Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Changing gear ratios

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Changing gear ratios

Old 04-24-24, 12:26 AM
  #51  
Senior Member
 
Join Date: Apr 2017
Posts: 2,313
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1057 Post(s)
Liked 569 Times in 458 Posts
Originally Posted by Bill Kapaun
Don't care.
..
Duragrouch is online now  
Old 04-24-24, 05:02 PM
  #52  
Senior Member
 
Kontact's Avatar
 
Join Date: Apr 2011
Posts: 7,402
Mentioned: 43 Post(s)
Tagged: 0 Thread(s)
Quoted: 4623 Post(s)
Liked 1,773 Times in 1,160 Posts
Originally Posted by Duragrouch
I dunno about that. If, theoretically, you have a big enough difference in chainrings so that there is no overlap, then you start on the small ring, go through the entire cassette, switch to the big ring, then go through the entire cassette. Sequential. Bromptons are like this, no overlap. Low range on the IGH, 1,2 on the cogs. Medium range, 1,2 on the cogs. High range, 1,2 on the cogs. Zero overlap. And, the spacing between 1,2 on the cogs, is the same as the jump to the next range. So 6 equally spaced gears. I prefer no IGH, but darnit, they really did think out the gearing well. But they also have a special "Brompton Wide Range" IGH, not a standard Sturmey Archer 3.
People did stuff like this 40 years ago. And stopped. Bikes are semi trucks - you don't start in 1 and work your way up to 21. The reason this kind of gearing sucks is that we normally ride in the middle gears, which would make this a huge double shift all the time.

Alpine gearing where you switch back and forth big/small/big/small was also abandoned 40 years ago.

And then there is cross overs, which also suck.
Kontact is offline  
Likes For Kontact:
Old 04-24-24, 05:31 PM
  #53  
Senior Member
 
Join Date: Apr 2017
Posts: 2,313
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1057 Post(s)
Liked 569 Times in 458 Posts
Originally Posted by Kontact
People did stuff like this 40 years ago. And stopped. Bikes are semi trucks - you don't start in 1 and work your way up to 21. The reason this kind of gearing sucks is that we normally ride in the middle gears, which would make this a huge double shift all the time.

Alpine gearing where you switch back and forth big/small/big/small was also abandoned 40 years ago.

And then there is cross overs, which also suck.
Middle gears... yeah that make sense. I just feel like I still have too much overlap. On my old race bike, 52/42x7, I think 6 gears were dupes. On my current 50/34x7, 5 gears are dupes. I'd like a bit wider crank range to get a bit more than 400% total, without needing bigger steps at the cassette.

When I upgraded my road bike to a triple when I moved to hilly country, I didn't have an even spaced triple. I was working on the road and passing the time outside of work, buying, fixing, then selling bikes. One had a triple, which I swapped with my 52/42 biopace and then sold that bike. The triple was half-step-plus-granny, I don't recall the numbers, and yes, a true middle ring might have been better, I could swap that out easy if I ever ride that bike again. However I don't recall any problems riding it, in fact that middle ring (I'm guessing 46 or 47?) was very versatile, used 98% of time (so proves your argument), I was just super glad for that bailout-low given that my low cog was I think 24 or 25, so that was a huge difference in big hills. I was always spinning back then, hadn't learned to climb out of the saddle like now.

I had to look up up cross-over gearing, and also read the descriptions of all other strategies. I'll have to digest.

