Hello all. New to working on my bikes and I had a question. I want to change the cassette on one of my bikes to something a bit better and am soliciting any advice for doing so. My bike currently has a 14-28 cassette and a Shimano Tourney derailleur (see pictures). I want to install something like a 11-32 or at least 11-28.

1. Do I also have to change the chain?
2. Any difficulties to look out for or special tools needed to change the cassette?
3. Will the existing derailleur still work? Is it compatible (reach) with new cassette?
4. Anything else I should know before attempting it?

I attempted to post a photo but due to my new status to the forum was unable. I hope I have described the situation well enough.

How many rear cogs do you have? A Touney derailleur suggests that you might well have a freewheel and not a cassette. If the rear has 7 cogs, it is very likely that you have a freewheel. If you have a freewheel, an 11 tooth small cog isn't going to happen
This is why it is a good idea to include a few more details about your bike

Shimano Tourney is a low end derailleur and you most likely have the matching Shimano MF-TZ21 which is the common 7sp freewheel that is threaded to the hub.

You can only change the FW for another FW.

You cannot slide a cassette onto a threaded hub that expects a FW.

Assuming you do find another FW with the cogs you want (SunRace, SRAM, DNP, Falcon, Power) I always recommend riders to try it first with their existing chain, because if a rider never uses the extremes like 11T x Granny-gear, or 34T x 48T, then the existing chain is ok as most folks just stuck to the FW x 38T up there.

14-28 & Tourney screams Free Wheel, not Casstte.
Here's how to tell the difference.
https://www.sheldonbrown.com/free-k7.html

what is the tooth count of the FRONT large sprocket? it will be far easier the swap on a different, better, LIGHTER crankset and then go to a 13-34 freewheel in the future...

Does your tourney rear derailleur say "MegaRange" on it?
is the large sprocket on the front a 42 tooth?
if yes, then you can locate an old 46/36/24, or something similar to replace the stock crankset... and it will be smart to upgrade to an aluminum crank/sprockets at the same time...
And.. if you get help selecting the crankset, the bottom bracket spindle will not need to be changed... i look at the spindle hole at the inside of the cranksets, and how it relates to the smallest sprocket on both cranksets.... there are three basic configurations... inny, outy, and middy.

and yes, you will need a new chain.. KMC and SRAM make nicely priced, but far better, chains than the one on your bike when it was new.

And since you're new here.. Hi... if you tell us what bike you have, Model and brand, we can look it up if it's not one that's already known.

This bike (I worked on a Tourney equipped bike over the last few weeks for a friend which did indeed have a 7speed freewheel rather than cassette+freehub) probably has a 126mm spacing between the rear dropouts which isn’t compatible with 8speed or higher casettes even if you change the wheel & therefore hub. You can stretch it in some cases but likely not to the 135mm you’d need. If you need more gears to get the 11-32 range you want which I think you would. And you also need to change the shifters of course in that case.

You do need a special splined tool to get that freewheel off, and to work with a cassette you need the same splined tool to loosen and tighten the lockring plus a chain whip to stop the freehub spinning, just when you try to loosen it.

fify

The same splined socket fit both my old Giant FW and my 105 11spd cassette, so there is a good chance his will do the same, if he buys one. Just saying

Park FR-5g and Park FR-1.2 will not work like that... i can see how a cheaper version of a FR-1.2 MIGHT work in both...
the FR-5g is too big to go into a freewheel spline.
the FR-1.2 would be too loose in a cassette lockring, if the splines were narrower than they are, or they were forced into the lockring..
lockrings have been known to break.... i'll keep using two different tools.

Hmmm

I’m 99% sure I used the same one on this freewheel

First, people are assuming that it's a Shimano type freewheel, which it may not be. We have no clue about the bike 5/6/7/8 speed? Tourney a later replacement on an old bike?
Are FR-1 and FR-5 interchangeable in use? Sometimes, sometimes not, but they are not the same.

yeah very good point.

Pic assist:

Everyone above is correct- this is a 7 speed freewheel.

https://si.shimano.com/en/pdfs/si/6V...-SINGAPORE.pdf
From the documentation, this RD-TY21 is limited to: rear largest sprocket = 28t, and rear smallest sprocket of 14t. So unfortunately you are stuck with what you have.