Depends on the course I guess. Anything you'd need that 28 for?

My TT bike is a "speed machine" only. So 12-25 to race. I really appreciate the single gear changes in the "meat". People pick on my love of the 16t and 18t cogs. They can't be pried from my rabid hands.

Now, if I had to go 56 or 112mi instead of just 25 or less, and I had a couple hills to get up I would consider the 11-28 instead.

If in debate, just buy a few discounted 5800 cassettes on the cheap and try it out. Then sell if you don't like something at a loss of a couple craft brews worth of cash.

Then, buy a nicer version of what you end up liking.

I have a 52/36 crankset. I run 11-25 cassettes on my bikes all the time. I rarely hit a climb that needs a 28. My only three exceptions when I used a 11-28 cassette are when I rode the Six Gap Century, when I spent a few days riding the mountains in South Carolina, and when I did the WC 70.3 in France. I lived on the 28 tooth on those rides.

I was using it on 7% plus climbs. I'm a spinner and prefer to keep my cadence higher. I used to mash and now the opposite maybe to a fault. I have that triathlete mindset...save the legs at all costs. Haha!

Will my 11-28 on the trainer be utterly useless? I just set it up and hate to swap it around. I could move it over to my snappy 30mm training wheels for days where there is more climbing and run an 11-25 on the 90, disc and trainer. I'm really not sure.

I'm almost leaning to keeping the 11-28 on the trainer and adding an 11-28 to my 30mm.

11-25's on the 90mm and disc.

Don't tie the cassettes to specific wheels. if you have a course that warrants a disc and an 11-28, then put that on. if you only need an 11-25 (or less) then run that.

For flat courses, (which we don't have around here) I'd just run an 11-23 to get nice tight spacing.

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This X10. You reminded me of something I forgot...I do not have an 11-25 on my TT disc wheel, I have an 11-23. I forgot I bought a prior gen Dura Ace cassette before Shimano abandoned the 23. It is freakin' great on flat courses, and I almost never need more.

There is no should. There's what suits you, and I don't see why it would change between racing and training unless you always train on one type of terrain and race on another.
Cassette choice depends primarily on the terrain and weather you'll ride in, how strong a rider you are, how far you'll be riding, and the cadence ranges you favour.

If you're only getting one cassette and you don't know what you should get, then by default you should go with the wider range cassette. Far, far, far better to have more range than you need as opposed to not enough!

If you're on an 11 speed, then an 11-28 isn't much of a compromise in my opinion. I put an 11-32 on my road bike one year just as a fall back plan for riding La Marmotte. It stayed there a loooong time, since it really had no down side and meant I could spin up any climbs I liked. I kinda expected to find it too wide but that really wasn't a problem. Remember 9 speed was the norm only a decade or so back. An 11 speed 11-32 gives you similar gaps to a 9 speed 11-25, and just adds another 2 sprockets. 11sp 11-28 is approximately equivalent to a 9sp 11-23 or a 10sp 11-25. Wide range cassettes should be the norm for almost everyone, with narrower cassettes being a luxury for those who hang onto multiple cassettes and will change the cassette to suit the individual ride.

My tri bike has 52/36 chainrings and 11-28 cassette most of the time, but I switch to an 12-25 occasionally on really flat or shorter routes when I could be bothered to take 5 mins to change the cassette. I'd hardly notice if I didn't own a 12-25, I wouldn't be without the 11-28.

I do the same thing. I've run 11/23 to 11/36 on race wheels

I'm still on 9s, so I'm using 12-twentysomething on all my cassettes. I've got a 12-21 on one of my wheels right now.

I really do need to pick up a 12-27 or 28 though. my biggest cassette now is a 12-25 with 53/39 cranksets. Its uphill to get to my house, if I go the steep way I think the grade is like 15%. not too long though, but if my legs are trashed then it means either struggling up the wall, or riding around to the other side, which is more climbing and about an extra 3 kms.

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Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly

Same. I train on my road bike with a compact 50/34 and 11-28 at the back. I've got a standard crankset 53/39 (but sometimes 53/38) on my TT bike that I won't swap for races because it is also my power meter. If I do the Outlaw, which is 95% flat, I'll ride a 11-25 cassette but when I went to do Norseman I bought a 12-30 (Miche as it has better spacing) and put the 38 tooth small ring on the front, because it is hilly AF.

