6 Speed vintage raod bike gear ratio
11-24-20, 12:55 PM
#1
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Thread Starter
6 Speed vintage road bike gear ratio equivalent.
I have a Vintage Miyata 512 with 6 speed indexed down tube shifters and a double up front. I have the RD-1050 rear derailleur and has replaced the cassette to 14/28T. However the front is 52/42T and I need a 34 in the front at least. My RD-1050 rear derailleur specs are supposed to be Min/Max rear - 12-28; Max fr/rr diff - 28; Max fr diff 13 . If I go with 48/34 in the front, my front diff will be 14 ( specs says 13 ), would that be OK? I found a 44/34T crank for sale locally and I would like to ask if a 44 in the front and a 14 at the back is good for road biking. As I have another road bike with 50/34 in the front and 12/28, my question if I am at 50 in the front, what is the cassette teeth number at the back that would be equivalent to a 44F/14R gear ratio. I am just trying to compare the feel between the two ratios. Thanks so much.
Last edited by gsulit@shaw.ca; 11-24-20 at 12:59 PM.
11-24-20, 12:58 PM
#2
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This website is pretty neat and worth spending a little time on: https://www.gear-calculator.com/
Where it says "Display," make sure to pick gear inches or ratio, whichever makes more sense to you, and you can compare the results for different combinations of chainring to cog.
Click "Compare" in the bottom right to look at two different setups simultaneously.
Edit: Looks like 44/14 would be roughly equivalent to 50/16.
Where it says "Display," make sure to pick gear inches or ratio, whichever makes more sense to you, and you can compare the results for different combinations of chainring to cog.
Click "Compare" in the bottom right to look at two different setups simultaneously.
Edit: Looks like 44/14 would be roughly equivalent to 50/16.
Last edited by noobinsf; 11-24-20 at 01:11 PM.
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11-24-20, 05:27 PM
#3
feros ferio
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I do not use particularly high gears, but I like to have something in the mid-90 gear inches, such as 50/14 (96), 49/14 (94.5), 46/13 (96). A 50/16 equivalent would leave me spinning out.
As for your derailleur working with 48/34 up front, that should not be an issue at all. The only potential hitch I can see is the curvature of your front derailleur cage.
As for your derailleur working with 48/34 up front, that should not be an issue at all. The only potential hitch I can see is the curvature of your front derailleur cage.
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Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069
"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069
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11-24-20, 07:48 PM
#4
Newbie
Thread Starter
This website is pretty neat and worth spending a little time on: https://www.gear-calculator.com/
Where it says "Display," make sure to pick gear inches or ratio, whichever makes more sense to you, and you can compare the results for different combinations of chainring to cog.
Click "Compare" in the bottom right to look at two different setups simultaneously.
Edit: Looks like 44/14 would be roughly equivalent to 50/16.
Where it says "Display," make sure to pick gear inches or ratio, whichever makes more sense to you, and you can compare the results for different combinations of chainring to cog.
Click "Compare" in the bottom right to look at two different setups simultaneously.
Edit: Looks like 44/14 would be roughly equivalent to 50/16.
11-24-20, 07:52 PM
#5
Newbie
Thread Starter
I do not use particularly high gears, but I like to have something in the mid-90 gear inches, such as 50/14 (96), 49/14 (94.5), 46/13 (96). A 50/16 equivalent would leave me spinning out.
As for your derailleur working with 48/34 up front, that should not be an issue at all. The only potential hitch I can see is the curvature of your front derailleur cage.
As for your derailleur working with 48/34 up front, that should not be an issue at all. The only potential hitch I can see is the curvature of your front derailleur cage.
I agree that 50/16 would be a little be easy on the flats even for a weak biker like me especially if it is a little on the downhill. I think that a 48/34 would be best in my situation. Thanks for your response. I appreciate it.
11-25-20, 11:51 AM
#6
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True. 48/14 (92.6 gear-inches) isn't bad as a top gear -- it's only 1 percent lower than 52/15 (93.6) or 45/13 (93.5). I use that last one on my Peugeot beater (45-42/13-15-17-20-23-26, nice half-step).
__________________
"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069
"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069
11-25-20, 12:07 PM
#7
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I've been running 48-36t with a 14-28t free wheel. It feels pretty balance for the riding I do locally. I'm going to try 50-34 next push a little harder and try to find as much climbing as possible around here.
Last edited by bark_eater; 11-25-20 at 01:22 PM.
11-25-20, 12:36 PM
#8
Senior Member
"How high is high enough?" is always a relative thing. Between the gear charts and your own experience it looks like you can figure that out.
Looking at what you've written, a few things come to mind.
1. Is your current crank unable to take a 34t chainring? If it's a 110bcd crank, you could just replace the inner ring, spare yourself the add'l hassles of swapping out the crank.
