[yukmak]

Hi folks,

My wife and I moved to Colorado and the hills here are killing us! That, coupled with the need to pull a child trailer (new baby), has made me decide to look at getting easier climbing gears for our road bikes. And no, getting in better shape is not something I would suggest to my wife.

I'm trying to find out the cheapest way to go. I've talked to several bike shops, and have heard suggestions ranging from upgrading to triples, to getting smaller front gears, to bigger rear cassettes (including going to MTB cassettes and derailleurs). It seems like every approach has its caveats, like going with a bigger cassette might force me to get new derailleurs, and going with a MTB cassette might make the gaps between gears too big. So any opinions on what would be the best way vs the most economical way?

My bike has Campy Mirage with 53-39 front, and 12-23 rear (8 speed). My wife's is Shimano Tiagra with 48-36 front, and 12-25 rear (9 speed), which is lower than mine because it started out as a cyclocross bike.

 

[Spoke Wrench]

That's really a question that only you can answer. How low of a gear do you think that you need?

I put a compact crankset on my road bike and I like it a lot. I kept my same cassette and front derailleur and shortened my chain by one inch so the only thing that I had to buy was the crankset. It gives me just enough boost to get up some hills that I used to avoid riding with this bike before.

If you need even lower gears, you'll probably have to convert to a triple crankset but that's expensive because you have to buy so many parts.

 

[yukmak]

I might be OK with a compact, come to think of it. Any idea what the smallest is you can get? My wife's crankset is 48-36, would that be considered a compact already? Perhaps the cheapest way to go would be, if they make one smaller than she has now, get her the smaller crankset, and install her current one on my bike. Or would the whole Campy vs Shimano and/or 8 speed vs 9 speed prevent me from doing that? Can't we all just get along?

 

[nazgul]

I might be OK with a compact, come to think of it. Any idea what the smallest is you can get? My wife's crankset is 48-36, would that be considered a compact already? Perhaps the cheapest way to go would be, if they make one smaller than she has now, get her the smaller crankset, and install her current one on my bike. Or would the whole Campy vs Shimano and/or 8 speed vs 9 speed prevent me from doing that? Can't we all just get along?

Sounds like your wife already has a compact (the smallest ring you can put on a regular crankset is a 38). You can start by getting her a smaller small chainring (a 34), and if that's not enough, get her a cassette with easier gearing (e.g. a 12-27). If a 34/27 isn't low enough of a gear, the next step would be to go for a tripple, which could give you a 30/25 or 30/27 low gear.

 

[ericm979]

"compact" means a 110mm bolt circle diameter (the diameter of the circle of bolts that hold the chainrings on to the crank arm). Normal shimano and aftermarket cranks use 130mm bolt circle; Campy standard is 135mm. The smallest chainring that fits on 135mm BCD is 39t, the smallest that fits on 130mm BCD is 38t although 39t is most common. The smallest that fits on 110mm BCD is 33t although 34t is most common.

Use www.sheldonbrown.com/gears to calculate gear ratios of different combos.

Going to a compact for your bike, and smaller chainrings on your wife's bike (assuming it is already a compact; most CX bikes have 48/38 non compact cranks) would be the next to cheapest way to get lower gears. The cheapest would be new casettes, or new MTB cassettes and used MTB rear derailleurs off ebay.

 

[yukmak]

"compact" means a 110mm bolt circle diameter (the diameter of the circle of bolts that hold the chainrings on to the crank arm). Normal shimano and aftermarket cranks use 130mm bolt circle; Campy standard is 135mm. The smallest chainring that fits on 135mm BCD is 39t, the smallest that fits on 130mm BCD is 38t although 39t is most common. The smallest that fits on 110mm BCD is 33t although 34t is most common.

Use www.sheldonbrown.com/gears to calculate gear ratios of different combos.

Going to a compact for your bike, and smaller chainrings on your wife's bike (assuming it is already a compact; most CX bikes have 48/38 non compact cranks) would be the next to cheapest way to get lower gears. The cheapest would be new casettes, or new MTB cassettes and used MTB rear derailleurs off ebay.

I took a closer look at my wife's bike, and I the crankarm has another set of bolt holes on the inside of the ones that hold the two chainrings, almost like a granny gear could fit there. Also, we bought it in 2002 (it's a Surly Crosscheck), and some of the posts I've read seem to suggest compact cranks didn't show up until 2003. So, if she doesn't have a compact crank, what does she have then? Will I still be able to get a smaller chainring for it? If that second set of bolt holes can fit a granny gear, would I be able to get one, and get her a new shifter, without having to get a new BB?

Ok, I ran out to measure the diameter of the bolt holes, and while I had to make an estimate because there are no diametrically opposed bolts, the result was much closer to 110 mm than 130 mm, I actually measured about 4.25 inches = 108 mm. I assume the measurement would be from the center of the bolt, across the center of the crankarm, to where another bolt would have been? So I am hoping it is a compact then. Here are pics of it.

 

[gmcastil]

That is a moutain crankset without the granny ring. You can see the mounting holes milled into the spider. Looks a lot like a touring setup, which would probably work pretty well for you. I, too, live in Colorado and run a 50/34 with an 11/23 and have found that I spend an awful lot of time in the big ring. I would probably appreciate a 36 tooth ring instead of the 34.

 

[Bikinfoolferlife]

To measure your crank's bcd, use Sheldon Brown's shortcut method of measuring center to center http://www.sheldonbrown.com/gloss_bo-z.html

 

[Al1943]

I took a closer look at my wife's bike, and I the crankarm has another set of bolt holes on the inside of the ones that hold the two chainrings, almost like a granny gear could fit there.

If you add a granny gear you will probably need a longer "triple" bottom bracket but not a new shifter, the 9-speed Tiagra shifter is double/triple.

Al

 

[Cory]

If you add a granny, go small--26 or 24t.

I live in similar country (eastern side of the Sierra), and I have triples on both my road bikes for that reason. I just got tired of grinding the mountains in that lame 53-39.
The Surly looks like it will take a granny gear, and depending on the length of the BB spindle, it might be a straight bolt-on. All you'd need is a ring and fasteners. I'd go to a shop and ask them if it will work that easily, but if they say yes, you're obligated to buy the parts from them, not order them someplace to save four bucks.
If there's no clearance for a small ring, it used to be possible to buy a new BB spindle alone--just a longer spindle, not the rest of the BB--but I haven't done it in years, and I wouldn't be surprised if Shimano has made it impossible now. They're not big on parts replacement if they can sell you a whole assembly.
If you mentioned what rear derailleur you have, I missed it, but you may wind up needing a new one of those, too. Depends on how the bike was built originally.
Finally: If you do add a granny, don't dork around with a 30t. Go small, 24 or 26t, and you can climb walls.

 

[yukmak]

If you add a granny gear you will probably need a longer "triple" bottom bracket but not a new shifter, the 9-speed Tiagra shifter is double/triple.

Al

Thanks everyone for your responses, they have been extremely helpfull, and I am well on my way to achieving what I set out to do for a lot less than I thought I would spend.

One little follow-up question. Is the the 1998 8-speed Campy Mirage a double/triple front shifter by any chance? I tried to look it up, but their website only seems to have info on their current stuff. If so, I might consider going triple on my bike also.