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Flatland gearing for old guy

Old 08-05-19, 06:08 AM
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Flatland gearing for old guy

Perhaps folks who play with gearing charts can chime in on this. I am 62 and ride in flat NW Ohio. Nearly all riding is between 10-20mph depending on wind and the very occasional minor short hill or overpass. I find it rewarding to get that perfect gear. After playing with a recently acquired Frejus with half step gearing, I would like to do this with a recent purchase of a 1983 Trek 700. The freewheel that came on this bike was a non stock 13-22t 6 speed.

I purchased a 7 speed 14,16,18,20,22,24,28. Moved a spacer to drive side and will take wheel to shop to see about re-dishing it. This model Trek has the Superbe group, so crank is 144bdc 42-52. I have 32mm Pasela Gravel Kings mounted. They came out to be about exactly 27" diameter which works out to the numbers shown on attached chart on BikeCalc for a 32mm tire. I am kinda new to this, so not too familiar with playing with other calculators.

The 144bdc only allows a 42T small sprocket, so I am looking to replace the 52 which I almost never use on any of my bikes except for a gear or two. My limited exposure to half step gearing would show a 3 tooth difference. The attached chart seems to show a 44T sprocket being a much better half step than the 45T. Advise and educate me please.

I believe in this bdc size the 44 would perhaps have been an inner. Can this be purchased and flipped and used as an outer, or am I crazy. Remember, max speed is 25mph for 100 yards down the rare overpass or short hill. The other option is a 48 which gets a couple intermediate gears. Most riding depending on wind is in the 45-65 inch range.

Thanks
Steve
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Old 08-05-19, 07:13 AM
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I would keep the 42 and replace the 52 with a 50. Then contact PastorbobinNH and have him make you a custom 14-16-17-18-19-22-25 seven speed freewheel. I find with flatland gearing that in the 15-20 mph range having several one tooth difference gears in the middle allows me to maintain speed at a comfortable cadence.
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Old 08-05-19, 07:30 AM
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Originally Posted by rccardr
I would keep the 42 and replace the 52 with a 50. Then contact PastorbobinNH and have him make you a custom 14-16-17-18-19-22-25 seven speed freewheel. I find with flatland gearing that in the 15-20 mph range having several one tooth difference gears in the middle allows me to maintain speed at a comfortable cadence.
Thanks for the info. I like your idea, but remember, I am an OLD guy(weaker). At 62 years old, my pace on the flatlands with no wind is in the 13-18mph range.
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Old 08-05-19, 08:05 AM
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This is a better gear calculator and get a 45 not a 44.
Bicycle Gear Calculator

This shows with a 49
Bicycle Gear Calculator
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Old 08-05-19, 08:20 AM
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I suspect that the gearing suggested by rcardr will work nicely for you. I prefer to look at the gearing graphically. Easy to do with a spreadsheet. In the graph below you see the gearing you describe, with the gearing proposed by rccardr. The latter is more evenly spaced. If you feel you need the 28 tooth low gear, you may wish to play around with a spreadsheet to see what you come up with.


I see bwilli88 beat me to the punch, and highlighted a better gearing calculator. Thx, bwill88.
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Old 08-05-19, 08:28 AM
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Originally Posted by sd5782
Thanks for the info. I like your idea, but remember, I am an OLD guy(weaker). At 62 years old, my pace on the flatlands with no wind is in the 13-18mph range.
Aha. Well, I'm 68, so there's that.

