Chain ring question

[ny biker]

My road bike came with a compact double crank, 50/34 chain rings, and a 10-speed 11/28 cassette. All SRAM Rival. I rarely use the large chain ring because it tends to hurt my knee -- I have a bit of a patella-tracking issue. I'm also prone to asthma problems on steep hills, so I typically just shift way down to a low gear and slow my cadence as needed to protect my lungs.

The cassette is pretty worn, so I'm looking into replacing the it with an 11/32 to make steep hills a bit easier. This will necessitate a new rear derailleur. While I'm changing gears, I'm also investigating a smaller large chainring. The people at the LBS suggested I get a 44.

However I'm looking now at SRAM's website and I'm a little confused.

https://www.sram.com/sram/road/produ...l-oct-crankset

Looking at the crankset for the Rival 10-speed group, these are the available ratios:

53/39, 52/38, 52/36, 50/36, 50/34, 46/38

First, there's no 44, and the only choice below 50 is a 46. Okay, fine. But if I want a 46, do I have to go up to 38 for the small ring? Because that works against the goal of getting the cassette with the 32 cog in order to make hills easier .

Is it just that SRAM chooses these particular chainring combinations, or does the ratio between the rings matter? Can I just swap the 50 for a 46 and keep the 34?

I'd really like to limit the components that need to be replaced in order to change to gears that work better for me.

Thanks!!

[Aromig]

Sorry, no advice here, but I'm watching this thread with fascination because I think we could be twins (knee issues, only use my big chain ring on downhills for that reason, and asthma issues). Most of last season I had an easier cog, with a long-arm mountain bike derailleur on my bike to help with hills, but changed it back because honestly the shifting suffered and I hadn't planned so many hilly rides for this year. I never ever thought about changing out the chain ring too! I'd love the option to make hills a little easier without sounding like the engine that could (literally, on the Horsey Hundred this year as I was going up hills people would look around them to see who was breathing so loudly).

[north woods gal]

There are lots of aftermarket options for chainrings and cassettes designed to work on either Shimano or SRAM. Don't assume you have to go with only what SRAM markets. Changing out chain rings is quite common. Check with a real deal bike mechanic, directly, who has done gear changes. Don't rely on what someone on the sales floor tells you.

No, you do not have to maintain the exact ratio between small and large chainring that you have, now, but if you do go smaller on one or the other, you may have to shorten the chain a bit. No big deal, though. Your bike mechanic will know how to handle it. Also, by reducing the spread between the small and large chainring, you may find that you do not need another rear derailleur to accommodate an 11/32 cassette. In fact, I recently went from an 11-30 to a 11-32 cassette on one of my Shimano equipped bikes and didn't have to change a thing.

Another option is to go whole hog and go with an SRAM MTB cassette and MTB derailleurs. They will work with your Rival shifters, but the chain ring route is going to be simpler and less expensive.

Finally, as a chronic "upgrader" let me say that you reach a point where it really just makes more sense to get a different bike, one better equipped for what you want to do. If you're not using that big chainring at all, might want to look at a bike with more touring type gearing or even mountain bike gearing and, yes, there are drop bar bikes like my Salsa Fargo that have MTB gearing and derailleurs (Force with X7 and X9).

With you all the way on the gearing issue, by the way. As I get older, I find that having enough low end on the gearing is ever more critical. Best of luck.

[ny biker]

Thanks North Woods, this is helpful.

I would say that I am locked into the LBS more than the brand of components. I have a great relationship with them so I want them to do the work, and to get the revenue from selling the parts. So when I talk to them again I will ask about different brands that they carry, but won't go outside of that.

I did talk briefly to a mechanic the other day as well as to the sales person. The mechanics were both very busy at the time so there wasn't much chance to to chat. He (the mechanic) was the one who recommended the 44 in place of the 50 chain ring, because it's what he uses on his cross bike. He also said something about needing a derailleur with a clutch to keep the chain from falling off. I had assumed he meant a front derailleur, but looking online it seems that clutch derailleurs are for the rear, not the front.

I do have to consider cost and try to keep things from getting too expensive. As for getting a different bike, you should talk to one of my friends who keeps bringing that subject up! He insists I have the wrong bike and that I need a new one. Unfortunately that is not in the cards for me, I just don't have the cash. At least not right now.

Aromig, I know several people who have put MTB gearing on their road bikes in order to do hillier rides. I don't know if they've had shifting issues. Many of us seem to have asthma, knee problems or both! At least we have options available so we can keep cycling.

[wnyrider]

I had a new, old stock SRAM 10 speed triple crank installed recently on my 11 speed bike. Attachment 18114

The builder used the 30t chainring with an added 44t chainring. No third chainring used. I have the option to go with a 46t. It just wasn't available at the time. My cassette is a 12-36. For some reason the Force 22 rear derailleur wouldn't work well, but the Rival one does. So far, the 44t seems enough for the riding I've been doing. I found this to be helpful when I was trying to understand this subject... http://www.peterverdone.com/spider-attack/

[Crankin]

I have a Shimano mtb derailleur on my custom road bike. The low gear combo is 1:1, a 34-34. I did this in 2011, before road cassettes had lower gears than 27 or 28. I have never had an issue with it. My friend has the SRAM version of it on her 2010 Ruby.
I have the 11-32 road gearing on my Trek and it is fine, but I will go to the 34 next year when it comes out.
Anything to save my aging parts.

[north woods gal]

You know, in all my years of riding, I have never once felt the need to go to higher gearing, but going lower has been something I've done a lot. A gal thing, maybe? Honestly, on some bikes I've had, have never been in the highest gear combo, even going downhill because that would put me in a higher speed than I would consider safe.