Practical to put new cogs on MF7400 7 speed DURA ACE Freewheel?

"daveornee" wrote in
message ...

Is is practical to put new cogs on an old DURA ACE 7 speed MF7400
freewheel?


David: go into a bike store and buy a few Shimano HG22 freewheels. $15
each. Here is an example:

http://bethelcycle.com/site/page.cfm...=65&SKU=FW8125

Put it a vise. Crack the lockring with a punch or flat blade screwdriver -
its a standard right-hand thread. Take off the Upper 5 cogs and throw away
everything else - do not use the new spacers. Use these to replace the
upper 5 cogs on your Dura-Ace 7400 freewheel.

Since these cogs are Hyperglide and each cog is oriented in a specific
position relative to the other, be careful how you align these on
re-installation.

BTW: one of the 13 or so splines on each of these cogs needs to be filed to
make it fit on the Dura-Ace body. A few minutes with a flat file will fix
that.

On the upside, since the new cogs are Hyperglide, they will shift much
better than the originals.

On Sat, 28 Aug 2004 05:13:46 +1000, daveornee
wrote:


Is is practical to put new cogs on an old DURA ACE 7 speed MF7400
freewheel?

I have an old DURA ACE 7 speed MF7400 freewheel with some broken and
bent teeth. The freewheel seems to function fine, but it is worthless
with it's current cogs. I know the days are gone when you walked into
a bicycle shop and they had a board full of different cogs. However, I
still have a couple of good freewheel wheels and a couple of MF7400 DURA
ACE freewheels that seem to work well and last a long time.
Anywhere to go with an old DURA ACE 7 speed MF7400 freewheel to get new
cogs?
I would like something like 13 - 26.
Ideas beyond doorstop or boat anchor?

Before you go shopping, try getting the old sprockets off the used
body; I've tried with mine, and snapped the chain on my chain whip
without moving the sprocket! This may partially explain the industry's
move to cassette hubs, where the pedalling torque DOESN'T keep
tightening the sprocket/freewheel threads to the point where you need
a 600lb gorilla of a mechanic to change ratios.

The MF7400 is widely regarded as the pinnacle of multiple freewheel
design, but I fear it is now the pinnacle of paperweight design.


Kinky Cowboy*

*Batteries not included
May contain traces of nuts
Your milage may vary

On Sat, 28 Aug 2004 05:13:46 +1000, daveornee
wrote:


Is is practical to put new cogs on an old DURA ACE 7 speed MF7400
freewheel?

I have an old DURA ACE 7 speed MF7400 freewheel with some broken and
bent teeth. The freewheel seems to function fine, but it is worthless
with it's current cogs. I know the days are gone when you walked into
a bicycle shop and they had a board full of different cogs. However, I
still have a couple of good freewheel wheels and a couple of MF7400 DURA
ACE freewheels that seem to work well and last a long time.
Anywhere to go with an old DURA ACE 7 speed MF7400 freewheel to get new
cogs?
I would like something like 13 - 26.
Ideas beyond doorstop or boat anchor?

Before you go shopping, try getting the old sprockets off the used
body; I've tried with mine, and snapped the chain on my chain whip
without moving the sprocket! This may partially explain the industry's
move to cassette hubs, where the pedalling torque DOESN'T keep
tightening the sprocket/freewheel threads to the point where you need
a 600lb gorilla of a mechanic to change ratios.

The MF7400 is widely regarded as the pinnacle of multiple freewheel
design, but I fear it is now the pinnacle of paperweight design.


Kinky Cowboy*

*Batteries not included
May contain traces of nuts
Your milage may vary

Kinky Cowboy wrote in message
...
On Sat, 28 Aug 2004 05:13:46 +1000, daveornee
wrote:


Is is practical to put new cogs on an old DURA ACE 7 speed MF7400
freewheel?

I have an old DURA ACE 7 speed MF7400 freewheel with some broken and
bent teeth. The freewheel seems to function fine, but it is worthless
with it's current cogs. I know the days are gone when you walked into
a bicycle shop and they had a board full of different cogs. However, I
still have a couple of good freewheel wheels and a couple of MF7400 DURA
ACE freewheels that seem to work well and last a long time.
Anywhere to go with an old DURA ACE 7 speed MF7400 freewheel to get new
cogs?
I would like something like 13 - 26.
Ideas beyond doorstop or boat anchor?