Maybe a better way to express my point is to suggest that you determine the one 'best' flatland gear combinaion for you, and then add cogs above and below it in one tooth increments. You don't need a wide range, just a close range around the ideal, maybe with a bailout.
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Old 08-05-19, 10:21 AM
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I calculate using Excel. For a half-step, the outcome is that you have nearly the same incremental number of teeth difference as you progress through the gears, but the increment gets bigger as the gears get harder. I use two assumptions:

  1. The multiplier between adjacent sprockets is nearly constant across the sprocket. for your 14-28 the overall ratio is two, the ideal gear to gear multiplier is 1.122. The actual gear to gears range from 1.143 to 1.091. Not ideal but actualy pretty good.
  2. The multiplier between the chainrings is half the ideal gear to gear - this is where the "half-step" term comes from. So for this 7-speed, the chainring ratio is 1.061. Notice 122 = 2*6.1. If you choose a 52 tooth big ring (sticking with the one you have), the corresponding small ring is 49.0. This combo has a range of 100 inches down to 47. If you want to reduce the range a bit because you don't need so much high end, try a 48 tooth big ring. Now your smal needs to be 45.2 rounded to 45 teeth. The range in this case is 93 inches down to 43.6 inches. That covers your "most likely" 45 inch low end, but what about the continuous high 20-ish mph west wind we all love in the Midwest?
If the 45 inch option is good for you, buy rings for a 48 big ring and a 45 small ring. If you can go a little higher in bottom end, keep your 52 inch (cheaper!! ) and buy a 49 tooth for the second position. If you are friction shifting you don't need to worry about inner ring versus outer ring.

If you need serious help in the wind (welcome to my world!) a half-step may not be viable. I'd then look at adding a granny, maybe a 34.5 inch bottom, you could use a 36 tooth small ring, but I don't know what your crankset can support.

You could also change to a modern-style 50-34 with a different crankset. It gets you the range, but gives away your "find the right gear" need.

So, a number of options. exist.

BTW, I'm 66.
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Old 08-05-19, 11:01 AM
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Lots of good answers

I knew there would be some alternative views here. I will look into that other gear calculator that willi88 posted about. I didn't want to spend a ton of money, so hoping to just replace one sprocket which limits me already with the more uncommon 144bdc. I certainly don't want to get rid of the stock Superbe crank either. Perhaps as Road Fan says the 45-48 might be a compromise. Wheel at shop now getting redished for the 7 speed, so after that I will ride it a bit with the 42, and see how much I need that vs a 45. My half step Frejus is 47-50 which is pretty tall, but I really don't want to part with that original setup either. I am thinking that as I get older I will probably not want the 45 small ring.

So, anyhow with both those calculators a 44 big looks nearly perfect as far as gear spacing with just one sprocket change but maxing out at low 20mph. What is wrong with this setup, especially as I get older?

Edit: Actually, looking over the gaps again the 45T has closer spacing at the upper ranges for me. I guess the wider gaps at lower speeds is not such a concern compared to higher speeds. (for an old guy)

Last edited by sd5782; 08-05-19 at 11:13 AM. Reason: more info.
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Old 08-05-19, 01:58 PM
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Originally Posted by sd5782
am I crazy. Steve
I think so. If it was my bike I'd buy the closest ratio 6-speed freewheel I could find and then, only if necessary, swap chainrings to achieve gearing match where and how you ride. You're talking about a ton of expense and trial and error experimentation to achieve a minimum benefit.
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Old 08-05-19, 03:36 PM
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Originally Posted by rccardr
I would keep the 42 and replace the 52 with a 50. Then contact PastorbobinNH and have him make you a custom 14-16-17-18-19-22-25 seven speed freewheel. I find with flatland gearing that in the 15-20 mph range having several one tooth difference gears in the middle allows me to maintain speed at a comfortable cadence.
That is a nice cassette. I ride in the rolling hills of New England, and would choose a 42-38 in the front with it. But you’re in the flats, follow your heart and your legs.
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Old 08-05-19, 08:56 PM
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Originally Posted by sd5782
I knew there would be some alternative views here. I will look into that other gear calculator that willi88 posted about. I didn't want to spend a ton of money, so hoping to just replace one sprocket which limits me already with the more uncommon 144bdc. I certainly don't want to get rid of the stock Superbe crank either. Perhaps as Road Fan says the 45-48 might be a compromise. Wheel at shop now getting redished for the 7 speed, so after that I will ride it a bit with the 42, and see how much I need that vs a 45. My half step Frejus is 47-50 which is pretty tall, but I really don't want to part with that original setup either. I am thinking that as I get older I will probably not want the 45 small ring.

