donheff

My wife and I are looking at a variety of road bikes to replace our current cyclocross bikes. We will be keeping the old bikes at a weekend house. I would describe our riding style as quick touring. We will cruise along at 15-18 but rarely get up to 20 on the flats. we both are wusses on the hills and both ride triples on our current bikes. On steep hills we both frequent the granny. It looks like almost everything available in 105 road bikes are 50-34 compact doubles with 11-28 cassettes. So far we haven't really liked the SRAM (which we have seen with larger cassettes). My question - if we go with 105 do we have a lot of flexibility on cassettes if we decide we want more low end? Can we just swap in an Ultegra 11-30 or even a mountain bike cassette with more low end or do each of these things fit on different hubs or demand different derailleurs?

chasm54

Before worrying about the cassette (there are limitations, and beyond a 28 I think you may need a new rear mech) I'd suggest you don't give up on the triple. The Specialized Roubaix comes with a triple variant, in both the Elite and Expert configurations. And speaking for myself, if you feel you want the low gears I think you are better with a triple than a big cassette at the back, because you can have the range while keeping nice close ratios.

I'm sure there are other options with a triple, too. They are becoming fewer in number, but there are still some out there.

Barrettscv 

I agree, stay with a triple.

The newer Shimano road ten speed rear derailleurs accept larger cogs than before. Tiagra is now ten speed. Current Ultegra, 105 and Tiagra can take a ten speed 12-30 cassette easily. It's also possible to fit a 11-32 ten speed cassette with current Ultegra, 105 or Tiagra series long arm "GS" rear derailleur, unless the rear derailleur hanger is shorter than normal.

I'm using a ten speed Tiagra 12-30 cassette with a current Ultegra rear derailleur, it works perfectly.

cccorlew

There is in theory an Ultegra 12-30, but no one has seen it. There is a Tiagra in that size, which I've used on hilly double centuries.
The regular deraileur works on some bikes. On others you need a long cage.
I prefer a triple as I hate big gear jumps.

Barrettscv 

The Ultegra 12-30 is not available yet, but will be soon: https://techdocs.shimano.com/media/te...9830799947.pdf

cyclinfool

Maybe I missed it but you did not mention what your current cassettes are. You may find that a compact with a 28 low gear is equivalent or close to what you are currently riding.

You can run the numbers on this calculator: https://sheldonbrown.com/gears/

stapfam

I know I have hills and run a triple 50/39/30 with an 11/25 cassette. If steeper or more hills I change to 11/27 cassette and at 30/27 on most of our hills I manage to keep the cadence above stress level. There are occasions when I feel that a 30t may help and that would give me a low gear of 30/30 which is sustained mountain gearing to me and is what I used in the Alpes a few years ago.

Problem is finding the bike you want with a triple. I also ride compacts with 50/34 and I am not fit at present so the steep hills are taken at a low cadence and a bit more joint stress. There is always the chance that the shop will change a compact to a triple at a "Nominal" charge but there are several manufacturers that make bikes in compact or triple. Saying that I thought Giant did but can't see one on their site.

But getting back to that low gearing-I climbed mountains with 30/30 gearing-or 1 to 1 ratio. If you try to get this with a compact you will have to think a 34 cassette and 34/34 will be that 1 to 1. It would involve a rear derailleur change and a longer chain but would do the job. The problem would be the ratio between the gears and it could bug you on the lower gears. Just struggling in one gear with cadence low and change down and find yourself spinning a bit too fast. I get that with the 12/27 so for me an 11/34 would be worse. But when gravity goes the wrong way and you start slipping into those lower gears- you need them. I know I do.

But have you been able to try a compact geared bike up your steeper hills? The jump between the 50 and 34 is something you get used to so will not be a problem. First road bike with a triple and low gear was 30/26. I was blowing first few times up the steep hill in our area and never got any easier. Then I got a compact with 34/27 and eventually tried that hill. It was hard with the compact but no harder than with the triple but it was faster. Different quality of bike I know but the gearing was something I did get used to. Bought my last bike only a few months ago and a compact 50/34 with a 12/25 cassette. That is not a hill bike for me but will be when the Tiagra 30t goes on it.

BluesDawg

For the most flexibility, either go with a triple or on a compact double, replace the rear derailleur with a MTB version so you can go with the widest range of cassettes, up to 36 teeth. 30 and possibly 32 teeth on the cassette are doable with most standard compact setups.

