.

Let us know how it goes.

Thanks,

JB

Johan Bornman said:

Quoted message said:

It changes the position/alignment of the jockey pulley relative to the
sprockets. One symptom of this is that you may be able get the bike to
shift fine in the small ring, but not the large ring. Or vice versa.

That mirrors my experience. It shifts fine in the higher gears but
going up to the lower gears causes problems, even skipping.

Quoted message said:

If possible, try putting on a different freewheel, one with modern
tooth design and see what happens. If the symptoms persist, have the
derailleur hanger alignment checked.

Hmmm...easier said than done. I may have to build a new wheel to do
this.

I'm not sure I understand. Is the freewheel seized onto the hub?

Quoted message said:

Quoted message said:

Oh, one last thing: try putting a new piece of "compressionless"
derailleur cable housing on the bike. Some older housings that work
fine in friction mode can cause problems with indaxed shifting.

Let us know how it goes.

Thanks,

JB

Quoted message said:

I'm not sure I understand. Is the freewheel seized onto the hub?

No, it isn't seized. It's just that that freewheel on there is the very
last one in the world, if I listen to the bike shops around here. I
cannot get any more, so putting a new one on equates to me building a
new wheel with a freehub.

I have been replacing worn sprockets on this freewheel with an
incredible combination of [censored] sprockets from different
manufacturers. At present I'm cannibalising a Sachs-Mailard 8-speed
for its sprockets - after that, it's over to newer technology...circa
1990s perhaps.

JB

Johan Bornman said:

Quoted message said:

I'm not sure I understand. Is the freewheel seized onto the hub?

No, it isn't seized. It's just that that freewheel on there is the very
last one in the world, if I listen to the bike shops around here. I
cannot get any more, so putting a new one on equates to me building a
new wheel with a freehub.

7SP freewheels are readily available. In fact, Shimano released a new
design about 5-6 years ago. And many inexpensive bikes come with
freewheels, not cassettes.

Quoted message said:

I have been replacing worn sprockets on this freewheel with an
incredible combination of [censored] sprockets from different
manufacturers.

Aha! That may be the cause of your shifting problems. You can do this
sort of thing with friction shifting, but not wirh indexed shifting.

Quoted message said:

At present I'm cannibalising a Sachs-Mailard 8-speed
for its sprockets - after that, it's over to newer technology...circa
1990s perhaps.

JB

Johan Bornman said:

Quoted message said:

I'm not sure I understand. Is the freewheel seized onto the hub?

No, it isn't seized. It's just that that freewheel on there is the very
last one in the world, if I listen to the bike shops around here. I
cannot get any more, so putting a new one on equates to me building a
new wheel with a freehub.

I've got an LBS that I love that doesn't tell me stinking piles of lying
[censored] like that. Then there's the other ones. You've got one of the other
ones.

Nashbar has 'em, anybody with a QBP catalog's got 'em. Cool old LBS's with back
rooms have NOS. And, yes they make freewheels with modern notches and cams and
chain lifty ramps and stuff.

Say no to the yuppie traps.

Quoted message said:

I have been replacing worn sprockets on this freewheel with an
incredible combination of [censored] sprockets from different
manufacturers. At present I'm cannibalising a Sachs-Mailard 8-speed
for its sprockets - after that, it's over to newer technology...circa
1990s perhaps.

Only if you want to.

Ron

Johan Bornman said:

Quoted message said:

I'm not sure I understand. Is the freewheel seized onto the hub?

No, it isn't seized. It's just that that freewheel on there is the very
last one in the world, if I listen to the bike shops around here.

Quoted message said:

JB

What are you bid for the one in my Basement?

NOS as is came on a wheel and I replaced it with Dura-Ace before it had
turned more than a test ride.

Johan Bornman said:

Quoted message said:

I'm not sure I understand. Is the freewheel seized onto the hub?

No, it isn't seized. It's just that that freewheel on there is the very
last one in the world, if I listen to the bike shops around here.

Quoted message said:

JB

What are you bid for the one in my Basement?

NOS as is came on a wheel and I replaced it with Dura-Ace before it had
turned more than a test ride.

Quoted message said:

What are you bid for the one in my Basement?

NOS as is came on a wheel and I replaced it with Dura-Ace before it had
turned more than a test ride.

What ratios? I'l like something like a 13 to 23 or 25.

What country are you in?

I'm in South Africa.

JB

RonSonic said:

Quoted message said:

Nashbar has 'em, anybody with a QBP catalog's got 'em. Cool old LBS's with back

rooms have NOS. And, yes they make freewheels with modern notches and cams and
chain lifty ramps and stuff.

Say no to the yuppie traps.

I can assure you of the latter, otherwise I'd be asking questions about
10-speed life-span etc.

The only 7-speed freewheels I can find are Shimano 14-32 ones. They're
also pretty crude, with a twisted tooth design instead of ramps. The
problem with these is 1. that 32-tooth sprocket (too big for my
deraileur) and 2. that 14-tooth sprocket (not small enough).

What is a QBP catalogue?

JB

Johan Bornman said:

Quoted message said:

What are you bid for the one in my Basement?

NOS as is came on a wheel and I replaced it with Dura-Ace before it had
turned more than a test ride.

What ratios? I'l like something like a 13 to 23 or 25.

What country are you in?

I'm in South Africa.

JB

If memory serves it is 13 25, I'll check. Since I'm in Canada and you
probably wont be buying from the same people as me if you find a
Dura-Ace 7 speed thread on (Uniglide) you can give that a try (IMO best
shifting ever with 7 speed XT (DX ) or Dura-Ace). Heck if you see one
for sale let me know and I'll buy it.. I'm down to one spare now..

Johan Bornman said:

RonSonic said:

Quoted message said:

Nashbar has 'em, anybody with a QBP catalog's got 'em. Cool old LBS's with back

rooms have NOS. And, yes they make freewheels with modern notches and cams and
chain lifty ramps and stuff.

Say no to the yuppie traps.

I can assure you of the latter, otherwise I'd be asking questions about
10-speed life-span etc.

The only 7-speed freewheels I can find are Shimano 14-32 ones. They're
also pretty crude, with a twisted tooth design instead of ramps.

The twist tooth design is called Uniglide. That design shifts quite
well and puts less lateral stress on chains than Hyperglide and it's
imitators. If you can find a Uniglide FW in the ratios you want, don't
hesitate to buy it.

Quoted message said:

The
problem with these is 1. that 32-tooth sprocket (too big for my
deraileur) and 2. that 14-tooth sprocket (not small enough).

What is a QBP catalogue?

QBP is a distributor used by nearly all bike shops in the US. QBP
sells to the shop, the shop sells to you.

Are you willing to buy from a US source? Or do shipping and customs
make that cost prohibitive?

If a US source is workable for you, look at this:

http://tinyurl.com/kae69

a 13-24 7SP freewheel with hyperglide cogs for US$20

Quoted message said:

Quoted message said:

Are you willing to buy from a US source? Or do shipping and customs

make that cost prohibitive?

If a US source is workable for you, look at this:

http://tinyurl.com/kae69

a 13-24 7SP freewheel with hyperglide cogs for US$20

We have zero tarriffs and zero duties on bicycle part imports, only 14%
VAT. $20 US is very reasonable, even if I double that to take care of
shipping. I'll definitely have a look at your source.

Thanks
JB