So, anyhow with both those calculators a 44 big looks nearly perfect as far as gear spacing with just one sprocket change but maxing out at low 20mph. What is wrong with this setup, especially as I get older?

Edit: Actually, looking over the gaps again the 45T has closer spacing at the upper ranges for me. I guess the wider gaps at lower speeds is not such a concern compared to higher speeds. (for an old guy)
All gearings are compromises, for sure. It sounds like you are interested in 45 big/42 small. Let me go back to my Excel model, and see what the built-in Magic 8-Ball says ... So! If you choose 45 as your big ring, the exact solution for the small ring is 42.4, so 45/42 is a good match for the required 6.1% increment (exact solutions mean you need fractional teeth and chain links - not possible!). You get a high gear of 86.8 inches and a low gear of 40.9 inches. That is pretty darn good as long as you're happy with an 87 inch top gear.

Another refinement I can do on my spreadsheet, though it might not be possible in the real world, is to optimise the freewheel. A better freewheel design would be 14-16-18-20-22-25-28. The difference is the next to largest gear is 25 rather than 24. That change results in making the gear increments nearly perfectly spaced, given the weird world of half-steps. But to find that freewheel in the wild is a hunting expedition. But that refined design gives you double-shifts that are more closely matched to their corresponding single shifts. Small improvement, but real.

Last edited by Road Fan; 08-05-19 at 09:06 PM.
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Old 08-06-19, 06:06 AM
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Thanks Road Fan. I was out on the old half step Frejus yesterday in a fairly stiff breeze and the 48ish inch low was just adequate. It made me happy with the cheap new sunrace 28T purchase for the new to me Trek. Like I said, no real hills here, so I am almost never on the big chainring.

I think I may be stupid and try a 44. I see some nice NOS ones on ebay for perhaps $50. Hey, you only live once and experimenting is fun. The gear gaps just look too appealing to me, and the longest hills here are the occasional overpasses or minor stream valleys. I hit 25mph maybe for 50-100 yards just to say I did it and to use a couple gears. If I spin out with an 85 inch high I can coast.

I did want the 28 low, and that Sunrace seemed to be a cheap option to a newbie like me. I have a 13-25 7speed sunrace on my Ironman that I like too. I changed out the 42T for a 39T on that one too. Thanks

Last edited by sd5782; 08-06-19 at 08:01 PM. Reason: Spelling
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Old 08-06-19, 06:36 AM
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Sunrace also has a 7-speed 13-15-17-19-21-23-25 freewheel. I just installed one on my Fuji America (with a triple up front). So far, so good.
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Old 08-06-19, 08:38 AM
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Originally Posted by sd5782
Thanks Road Fan. I was out on the old half step Frejus yesterday in a fairly stiff breeze and the 48 fish inch low was just adequate. It made me happy with the cheap new sunrace 28T purchase for the new to me Trek. Like I said, no real hills here, so I am almost never on the big chainring.

I think I may be stupid and try a 44. I see some nice NOS ones on ebay for perhaps $50. Hey, you only live once and experimenting is fun. The gear gaps just look too appealing to me, and the longest hills here are the occasional overpasses or minor stream valleys. I hit 25mph maybe for 50-100 yards just to say I did it and to use a couple gears. If I spin out with an 85 inch high I can coast.

I did want the 28 low, and that Sunrace seemed to be a cheap option to a newbie like me. I have a 13-25 7speed sunrace on my Ironman that I like too. I changed out the 42T for a 39T on that one too. Thanks
Why is the 44 stupid? What small ring would you use? The calculated solution would be to use a 41, but I don't know if your chainset can go that small. The pattern of steps is not bad with 41 or 42, but a lot of steps are rather small. For all of these, that's true. A 5-speed or 6-speed might also be acceptable.
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Old 08-06-19, 07:41 PM
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I was thinking 42-44 on the chainrings. Indeed, the pretty superbe crank will only take a 42 minimum with the 144bdc. That was a reason for the 28 tooth freewheel vs a 25 or 26. The superbe is supposed to be an upper level, so I wanted to keep it.



