Can I replace 34t sprocket...

on 9/10/2004 3:20 PM Tomek Li said the following:

Quoted message said:

...of the Shimano's Mega 7 speed freewheel with some more reasonable 28 or
30t?
My son's bicycle is in need of a new freewheel. The only available 7 speed
is the famous reingeneered megarange, which is not compatible with his Sachs
Quartz der - the capacity is too small, chain slacks. Moreover, Quartz can
hardly cope with 34 teeth - it is rated for 32 max.

Would it be possible to replace the 34t with 28 taken from his old 6 speed
freewheel? It's not much worn. I don't know if the shape of splines is the
same (or similar enough to take some filing and grinding...)

Thx,

Tomek Li

Try http://sheldonbrown.com/harris/freewheels.html#7

or

http://www.nashbar.com/results.cfm?category=87&subcategory=1109&storetype=&estoreid=

They each have several 7-speed FW's that max out at 32t or less.

--
David
dja--dot--mail--at--comcast--dot--net

Tomek Li said:

...of the Shimano's Mega 7 speed freewheel with some more reasonable 28 or
30t?
My son's bicycle is in need of a new freewheel. The only available 7 speed
is the famous reingeneered megarange, which is not compatible with his Sachs
Quartz der - the capacity is too small, chain slacks. Moreover, Quartz can
hardly cope with 34 teeth - it is rated for 32 max.

Would it be possible to replace the 34t with 28 taken from his old 6 speed
freewheel? It's not much worn. I don't know if the shape of splines is the
same (or similar enough to take some filing and grinding...)

Depends which of the Mega 7 freewheels you have. If yours tops out with
a 13 or 14 sprocket, yes, you can do this if the 6-speed is a Shimano.

If you have the version with an 11 top sprocket, no, you can't. That
model features a revolutionary new design, comes apart from the back
side, and needs a larger spline pattern for the big sprocket.

http://sheldonbrown.com/mega7

This is the finest multi-speed freewheel ever made. Lately I've been
riding one on my Rambouillet: http://sheldonbrown.org/rambouillet

Sheldon "MegaRange" Brown
+--------------------------------------------------------+
| I met a traveler from an antique land |
| Who said: Two vast and trunkless legs of stone |
| Stand in the desert. Near them, on the sand, |
| Half sunk, a shattered visage lies, whose frown, |
| And wrinkled lip, and sneer of cold command, |
| Tell that its sculptor well those passions read, |
| Which yet survive, stamped on these lifeless things, |
| The hand that mocked them, and the heart that fed, |
| And on the pedestal these words appear: |
| "My name is Ozymandias, King of Kings: |
| Look upon my works, ye Mighty, and despair! |
| Nothing beside remains. Round the decay |
| Of that colossal wreck, boundless and bare |
| The lone and level sands stretch far away. |
| -Percy Bysshe Shelley |
+--------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

"Sheldon Brown" <[email hidden]> wrote in message
news:[email hidden]...
(...)

Quoted message said:

Depends which of the Mega 7 freewheels you have. If yours tops out with
a 13 or 14 sprocket, yes, you can do this if the 6-speed is a Shimano.

Unfortunately, it's the 11-34 version.

Quoted message said:

If you have the version with an 11 top sprocket, no, you can't. That
model features a revolutionary new design, comes apart from the back
side, and needs a larger spline pattern for the big sprocket.

http://sheldonbrown.com/mega7

I've read your article mor than once, but I could not figure out if the 34t
can be replaced... Now I know.

Quoted message said:

This is the finest multi-speed freewheel ever made. Lately I've been
riding one on my Rambouillet: http://sheldonbrown.org/rambouillet

I do not doubt it's mechanical virtues. Frankly, it is a bit too wide for
the derailer, which is still fine, and nothing narrower is locally
procurable.

Thx,

Tomek Li

I said:

Quoted message said:

This is the finest multi-speed freewheel ever made. Lately I've been
riding one on my Rambouillet: http://sheldonbrown.org/rambouillet

Tomek Li said:

I do not doubt it's mechanical virtues. Frankly, it is a bit too wide for
the derailer, which is still fine, and nothing narrower is locally
procurable.

Derailers are cheap. You can get a suitable derailer for under $20.

http://sheldonbrown.com/harris/derailers

Sheldon "Economics" Brown
+-----------------------------------------------+
| A government that robs Peter to pay Paul |
| can always depend upon the support of Paul. |
| --George Bernard Shaw |
+-----------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com