Replace a Chain ring from 50T to 52 T

[macaw]

I've a chainring 50/39/30 on my bike & i want to change the 50T to 52T can i use the same chain, will i have to make any adjustments to the derailer system or do i have to increase the length of the chain can anybody HELP.

[xerxes]

You may have to move the front derailleur up the seat post by a millimeter or two if it is already very tight to the 50T ring. It's difficult to say about the chain it might be a bit tight when you're on the largest chainring and rear sprocket, but that's an odd combination anyway, so you'll probably be OK.

[macaw]

(08-07-2010, 10:04 AM)xerxes Wrote:  You may have to move the front derailleur up the seat post by a millimeter or two if it is already very tight to the 50T ring. It's difficult to say about the chain it might be a bit tight when you're on the largest chainring and rear sprocket, but that's an odd combination anyway, so you'll probably be OK.

I've got 6mm gap between the 50T chainring & the top curve of the derailer when the chain is on the top ring.

[trevgbb]

Assuming you have a chainset with replaceable rings, and to state the obvious, make sure your new one has the same pcd and number of bolts as the old one.

However, if your existing chain is stretched and your existing rings are worn, you may find your old chain will not work with the new ring and you need to replace this also..

Then you get into the problem of will your new chain work with the old teeth on the remaining rings and rear cogs?
You do not know for sure until you have carried out the work, all you can do is assess the possibility by examining all the rings and cogs critically, if any of them look pointed or hooked, you may have problems, although the opinion of an experienced mechanic at your lbs can be invaluable.

Sorry to be a bit of a Jeremiah, but you do have to think about these things.

[macaw]

(08-08-2010, 05:35 AM)trevgbb Wrote:  Assuming you have a chainset with replaceable rings, and to state the obvious, make sure your new one has the same pcd and number of bolts as the old one.

However, if your existing chain is stretched and your existing rings are worn, you may find your old chain will not work with the new ring and you need to replace this also..

Then you get into the problem of will your new chain work with the old teeth on the remaining rings and rear cogs?
You do not know for sure until you have carried out the work, all you can do is assess the possibility by examining all the rings and cogs critically, if any of them look pointed or hooked, you may have problems, although the opinion of an experienced mechanic at your lbs can be invaluable.

Sorry to be a bit of a Jeremiah, but you do have to think about these things.

The bike is absolutely new only about 500 miles on it & there is no wear on the chain or any of the chainrings or the rear cassette gears .