As it came to me with 22T freewheel and Shimano rear derailleur


So, I thought the 42-44 would be a half step which interested me for the flatlands. Many ride 11 speed hubs with 2 or 3 gears in front, so obviously have pretty close gear spacing too. I have a couple other bikes, so I thought I would try something different on this one.

Another factor is that I am not retired yet, and with midwest winters, my bikes don't really get ridden that much. I keep a "cheat sheet" in my bag so I can remember some of the spacing on each bike. For this one I thought I would try to get more than 2 useful gears on the big ring. The bike calc points to non complicated jumps for each gear on each ring. It looks like I could be old, weak and feeble minded and just have to remember that there is a half step between EVERY cog. It just looked interesting.

It may be a bit, but I will post results here. Being anal, I got rid of the Shimano RD and have a Suntour VXs to put on, so the freewheel also had to be the sunrace. The Shimano with the same spacing is well thought of, but I couldn't look at that black big ring with the writing on it. It looks like something from on a department store bicycle. Thanks
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Old 08-07-19, 08:49 AM
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There is way too much talk on this thread about 62 being old. First thing I would do is a hard reset on that view.
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Old 08-19-19, 08:28 AM
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All cleaned up and ready to try

Slower than most in getting things sorted as work gets in the way. All bearings done now including the nice SR SP-11 platform pedals that I think are specced for the Trek 720. I think I will like these. Nice used Suntour VX-S mid length RD with the Sunrace 14, 16, 18, 20, 22, 24, 28 freewheel and a 44T SR front to go with the 42T and a new Sram 830 chain. I have only been on it for a couple of miles, but it seems interesting. When time allows, I need to get some distance and ride into some wind to see if the little steps are too my liking. I had to take time to sort the brakes and cables too, but now done. I also put on some Pasela Gravel Kings in 32 which I think will be nice.



Flatland gearing on 1983 Trek 700 for an older guy


Nice vintage Suntour VX-S and kept the Dork disk
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Old 08-20-19, 01:42 PM
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61 y/o here, with mediocre climbing ability. With a lot of hard work I've managed to improve from dead last on every Strava climb segment to solidly middle of the pack. I'm not even a strong climber in my own age group, but we have some seriously strong older riders here. Probably as good as it'll get. So I've fiddled a lot with gearing to find combos that suit conditions and my ability.

I had similar issue with one road bike (sub-20 lb 1993 Trek 5900) and the supplied 52/42 double chainring (Biopace) and 14-28 Shimano 7-speed freewheel. Some steps didn't feel quite right.

The steps felt better after switching to a SunRace 7-speed 13-28. It's basically a fairly closely spaced 5 speed (13-15-17-19-21) with a couple of bailout gears: 24 for when the legs are a little tired and I'm just trying to keep up with a B-group pace; 28 for when the legs are shot and I'm just trying to limp uphill or home instead of walking or calling Uber.

I tried a 38T chainring in place of the 42 for a week or two but it required more double shifting to maintain cadence and speed. And too many chain drops on front derailleur downshifts, no matter how carefully I adjusted the FD. Just when I thought I had it set up for no drops, it dropped on a hill on a group ride this past weekend. Fortunately a friend literally had my back and gently supported my back while I horsed the chain back on (tricky with indexed brifters). After that I stuck with the big ring for most of the ride and my legs were dead after 50 miles of punchy rollers (North Central Texas, no real climbs, just lots of roller coasters with short steep climbs). The 42 is back on for now, although I might try a 39.

But the Biopace rings may defy comparison to circular chainrings. Depending on where the modestly elongated lobes are set on the cranks, the pedal stroke can feel smoother or jerky and surge-y. Seems to vary with individuals. For me, the 52T Biopace big ring feels best rotated one notch counter-clockwise; but the small 42T Biopace feels surge-y in that position, so I'll return it to the original orientation where it felt pretty good. Just a quirk of non-circular chainrings, wouldn't apply to other scenarios.

