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-   -   The need for speed (taller gears) (https://www.bikeforums.net/showthread.php?t=1188773)

Bigbus 11-23-19 10:24 PM

The need for speed (taller gears)
 
Okay, I'm finding the current gearing on my old Giant RB is just not tall enough. The larger chain ring is 52T and a 14T on a 6spd cassette. I really would like to step the 14T up to at least a 12T but preferably an 11T. Why am I having such a tough time trying to find that gear? Is it not doable? We're talking Shimano here. Will an 11T from an old MTB cassette fit the hub? Or does it have to come off a road bike due to hub differences? Am I just not looking in the right places? Are we having fun yet?
Thank you in advance for any sharing of knowledge,

Bill Kapaun 11-23-19 10:46 PM

Likely you have a Free Wheel, not a cassette.
IF a cassette, likely it's a Uniglide and uses a threaded smallest cog.

Freewheel or Cassette?

veganbikes 11-23-19 11:07 PM

IRD does a 13-24 so that sort of corncob set up that was popular for racing. You can apparently also now build your own freewheel again which was something they did back in the day. However if not running a freewheel as Bill said you will probably have a uniglide cassette and those aren't in existence anymore but you might be able to swap out the free hub body to a hyper glide (I did that once and the hub was used and worked). Your frame might not be spaced right and if steel you can possibly cold set it but if not you really can't.

Get some info on the bike and we can help you out more. If the bike is steel and you are running friction shifters you can respace the frame get a new rear wheel and run more gears. If you space out a steel frame to 130mm you can easily get a road wheel with a hyperglide free hub and you could run 10 speed frictionally without a ton of problem and 9 and below with even less issues. Your derailleur might be able to handle it just fine. I am running an 7 speed RD with a 9 speed indexed shifter.

davidad 11-23-19 11:17 PM

a 52-14 is a 99 inch gear. At 85 rpm you are going 25 mph and at 105 you are doing 31 mph. How fast do you want to go?

rccardr 11-24-19 12:02 AM

If a Shimano UG freewheel (likely) you can go down to a 13 tooth small cog pretty easily. I have some, and so does @PastorBobinNH.
In fact, there are freewheels with 12 tooth small cogs, for example Sachs, but all the ones I have seen are 7 speed and may require you to slightly lengthen your rear axle on the drive side by a mm or two.
If a freehub (possible) with standard diameter UG threading end, then a 13 is the smallest you can go. I have those.
If a Dura Ace freehub with the smaller UG threaded end, you can go to a 12 tooth. I have those.
To go to an 11 tooth small cog, you need a later 130OLD HG style freehub, none of which can be installed on a pre-7 speed Shimano hub.

You may find it easier to purchase a larger chain ring- like a 56 or larger.

3alarmer 11-24-19 12:35 AM


Originally Posted by rccardr (Post 21221103)

You may find it easier to purchase a larger chain ring- like a 56 or larger.


+1...if it's all Shimano (including the crank), it's pretty easy to find 130 BCD chainrings in 53, and I've seen them in 54 tooth versions. I've seen 56, but only occasionally.

CliffordK 11-24-19 12:59 AM

Verify Freewheel vs Cassette:
https://www.sheldonbrown.com/free-k7.html

DNP Epoch makes a 11T, 7-Speed Freewheel.
https://www.amazon.com/DNP-Epoch-Fre.../dp/B007A8RPUS

The one I had was slightly wider than the average 7 speed freewheel, although that might have been changed. But, in many cases you can just flip around a few spacers on the rear hub and redish the wheel to make it work.

Friction Shifting, of course, is easier to deal with than indexed shifting if you change the number of sprockets.

One issue that I had with the DNP Epoch is that it skipped a number of sprockets.
11-13-15-18-21-24-28.

