trinamuous

Just bought a new (to me) road bike with a 6500 groupset. It has a 12-23 cassette currently, but I think that having a 25 cog would be handy, given that I am in the infancy of my cycling journey. I would prefer to buy a used cassette off of Ebay. Ebay ONLY has 12-25 cassettes (currently at least). It seems that a 13-25 might be preferable, as it retains the 16 cog present on the 12-23, at the expense of the 12 cog. Is the 53/12 combo utilized that often on training rides? I can understand needing the 12 for race situations. Note that I am not racing, at least not anytime soon. Also note that I can have my cake and eat it too with a 10 speed, but I will not be building a 10 speed rig until I have spent enough time on my $200 bargain buy and know what I want. Thanks.

tiggermaxcocoa

I run a 46/34 with an 11/32 9 speed cassette cassette on my road bike. I barely ever use the 46/11, or even the 46/12. I think people worry too much about "having the right gear." Honestly, I doubt you'll ever notice not having the 16t cog. And if you switched to the 13/25 cassette, I doubt you'd ever notice not having the 12t cog.

Check out Sheldon Brown's gearing page: https://www.sheldonbrown.com/gears/

rm -rf

I have a 13-26 Campagnolo 10 speed cassette, with 50-34 chainrings. The cogs are 13,14,15,16,17,18,19,21,23,26. I like having the 16 and the 18. I can spin up to about 33 mph or so, then I coast on downhills above that speed. With a 12 cog, I could probably pedal up to 36 mph.

The 34-16 is good right about 15 mph, and the 50-18 near 19 mph. I like having very close ratios between 18 and 21 mph.

See Mike Sherman's gear calculator. You can see the speeds for any pedal rpm for your set of gears. It now has a nice graph with the speed ranges for each gear combination for a range of rpms.

Edit-- Like tiggermaxcocoa says, you probably won't miss having a particular gear. In the winter, I use my older cassette on a winter wheel. It's 12-25 and I don't really notice the difference. Of course, I'm not going on long rides or big climbs in the winter.

trinamuous

Heh...I use that extensively...and have a massive Excel spreadsheet doing all sorts of ratio comparisons that goes way above and beyond Sheldon's calculator (I'm an Excel geek).

I have a 52/40 14-28 (6 speed) Columbus Tenax steel bike with a Brooks I can use for long, steady rides if I want it. My 9 speed bike will be used more for fast-paced group rides.

You're in all liklihood correct that I would be fine with either the 12-25 or 13-25, but I am curious why the 12-25 seems so much more prevalent. It's probably just because that's what comes stock more often, despite the fact that on paper the 13-25 seems to make more sense. I would think that if one is Billy enough to need the 53/12 often, that said person wouldn't need the 25 anyway (not in flatish DC anyway).

a_phat_beat

i've had a shimano 10 s setup on my first road bike for a while, 53/39 and 11/25 (i believe). and the shifting was perfect.

recently built up another ride with campy 10s, same setup on front but a 13/29 in the back. the transitions between gears are definitely more noticeable.

i put the wide gearing on the back mainly because it's an old steel bike, relatively heavy and i plan on doing longer rides with it.

If what you have works for you, go with it. experimentation doesn't hurt either. try some new stuff out. if you don't like it, at least you won't be left wondering.

trinamuous

I'm basically just annoyed that there are no 13-25 6500 cassettes on Ebay

Yaniel

it depends on the rider and what you're doing though. i have a 12-25 on my bike and find myself rarely using the 25 but very often I'm in the 53x12 trying to switch another gear because going over 90 rpm for extended time wears me out too quickly. Also when cruising along I'm usually jumping between 53x17 and 53x19 wishing I had an 18 because I find the difference in cadence to be uncomfortably large between them.

trinamuous

I figure by the time I get conditioned to your level, I will be itching to build my next project: Rival groupset on a cheap Ebay frame of my choice. I'll also know what high/low gears I need. Good to know that people really do find use for the 18 though. I'm probably be doing a ~25 mi (+18 miles rountrip to get to the start and back) non-competitive event ride this weekend with the 12-23. We'll see how I handle it without the 25. Who knows, maybe I'm not as weak as I think I am. It's been hard to gauge progress doing only loaded winter commuting for the past several months.

Yaniel

haha i'm not a very conditioned rider, i'm just a really good wheel sucker!

trinamuous

Ha. I suppose I need to get out on some group rides and before making cassette decisions. Mother Nature's quest to deny me this experience ends this month!

Yaniel

I wouldn't worry about the cassette, just get out there and ride when you can! I'm dying to change my cassette but wont do it until is worn out, it seems like a waste of money other wise.