Fit larger Cassette & New Chain

joefisher

Hi guys,

I have a new cassette coming (Ultegra 6700 11-28) and chain (Ultegra 6701) to replace a 12-25 Ultegra 6700 cassette and chain, using with a 53/39 FSA Carbon Crank on a CAAD10 Ultegra 6700.

I have never done this before and can't do this until the day before I ride some hills on it and would really appreciate and idiots guide to doing this. So:

How do I do this?
What tools/stuff do I need?
Will I need to re-tune the gears (if so just the rear mech?)
Once I have set it up, and say days later I have a flat course and need the 12-25 - is it possible to re-fit this and that chain easily? Will I need a masterlink etc if so which one and how?

FWIW I'm a total NOOB at this and often end up breaking my bike when I try to fix stuff!..

I know I have to put the chain in the big/big and cut appropriately - how and using what tools and again can I continue to swap these cassettes and chains around when I need them and re-tune the gears?

Thanks

majormantra

Check Park Tool for specifics on swapping cassette etc.

If your gears are already correctly set up you shouldn't need to make adjustments with the possible exception of the B screw on your rear mech, but only if the mech fouls on the bigger cassette.

I suggest getting some KMC links (Shimano 10 sped specific version) if you want to swap chains. I doubt you'll feel the need though. After all your new cassette has a wider range, so you'll be fine unless you're being obsessive about gaps between gears.

FWIW it's easier to set chain length in small/small WITH the chain threaded through the rear mech. Just cut the chain to be as long as possible without rubbing on the upper jockey wheel.

JayKosta

You will need a lockring spanner to remove the lockring that holds the cassette to the freehub body. The rest of the cassette should be able to be removed/replaced without additional tools.

You'll need a chain tool - it is used to push the chain's pin in & out so you can add/remove links and adjust the length.

I'd try the new chain at its full length with the new cassette, and see how it functions on a test stand.
As long as the rear deraileur is able to accommodate the length of the chain in all gear positions, AND the pulley doesn't rub/hit on the gears, it should be ok.
Watch the chain and deraileur closely and don't try to force anything.
The front deraileur should be ok as-is.


There are probably thin spacers that are used on the 'big end' of the cassette to get the gears of the new cassette into the same position as the old cassette.

If the gears on the old cassette have a lot of wear (shape of the teeth is different than new), then the old cassette might not work well with the new chain.

The new cassette should be good for your 'flat ride'. Trying to swap cassettes is asking for problems.

Jay Kosta
Endwell NY USA

joefisher

Thanks guys.

Jay - I bought the 11-28 for the hills, not the flats!

Can you recco good chain tools. Park Tools I guess?

The other cassette (12-25 and chain are both brand new so wear shouldn't be an issue, more cable stretch as the bike is new too.

Majormantra - not sure what you mean about "your new cassette has a wider range, so you'll be fine unless you're being obsessive about gaps between gears." Can you please explain more? Sorry!

Thanks

Joe

majormantra

As in, the only advantage of the 12-25 over your new cassette is that the jumps between gears are smaller, so I wouldn't bother switching back to it for the flat.