My other road bike (25 lb 1989 Ironman) has had a 50/39 double and SunRace 7-speed 13-25 freewheel for more than a year and it's just about perfect. Downtube shifters so I tend to shift less often than with the other bike and brifters. With downtube shifters double shifting to get the desired gear can be annoying, so I'm leaving this setup alone. Only downside is there are occasions when I'd like a 28T bailout cog for dead-leg days, but there isn't another combo of double chainring and 7-speed freewheel or cassette with the steps I'd want. The only alternative would be to switch wheels or hubs to get an 8-speed cassette with the same 13-25 steps and a 28 or larger bailout cog.
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Old 08-20-19, 05:35 PM
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I had 1/2 step gearing on my 1970's 27" 10 speed racer and loved it. BUT the 5 rear cogs on my bike were 21 - 24% apart (14, 17, 21, 26, 32T). Almost 2 full steps by todays standards. So the 1/2 step gearing was really just single steps.

The 5 middle cogs of 7 on my new bike are just 9 - 12% apart already, Almost perfectly spaced for the vast majority cyclist's. A super low bailout gear (34T) I only need in extreme conditions is nice to have, And my tallest gear of 14T is still just a 14% jump and ideal for down hill.

In this case I find my wide range triple chainring (28/38/48) or double (46/30) to be much more convenient then the 1/2 step ring, allowing a double or triple shift in one step as we ride over hills or approach a stop where we should accelerate quickly to not linger in traffic.

That said, With a little practice I'm sure most of us can work with 12 (2 x 6) to 27 (3 x 9) gears. Think of those poor soles out there in bike land that only have one gear.

Last edited by xroadcharlie; 08-20-19 at 06:20 PM.
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Old 08-20-19, 08:39 PM
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Well, I'm 75 riding in flat Northern Illinois - think 420' elevation change over 25 miles. I've been riding 45/42 with 14-16-18-20-23-26 for the past 2-2.5 years. That's down from 49/46 a few years ago (which I rode in hilly RI).

I've almost decided to change to 14-16-18-20-22-24-28, still with 45/42. That seems closer to half-step than 44-42. Reducing the chainwheel sizes was a great idea. Campy and Campy-copy 45s are available, but I can't see spending money changing the 44 to a 45.

I find the 45/42 - 14-26 eminently usable. I'm not a strong rider, but I never need the smallest gears except in the early days of each season if I've done no work on a trainer. I never need the biggest gears. As I said, I'm not a strong rider.

I'm considering the 7-speed, because I'd like SIS shifting.
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Old 08-21-19, 01:13 PM
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Last night I rode my Ironman on a club ride for the first time in a couplafew weeks. It's the bike with the 50/39 chainrings (Vuelta, including ramped and pinned big ring) and 13-25 SunRace 7-speed MFR30 freewheel. Gear steps feel so much better than my Trek 5900 setup I'm tempted to ditch whatever I have on the Trek and switch both bikes to the same setup. Unless I can find a 7-speed freewheel that matches the steps to suit the existing Biopace 52/42.

Another factor may be the different crank arm lengths. The Ironman has 172.5, the Trek has 170. At 5'11" with 33" inseam and size 11 feet, the 170 may be just a wee bit short for me. It doesn't feel bad, but it doesn't feel quite as smooth as the Ironman. Despite being 5 lbs heavier, the Ironman feels subjectively "lighter" on our modest climbs -- mostly rollers with a few short, steep punchy hillettes.

Originally Posted by canklecat
61 y/o here, with mediocre climbing ability. With a lot of hard work I've managed to improve from dead last on every Strava climb segment to solidly middle of the pack. I'm not even a strong climber in my own age group, but we have some seriously strong older riders here. Probably as good as it'll get. So I've fiddled a lot with gearing to find combos that suit conditions and my ability.

I had similar issue with one road bike (sub-20 lb 1993 Trek 5900) and the supplied 52/42 double chainring (Biopace) and 14-28 Shimano 7-speed freewheel. Some steps didn't feel quite right.

