I did a group ride this morning in the hills of San Antonio,Fl. I felt good but bottomed out on a compact crank- 50/34 &/11-25 cassette which has me worried about when I do the 3Gap ride of 6Gap later in September! I do have a new 11-28 cassette waiting to be installed. Should I change the chain rings to smaller rings as well?

After quick search I guess Shimano doesn't make a smaller inner ring then the 34 tooth ring?

It's not so much that Shimano doesn't, it's that the F derailer may not like more then a 16 tooth jump.

I've pushed to 20 but not with an indexed F shifter, only with Bar-Cons.

In any event a different cassette will work, up to a point and that's R derailleur dependent and 11-28 will give you an extra gear, but in truth that maybe all the R derailer will handle as well.

Also pay attention to hill gradient. There are actually steeper hills on my native Long Island then what I encountered on the Bike Tour of Colorado. Thus not so much a need for different gearing, just the fitness and lungs to ascend 8 mile Wolf Creek Pass at 10,000 ft., LOL. Having a bike for these kinds of rides is one reason I keep a triple on my steel Soma.

With advice from a poster here, I determined in gear inches the gearing the size of gears needed for myself in advance. This required customizing a cassette with a 30 tooth largest cog with a triple chainring. You might consider the need for, say, a 30 or 32 tooth cog. There are more choices available today and such a cassette may exist without the need to customize.

I ride The old Phosphate mines at the Balm Boyette Scrub preserve and Alafia to name a few.

I rode a 27.5" full squish that had a 3 x 9 system,,I used about 6 of these gears. As soon as I wore out a chain I went to a 1 x 11 with a 32T up front and a 11-42 out back.

I still use about 6 gears

Google Rotonda West and that's my front yard. Will be riding 135 miles July 9th for my 66th birthday around there and surrounding area where I should have about 125' of total climbing since things are soooooo flat. Last year at Six Gap I had my 53/39 with a 12/28 and rode the 103 miles 11,000+' of climbing without major issue on 10 days of notice. My 39/28 is a 36.6 and your 34/28 would be a 31.9 compared to your current 34/25 at 35.8. If your rear can handle it, you might want a 32 for extra cushion if in doubt 34/32 at 28. For as short as it is, Sugarloaf is a good climb for Florida Flatlanders especially at the almost end of the Horrible Hundred and the % is the cause of that compared to the mostly gradual climbing at Six Gap.

If in doubt, have a low-low just in case. Doesn't mean you have to use it.

Friends with LBS just got a house a couple miles from the high school and it sleeps 20. Wife and I are staying next to McDonald's at Motel Inn, also a couple miles from the HS.

You won't be able to simply chage chainring to anything smaller than your 34t.

Yor 50/34 crankset has a bolt center diameter of 110mm. The smallest ring that will fit is 34T. To go smaller would require a different crank. Only a few double chainring cranks on the market combine road pedal spacing and lower ring capability. The 11-28 cassette will help and will probably work fine with your current rear derailleur.

If you have a Shimano 10 speed setup, you could switch to 9 speed MTB rear derailleur (10 speed RD has a different pull ratio and will not work right) and a cassette with up to 36 teeth. You'll need a longer chain as well.

I've ridden 6 Gap several times. If 3 Gap doesn't take you over Hogpen you should be fine with the 11-28. However it if does include Hogpen I'd suggest putting on a 11-32 rear cassette and leave the 50/34 as is. I use the 11-32 with a 50-34 and it's just perfect for Hogpen.

Thanks for your response. 3 gap does the Neels, Wolfpen and Woody gaps. So i should be okay.

Thanks, I'm doing Sugarloaf up and back a couple times a month starting in two weeks so I'll get a better idea of what's needed like you mentioned.

Thanks for everyone's advice! I'll be installing the 11-28 cassette this week and getting a feel of what it'll be like whilst doing the same San Antonio route this coming weekend!

While it may not be the same as to what you will be doing in 3Gap, I have done Sugarloaf on a compact with an 11/25 cassette. It wasn't pretty but I got it done. I don't know what the grades are for the three climbs you will be doing in GA but Sugarloaf goes from a 6% to 9% to 13% grade pretty quickly. If you've never ridden Sugarloaf, here's what to expect:

The RD may well be able to handle a larger cassette than a 28; you may want to use the max cassette in the rear.

Agreed. Hogpen is the only really tough climb of the 6 Gap ride. But I'd rather climb it 10 times on a fixie than come down it once.

John V: Very nice picture, for gearing it is a question of fitness besides grades--if one mostly rides flats it will be harder to ride hills. I don't have a choice where I ride so I do enjoy hills except when it is so hot like yesterday at 98 degrees with no wind!

I checked and I have the 6800SS which max's out at a 28t cassette.

Thanks for posting this John as that's THE Best picture I've seen of Sugarloaf!!! You really get a nice perspective of the different gradients of the hill! Oh, I'll be showing my northern friends this pic to let them know there really are hills of note in here in FLAT FLORIDA!!!

Spending the last year and a half on the beach on my fatbike really opened up my eyes to appropriate gearing. Strange to be spinning away in sand or into fierce headwinds at 6-8 mph. We're pretty flat here though within 7 miles are two sets of headlands that'll give me 800' of very good climbing in a 14 mile over and back. Grades vary from 3% to a couple of 18% pitches () but that fat bike gearing (22, 11-32) allows spinning up with fabulous cardio training at a knee saving pace.

Of course the fatbike weight penalty (33 pounds) and my weight penalty () reminds me that I'm ascending as a touring level cyclist. But it makes riding the Colnago that much sweeter. And my knees thank me.

It is indeed a great if not impressive picture but the hill is relatively short, unless they are many more in succession behind this one! :roll eyes: ;-)

What should be taken into consideration is that the climbing done on that one short hill is more than all the climbing combined for 500 to 1,000 miles worth of bicycling here in SW FL where I live.

I think I spotted at least 7 people pushing their bikes........it probably does feel steeper if you're coming off of flats all day. I wonder how'd they feel facing 3 miles of a climb like that after riding close to 100 miles (Mountains of Misery in Va).

Hey, don't dis on our mountain!

Singular!

Funny thing is that out here we can't ride up our mountains, heck, most people cannot even climb them on foot

Correct me if I'm wrong, but moving DOWN 4 teeth in the front isn't as helpful as moving UP 4 teeth in the rear.

So an 11-32 on the rear (32 - 25 = 7) is going to be massively better for climbing than doing anything on the front.

I have a 50/34 and 11-32, and normally leave my 32 for just in case moments. Not sure what my next size gear is one away from the 32 -- maybe a 28? Either way, the 2nd ring in the back will get me up ~10% for a mile...but it's a struggle.