My current bike (folder with huge diameter seat tube) won't do a triple on a standard hollow spindle, FD wouldn't go in far enough, I'd need to go back to square taper and get a wide-spindle BB cartridge. I love the hollow spindle system, so I'm hoping in future years for greater than 16T jump, but my guess is development on 2Xs has halted in favor of 1Xs. With lift pins on the outer ring, I would bet I could do a 20T jump, but I would need a 74mm BCD on the inner, I can't go smaller than 34T on 110 BCD.
Duragrouch is online now  
Old 04-24-24, 08:10 PM
  #54  
Senior Member
 
grumpus's Avatar
 
Join Date: Apr 2016
Posts: 1,433
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 568 Post(s)
Liked 508 Times in 387 Posts
Originally Posted by Duragrouch
Yep. In flat land, I rode my road race bike with 52/42 for well over a decade. Moved to a place with hills, it wasn't long until I traded that out for a triple. But that was before wide doubles.
Wide doubles have been around since at least the 1970s, they just weren't mainstream.
grumpus is offline  
Likes For grumpus:
Old 04-24-24, 08:32 PM
  #55  
Senior Member
 
Join Date: Apr 2017
Posts: 2,313
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1057 Post(s)
Liked 569 Times in 458 Posts
Originally Posted by grumpus
Wide doubles have been around since at least the 1970s, they just weren't mainstream.
Huh, good to know. I think that was before lift pins on the large chainring, right? So how big a jump would upshift OK? I'm thinking that lift pins (or formed protrusions in thin steel rings) help a lot for big up-jumps, but I don't know for sure.
Duragrouch is online now  
Old 04-24-24, 08:39 PM
  #56  
aka: Dr. Cannondale
 
rccardr's Avatar
 
Join Date: Jul 2009
Posts: 7,775
Mentioned: 236 Post(s)
Tagged: 0 Thread(s)
Quoted: 2175 Post(s)
Liked 3,531 Times in 1,237 Posts
The early 80’s SR Apex 86bcd crank on the Raleigh Gran Tour currently carries a set of 48/28 chainrings (no pins, flat rings) and shifts like buttah. Mated to an 8 speed 12-34 cassette, friction shifted, it gets me pretty much anywhere. Well, at least anywhere my 72 year old legs can take me with a 28/34 low gear…somewhere in the low 20’s gear-inch-wise.
__________________
Hard at work in the Secret Underground Laboratory...
rccardr is offline  
Likes For rccardr:
Old 04-24-24, 08:41 PM
  #57  
Senior Member
 
Kontact's Avatar
 
Join Date: Apr 2011
Posts: 7,402
Mentioned: 43 Post(s)
Tagged: 0 Thread(s)
Quoted: 4623 Post(s)
Liked 1,773 Times in 1,160 Posts
Originally Posted by rccardr
The early 80ís SR Apex 86bcd crank on the Raleigh Gran Tour currently carries a set of 48/28 chainrings (no pins, flat rings) and shifts like buttah. Mated to an 8 speed 12-34 cassette, friction shifted, it gets me pretty much anywhere. Well, at least anywhere my 72 year old legs can take me with a 28/34 low gearÖsomewhere in the low 20ís gear-inch-wise.
What front derailleur makes that work?
Kontact is offline  
Old 04-24-24, 08:58 PM
  #58  
aka: Dr. Cannondale
 
rccardr's Avatar
 
Join Date: Jul 2009
Posts: 7,775
Mentioned: 236 Post(s)
Tagged: 0 Thread(s)
Quoted: 2175 Post(s)
Liked 3,531 Times in 1,237 Posts
Currently a Shimano CX-70, (the Do Everything FD) but have also sucessfully used a Dura Ace 7400.
__________________
Hard at work in the Secret Underground Laboratory...
rccardr is offline  
Likes For rccardr:
Old 04-24-24, 09:00 PM
  #59  
Senior Member
 
Join Date: Apr 2017
Posts: 2,313
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1057 Post(s)
Liked 569 Times in 458 Posts
Originally Posted by rccardr
The early 80ís SR Apex 86bcd crank on the Raleigh Gran Tour currently carries a set of 48/28 chainrings (no pins, flat rings) and shifts like buttah. Mated to an 8 speed 12-34 cassette, friction shifted, it gets me pretty much anywhere. Well, at least anywhere my 72 year old legs can take me with a 28/34 low gearÖsomewhere in the low 20ís gear-inch-wise.
I like that, I ran the numbers, fewer duplicate gears in the middle, great gear range 500% without big jumps at the cogs. That's good news for me. If I need a higher high from my current 85 gear inch (on 20"/406 wheels), I could go 54/34 if I can find a 54 ring on 5x110mm, or if I need a lower low from my current 21 gear inch for loaded touring, I could go 50/30 (would need a new crank on 110/74).