The steps felt better after switching to a SunRace 7-speed 13-28. It's basically a fairly closely spaced 5 speed (13-15-17-19-21) with a couple of bailout gears: 24 for when the legs are a little tired and I'm just trying to keep up with a B-group pace; 28 for when the legs are shot and I'm just trying to limp uphill or home instead of walking or calling Uber.

I tried a 38T chainring in place of the 42 for a week or two but it required more double shifting to maintain cadence and speed. And too many chain drops on front derailleur downshifts, no matter how carefully I adjusted the FD. Just when I thought I had it set up for no drops, it dropped on a hill on a group ride this past weekend. Fortunately a friend literally had my back and gently supported my back while I horsed the chain back on (tricky with indexed brifters). After that I stuck with the big ring for most of the ride and my legs were dead after 50 miles of punchy rollers (North Central Texas, no real climbs, just lots of roller coasters with short steep climbs). The 42 is back on for now, although I might try a 39.

But the Biopace rings may defy comparison to circular chainrings. Depending on where the modestly elongated lobes are set on the cranks, the pedal stroke can feel smoother or jerky and surge-y. Seems to vary with individuals. For me, the 52T Biopace big ring feels best rotated one notch counter-clockwise; but the small 42T Biopace feels surge-y in that position, so I'll return it to the original orientation where it felt pretty good. Just a quirk of non-circular chainrings, wouldn't apply to other scenarios.

My other road bike (25 lb 1989 Ironman) has had a 50/39 double and SunRace 7-speed 13-25 freewheel for more than a year and it's just about perfect. Downtube shifters so I tend to shift less often than with the other bike and brifters. With downtube shifters double shifting to get the desired gear can be annoying, so I'm leaving this setup alone. Only downside is there are occasions when I'd like a 28T bailout cog for dead-leg days, but there isn't another combo of double chainring and 7-speed freewheel or cassette with the steps I'd want. The only alternative would be to switch wheels or hubs to get an 8-speed cassette with the same 13-25 steps and a 28 or larger bailout cog.
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Old 08-21-19, 01:25 PM
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Beautiful bike. I know you live in a flattish area but personally I prefer a 110 bcd crank over a 144 bcd. You can run the gears closer together in the rear and drop the size of the chain rings up front to get whatever climbing gears you need. The sugino mighty tour double might be a perfect "upgrade" for your bike.
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Old 08-22-19, 06:32 AM
  #23  
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Gotta at least try with stock crank first

Originally Posted by bikemig
Beautiful bike. I know you live in a flattish area but personally I prefer a 110 bcd crank over a 144 bcd. You can run the gears closer together in the rear and drop the size of the chain rings up front to get whatever climbing gears you need. The sugino mighty tour double might be a perfect "upgrade" for your bike.
Oh yes, I know the 110bdc crank is the sensible and practical thing to get. I just wanted to see if I could make things workable with the stock 144bdc with its 42T small as a minimum. That Superbe crank is very pretty so I kinda hoped it could remain. I know the Superbe group of that era was nearly top notch. I just didn't want to change it that much without trying first. On my Frejus, it is the same thing, but I couldn't swap out that pretty steel 47/50 half step crank.



1964 Frejus with 47/50 front and 14-26 six speed in back.


Other posters mentioned the 13-25 seven speed sunrace, and I put one of those on my 85 Ironman and really like that also. On that one, I was able to swap out the 42T low ring for a 39.

As to the 44 vs 45 for half step in my application, the jury is still out. I put 32c tires on the Trek, so according to Bike Calc the 44 is closer to half step than 45 with these size tires. On my short 10 mile ride, I can say that the gears are close and there is no racy top end. I know on my other bikes there are always gaps of perhaps 1.5 mph with my usual cadence. I don't think I will know much until I get a computer and get some long rides. Ideally I would like to see the same cadence and effort produce gear spacings of perhaps 1mph over a range of maybe 11-20mph depending on wind. I realize it may be a silly experiment, but I never used the tall gearing anyhow, so why not play around?
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