Bicycle Mechanics - wheel dish question - 6 to 7 speed freewheel change

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jettore
10-22-10, 08:00 AM
I'm thinking of changing to a Shimano 7 speed freewheel from the current 6 speed. Will this require a dish change for the wheel?


ultraman6970
10-22-10, 08:15 AM
Doubt it. 6 and 7 wheelsets are 126 mm hubs.

HillRider
10-22-10, 09:02 AM
Unless your current 6-speed is a Sun Tour Ultra-6 on a 120 mm hub, you won't have to change anything but the freewheel. As mentioned above both standard 6 and 7-speed freewheels use 126 mm spacing.

You will have to change your chain unless yours is already a 6/7/8-speed width. You should probably install a new chain anyway to avoid skipping problems with the new freewheel.


jettore
10-22-10, 09:49 AM
Unless your current 6-speed is a Sun Tour Ultra-6 on a 120 mm hub, you won't have to change anything but the freewheel. As mentioned above both standard 6 and 7-speed freewheels use 126 mm spacing.

You will have to change your chain unless yours is already a 6/7/8-speed width. You should probably install a new chain anyway to avoid skipping problems with the new freewheel.

I just did install a new Shimano 6 speed freewheel and chain 2 months ago so hopefully the chain should be ok. I think the chain was a KMC Z50. I'm thinking of changing to 7 speed so I can switch out the friction thumb shifter to an indexed 7 speed shifter setup. Maybe also go with the Megarange Shimano 7 speed freewheel. The RD is a Shimano Deore with long cage so I think it should all work together.

top506
10-23-10, 06:33 AM
I'm thinking of changing to a Shimano 7 speed freewheel from the current 6 speed. Will this require a dish change for the wheel?

Not if you're lucky.
I've done 6-7 upgrades that were as easy as swapping out the freewheels. Others have required a complete re-space and re-dish. Most were in between.

Top

Retro Grouch
10-23-10, 06:52 AM
Not if you're lucky.
I've done 6-7 upgrades that were as easy as swapping out the freewheels. Others have required a complete re-space and re-dish. Most were in between.

That's been my experience too. What it really depends on is the relationship between the smallest cog and the hub's locknut. If you have enough space so that the chain will shift onto the smallest cog and not rub the chainstay, you're good. If it does, you'll have to put a washer or a spacer or something under the drive side locknut. Depending on how much you have to add, you may have to take a spacer out of the non-drive side. Obviously, the more that you do, the more likely you'll have to adjust the dish.

If you do find that you have to adjust the dish, make sure that you have a supply of new nipples before you start. On a wheel that old some of the nipples are going to be stubborn and will round off when you try to adjust them.

Good luck!

Al1943
10-23-10, 01:20 PM
When I upgraded a friend's bike from 6 to 7 freewheel I had to replace the axle with one slightly longer and had to redish the wheel some. I don't remember the frame but it was European and had good Campy components. I think the old freewheel was 12-17 and the chainrings were 52-42. Ouch!