Last edited by Duragrouch; 04-24-24 at 09:12 PM.
Duragrouch is online now  
Old 04-24-24, 10:59 PM
  #60  
Senior Member
 
70sSanO's Avatar
 
Join Date: Feb 2015
Location: Mission Viejo
Posts: 5,846

Bikes: 1986 Cannondale SR400 (Flat bar commuter), 1988 Cannondale Criterium XTR, 1992 Serotta T-Max, 1995 Trek 970

Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 1956 Post(s)
Liked 2,201 Times in 1,339 Posts
Originally Posted by rccardr
Currently a Shimano CX-70, (the Do Everything FD) but have also sucessfully used a Dura Ace 7400.
Suntour Cyclone FDís are also a good swiss army knife choice.

John
70sSanO is offline  
Old 04-25-24, 06:27 AM
  #61  
aka: Dr. Cannondale
 
rccardr's Avatar
 
Join Date: Jul 2009
Posts: 7,775
Mentioned: 236 Post(s)
Tagged: 0 Thread(s)
Quoted: 2175 Post(s)
Liked 3,531 Times in 1,237 Posts
Originally Posted by 70sSanO
Suntour Cyclone FDís are also a good swiss army knife choice.

John
Yep, also a Shimano 6207, which shifted a 48/34/24 triple reasonably well at Eroica CA.
__________________
Hard at work in the Secret Underground Laboratory...
rccardr is offline  
Old 04-25-24, 12:09 PM
  #62  
Senior Member
 
grumpus's Avatar
 
Join Date: Apr 2016
Posts: 1,433
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 568 Post(s)
Liked 508 Times in 387 Posts
Originally Posted by Duragrouch
Huh, good to know. I think that was before lift pins on the large chainring, right? So how big a jump would upshift OK? I'm thinking that lift pins (or formed protrusions in thin steel rings) help a lot for big up-jumps, but I don't know for sure.
Stronglight 49D with 32-52 and 14-28 5s on the back. The rings were completely flat and with full profile teeth, as befits a crankset introduced in 1949 (the steel 49A was ten years older but otherwise the same). Campy Record/Rally derailleurs. Wasn't the smoothest upshift but was never a problem as long as you weren't late. The FD broke at the clamp after 11 or 12 years, the RD had already been replaced with IIRC Suntour ARX GT when its cage spring broke.
At some point before the FD broke I'd switched to a Stronglight 99 with 32-44 and 13-32 7s on the back, I don't recall what the replacement FD was.
grumpus is offline  
Old 04-26-24, 04:42 PM
  #63  
Senior Member
 
Join Date: Aug 2007
Location: Locust NC
Posts: 726

Bikes: 1992, Cannondale R900. 1991 Paramount pdg

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 63 Post(s)
Liked 185 Times in 72 Posts
I had 23 tooth cassette on my 91 pgd Paramount. I put on 28 tooth and the old 105 short cage shifted it fine. I later went to a 32 tooth cassette and it would not clear the big gear. I went on line and found a short cage that is rated to 34 teeth. It works very smooth shifting into the big gear. I put the old short cage 105 on another 8 speed 28 tooth cassette bike and it is smooth shifting. Both bikes are 52-39 chainrings. I did replace chain.
EddyR
EddyR is offline  
Likes For EddyR:
Old 04-28-24, 02:33 AM
  #64  
Wheelman
 