In particular, the 12T and 14T would have been very nice. Anyway, I found the gaps in the freewheel were unacceptable, but that led me down a rabbit hole of changing from a freewheel to a cassette, and trying to get higher gearing and fewer gaps in the cassette. And, thus more speeds... 5s, 6s, 7s, 8s, 9s, & 11s (I seem to have skipped 10s for various reasons).

BengalCat 11-24-19 01:50 AM

Tony Martin loves his 58T big ring and 11 speed 11-32T. He's very fast.

JohnDThompson 11-24-19 07:54 AM

As others have noted, your hub may limit the smallest cog size on the rear cluster. Depending on make/model of your crank, larger chainrings may be available to provide higher gearing.

HillRider 11-24-19 09:05 AM


Originally Posted by davidad (Post 21221085)
a 52-14 is a 99 inch gear. At 85 rpm you are going 25 mph and at 105 you are doing 31 mph. How fast do you want to go?

The real question is "how fast can you go?" Are you strong enough to turn an 11x52 or even a 12x52 effectively? For all but the strongest riders or those who insist on pedaling down hills, an 11T cog is wasted. You ain't Tony Martin (to paraphrase a famous movie).

Trakhak 11-24-19 09:45 AM


Originally Posted by HillRider (Post 21221323)
The real question is "how fast can you go?" Are you strong enough to turn an 11x52 or even a 12x52 effectively? For all but the strongest riders or those who insist on pedaling down hills, an 11T cog is wasted. You ain't Tony Martin (to paraphrase a famous movie).

Agreed. I set a course record in a flattish 10-mile time trial back in the early '80s and never got out of my 52 x 15. Most "need for speed" threads are "I don't like pedaling fast" threads in disguise.

That said, there are some powerful riders out there who really can turn over a big gear at impressive speed, although lighter riders tend to be able to drop them on climbs.

Bigbus 11-24-19 10:40 AM


Originally Posted by HillRider (Post 21221323)
The real question is "how fast can you go?" Are you strong enough to turn an 11x52 or even a 12x52 effectively? For all but the strongest riders or those who insist on pedaling down hills, an 11T cog is wasted. You ain't Tony Martin (to paraphrase a famous movie).

Right now I'm finding that I'm always in high gear and it doesn't feel high enough. I keep looking to shift up and then glancing down to see I'm already in the highest gear on the bike. I guess I'm just used to riding my MTB which with all the gear on it weighs in at close to 60# and this Giant feels super light to me. Thanks for your input.

Bigbus 11-24-19 10:43 AM


Originally Posted by veganbikes (Post 21221078)
IRD does a 13-24 so that sort of corncob set up that was popular for racing. You can apparently also now build your own freewheel again which was something they did back in the day. However if not running a freewheel as Bill said you will probably have a uniglide cassette and those aren't in existence anymore but you might be able to swap out the free hub body to a hyper glide (I did that once and the hub was used and worked). Your frame might not be spaced right and if steel you can possibly cold set it but if not you really can't.

Get some info on the bike and we can help you out more. If the bike is steel and you are running friction shifters you can respace the frame get a new rear wheel and run more gears. If you space out a steel frame to 130mm you can easily get a road wheel with a hyperglide free hub and you could run 10 speed frictionally without a ton of problem and 9 and below with even less issues. Your derailleur might be able to handle it just fine. I am running an 7 speed RD with a 9 speed indexed shifter.

Right now I'm finding that I'm always in high gear and it doesn't feel high enough. I keep looking to shift up and then glancing down to see I'm already in the highest gear on the bike. I guess I'm just used to riding my MTB which with all the gear on it weighs in at close to 60# and this Giant feels super light to me. It's a Giant Quasar 12 speed indexed from the late 80's. Thanks for your input.

Bigbus 11-24-19 10:52 AM

Some really good information in this thread and even though that 52T chainring looks huge. to me, I;m thinking now that it might be easier to find a larger one rather than mess with the rear gearing. By keeping the 36T up front I won't lose my current low range either. Sounds like a good fix for me if the front DR can handle the difference in gear size without too much adjusting or modifying. Thanks for all the good input.