2. If you have to replace the crank, make sure you're aware of whether there are any taper differences. You could wind up needing a new bottom bracket as well. See #1.
3. You said you switched the cassette, but is it a cassette or a freewheel?
a. If it's a cassette, you may be able replace the outer/smallest 14t cog with a 13t or 12t, which could mean you could use a smaller outer chainring without losing your top gear.
b. If it's actually a freewheel, not a cassette, you could find a freewheel that starts with a 13t cog, which again might help you with the outer chainring situation.
>This could involve spending more money, but if you're able to save $ by just replacing your inner ring, that may leave budget for re-working the rear a bit. See #1.
4. One problem with smaller outer rings is, as John E mentioned, the bottom edge curve on the front derailleur may leave you with a less-than-ideal gap above the large ring. Generally not a fatal problem, but might impact shifting somewhat.
5. Another issue, if your frame has above-bb cable guides, is the rear edge of the fder cage may hit the rder cable before you get the fder low enough over the outer ring. I think a higher-than-ideal fder impacts shifting more than a mis-matched cage radius. This usually isn't a problem if you've got under-bb guides, unless you're looking at even smaller outer rings. I changed from a 38t to 39t outer on this Riv because the rear of the fder cage was hitting the top of chainstay while there was still a pretty large gap under the cage. With a Shimano CX-70 fder, that's designed for smaller cyclocross rings, and has a shorter cage. You can see how big that gap is in the photo.
The Riv is running an 11t cassette, and 36/11 is just under 96", which is plenty high enough for me.
Looking at what you've written, a few things come to mind.
1. Is your current crank unable to take a 34t chainring? If it's a 110bcd crank, you could just replace the inner ring, spare yourself the add'l hassles of swapping out the crank.
2. If you have to replace the crank, make sure you're aware of whether there are any taper differences. You could wind up needing a new bottom bracket as well. See #1.
3. You said you switched the cassette, but is it a cassette or a freewheel?
a. If it's a cassette, you may be able replace the outer/smallest 14t cog with a 13t or 12t, which could mean you could use a smaller outer chainring without losing your top gear.
b. If it's actually a freewheel, not a cassette, you could find a freewheel that starts with a 13t cog, which again might help you with the outer chainring situation.
>This could involve spending more money, but if you're able to save $ by just replacing your inner ring, that may leave budget for re-working the rear a bit. See #1.
4. One problem with smaller outer rings is, as John E mentioned, the bottom edge curve on the front derailleur may leave you with a less-than-ideal gap above the large ring. Generally not a fatal problem, but might impact shifting somewhat.
5. Another issue, if your frame has above-bb cable guides, is the rear edge of the fder cage may hit the rder cable before you get the fder low enough over the outer ring. I think a higher-than-ideal fder impacts shifting more than a mis-matched cage radius. This usually isn't a problem if you've got under-bb guides, unless you're looking at even smaller outer rings. I changed from a 38t to 39t outer on this Riv because the rear of the fder cage was hitting the top of chainstay while there was still a pretty large gap under the cage. With a Shimano CX-70 fder, that's designed for smaller cyclocross rings, and has a shorter cage. You can see how big that gap is in the photo.
The Riv is running an 11t cassette, and 36/11 is just under 96", which is plenty high enough for me.
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11-25-20, 03:53 PM
#9
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Thread Starter
"How high is high enough?" is always a relative thing. Between the gear charts and your own experience it looks like you can figure that out.
Looking at what you've written, a few things come to mind.
1. Is your current crank unable to take a 34t chainring? If it's a 110bcd crank, you could just replace the inner ring, spare yourself the add'l hassles of swapping out the crank.
2. If you have to replace the crank, make sure you're aware of whether there are any taper differences. You could wind up needing a new bottom bracket as well. See #1.
3. You said you switched the cassette, but is it a cassette or a freewheel?
a. If it's a cassette, you may be able replace the outer/smallest 14t cog with a 13t or 12t, which could mean you could use a smaller outer chainring without losing your top gear.
b. If it's actually a freewheel, not a cassette, you could find a freewheel that starts with a 13t cog, which again might help you with the outer chainring situation.
>This could involve spending more money, but if you're able to save $ by just replacing your inner ring, that may leave budget for re-working the rear a bit. See #1.
4. One problem with smaller outer rings is, as John E mentioned, the bottom edge curve on the front derailleur may leave you with a less-than-ideal gap above the large ring. Generally not a fatal problem, but might impact shifting somewhat.
5. Another issue, if your frame has above-bb cable guides, is the rear edge of the fder cage may hit the rder cable before you get the fder low enough over the outer ring. I think a higher-than-ideal fder impacts shifting more than a mis-matched cage radius. This usually isn't a problem if you've got under-bb guides, unless you're looking at even smaller outer rings. I changed from a 38t to 39t outer on this Riv because the rear of the fder cage was hitting the top of chainstay while there was still a pretty large gap under the cage. With a Shimano CX-70 fder, that's designed for smaller cyclocross rings, and has a shorter cage. You can see how big that gap is in the photo.