Join Date: Aug 2021
Location: Putney, London UK
Posts: 896

Bikes: 1982 Holdsworth Avanti (531), 1961 Holdsworth Cyclone

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 310 Post(s)
Liked 728 Times in 369 Posts
Originally Posted by grumpus
Stronglight 49D with 32-52 and 14-28 5s on the back. The rings were completely flat and with full profile teeth, as befits a crankset introduced in 1949 (the steel 49A was ten years older but otherwise the same). Campy Record/Rally derailleurs. Wasn't the smoothest upshift but was never a problem as long as you weren't late. The FD broke at the clamp after 11 or 12 years, the RD had already been replaced with IIRC Suntour ARX GT when its cage spring broke.
At some point before the FD broke I'd switched to a Stronglight 99 with 32-44 and 13-32 7s on the back, I don't recall what the replacement FD was.
I've gone almost that far:
.
Stronglight 49D with 52-36
SunTour Ultra 6 13-32
SunTour Cyclone front and back
126 OLD
.
I think that actually gives me slightly more range:
https://www.gear-calculator.com/?GR=...22,28&UF2=2125

Running new TA chainrings and I think 26 is the smallest available (£28.99 new) but reading around suggested that a front jump of 16 was the largest reasonable amount.
Good to know I could try 32 at some point.
Aardwolf is offline  
Old 04-30-24, 07:29 PM
  #65  
Senior Member
 
PromptCritical's Avatar
 
Join Date: Mar 2024
Location: San Diego
Posts: 542

Bikes: Columbine, Paramount Track Bike, Colnago Super, Santana Tandems (1995 & 2007), Gary Fisher Piranha, Trek Wahoo, Bianchi Track Bike, a couple of Honda mountain bikes

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 264 Post(s)
Liked 176 Times in 114 Posts
I'm looking for a Shimano 9-speed cassette with the largest cog in the 42T range. The only ones I can find are from the CUES groupset. Since this is for a tandem, the "E-Bike rated" design seems like a good idea. Does anyone know if these are interchangeable with my current Deore XT setup?
__________________
Cheers, Mike
PromptCritical is offline  
Old 04-30-24, 11:22 PM
  #66  
Senior Member
 
Join Date: Apr 2017
Posts: 2,313
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1057 Post(s)
Liked 569 Times in 458 Posts
Originally Posted by PromptCritical
I'm looking for a Shimano 9-speed cassette with the largest cog in the 42T range. The only ones I can find are from the CUES groupset. Since this is for a tandem, the "E-Bike rated" design seems like a good idea. Does anyone know if these are interchangeable with my current Deore XT setup?
First, if the ebike has a hub motor, the gears don't get stressed more. Mid-drive, yes. But I would only respect "e-bike rated" if there were numbers to back up that claim. Since cog dimensions are required to be the same, that means either better steel or better surface treatment or both, and test data to back up claims. Otherwise, it's just hype. (Not to be confused with Hyperspaceglide which actually works. Those were the days, significant improvements every year or two, constant trickle-down to the lower groupsets.)

Last edited by Duragrouch; 04-30-24 at 11:27 PM.
Duragrouch is online now  
Old 06-08-24, 06:07 AM
  #67  
Newbie
Thread Starter
 
Join Date: Apr 2024
Posts: 6
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Likes: 0
Liked 5 Times in 2 Posts
I wanted to close the thread by reporting on what I ended up doing.

I bought a Shimano 50/34 crank for $51.00 US. It required a different bottom bracket so I bought a new bottom bracket for $27.00 US. The local do it yourself bike shop helped me install them along with a new chain they supplied. They also trued my rear wheel, adjusted the shifters and checked the headset. Total charge for their services was $10.00 US including the chain. I gave them a $10.00 tip. So, for under $100.00 US, I'm back in business and I have to say the bike rides great and the hills are a little flatter

Thank you to everyone who provided advice!
siearly is offline  
Likes For siearly:
Old 06-08-24, 08:04 AM
  #68  
Senior Member
 
grumpus's Avatar
 
Join Date: Apr 2016
Posts: 1,433
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 568 Post(s)
Liked 508 Times in 387 Posts
Originally Posted by siearly
I have an older Cannondale R600. I've had it 20 years and it was at least 2 years old when I bought it. I am 57 years old and 6' 4" (193 CM). The bike frame is 63 CM.


