Problems with upper gears

On 9/9/2019 8:59 PM, Ralph Barone wrote:
AK wrote:
On Monday, September 9, 2019 at 7:45:43 PM UTC-5, Sir Ridesalot wrote:
On Monday, 9 September 2019 12:04:07 UTC-4, AK wrote:
On Monday, September 9, 2019 at 1:38:53 AM UTC-5, Chalo wrote:
6 speed freewheel and 8 speed shifter/derailleur are never compatible.
7 and 8 speed are compatible with Campagnolo parts, but for the love
of God don't do that.

7 speed Shimano pattern freewheel or cassette and 8 speed Shimano
pattern shifting are not compatible, but can be coerced to kinda-sorta
work poorly together. There's a 0.2mm difference in gear intervals
that stacks up to 1.2mm discrepancy across the extremes. It's likely to make noise.

Thanks for the info. So what do I need?

Andy

What you need to shift a SIX speed INDEX cassette or freewheel is a SIX
speed INDEX shifter.

Was your original shifter (the one that was replaced) a SIX speed INDEX
shifter? If it was a FRICTION shifter then the 8-speed shifter should
work IF it has a FRICTION MODE on it besides index.

Cheers


I talked to the bike shop owner. He will replace the 6 speed freewheel
with a new 7 speed at no additional charge.

So I guess I will have 3 more gears. :-)

Andy
7 speed


And if the text upthread is correct, your shifting will still be screwed up
because you will be using an 8 speed shifter with a 7 speed cassette.


Shimano recommends STi 8 shifters on seven drive trains,
having dropped seven STi levers. As Chalo notes, in
practice they are only negligibly askew. If you set the
index in the center sprocket the variance at both extremes
is not discernible.

Ditto with Campagnolo rear changers having B screw on the
top pivot (old) or on the lower pivot (new). They are not
the same, but the difference is very small and setting index
in the middle works just fine in our real world.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971