The Riv is running an 11t cassette, and 36/11 is just under 96", which is plenty high enough for me.
Looking at what you've written, a few things come to mind.
1. Is your current crank unable to take a 34t chainring? If it's a 110bcd crank, you could just replace the inner ring, spare yourself the add'l hassles of swapping out the crank.
2. If you have to replace the crank, make sure you're aware of whether there are any taper differences. You could wind up needing a new bottom bracket as well. See #1.
3. You said you switched the cassette, but is it a cassette or a freewheel?
a. If it's a cassette, you may be able replace the outer/smallest 14t cog with a 13t or 12t, which could mean you could use a smaller outer chainring without losing your top gear.
b. If it's actually a freewheel, not a cassette, you could find a freewheel that starts with a 13t cog, which again might help you with the outer chainring situation.
>This could involve spending more money, but if you're able to save $ by just replacing your inner ring, that may leave budget for re-working the rear a bit. See #1.
4. One problem with smaller outer rings is, as John E mentioned, the bottom edge curve on the front derailleur may leave you with a less-than-ideal gap above the large ring. Generally not a fatal problem, but might impact shifting somewhat.
5. Another issue, if your frame has above-bb cable guides, is the rear edge of the fder cage may hit the rder cable before you get the fder low enough over the outer ring. I think a higher-than-ideal fder impacts shifting more than a mis-matched cage radius. This usually isn't a problem if you've got under-bb guides, unless you're looking at even smaller outer rings. I changed from a 38t to 39t outer on this Riv because the rear of the fder cage was hitting the top of chainstay while there was still a pretty large gap under the cage. With a Shimano CX-70 fder, that's designed for smaller cyclocross rings, and has a shorter cage. You can see how big that gap is in the photo.
The Riv is running an 11t cassette, and 36/11 is just under 96", which is plenty high enough for me.
Thanks for your evaluation of my situation. Here is my thoughts on your points.
1. Yes my current BCD is 130 so I cant just replace the smaller chain ring.
2. Good point.
3. Its a frewheel actually and finding one with 13T would help.
4. Good point.
5. That is a realy good point. Never thought of that. You have a lot of experience with this.
I have now thought of just replacing the smaller ring with a 39T. I remember before that I could negotiate the small hills around me with a 39/27 combination before. If there is a headwind on the hills, I have another road bike ( an 11 speed Cervelo with 50/34, 12/32 combination ) that I could use instead. I like riding the vintage one when I'm by myself and I ride the other when I'm with friends. I could use the vintage bike to train on the hills and in the future when I really needed some more gears, I'll do a more intense modification then. Thanks again. I appreciate it.
11-25-20, 04:05 PM
#10
Newbie
Thread Starter
This is the Miyata 512 that I was talking about. Thanks everyone for your replies.
11-25-20, 05:18 PM
#11
Senior Member
The 512 looks very nice!
Clearly I've spent way too much time futzing around with gears. If I put all that time into actually riding, I'd be like Eddy by now.
You can get 38t rings in 130bcd. Suntour made them, if you want to find vintage. New/affordable choices from Origin-8 and SRAM, from a zillion retailers. Higher-zoot TA Alize ring from Peter White. I know that 38t is just 1 less toofie than 39t, but in my world every little tooth counts. And if you're snagging a new ring, might as well look at a 38t i/o a 39t.
You could also see if you can cheat another couple of teeth out of that rear derailleur. Somebody on velobase said they could run a 32t cog with 48/38 in the front. Sometimes a longer angle adjust screw helps. How much you can "cheat" depends on the frame configuration and chain length and other stuff.
And if you're not spending $ on a new crank, maybe use some of that $ to find a 13-34 freewheel and a longer-cage rear derailleur.
I like that there are options, anyway.
Clearly I've spent way too much time futzing around with gears. If I put all that time into actually riding, I'd be like Eddy by now.
You can get 38t rings in 130bcd. Suntour made them, if you want to find vintage. New/affordable choices from Origin-8 and SRAM, from a zillion retailers. Higher-zoot TA Alize ring from Peter White. I know that 38t is just 1 less toofie than 39t, but in my world every little tooth counts. And if you're snagging a new ring, might as well look at a 38t i/o a 39t.
You could also see if you can cheat another couple of teeth out of that rear derailleur. Somebody on velobase said they could run a 32t cog with 48/38 in the front. Sometimes a longer angle adjust screw helps. How much you can "cheat" depends on the frame configuration and chain length and other stuff.
And if you're not spending $ on a new crank, maybe use some of that $ to find a 13-34 freewheel and a longer-cage rear derailleur.
I like that there are options, anyway.
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