Drivetrain questions

[Sectrix]

I'm in the midst of upgrading my bike for a TA tour. I did consider buying a new one, but it was far too expensive. I've gotten to the point of looking at my gearing, and from the few thousand miles I've put on it on day trips I think I need some lower gearing. It's an 8 speed, and currently I'm running 28-38-48 up front and 11-12-14-16-18-21-26-32 on the rear. I was thinking of Sheldon Brown's custom cassette:13-15-17-19-21-23-26-34. Has anyone used these before? Does the combination work well for you? Should I also perhaps find a smaller front sprocket? Would it be worth it to upgrade my derailleur to a long cage version? I realize vastly different solutions work well for different people, but I was just wondering what everyone thinks about this topic.

Thanks for any help!

[staehpj1]

I'm in the midst of upgrading my bike for a TA tour. I did consider buying a new one, but it was far too expensive. I've gotten to the point of looking at my gearing, and from the few thousand miles I've put on it on day trips I think I need some lower gearing. It's an 8 speed, and currently I'm running 28-38-48 up front and 11-12-14-16-18-21-26-32 on the rear. I was thinking of Sheldon Brown's custom cassette:13-15-17-19-21-23-26-34. Has anyone used these before? Does the combination work well for you? Should I also perhaps find a smaller front sprocket? Would it be worth it to upgrade my derailleur to a long cage version? I realize vastly different solutions work well for different people, but I was just wondering what everyone thinks about this topic.

There are personal variables, like your preferred speed and cadence, what you weigh, and how much you will be carrying.  Some folks like super low  or rather high gearing and some get by on less extreme combinations.  Three of us did the TA on bikes that came with  30/42/52T paired up with and 11-32.  We all replaced the crank with one that was 46-36-26.  One of us put a 24 on in place of the 26 before the start and another did the same in Missoula.  I did the Whole TA with the 46-36-26 and the 11-32.

I didn't feel the need for anything lower than the 26-32 in the Cascades or the Rockies.  There were a few places in the Appalachians where a 24 would have been nice and I have since installed one.  Still the 26 was "adequate".  Personally I used the 46-11 high gear a lot and would not have wanted to lower the top gear much if any lower.

[DaveB]

Easiest and cheapest change is to replace the 28T chainring with a 24T.  It's a bigger % change than going from a 32 to a 34T rear cog and much less expensive than changing the cassette.

Are you sure you don't already have a long cage rear derailleur?  Almost all bikes with triple cranks come with them and your current gearing would be very limited if your rear derailleur is now a short cage.

[staehpj1]

Easiest and cheapest change is to replace the 28T chainring with a 24T.  It's a bigger % change than going from a 32 to a 34T rear cog and much less expensive than changing the cassette.

I agree.

Are you sure you don't already have a long cage rear derailleur?  Almost all bikes with triple cranks come with them and your current gearing would be very limited if your rear derailleur is now a short cage.

I agree here too.  It seems unlikely that you have an 11-32 and a triple and do not have a long cage RD already.

[paddleboy17]

If swapping the granny gear to a 24 works for your then I say great.  I have not researched that in a while so I don't know if there is a 24 tooth granny available that will git your crank or not.  It may (or may not) shift like crap as going to a 24 from your middle is a big drop.  I think you will just have to try it out and see how it works.

If you want to swap out the crank, a compact drive mountain crank should be just the thing.  You will also need the corresponding front derailleur changes out too.  I like the new Shimano LX crank, but there are other good choices from the other component makers.

[Sectrix]

Are you sure you don't already have a long cage rear derailleur?  Almost all bikes with triple cranks come with them and your current gearing would be very limited if your rear derailleur is now a short cage.

Not sure at all, but it sure makes sense now that you mention it. It appears to be a SRAM SX4. After some research, I've found it is a long cage.

I see your point, staehpj1. Even in relatively flat Illinois, I've still hardly used my highest gears, so I think on a fully loaded tour I'll be more likely to stay relatively low. My buddy I'm riding with is using a mountain bike, so he won't have very high gears either. Thanks for the advice everyone, I think I'll swap out to a 24T and see how it goes.

[Westinghouse]

It depends of what kind of cycling you will be doing, and the terrain. Getting around occasionally on level to rolling roads with no considerable load can be done easily enough with just about any combination of gearing, such as what you already have. If you are talking about crossing the Apls and Rockied on a fully loaded, self contained tour of thousands of miles, I would say you might want to give a bit more consideration to your choice of gearing. How strong are you. What do you weigh? I cycled loaded over the Alps with a double chain set on the front, and a five gear freewheel. That was years ago. If I were to do it again, I would definitely use a triple chain set on the front.