# 10 speed gear pattern



## Stinky_Sullivan (Jun 9, 2014)

I just calculated the gear ratios of all the gears on my 10 speed.

The chain ring is a 39/50.
The cassette is a 14/17/20/24/28.

I haven't ridden a road bike since I was 14 or 15 but I always though you started out on the smallest chain ring and the largest cog, ran through all the cogs in the cassette until you got to the smallest, then switched to the largest chain ring and ran through the cassette again from largest to smallest. If I did that, I'd run through the gears in the following order based on the gear ratios.

1-2-4-6-8-3-5-7-9-10

What kind of sense does that make?


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## bulldog1935 (Jun 9, 2014)

___*39	__50*

*28*	37.6		48.2

*24*	43.9		56.3

*20*	52.7		67.5

*17*	61.9		79.4

*14*	75.2		96.4

This is your gear chart in gear inches (gear-inches is the equivalent diameter drive wheel if you had a penny-farthing with 10 wheel choices instead of gears, and is also the easiest unit to be conversant between bikes and cyclists)
38 inches to 96 inches, but not in the order that you expected.  You do have pretty typical "alpine gearing" from the 10-speed era.

Here's Sheldon's gear calculator
http://sheldonbrown.com/gears/ 





if you live in my neighborhood, though, you're going ot need a gear below 30 inches to pedal home - either that or be a biathlete (get off and push)


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## vincev (Jun 9, 2014)

Stinky_Sullivan said:


> I just calculated the gear ratios of all the gears on my 10 speed.
> 
> The chain ring is a 39/50.
> The cassette is a 14/17/20/24/28.
> ...





Stinky,you are starting to sound as weird as Dave.


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## Stinky_Sullivan (Jun 9, 2014)

Bulldog, I understand that each cog on the cassette translate to a given distance of travel and that distance increases as the chain moves to the next smaller cog on the cassette. What I'm referring to is that the fact that what I've always known as 5th gear, smallest chain ring and smallest cassette cog, is actually 8th gear when looking at the actual gear ratios in ascending order. A 39 tooth chain ring and 14 tooth cog is a 2.79:1 ratio. Then moving to the next gear, 50 tooth chain ring and 28 tooth cog, the ratio drops to 1.79:1 which is the 3rd smallest ratio.

In order, the chain ring/cog combinations that would have me progressing, in order, from the smallest ratio to the largest ratio are:

39/28
39/24
50/28
39/20
50/24
39/17
50/20
39/14
50/17
50/14

From 2nd to 9th gear I'd have to alternate back and forth between the two chain rings. I understand that's how the math works out. All the while, I'd have to go up and down the cassette one cog larger, two cogs smaller, one cog larger, two cogs smaller.

Since the 50/28 is actually the 3rd smallest gear, I might as well skip the 39 tooth chain ring and ride the bike as a 5 speed unless I'm climbing a steep hill.

What I need to do is just get myself one of those SA 8 speed hubs and forget the 2x5 gearing all together.

Here's what's REALLY f'd up. I'm too fat to ride road bikes without looking like I'm in a Shriner' parade. I'll never ride this bike. I don't have to worry about the shifting order. I'll probably still loose sleep over this though.


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## GTs58 (Jun 9, 2014)

It's a good thing one doesn't have to shift a 10+ speed bike like you do an 18 wheeler. I rode a 10 speed for years and there were a couple gears I never or hardly ever used. 10th gear going down a hill was fun just to see how fast you could go before you broadsided a car pulling out from a cross street.


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## Stinky_Sullivan (Jun 10, 2014)

Pedal downhill? Isn't that an oxymoron?


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## bulldog1935 (Jun 10, 2014)

Stinky_Sullivan said:


> Bulldog, I understand that each cog on the cassette translate to a given distance of travel and that distance increases as the chain moves to the next smaller cog on the cassette. What I'm referring to is that the fact that what I've always known as 5th gear, smallest chain ring and smallest cassette cog, is actually 8th gear when looking at the actual gear ratios in ascending order. A 39 tooth chain ring and 14 tooth cog is a 2.79:1 ratio. Then moving to the next gear, 50 tooth chain ring and 28 tooth cog, the ratio drops to 1.79:1 which is the 3rd smallest ratio.
> 
> In order, the chain ring/cog combinations that would have me progressing, in order, from the smallest ratio to the largest ratio are:
> 
> ...