Cassettes need to be viewed as interchangeable and geared (literally) towards the course.

Cheers, Rich.

I would not run an 11/28 on race day. If the course is hilly and you need a 28, use an 11/30 instead. Better safe than sorry, and they’re the same gears from the 21 to the 11.

But, if you don’t need the 28, definitely go with the 11/25. The 11/25 has the 16t cog where the 11/28 has a gap between the 15 and 17.

A very handy tool: http://ritzelrechner.de/ just be sure to correct all the defaults entries!

One more truth you reminded me of... I think the 11 cog is useless. If I could ride a 12-23, that is what I would use.

Yessir!

I have seriously considered buying a rivet tool and making my own cassette. I always see the barrier to 12/23 in the cogs that are riveted to the body together versus what is available randomly “loose” on the internet.

So I need an 11-25 on my disc for flat race courses. I have an 11-28 on the trainer, which I suppose is fine. I'm thinking of running 11-28 on my 30mm's and I could go either way on the 90mm.

that's one of the reasons I never migrated to 10s. All I would gain is a useless 11T cog. and my wheels aren't 11s compatible, so I'm stuck in the dark ages.

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Swimming Workout of the Day:

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Train on whatever you need, but own that smaller cassete for days when you want the closer range. Buy a lockring tool and chain whip if needed, they are very inexpensive or make the chain whip yourself.

The only thing to be aware of is wearing the chain to the point where it skips when you put your race wheel on. That's no fun.

I have the whip, lock ring and crescent wrench. Sounds like I need one 11-25 minimum. The rest would be whatever combo preferred 11-28, 11-30, etc.

As a few others above commented, there really is not one "should." You should outfit your bike with the wheel and cassette specifically optimized for the upcoming event. I dislike riding a cassette with wide spacing, so I will always prefer the smallest cassette I can for the conditions.

In my case, I rarely need anything more than a 25 unless I get extended climbs steeper than 8%. So, I have an 11-23 and a disc wheel setup on my TT bike most of the time. (The disc is the only wheel I have for the TT bike.) I have an 11-25 on my road bike most of the time. I have an 11-28 on my trainer because that is simply what I had left over. On the occasion when I am taking my road bike or TT bike on a ride or race with tough climbing, I swap to an 11-28 on that bike.

Yes, if the 25 is just going to be your race day setup then no sense in owning more than one.

The rule of thumb is: train as you race. So if you're used to the 11-28, then stick with that.

what is there to get used to? Unless you're always training on the same courses that you're racing on, at the same power outputs, for the same durations, you want to run the appropriate gearing for whatever event you are doing, whether you are "used to" that cassette combo or not.

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Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly

I'm thinking 11-25 on the disc and 11-28's on the trainer (existing), 30mm (training wheels) and the 90mm (can go 11-28 for ripping around on or 11-25 off the disc wheel for racing if I ever KQ...wink). Unless there are other thought. I could use an 11-30, but it's bigger perhaps I don't need the extra gearing and weight. My bike build comes with a standard 11-28 as well.

If you want an 11-30, make sure your RD can accommodate it.

Forget about weight differences when selecting ratios, the weight is inconsequential to having the correct gearing. If you want to chase weight savings, then go with a higher end cassette, eg DA instead of Ultegra.

I wouldn't get too hung up on 11-25 vs 28 if you're looking at something for flat courses. neither are ideal for that scenario, although I understand that an 11-23 is hard to come by these days. on a flat course, I'd run as close to a straight block as I could for the smaller jumps. it's not just about being closer to the optimal cadence, it's also smoother transitions in cadence when shifting gears.

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Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly

di2 braze on short cage RD. Should accommodate 11-30, but I think I'll roll 11-28 and one 11-25 for flat races. I think 11-28 should cover most terrain.

I don't think anyone has mentioned this yet, but you may also need to consider chain length if you are planning to swap between a 11-25 and a 11-30. You are probably ok if you are just swapping between 11-25 and 11-28. The loosest (small-small) gear is the same, so no worries there. But the big-big gear might be an issue if you sized your chain on the 11-25 cassette. (not that you should use that big-big combo anyway)