Chain ring question

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!!

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).

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.

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.

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/

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.

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.

The more I read and think about this, the more there is to read and think about. What's very cool is that I can go to the Bike Archive on Trek's website and get the specs for the road bike that I bought in 2003 and replaced with my current bike in 2010:

Shimano 105 52/42/30
Shimano HG-50 12-25, 9spd

So I can run those numbers through Sheldon Brown's gain ratio calculator for comparison to what I have now. The old bike had a triple, and I mostly used the middle chain ring, though I never hesitated to drop to the granny when I felt it was necessary. Before buying the new bike I made sure that the lowest gears were comparable to the old one, but now I will look more closely at how the middle ring gain ratios compare to the gears I often use now with the compact double.

In another thread we recently talked about the aging brain, and how it's harder to learn new things as we get older, except some things that really interest us seem not so hard to grasp. This is a perfect example for me -- learning more about gearing is interesting, and therefore relatively easy.

Been a re-learning experience for me, too. Actually getting hard to find a triple, these days, even on MTBs. The trend is definitely to doubles and, now, even single chainring bikes with big cassettes in the back.

Still working on this. A few developments.

A friend sent me a link to an article on choosing chain rings, but I haven't had a chance to read it yet. Hoping to get to it today.

While out riding the other day I was thinking about how rarely I use the 11 cog on my cassette. So now I'm thinking the new one will be a 12/32 -- 12-13-14-15-17-19-22-25-28-32 (as compared to an 11/32 with 11-12-13-15-17-19-22-25-28-32).

But the big thing is -- the cassette currently on my bike is not actually an 11/28. I got down on my hands and knees this morning with a magnifying glass and a flashlight to look at the cassette that's now on the bike, and the cogs are labeled: 11-12-13-14-15-17??-19-21-23-26. (The 17?? is the cog that I can't see right now because the chain is in the way. Most likely it's a 17.)

The original bike specs say it came with an 11/28 -- I can find a post on this forum from when I bought the bike where I discuss the differences between the new bike and my old one, and it clearly shows I was expecting the new bike to have 11/28. The cassette has been replaced once or twice since then and I always thought the mechanics at the shop put on a new cassette that was the same as the old one. So either the bike originally came with the wrong cogs or somewhere along the way someone changed the cogs without telling me. Maybe this was just a simple mistake, or maybe there was no 11/28 in stock at the time it needed to be replaced and someone was just being lazy and using whatever cassette they had available without asking me first. Either way I'm feeling... not mad, but definitely upset. I have always trusted the people at this LBS. I'm not sure what I will do about this; I will definitely point it out to someone at the shop, since it's a quality control issue. I just haven't decided yet if I should email the owner directly or talk to someone else.

Assuming the bike's original cassette was really an 11/28, I probably didn't notice the change to totally different gears because it was most likely done over the winter when I wasn't riding as often.

I'm really disappointed by this.

Anyway, I will rerun Sheldon Brown's calculator with these numbers. But the big thing is that my largest cog right now is NOT a 28 -- it's only a 26. Trying to look on the bright side -- I will be gaining two easier gears than what I have now when I make the change.

Okay so, new parts have been ordered and the bike is at the shop. It should be finished in a couple of days.

Old: SRAM Rival 10-speed group set
Compact double crankset, 50/34
10-speed cassette, 11/26
short-cage rear derailleur

New: still all SRAM Rival 10-speed
Compact double crankset, 46/34 (swapping out the large chain ring)
10-speed cassette, 12/32
SRAM Rival WiFli mid-cage rear derailleur

The old chain should be long enough so they will probably only replace it if it's worn.

I spoke with several people at the LBS to confirm all this should work well together. Their answers were based on their own bike set-ups as well as some changes that they've made for customers' bikes.

And now after almost 6 years of using only the small ring, I get to re-learn how to shift. :D

That sounds like a good plan. Glad you got this sorted out.

Excellent! That is going to be a nice change. I'm looking forward to doing something similar with my Trek next year unless I decide to spring for a new bike entirely. Will depend on finances. Either one will be a help on the hills! :D

I agree, that is a very nice change. My 2013 Domane Trek road bike is a standard Shimano 105 compact 50/34 up front, but a not too bad 12-30 in back. Gets me by for our hills, up here, but just. If I'm running out of gas, so to speak, or fighting a stiff headwind to get up one of my "special" hills (they all have names, now :)), I find myself wishing for one or, even better, two more gears to help.

Speaking of advertised specs being off, my new Salsa Warbird was advertised as having a 46/36 up front, but when I looked, it was actually a 34 on the small ring. Had planned on changing it to an even smaller ring, but instead went from an 11-30 in the back to an XT 11-32. Still very close to the Domane at the low end, 34 and 30 versus 34 and 32, but even that one extra gear makes a difference.