# Old Shimano 6 to 7 speed conversion.



## chas0039 (Jun 26, 2007)

I have an 25 year old Bianchi with a 6 speed Shimano freewheel and I was wondering if there would be any problems involved if I convert the freewheel to 7 speed. I also plan to change out the rear dérailleur as well as the shifters. Common sense tells me I should be OK but my experience with 6 speeds is lacking.

Thanks guys.


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## robert_shawn (Oct 5, 2005)

It should work just fine. I did the same thing with one of my bikes when I got a good deal on a set of DA 7 Speed tubular wheels. I only swaped out the chain and shifters since I already had a DA SIS derailler. IIRC, there was no major differneces between the 6 Speed and 7 Speed SIS deraillers.

Shawn


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## MR_GRUMPY (Aug 21, 2002)

Six and 99.9% of seven speed freewheels use the same 126mm hub spacing. You will need a seven speed chain because the spacing between the seven speed cogs is narrower.


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## Kerry Irons (Feb 25, 2002)

*Index?*



chas0039 said:


> I have an 25 year old Bianchi with a 6 speed Shimano freewheel and I was wondering if there would be any problems involved if I convert the freewheel to 7 speed. I also plan to change out the rear dérailleur as well as the shifters. Common sense tells me I should be OK but my experience with 6 speeds is lacking.


Do you have index or friction shifters? In either case, you probably don't need to replace the rear derailleur unless it is worn out. If friction shifting, you don't need to replace the shifters either.


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## FatTireFred (Jan 31, 2005)

Kerry Irons said:


> Do you have index or friction shifters? In either case, you probably don't need to replace the rear derailleur unless it is worn out. If friction shifting, you don't need to replace the shifters either.




were indexed shifters around for 6-spd? can't remember that far back... don't think so


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## MR_GRUMPY (Aug 21, 2002)

Yes.
Shimano SIS started with six speed downtube shifters and a six speed uniglide freehub and cassette. (They also sold a six speed freewheel for existing wheels)


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## burkeqc (Sep 25, 2006)

The seven speed freehwheel is wider than a six speed, so you likly will have to have to add extra spacers to the axle on the freewheel side. Otherwise, the smallest cog will drag on the dropout. There also is a good possibility you will have to get a longer axle & redish the wheel, depending on the current axle. If you stay with friction, shift levers make little difference. For indexed shifting, the 7 speed shimano (except DA) work with 6-8 speed shimano derailleurs.


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## chas0039 (Jun 26, 2007)

I planned to replace the original index shifters as well as the dérailleur due to wear in any case. The new freewheel is longer so I had to stretch the frame just a little and added a single washer. The rest of the new parts are due in today so things look good.


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## burkeqc (Sep 25, 2006)

If you had to add only 1 washer, about lilkely about 1mm thick, redishing may not be needed. For every washer you add to the freewheel side, it will move the wheel approx that same distance toward the non freewheel side dropout.


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