Monoborracho

I run a compact double Ultegra 50/34 with an XT - 11/32 mountain bike type on my road bike. It draws a few looks and comments from people at the rest stops on hilly charity rides, usually of the variety of "why didn't I get that" ?.

donheff

Sorry I should have mentioned. We both got 50/39/30 triples with 11/27 cassettes. These were our first bikes after returning to riding about 6 years ago. This is almost embarrassing but early on we were both noticing that the hills were still harder than on bikes we used on vacation (VBT - I think their standard uprights use MTB gearing) so we switched out the front 30s for 28s. I have been tempted to switch back to the stock 30 because the 28 is out of spec and my wife occasionally drops the chain off the small ring and I have to put it back on.

I think this is where I am. We recently traveled in California and rented a few road bikes at various places. We were surprised that the compact doubles seemed doable on some pretty nasty (for us) hills. Like you say, you end up taking them faster with more stress. Maybe the light bike weight helps as well. For this reason I am tempted to go with the bike that feels good to me but am interested in the issue of swapping cassettes if I end up with a double and want a bit more range.

From what I am reading here I will probably have some flexibility in that regard and should just explore the options with the LBS.

donheff

These quotes bring up new questions. While searching I read some posts about swapping a Tiagra cassette for a 105 and even one that talked about swapping two rings from something (I think Tiagra) into an Ultegra cassette to build a custom set with a wider range. So, it sounds like there is a lot of flexibilty in these things. What are the actual differences between the various 10 speed cassettes (Tiagra, 105, Ultegra) other than tooth counts -- different materials? And does a degree of interchangeability extend to other brands or just within a brand? Going even further to Monoborracho's situation, does switching all the way to an MTB cassette require changing the rear derailleur and or the shifter or can you just pop a new one in?

bud16415

On my tour bike that I mainly ride as a road bike I have the 12-36 (9 sp) and love the ranges I get. I went hog wild up front for touring with 52-42-24 and have a range of 6 granny gears to cascade on with rolling hills. I have a road bike with the modern double and much rather take out the heavier bike with the triple.

If your wife is missing the granny gear once in a while get a chain minder installed on her bike. There are a bunch of different ones on the market and they all work about the same way. I have one dropping from 42 to 24 and it never misses.

Barrettscv 

The shifting quality of Shimano cassettes is very much the same regardless of group, such as Tiagra, 105 or Ultegra.

Construction, weight and durability change with each level, although it's hard to find much difference between 105 and Ultegra cassettes. The less expensive cassettes tend to be the most durable, but are heavier. The more expensive cassettes are lighter, but might use alloy on a few of the cogs, these will wear more quickly.

Some of the newer cassettes need to use a matching chain for best performance.

BluesDawg

If you go with a 34 or 36 tooth MTB cassette, you will definitely need to change to a MTB rear derailleur. You can most likely go to 30 and quite possibly 32 teeth with the standard road RD, but it may require adjustments to make it work best.
Just to confuse things further, Shimano 9 speed MTB RDs work fine with Shimano 10 speed road shifters and either Shimano or SRAM 10 speed road or MTB cassettes, but Shimano 10 speed MTB RDs will only work right with Shimano 10 speed MTB shifters, not with road shifters.

chasm54

Seriously, before going to the mega range cassettes and derailleurs, consider what you can do by keeping the triple. Speaking for myself, I find the big drop at the front - 50/34 - coupled with big steps up at the back, make it more difficult to find the "right" gear than with a triple and a smaller cassette.

donheff

Thanks, I get that. I am just curious about the options available if I fall in love with something that only comes in a compact double.

bud16415

Many seem to like the Granny gear in the front as kind of a one trick pony. And that’s how they use them on the mega range cassettes. I don’t care for just having that one choice when on the Granny and looked at it as if you have a triple why not give yourself a good 6 granny gears to pick from and avoid making shifts up front while climbing. Rear shifts are much easier shifting off the bottom of the chain line where it isn’t under tension while climbing. Also keep in mind a 3 tooth jump on the bigger gears is about the same percentage wise as 1 tooth on the small end of the cassette.

Barrettscv 

+1

I'll use the granny on any long hill greater than 5%. Once I know my speed will stay above 8 mph for the next few miles, I'll go to the middle ring and stay there. It's best to avoid upshifts on the front chainrings under any real load.