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Discussion Starter · #1 ·
I'm a new member and a road cyclyst. Am a 62 male and have two artificial knees. Thru a connection I was virtually given a Trek 5900 Super Light. Had to put a stem extender because I can't bend over fully 'cuz of my knees. Used to have a hybred that was a 9 speed with three rings on the crank. Now I have a 10 speed with just two rings and my problem is the bike is geared way too long, that is the gears are not low enough for my strength and climbing ability.

I have the Shimano Dura-Ace 11-23 on it now and there is a 12-27 in a 10 speed set also available. My question is how much lower a low gear is the difference between the 23 and the 27. In non-technical terms, on my old bike the lowest gear at my comfortable cadence was about 7 mph. The 23 on the 5900 is about 11.5 mph. I can't ride standing very well at all, knees again, so I need a low gear.

I assume if I went to three rings on the crank, I need to go to a 9 speed in the rear which means changing out all the trick stuff on the bike. Can someone give me an approximation of what the difference between the 23 and 27 will really be???
 

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aka Zonic Man
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It will be a lot.

I suggest doing this: get the 27t on the rear, and buy a new "compact" crankset by FSA at your local bike shop. This has chainrings (2) of 34/50 as opposed to the 39/53 you have now. HUGE difference with the 27.

Then sell the Dura-Ace cranks here or on ebay.
 

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First of all, Congrats on getting a great bike!

I ran the numbers you posted thru Sheldon Brown's gear calculator http://www.sheldonbrown.com/gears/
and it looks like your comfortable cadence is somewhere between 80 and 100 rpm (just based on your existing gearing and your speed in your comfortable rpm). Switching cogs to 12-27 would help you out a lot. At 80 rpm on the 27 you would be going about 9mph. Closer to your comfort zone of 7mph but only you can tell if it would be close enough.

If that's not close enough for you, you have a couple of options:
1) go for the currently available triple chainring setups; would be a pretty costly changeover
2) wait for either shimano, or another partmaker, to come out with a wider cassette; I'd be willing to be there will be 29 tooth options relatively soon
3) try a compact crankset that would give you a different range of chainrings up front, like 50/34.

msohio said:
I'm a new member and a road cyclyst. Am a 62 male and have two artificial knees. Thru a connection I was virtually given a Trek 5900 Super Light. Had to put a stem extender because I can't bend over fully 'cuz of my knees. Used to have a hybred that was a 9 speed with three rings on the crank. Now I have a 10 speed with just two rings and my problem is the bike is geared way too long, that is the gears are not low enough for my strength and climbing ability.

I have the Shimano Dura-Ace 11-23 on it now and there is a 12-27 in a 10 speed set also available. My question is how much lower a low gear is the difference between the 23 and the 27. In non-technical terms, on my old bike the lowest gear at my comfortable cadence was about 7 mph. The 23 on the 5900 is about 11.5 mph. I can't ride standing very well at all, knees again, so I need a low gear.

I assume if I went to three rings on the crank, I need to go to a 9 speed in the rear which means changing out all the trick stuff on the bike. Can someone give me an approximation of what the difference between the 23 and 27 will really be???
 

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Discussion Starter · #4 ·
Thank You

Jed and Torquecal....Many thanks for the fast response. I'm gonna go for the 12-27 and see if it gets me there. If not, I'll add the the FSA 50-34 crankset. Glad to know I don't have to trash the bike just 'cuz I'm old and feeble...Mike
 

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OR...you could go to Sheldon Brown's (Harris Cyclery) website and buy one of their pre-made cassettes that have lower gears for $60.-$80., (11-28, 13-30, 13-34, 14-34, etc.), or buy some loose single cogs from them and make your own lower-geared cassette using the one you already have.

With your handicap, I doubt you would ever really use an 11T, 12T, or even a 13T gear. I'd get in the range of a 14-32 or 34. That would give you many more usable gears that were placed closer together, AND save you way bucks over getting a whole new crankset or changing to a triple set-up.

For example: you could take your 12-27 cassette and remove the 12T, 13T, & 14T cogs. Buy a 14T top-gear (a 14T cog with the built-in spacer attached) and then buy a 30T & 34T and put those after the 27T. Voila! You now have a decent 14-34 cogset that only cost about $35. to customize. You'll then have at least 4 very useable lower gears (24, 27, 30, 34), and will have tossed out a couple that you'll never need (12, 13).

Here's the link: http://www.sheldonbrown.com/harris/k7.html#9cassettes
 

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Good idea, and I'm sure he'll be offering 10 spd customs soon, but all of his shimano custom cassettes are 9 spd right now.

AJS said:
OR...you could go to Sheldon Brown's (Harris Cyclery) website and buy one of their pre-made cassettes that have lower gears for $60.-$80., (11-28, 13-30, 13-34, 14-34, etc.), or buy some loose single cogs from them and make your own lower-geared cassette using the one you already have.

With your handicap, I doubt you would ever really use an 11T, 12T, or even a 13T gear. I'd get in the range of a 14-32 or 34. That would give you many more usable gears that were placed closer together, AND save you way bucks over getting a whole new crankset or changing to a triple set-up.

Here's the link: http://www.sheldonbrown.com/harris/k7.html#9cassettes
 

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Solution: go with a 9-speed set-up, not the 10-sp. Does he really need that extra 1 gear for all the hassle and expense it brings, when he can solve his problem much easier by modding a 9?

But it might be a hassle/expense if he tried to change to a 9-sp from what he has now, as much as changing cranksets would be. :(
 

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Knees & gears

I'm 61 and close to needing knee replacements too. My advice is try the 12-27, you're better off with 10 cogs than 9 because having more gears allows you to maintain higher cadences in more situations, and high cadence is important for problem knees. If I read your post correctly you already have a 5900 10-speed so converting back to a 9 would be a very expensive and in my opinion an unwise move. If it turns out that you need lower gearing you can probably cobble together something like a 13-29, or even a 14-30. Maybe Shimano will wake up and offer a 13-29 10-speed like Campy. I suspect that your legs will become stronger as you ride more and the 27 will get the job done. My lowest gear combination is a 39 X 26 and I routinely climb 10 to 15% grades. What you need will depend on you and where you ride, none of us really know what you need.
~Al
 
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