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Old 01-12-11, 05:44 PM   #1
Paintking
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How to achieve lower gearing, best way/

I have an 82 Pro Miyata with a high geared 'racing' setup. I'd like to achieve lower gearing in the least expensive way, but also with the least disturbance to the original equipment drive train. My old legs just cant take the current setup.

I currently have a Sugino Aero Mighty crank (52/42), Suntour Superbe FD & RD, and a 13-18 freewheel 6-speed (probably Suntour Winner). At first I considered switching out the freewheel for a bigger cog cluster. I figure I need a 28T cog to to be comfortable. It appears likely that I would have to also switch out the RD (see the thread on max cog for Superbe RD). One problem with this is that I'm not sure I would like the spacing/gear ration on a cluster that's like 14-28.

Now its occurred to me that I could also achieve lower gearing by changing the chainrings on the crank. Info on Velobase says that 42T is the smallest ring an Aero Mighty will accept. My thought is to switch it out with a touring crank, with something like 48/36 rings. I might still want to change the freewheel, but I could go with something with a closer range, like 14-23 If I do this I'd want to keep with a similar quality product.

So my questions are:
  • Does my idea of changing the crank hold water in general?
  • If I find a touring triple crank with the right size rings (and the right cheap price) can I simply remove the smallest chainring? Will it work with my current FD and fit my BB?
  • What crank makes might be compatible? Suntour, Shimano, Sakae, etc.?
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Old 01-12-11, 06:01 PM   #2
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I think the quickest and easiest approach for you is to swap out your current crankset with one with a smaller BCD. The Aero Mighty has a 144 BCD, which pretty much limits you to high gears, as you have now learned. Lucky for you, cranks are widely available in 110 BCD, which can allow a chainring of 34 teeth, substantially lowering your gearing. Most triples use a 110 BCD, and there are a nice many doubles available as well. Currently they are sold as 'compact' cranksets, but older versions may not be labelled as such.

I'd look for a Sugino Mighty Tour, because it seems appropriate.

You might run into problems with chain wrap on your rear derailer, but that's another issue.
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Old 01-12-11, 06:12 PM   #3
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Originally Posted by Paintking View Post
I have an 82 Pro Miyata with a high geared 'racing' setup. I'd like to achieve lower gearing in the least expensive way, but also with the least disturbance to the original equipment drive train. My old legs just cant take the current setup.

I currently have a Sugino Aero Mighty crank (52/42), Suntour Superbe FD & RD, and a 13-18 freewheel 6-speed (probably Suntour Winner). At first I considered switching out the freewheel for a bigger cog cluster. I figure I need a 28T cog to to be comfortable. It appears likely that I would have to also switch out the RD (see the thread on max cog for Superbe RD). One problem with this is that I'm not sure I would like the spacing/gear ration on a cluster that's like 14-28.

Now its occurred to me that I could also achieve lower gearing by changing the chainrings on the crank. Info on Velobase says that 42T is the smallest ring an Aero Mighty will accept. My thought is to switch it out with a touring crank, with something like 48/36 rings. I might still want to change the freewheel, but I could go with something with a closer range, like 14-23 If I do this I'd want to keep with a similar quality product.

So my questions are:
  • Does my idea of changing the crank hold water in general?
  • If I find a touring triple crank with the right size rings (and the right cheap price) can I simply remove the smallest chainring? Will it work with my current FD and fit my BB?
  • What crank makes might be compatible? Suntour, Shimano, Sakae, etc.?
Something like this: http://store.velo-orange.com/index.p...et-34x48t.html

or even this if you want gearing for very steep routes and/or touring loads: http://store.velo-orange.com/index.p...-crankset.html

Both should work with your existing deraillaurs and shifters.
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Old 01-12-11, 06:12 PM   #4
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you could get a compact crankset. It'd be a double and something like 50-34. Just have to figure out your BB sizing (french, italian, english, etc.)...might say on your existing BB. There's a lot of options, depending on how much you want to spend. SRAM Apex comes in 48-34. Would need to move your front derailleur, but if its a friction shifter, it should be able to adapt to any front crankset.
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Old 01-12-11, 06:25 PM   #5
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I think going to a compact crankset and swapping out the freewheel will be needed to get the gearing where you want it.
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Old 01-12-11, 07:37 PM   #6
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Despite your concerns about available ratios on a wider freewheel, that's the best first step. If your system is non-indexed you can go to a 13-28 7s freewheel which is the same overall width as a 6s. Odds are that with a longer chain you can skate by on the existing RD, by giving up the use of the inner chainring, with the outer few sprockets. With your 42/52 chainset, you'd need 25t of take up capacity, and I doubt you'll lose anything except the 42/13 crossed combination (which you wouldn't use anyway).

The reason I suggest starting with a freewheel swap, is that that's something you're going to need anyway, and if it works out you're that far ahead of the game. If not, you can always pull the plug and go for a crankset. Use a gear chart to compare all the possible options before spending any fough.
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Old 01-13-11, 06:49 AM   #7
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Despite your concerns about available ratios on a wider freewheel, that's the best first step. If your system is non-indexed you can go to a 13-28 7s freewheel which is the same overall width as a 6s. Odds are that with a longer chain you can skate by on the existing RD, by giving up the use of the inner chainring, with the outer few sprockets. With your 42/52 chainset, you'd need 25t of take up capacity, and I doubt you'll lose anything except the 42/13 crossed combination (which you wouldn't use anyway).

The reason I suggest starting with a freewheel swap, is that that's something you're going to need anyway, and if it works out you're that far ahead of the game. If not, you can always pull the plug and go for a crankset. Use a gear chart to compare all the possible options before spending any fough.
FB, I think your advice is spot on with consideration to all the other advice I've been given. Thanks
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Old 01-13-11, 06:49 AM   #8
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Thanks to everyone for the advice and suggestions. My legs are feeling better all ready!
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