The bike's gearing is fine for flats but when I hit hills, especially now that I'm getting older, I struggle, even in the lowest gear. The bike is geared as follows:
  • Crank length is 175. Gears are 53/39.
  • Cassette is 8 gears 23/13.
What would be the best approach to gearing this bike down without spending a lot of money? There is a local bike shop that helps you do the work yourself for a small fee so I'm thinking of going that route. Could I just go to a cassette that has more teeth than mine and be done? Change the crank as my bike shop recommended? Both?
A quick Google suggests that your bike has RX100 rear derailleur which can handle 12/28 cassette and 28t total. The cassette (and chain) would be the easiest cheapest upgrade, moving from 23 to 28 is a worthwhile extra low gear. Your 39/53 would be stretching the overall capacity slightly, but with careful chain sizing you should be OK.
grumpus is offline  
Old 06-08-24, 10:35 AM
  #69  
Senior Member
 
Kontact's Avatar
 
Join Date: Apr 2011
Posts: 7,402
Mentioned: 43 Post(s)
Tagged: 0 Thread(s)
Quoted: 4623 Post(s)
Liked 1,773 Times in 1,160 Posts
Originally Posted by siearly
I wanted to close the thread by reporting on what I ended up doing.

I bought a Shimano 50/34 crank for $51.00 US. It required a different bottom bracket so I bought a new bottom bracket for $27.00 US. The local do it yourself bike shop helped me install them along with a new chain they supplied. They also trued my rear wheel, adjusted the shifters and checked the headset. Total charge for their services was $10.00 US including the chain. I gave them a $10.00 tip. So, for under $100.00 US, I'm back in business and I have to say the bike rides great and the hills are a little flatter

Thank you to everyone who provided advice!
I'm glad you found a solution that works for you.

For anyone following the thread, the OP could have also replaced just his cassette with a 11-28 for $25 + labor and gotten a lower climbing gear than what he has now with a 34x23 low gear.
Kontact is offline  
Likes For Kontact:
Old 06-09-24, 08:15 PM
  #70  
Senior Member
 
Join Date: Apr 2017
Posts: 2,313
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1057 Post(s)
Liked 569 Times in 458 Posts
Originally Posted by siearly
I wanted to close the thread by reporting on what I ended up doing.

I bought a Shimano 50/34 crank for $51.00 US. It required a different bottom bracket so I bought a new bottom bracket for $27.00 US. The local do it yourself bike shop helped me install them along with a new chain they supplied. They also trued my rear wheel, adjusted the shifters and checked the headset. Total charge for their services was $10.00 US including the chain. I gave them a $10.00 tip. So, for under $100.00 US, I'm back in business and I have to say the bike rides great and the hills are a little flatter

Thank you to everyone who provided advice!
Sounds good! If the chain doesn't skip under high load climbing, cassette may be fine. But if cassette is worn, you may want to replace soon to reduce wear on chain and then same on your nice new chainrings.
Duragrouch is online now  
Old 06-09-24, 09:38 PM
  #71  
Really Old Senior Member
 
Bill Kapaun's Avatar
 
Join Date: Feb 2007
Location: Mid Willamette Valley, Orygun
Posts: 13,954

Bikes: 87 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds. 2019 Giant Explore E+3

Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 1829 Post(s)
Liked 1,315 Times in 907 Posts
Originally Posted by Kontact
I'm glad you found a solution that works for you.

