7 speed freewheel on 6 speed hub

I've read info at various sites about 6 & 7 speed freewheels (not
cassettes) being practically interchangeable on a bike built for a 6
speed FW. Has anyone done this or compared the overall thickness
between the two FW's?

My current frame spacing is about 126mm, and I use friction-type
shifters. I'm considering a mail order 7 speed FW and I'm concerned
that I can't compare prior to purchase.

Do I have to get a thinner chain to work with the narrower spacing
between the 7 speed sprockets?(1985 bike). Any other considerations
I'm not thinking about?

TIA,
Dave

google- My current frame spacing is about 126mm, and I use friction-type
shifters. I'm considering a mail order 7 speed FW and I'm concerned
that I can't compare prior to purchase. BRBR

Use any '8s' chain and you may have to add a few thin spacers to the right,
from the left and redish the wheel slightly. The spacing is essentially the
same from 6s to 7s.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

Sugob Wrote:
I've read info at various sites about 6 & 7 speed freewheels (not
cassettes) being practically interchangeable on a bike built for a 6
speed FW. Has anyone done this or compared the overall thickness
between the two FW's?


I have a number of 6- and 7-speed freewheels (Suntour and Shimano) and
the 7-speeds are just a bit wider - about 1-2mm. I also have a number
of 6-speed freewheel hubs (126mm) and I can use the 7-speed freewheels
on all of them although it's a tight fit on one of them.


--
Gonzo Bob

(Sugob) wrote in message . com...
I've read info at various sites about 6 & 7 speed freewheels (not
cassettes) being practically interchangeable on a bike built for a 6
speed FW. Has anyone done this or compared the overall thickness
between the two FW's?

I have done this on two bikes with no problem, one with 126mm
dropouts, one with 130mm.


My current frame spacing is about 126mm, and I use friction-type
shifters. I'm considering a mail order 7 speed FW and I'm concerned
that I can't compare prior to purchase.


The nominal dimensions are likely to be the same give or take a small
amount.

I recently put a new Shimano freewheel on my tandem to replace an
early 80's suntour. Despite both being 6-speed the slight difference
is size meant I had to put a thin washer on the drive size to avoid
chain rub on the chainstay. It is possible that you may have to do
the same (particularly if clearance was tight on the 6-speed to start
with), but nothing drastic.


Do I have to get a thinner chain to work with the narrower spacing
between the 7 speed sprockets?(1985 bike). Any other considerations
I'm not thinking about?

No. I would use SRAM PC-48 which should work fine. I would fit a new
chain to go with the new freewheel.

No other problems likely.

TIA,
Dave

Andrew Webster