Before you go shopping, try getting the old sprockets off the used
body; I've tried with mine, and snapped the chain on my chain whip
without moving the sprocket! This may partially explain the industry's
move to cassette hubs, where the pedalling torque DOESN'T keep
tightening the sprocket/freewheel threads to the point where you need
a 600lb gorilla of a mechanic to change ratios.

The MF7400 is widely regarded as the pinnacle of multiple freewheel
design, but I fear it is now the pinnacle of paperweight design.



Simple, get someone to whack chain on sprocket whilst you operate chain
whip. Had to use shock tactics on a 14 yo car wheel bearing after a 6 foot
bar would not shift the nut. 3 ft bar and big 'ammer shifted it. Apply
torque as normal and whack tool with hammer at nut position. Rarely fails.



Trevor

Kinky Cowboy wrote in message
...
On Sat, 28 Aug 2004 05:13:46 +1000, daveornee
wrote:


Is is practical to put new cogs on an old DURA ACE 7 speed MF7400
freewheel?

I have an old DURA ACE 7 speed MF7400 freewheel with some broken and
bent teeth. The freewheel seems to function fine, but it is worthless
with it's current cogs. I know the days are gone when you walked into
a bicycle shop and they had a board full of different cogs. However, I
still have a couple of good freewheel wheels and a couple of MF7400 DURA
ACE freewheels that seem to work well and last a long time.
Anywhere to go with an old DURA ACE 7 speed MF7400 freewheel to get new
cogs?
I would like something like 13 - 26.
Ideas beyond doorstop or boat anchor?

Before you go shopping, try getting the old sprockets off the used
body; I've tried with mine, and snapped the chain on my chain whip
without moving the sprocket! This may partially explain the industry's
move to cassette hubs, where the pedalling torque DOESN'T keep
tightening the sprocket/freewheel threads to the point where you need
a 600lb gorilla of a mechanic to change ratios.

The MF7400 is widely regarded as the pinnacle of multiple freewheel
design, but I fear it is now the pinnacle of paperweight design.



Simple, get someone to whack chain on sprocket whilst you operate chain
whip. Had to use shock tactics on a 14 yo car wheel bearing after a 6 foot
bar would not shift the nut. 3 ft bar and big 'ammer shifted it. Apply
torque as normal and whack tool with hammer at nut position. Rarely fails.



Trevor

David: go into a bike store and buy a few Shimano HG22 freewheels. $15
each. Here is an example:

http://bethelcycle.com/site/page.cfm...=65&SKU=FW8125

Put it a vise. Crack the lockring with a punch or flat blade screwdriver -
its a standard right-hand thread. Take off the Upper 5 cogs and throw away
everything else - do not use the new spacers. Use these to replace the
upper 5 cogs on your Dura-Ace 7400 freewheel.

Since these cogs are Hyperglide and each cog is oriented in a specific
position relative to the other, be careful how you align these on
re-installation.

Dave,

Any idea if this will work with other HG cogs, say for example Ultegra?

Thanks and regards,

Rob

"Rob Weinstock" wrote in message
om...
David: go into a bike store and buy a few Shimano HG22 freewheels. $15
each.
Put it a vise. Crack the lockring with a punch or flat blade
screwdriver -
its a standard right-hand thread. Take off the Upper 5 cogs and throw
away
everything else - do not use the new spacers. Use these to replace the
upper 5 cogs on your Dura-Ace 7400 freewheel.


Dave,

Any idea if this will work with other HG cogs, say for example Ultegra?

Thanks and regards,

Rob

Rob: I am talking about Shimano Hyperglide *FREEWHEEL* cogs here. Not
*CASSETTE* cogs. They look the same in terms of the tooth profiles.
However, when you crack the cogsets apart, you will see that the spline
pattern on these cogs is completely different.

Besides - an Ultegra cassette cogset will cost 3 times what a HG22 freewheel
cogset will.

Depends on how many cogs you want to replace. I have an old Dura-ac
6-speed freewheel that I still use regularly. I'm still running th
original 13T and 14T but all others have been replaced by either buyin
brand new from www.loosescrews.com or taking from a damaged FW (cog
were fine, body was locked up) I got on eBay for $1

--
Gonzo Bob