For anyone following the thread, the OP could have also replaced just his cassette with a 11-28 for $25 + labor and gotten a lower climbing gear than what he has now with a 34x23 low gear.
They still can.
As they get even older, the option is still available. Even a Shimano Tourney RDER would handle any 8 speed combination thrown at it.
Bill Kapaun is offline  
Old 06-09-24, 10:20 PM
  #72  
Senior Member
 
Kontact's Avatar
 
Join Date: Apr 2011
Posts: 7,402
Mentioned: 43 Post(s)
Tagged: 0 Thread(s)
Quoted: 4623 Post(s)
Liked 1,773 Times in 1,160 Posts
Originally Posted by Bill Kapaun
They still can.
As they get even older, the option is still available. Even a Shimano Tourney RDER would handle any 8 speed combination thrown at it.
Or they could have done the crank second. Who said one precluded the other?

The point I was making was that cassette could have been the only item replaced and would have yielded lower gearing for less cash than the crank. No new derailleur required.
Kontact is offline  
Old 06-09-24, 11:22 PM
  #73  
Senior Member
 
Join Date: Apr 2017
Posts: 2,313
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1057 Post(s)
Liked 569 Times in 458 Posts
Originally Posted by Bill Kapaun
They still can.
As they get even older, the option is still available. Even a Shimano Tourney RDER would handle any 8 speed combination thrown at it.
I agree, that was my first thought, next step in lower gearage, unless they mind the spacing.

I can attest to that Tourney, and works surprisingly well for a $13 new RD. It was just the only one that had a claw-mount version, which I needed. But works flawlessly.
Duragrouch is online now  
Old 06-10-24, 01:20 AM
  #74  
Senior Member
 
Join Date: Apr 2019
Location: UK
Posts: 1,447
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 700 Post(s)
Liked 473 Times in 350 Posts
Originally Posted by Duragrouch
I dunno about that. If, theoretically, you have a big enough difference in chainrings so that there is no overlap, then you start on the small ring, go through the entire cassette, switch to the big ring, then go through the entire cassette. Sequential. Bromptons are like this, no overlap. Low range on the IGH, 1,2 on the cogs. Medium range, 1,2 on the cogs. High range, 1,2 on the cogs. Zero overlap. And, the spacing between 1,2 on the cogs, is the same as the jump to the next range. So 6 equally spaced gears. I prefer no IGH, but darnit, they really did think out the gearing well. But they also have a special "Brompton Wide Range" IGH, not a standard Sturmey Archer 3.
On a normal RD/cassette though, youíre looking at a life of cross-chaining which Iíve always assumed is why the two ranges overlap by as much as maybe 3-4 cogs?

OP Iím amazed you can even get up any hills with a 39:23 low gear. Kudos.
choddo is offline  
Old 06-10-24, 02:29 AM
  #75  
Senior Member
 
Join Date: Apr 2017
Posts: 2,313
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1057 Post(s)
Liked 569 Times in 458 Posts
Originally Posted by choddo
On a normal RD/cassette though, youíre looking at a life of cross-chaining which Iíve always assumed is why the two ranges overlap by as much as maybe 3-4 cogs?

OP Iím amazed you can even get up any hills with a 39:23 low gear. Kudos.
Cross-chaining: If you mean constant switching of chainrings, I think it depends on where the border gears sit in the range. Right now, the 2X conversion on my folder, 21-85 gear inches, is about the lower 2/3 of a MTB range, as I am limited in my high gears without a monster chainring or IGH overdrive. With a normal gear range, and wider 2X spacing, I'd be on the small ring 98% of the time. If you mean bad chainline angle... that's the definition of modern 1X system, so I can't see how a wide 2X would be much worse, in fact I think that is still an advantage of a wide 2X, inner ring for the low half of the cassette and outer ring for the high half of the cassette.

Yeah, 39:23 would be too tall for my hills with my **20" wheels**, much less 700c. Calculating now for my old 700c road bike, eesh, with original 52/42x25 in flatland, low was 44 gear inches, and when I put a triple on it (I think 30T road triple), that still gives 32 gear inches, about what I started with on my 7 speed folder, which wasn't low enough.
Duragrouch is online now  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.