6/7 speed Freewheel dimensions
#1
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6/7 speed Freewheel dimensions
Hiya folks,
I'm an old git with dodgy knees so I was looking at fitting a lower gear on my 1982 Holdsworth Avanti.
Dropout spacing is 126mm
It's currently got the original Regina Corsa freewheel (14-15-16-17-18-19).
So I was looking at fitting the Shimano Hyperglide 7 speed freewheel (14-16-18-20-22-24-28) MF-TZ500-7
I've got it to fit in with an OLD of 127mm, but the (8 speed) chain is too close to the chain stay with no spacers on NDS.
I've ordered a thinner cone to try in the NDS, but it occured to me that the 6 speed version might be thinner or give more chain clearance:
Shimano Hyperglide 6 speed freewheel (14-16-18-21-24-28) MF-TZ500-6
From the photos on Amazon it looks like it does have more clearance:
Does anybody have the measurements that would confirm this ?
eg. freewheel width from shoulder to face of 14T cog.
Any other useful ideas considered
Cheers.
I'm an old git with dodgy knees so I was looking at fitting a lower gear on my 1982 Holdsworth Avanti.
Dropout spacing is 126mm
It's currently got the original Regina Corsa freewheel (14-15-16-17-18-19).
So I was looking at fitting the Shimano Hyperglide 7 speed freewheel (14-16-18-20-22-24-28) MF-TZ500-7
I've got it to fit in with an OLD of 127mm, but the (8 speed) chain is too close to the chain stay with no spacers on NDS.
I've ordered a thinner cone to try in the NDS, but it occured to me that the 6 speed version might be thinner or give more chain clearance:
Shimano Hyperglide 6 speed freewheel (14-16-18-21-24-28) MF-TZ500-6
From the photos on Amazon it looks like it does have more clearance:
Does anybody have the measurements that would confirm this ?
eg. freewheel width from shoulder to face of 14T cog.
Any other useful ideas considered
Cheers.
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#2
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If a thin washer added to the DS gives you room, go with that.
https://www.sheldonbrown.com/cribsheet-spacing.html
https://www.sheldonbrown.com/cribsheet-spacing.html
Last edited by Bill Kapaun; 10-09-21 at 12:13 PM.
#3
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Yep, I'm going to try that.
I've got several axle spacers of 0.5mm and 1.0mm.
I'm trying to keep the OLD down though and 127.5 or 128mm is getting a bit too large.
But it would probably fit and the frame is steel so the dropouts should cope.
I'm using a new (Weldtite) axle which has cones 1mm wider than the original axle (which has 1 pitted cone and a different thread).
So I should get another 1mm of adjustment when the new cone arrives.
I've got several axle spacers of 0.5mm and 1.0mm.
I'm trying to keep the OLD down though and 127.5 or 128mm is getting a bit too large.
But it would probably fit and the frame is steel so the dropouts should cope.
I'm using a new (Weldtite) axle which has cones 1mm wider than the original axle (which has 1 pitted cone and a different thread).
So I should get another 1mm of adjustment when the new cone arrives.
Last edited by Aardwolf; 10-09-21 at 12:27 PM. Reason: spelling
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Running a 9 speed chain will help you a very slight amount. I’m running one bike with a .5mm spacer on DS and a 9 speed chain with a 7 speed freewheel.
I’ve adopted a 2mm rule on spreading, not cold setting, the dropouts, although others will go beyond that.
John
I’ve adopted a 2mm rule on spreading, not cold setting, the dropouts, although others will go beyond that.
John
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I've padded it out to 128mm and I can still hear the 8 speed chain rubbing slightly.
I'll try 128.5 and hope the thinner cone will fit (Wheel Manufacturing CN-R098) which gives me back 4.4mm
On the upside my Suntour VX RD is handling 28T just fine - it's rated at 26T max.
Then I'll measure the dishing and see how terrible it is.
I'll try 128.5 and hope the thinner cone will fit (Wheel Manufacturing CN-R098) which gives me back 4.4mm
On the upside my Suntour VX RD is handling 28T just fine - it's rated at 26T max.
Then I'll measure the dishing and see how terrible it is.
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7-speed freewheels are usually a tiny bit wider than 6-speed. I'd try the Shimano 6-speed freewheel rather than add spacers to the axle.
(The extra cog on this particular 7-speed freewheel doesn't add any value, IMO.)
(The extra cog on this particular 7-speed freewheel doesn't add any value, IMO.)
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This is a common problem in going from 6 to 7. A 1 mm spacer should take care of the problem.
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You're probably right about the width, it looks that way in the pictures anyway.
Amazon is just too easy, 6 speed turning up tomorrow for £20.
So I'll be able to give the width measurements anyway
Amazon is just too easy, 6 speed turning up tomorrow for £20.
So I'll be able to give the width measurements anyway
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Here's one of Sheldon Brown's cribsheets about it: https://www.sheldonbrown.com/cribsheet-spacing.html
While 6- and 7-speed do technically fit in the same nominal OLD, you do have to sacrifice a little clearance with the latter, and not all bikes have that clearance to spare.
While 6- and 7-speed do technically fit in the same nominal OLD, you do have to sacrifice a little clearance with the latter, and not all bikes have that clearance to spare.
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Yep I saw the cribsheet, that and https://www.sheldonbrown.com/harris/freewheels.html is why I tried the 7 speed.
Regina Corsa measures 30.15 mm
Shimano MF-TZ500-7 measures 33mm, but Sheldon Brown says 31.9mm
Regina Corsa measures 30.15 mm
Shimano MF-TZ500-7 measures 33mm, but Sheldon Brown says 31.9mm
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And the results are in.
Measurement from hub side of inside sprocket to dropout side of smallest sprocket:
30.15 mm Regina Corsa
33mm Shimano MF-TZ500-7
29.5mm Shimano MF-TZ500-6
So 6 speed Shimano has 3.5mm more leeway than the 7 speed version
Took 3mm off DS and added 1mm to NDS to give OLD 126.29mm.
Can't hear chain rubbing and dishing should be about right.
Measurement from hub side of inside sprocket to dropout side of smallest sprocket:
30.15 mm Regina Corsa
33mm Shimano MF-TZ500-7
29.5mm Shimano MF-TZ500-6
So 6 speed Shimano has 3.5mm more leeway than the 7 speed version
Took 3mm off DS and added 1mm to NDS to give OLD 126.29mm.
Can't hear chain rubbing and dishing should be about right.
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