Riddle me this: Gear compatibility

thehamo

Hi folks

Question, that I cant find a straight forward answer to on t'internet.

My current set up is 105 5700 10sp compact Double with a Medium cage rear meche and 11-32T cassette

My question is, is the 32T too much for for the rear meche? Im looking to get as much "easiness" as I can on hills because I weigh the same as a small elephant. I am having issues with the gears at the moment, and im wondering is it as a result of changing over to the 32T.

THank you in advance!

Zen0

Shimano techdocs are your friend for all of these sorts of questions. The 5700 rear derailleur docs can be found here:

http://www.shimano-france.fr/media/techdocs/content/cycle/SI/SI_5X90B/SI-5X90B-003-00-ENG_v1_m56577569830702204.PDF

According to that, the largest your rear derailleur should go is 28 teeth on the casette. I think the Tiagra 4600 will get you to 30 teeth, but Google the tech docs to check. Latest Shimano rear derailleur will go to 32 but I think they have a different pull ratio and will not work with your shifters. Alternatively, have a look at this thread for another option:

http://www.boards.ie/vbulletin/showthread.php?p=103071136

magicbastarder

you say you're having issues with gears - what issues?

Alek

I am running 11-36 on a short Sora mech. As long as the top jockey wheel is not rubbing on the cassette, its just fine.

smacl

Running 50/34 with 11/32 on a medium cage Ultegra which was how it was built and delivered from Rose, no issues.

Eamonnator

Have you adjusted the "B" screw?
When you changed cassette, did you put on a new chain?
Your chain may be a bit short, particularly, if you cross chain.

thehamo

Eamonnator wrote: »

Have you adjusted the "B" screw?
When you changed cassette, did you put on a new chain?
Your chain may be a bit short, particularly, if you cross chain.

Cant say ive adjusted the b screw. Theres a brand new chain put on after i left the bike in to my lbs. The gears jump and skip all over the place shifting is useless.

smacl

thehamo wrote: »

Cant say ive adjusted the b screw. Theres a brand new chain put on after i left the bike in to my lbs. The gears jump and skip all over the place shifting is useless.

That's more likely bad indexing than size of largest sprocket. See

https://www.youtube.com/watch?v=Bbk5RcH0bbQ

thehamo

smacl wrote: »

That's more likely bad indexing than size of largest sprocket. See

https://www.youtube.com/watch?v=Bbk5RcH0bbQ

Thats what i was hoping the lbs would be able to sort out but they didnt seem to be able to get it right at all.

Ive tried indexing the gears my self. Which is why i gave it up to the lbs in the forst place!

MB Lacey

I have the same set up as you OP, 32t with a med cage deraileur is completely fine - so that's not the issue.
If the lbs fitted a new chain, it shouldn't be the chain.

Did you drop your bike or knock the RD since getting it back from the lbs?
Even a little knock could bend the RD mech in towards your wheel and could be why your gears aren't shifting properly?
Sounds like you need to go back to your lbs.

magicbastarder

thehamo wrote: »

Theres a brand new chain put on after i left the bike in to my lbs. The gears jump and skip all over the place shifting is useless.

that could also raise the possibility of a worn cassette?

thehamo

magicbastarder wrote: »

that could also raise the possibility of a worn cassette?

Cassette is brand spanking new also ðŸ˜

smacl

thehamo wrote: »

Ive tried indexing the gears my self. Which is why i gave it up to the lbs in the forst place!

If you've tried indexing the gears and have a new chain and cassette, next things I would be doing would be cleaning and oiling rear mech and jockey wheels, and if that did not help changing the gear cable inners and outers. A common enough cause of poor shifting in my limited experience is gunk / crap in the cable run which works against the spring in the mech when dropping into a bigger sprocket. Another one I've had is a frayed cable end in the shifter causing similar issues.

borris4

Did you get it sorted?
First thing to do is check the rear derailleur hanger is not bent, you'll be surprised how often this is the cause of erratic shifting especially on the middle cogs.

Keeks

borris4 wrote: »

Did you get it sorted?
First thing to do is check the rear derailleur hanger is not bent, you'll be surprised how often this is the cause of erratic shifting especially on the middle cogs.

This might seem light an obvious question but how do you check if it is bent? should all 3 wheels line up, Cassette cog and two jockey wheels?

borris4

Unfortunately you need a derailleur hanger alignment tool to do this.