WizardOfBoz 11-24-19 11:06 AM


Originally Posted by davidad (Post 21221085)
a 52-14 is a 99 inch gear. At 85 rpm you are going 25 mph and at 105 you are doing 31 mph. How fast do you want to go?

I'm over 60 and weigh 245, and (using the principle of Aerodynamic Geriatric Spandexed Bulkitude) I spin out my 53-11 and get up to around 43mph when going downhill. And that's with legs that are pretty clapped out. I don't doubt that a lot of riders out there could push the higher gear. If the OP is spinning out 53-14, I can see why he'd want 53-12 or 11.

For me, now, I worry about getting lower gears. I remember when I could run that corncob and go up hills no problem. Sigh.

Homebrew01 11-24-19 12:39 PM


Originally Posted by Bigbus (Post 21221414)
Right now I'm finding that I'm always in high gear and it doesn't feel high enough. I keep looking to shift up and then glancing down to see I'm already in the highest gear on the bike. I guess I'm just used to riding my MTB which with all the gear on it weighs in at close to 60# and this Giant feels super light to me. Thanks for your input.

Other than steep downhills, you'll probably find, as most of us do, that learning to pedal at a higher RPM, and a lower gear, actually results in higher speed, less fatigue, and more endurance.

Miele Man 11-24-19 01:04 PM


Originally Posted by Bigbus (Post 21221432)
Some really good information in this thread and even though that 52T chainring looks huge. to me, I;m thinking now that it might be easier to find a larger one rather than mess with the rear gearing. By keeping the 36T up front I won't lose my current low range either. Sounds like a good fix for me if the front DR can handle the difference in gear size without too much adjusting or modifying. Thanks for all the good input.

A jump fom 36 to 52 is 16 teeth. I wonder what front derailleur can handle many more teeth? Also, it takes more teeth on the front chainring to make the same increase as it does if you subtract a tooth or two to a rear cog.

Example. You currently have a 52 x 14 high gear which is 98.0" with 700 x 25 tires. Changing to a 54 chainring raises that high gear to 101.8" and a 56 chainring raises it to 105.5" whereas getting a 13 teeth rear cog with the existing 52 chainring gives a new high of 105.5" which is the same as you'd get with a 56 x 14. A 52 x 12 gives a high of 114.3" and a 11 x 52 gives you a high of 124.7". Have you given any thought to getting a new rear wheel with a freehub and a cassette?

Cheers

Bill Kapaun 11-24-19 01:04 PM


Originally Posted by Homebrew01 (Post 21221567)
Other than steep downhills, you'll probably find, as most of us do, that learning to pedal at a higher RPM, and a lower gear, actually results in higher speed, less fatigue, and more endurance.

+1
When I got my 1st speedometer, it became obvious I was slightly faster in the next lower gear. It was only .1-.2 MPH, but my stamina was "miles" better.
Air drag increases disproportionately with speed, so the faster you go, the more energy you waste.
Tuck in and make yourself "aero" on the downhills and save your energy for the uphills.
You'll get to "point B" sooner.

CliffordK 11-24-19 01:42 PM

12T Corncobs are available on E-Bay.
11T DNP Epoch is readily available (with the caveats above).

There are quite a few choices.

Think of gearing as a percent change. So, going from 13T to 12T = about 8% change.
13T to 11T = about a 17% change.

On the other end, 52T x 1.08 = 56T (equivalent of 13 to 12)
52T x 1.17 = 60T. (equivalent of 13 to 11).

And you get into mighty large chainrings very quickly.

Going from say 52T to 54T is only a 4% change, or half what you would get by dropping a single gear in the back.

You also have to start considering front and rear derailleur capacity, and the small front sprocket as you start going bigger up front. With some luck, it should still be able to handle it, but depending on the ultimate choice of components, it can be tight.

