pepsi4all

Hi guys,

I have 12 25 on my rear. I am having trouble when I installed 11 28. It seems that they are not compatible? is this is right? It installed pretty good but it seems the space between the gears are narrower/smaller for what chain I already have. I wanted a bigger gear for upcoming
11,000 feet climb... and a friend of mine suggested this since we are climbing ski lifts.

Thanks you guys for all your help.

I have 50 34 on the crank, and these are shimano 105 10 speed.

Bill Kapaun

You might delete your duplicate post.

Did you lengthen the chain? That may or may not be necessary for the 28T cog.
B screw adjustment made?

SkyDog75

So long as they're both Shimano (or SRAM) 10-speed, the spacing between each cog should be the same and therefore compatible with your shifters.

Derailleurs come in different cage lengths to accommodate different gearing ranges. I don't think your swap would require going to a longer cage, but after adjusting the chain length and b-screw on your rear derailleur, you'll know. Check out the tutorials on parktool.com to walk you through those adjustments, as well as fine-tuning your limit screws and indexing after swapping cassettes.

fietsbob

Bike shops can see stuff, why not drop by they will show you the difference ,

longer now means a New chain, as well , I suspect.



adding a link to the chain was practical back when the chains were wider.

AnkleWork

How many gears (sprockets) are on the 12/25?
How many gears are on the 11/28?

pepsi4all

Both have 10 gears/sprocket, my old gears and the new set of gears. I will ck the b screw... I don't think it's the b screw though... It could be that the chain is worn out or stretch out, that it won't seat properly.
The chain actually get caught in between the rear deraiuller spacer, between the grears because the chain is thicker. I just don't get it.

pepsi4all

My old gear is CS-5600 shimano, the new one I am installing is CS-5700. Both are shimano 105

fietsbob

Yea, Definitely , buy a new chain, for the new cassette, bag the old chain with the removed cassette.

Retro Grouch 

Such a simple change should be a straight bolt up and obviously it's not.

Whenever I encounter such a problem the first thing that I do is to check everything to be sure it's in the default condition. That means checking the derailleur hanger alignment. Most times, that fixes it.

pepsi4all

Hey guys, thank you so much for your help. I did change the chain itself also. The chain is just so worn off.

ultraman6970

My best guess because I have seen this before, is that you might have a 9 speed chain in there, if the old cassette had skipped cogs.. eg 12, 14, 16, 19... then the chain will sit in the right place but if the cogs in the new cassette dont jump all over probably (making up stuff here ok?) now the chain is nicking tiny bit the 15 cog when the the gear is in the 14 cog. If the chain is wider this will happen, sure doesnt happen in the big cogs (right?)

Second thing, did you check the allingment of the RD? with shimano sometimes if not in the right place the thing just dont work as intended.

Good luck.

pepsi4all

Hi ultraman... its already fixed. I change the chain to a brand new one and it works fine.

ultraman6970

Two thumbs up!