Yes, that is the way alpine shifting is supposed to work, so you can use either shifter to effect on rolling hills.  

again, it's easier to talk in gear-inches than gain ratios because we're talking in two-digit integers instead of one-point-yada-yada. 
(just about any touring or rando rider can tell you all about their gear inches)
On the 2nd rebuild of my old Raleigh, I went to half-step chainrings, 41/46T, which exactly split the steps between the rear cogs (I was running a wide Ultra-6 freewheel then).  Gearing was 39 inches to 95 inches in about 5-inch steps.  




My current, 3rd rebuild, I went with a cyclotouriste triple to give me really low gears - again half-steps, 42/47T plus a 26T escape ring.  Also spread the rear for a 700C, 126mm axle, wide 7-speed, 12 to 32 teeth.  



this set-up gives me 22 inches to 104 inches in about 5-inch steps.  

My daughter has a Nexus 8 on her utility bike
I changed the front chainring from 44 down to 42, and increased the drive sprocket from 20 to 22, so she could climb just about any hill in the TX hill country (including our neighborhood).  



Her 8 gears go from 23 inches to 85 inches - her lower 3 are hill-climbing gears, 4th and 5th are both good start-up gears, 6 and 7 are the real cruising gears, and the 85-inch downhill is all most people need.

(if you multiply gear-inches by pi, you get the distance the wheel rolls in one crank revolution)

Have you thought about an upright rebuild on your bike?  - that is what prompted my second rebuild - or actually the old-man cervical strain I was getting on my old long stem and Maes bars



tall Technomic quill plus Moustache bars, but you could go to Albatross bars if you really want to sit up.  Here's a great place to get some ideas:  http://www.rivbike.com/Staff-Bikes-s/766.htm


 

ps - there's a print-out of my gear chart in the map case on top of my rando bag




and here's the late Sheldon's take on the whole gear thing
http://sheldonbrown.com/gear-theory.html


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## Stinky_Sullivan (Jun 10, 2014)

The build will be what ever the eventual rider wants. That won't be me. Although the bike is tall enough for me, I'm 6', I'm not gonna let anyone see a 350# hairy fat man give himself a wedgie on a road bike. Besides, I have too many bikes needing work to be tweaking the gear ratios on a bike I never expect to ride. Plus, it's pretty flat around here. The ratios will probably be fine just like they are.

I have 2 road bikes I'm building; a '72 Rollfast 10 speed and an '83 Schwinn Le Tour 12 speed.

The Schwinn needs a completely new BB/crank/chain ring setup as well as a seat, tubes, tires, and cables. I found it on the side of the interstate in Cedar Rapids, IA last year along with two kids bikes. All three looked to have fallen from a trailer and dragged a ways. Fortunately, the Schwinn only suffered a damaged seat and chain ring and the front wheel was missing.

I bought the Rollfast from someone in Schenectady, NY for $39. Other than needing tubes, tires, cables, and a thorough servicing, the threads on the steer tube are a bit sloppy. Repair options on that are being discussed in another thread.

Until I get around to fixing that steer tube, the chain ring and derailleurs from the Rollfast are slated to go on a '69 Columbia muscle bike I picked up in Little Rock, AR for $50. There's room between the muscle bike dropouts for that road bike hub. I just need to pick up another hub to lace into a new 20" rim. When the Rollfast needs its chain ring back, I'll put the original 40t back on the muscle bike and leave it as a 5 speed.


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## bulldog1935 (Jun 10, 2014)

ah, I read your thread that you were having a tough time riding - I didn't connect it was a rebuild for someone else.  
I have a very nice Suntour Ultra-6 freewheel not in use, 13-27 teeth.  It fits in the same space as a 5-speed freewheel.


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## Stinky_Sullivan (Jun 10, 2014)

Shoot me a PM with a pic and a price.

I'm not actually building these bikes for anyone specific. I doubt I'll ever get rid of these road bikes. I'm just not building them for me. I hope to offer bikes for rent in one of the historic districts if we get the house there we want. The topic of the gear ratios came up because I got to thinking about what all the ratios actually were. For me, math is a borderline fetish.


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## bulldog1935 (Jun 10, 2014)

Hi Stinky, pm sent


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