Bigbus 11-24-19 02:17 PM

With regard to learning to pedal faster in a lower gear--You can't teach an old dog new tricks! I'm pushing 70years and can still do 240 situps, bench press 160X9 and ride 10+ miles/day. I burn out really fast when I try speed pedaling whereas when I'm climbing a hill and working the pedals hard, I never seem to reach bottom. Just me. But with that considered, higher gearing just makes sense. I have a 13T off an old MTB so when the weather turns nicer I'll see if I can swap it out with the 14T currently on it and go from there. Love it when you guys do all the math for me...

WizardOfBoz 11-24-19 03:05 PM


Originally Posted by Bigbus (Post 21221660)
With regard to learning to pedal faster in a lower gear--You can't teach an old dog new tricks! I'm pushing 70years and can still do 240 situps, bench press 160X9 and ride 10+ miles/day. I burn out really fast when I try speed pedaling whereas when I'm climbing a hill and working the pedals hard, I never seem to reach bottom. Just me. But with that considered, higher gearing just makes sense. I have a 13T off an old MTB so when the weather turns nicer I'll see if I can swap it out with the 14T currently on it and go from there. Love it when you guys do all the math for me...

Outstanding, Bigbus!

Bill Kapaun 11-24-19 03:42 PM


Originally Posted by Bigbus (Post 21221660)
With regard to learning to pedal faster in a lower gear--You can't teach an old dog new tricks! I'm pushing 70years and can still do 240 situps, bench press 160X9 and ride 10+ miles/day. I burn out really fast when I try speed pedaling whereas when I'm climbing a hill and working the pedals hard, I never seem to reach bottom. Just me. But with that considered, higher gearing just makes sense. I have a 13T off an old MTB so when the weather turns nicer I'll see if I can swap it out with the 14T currently on it and go from there. Love it when you guys do all the math for me...

I was 63 when I determined it was better for me to spin a lower gear faster. Not a lot faster, but "the next lower gear" faster. Probably a 14T to 16T. It's been quite awhile.
How much OVER 10 miles/day do you ride? If not much, you're basically doing a quick workout, since you must be doing 20-30 MPH. For you, that probably works.
Try riding 30-40 miles/day by mashing.

Nobody knows what your ACTUAL cadence is. OR if you have a double or triple up front and YOU don't seem that willing to provide that info.
What is the cadence you use and what cadence do you call "Speed Pedaling"? Maybe something in between will be the best of both worlds.
That's a problem when you only have a 6 speed on the back. Your steps between gears is too large to be most efficient. IF you had a cog between your "mashing" & "speed pedaling", you may be in a happy place?
Keep in mind, if you go to a smaller smallest cog, you widen the steps BETWEEN gears and may find you lack a gear you really used a lot more than you thought on the non downhill portions of your ride.

That's why my 2 bikes are 3X9 with close spaced cassettes. 12-27 on one and 13-25 on the other.
I simply have a better chance of having a "near perfect" gear a greater % of the time.

3alarmer 11-24-19 03:53 PM

...
...there was a Shimano 56 tooth chain ring over at the co-op here about a month ago, in the box of rings. I looked at it and smiled. :) If it's still there next time I visit, I'll grab it for you. Usually they sell chain rings there for five bucks or less.

Miele Man 11-24-19 05:43 PM

We could help a lot more if we knew what you have on that rear wheel ie a freewheel, a freehub, a freehub with Old Uniglide cogs where the high cog screws on. Also your current cadence and front setup. I think from your post that you have a double chainring with 42 and 52 rings.

Btw, some Shimano freehubs were a transitional typed having both external threads for a Screw on Uniglide cog and internal threads for a screw on Hyperglide cassette lockring. What freehub do you have? that is what groupset is it from?

Cheers

63rickert 11-24-19 06:09 PM

A move from a 14 to a 12 is just huge. Worry about an 11 much later.


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