Thread: 65-85+ Thread
View Single Post
Old 06-29-15 | 10:52 AM
  #1672  
Houseboy522
Newbie
 
Joined: Sep 2009
Posts: 11
Likes: 2
Originally Posted by McBTC
This is what I was thinking: 15 unique gears about equally spaced apart --e.g.,

Gear inch chart:

Shimano 50/34T Chainrings
11-Speed Freewheel

[TABLE="class: MsoNormalTable, width: 131"]
[TR]
[TD="width: 64, bgcolor: transparent"]
Rings
/
Cogs
[/TD]
[TD="width: 55, bgcolor: transparent"]
34
[/TD]
[TD="width: 56, bgcolor: transparent"]
50
[/TD]
[/TR]
[TR]
[TD="width: 64"]
11
[/TD]
[TD="width: 55"]
82
[/TD]
[TD="width: 56"]
120
[/TD]
[/TR]
[TR]
[TD="width: 64"]
12
[/TD]
[TD="width: 55"]
75
[/TD]
[TD="width: 56"]
110
[/TD]
[/TR]
[TR]
[TD="width: 64"]
13
[/TD]
[TD="width: 55"]
69
[/TD]
[TD="width: 56"]
102
[/TD]
[/TR]
[TR]
[TD="width: 64"]
14
[/TD]
[TD="width: 55"]
64
[/TD]
[TD="width: 56"]
95
[/TD]
[/TR]
[TR]
[TD="width: 64"]
16
[/TD]
[TD="width: 55"]
56
[/TD]
[TD="width: 56"]
83
[/TD]
[/TR]
[TR]
[TD="width: 64"]
18
[/TD]
[TD="width: 55"]
50
[/TD]
[TD="width: 56"]
74
[/TD]
[/TR]
[TR]
[TD="width: 64"]
20
[/TD]
[TD="width: 55"]
45
[/TD]
[TD="width: 56"]
66
[/TD]
[/TR]
[TR]
[TD="width: 64"]
22
[/TD]
[TD="width: 55"]
41
[/TD]
[TD="width: 56"]
60
[/TD]
[/TR]
[TR]
[TD="width: 64"]
25
[/TD]
[TD="width: 55"]
36
[/TD]
[TD="width: 56"]
53
[/TD]
[/TR]
[TR]
[TD="width: 64"]
28
[/TD]
[TD="width: 55"]
32
[/TD]
[TD="width: 56"]
47
[/TD]
[/TR]
[TR]
[TD="width: 64"]
32
[/TD]
[TD="width: 55"]
28
[/TD]
[TD="width: 56"]
41
[/TD]
[/TR]
[/TABLE]



So, a 50-22 combination at 70 rpm is 12.5 mph...
(60 * 70 * Pi / 12 * 60 / 5,280)

And, a 50-18 combo at 70 rpm = 15.4 mph

My suggestion for an improved 11-spd. freewheel combination for riders like me is:
15-16-17-18-19-20-22-24-26-30-34

Anything is possible with 1:1 and while a 34T may not be used that often, I for sure would get more use out of more closely spaced gears in the mid range than having the 11-12-13-14 cogs with the 50-ring as I won't be drafting in pelotons. The 50-15 combination with a cadence of 75 is about 20 mph -- other than when riding downhill, I'd need a tailwind to make that happen.

--e.g., something like this:

[TABLE="width: 240"]
[TR]
[TD="class: xl63, width: 64, bgcolor: transparent"][SUP]Ring[/SUP][SUB]Cog [/SUB]
[/TD]
[TD="class: xl64, width: 64, bgcolor: transparent"]34[/TD]
[TD="class: xl65, width: 64, bgcolor: transparent"]MPH (75 rpm)[/TD]
[TD="class: xl64, width: 64, bgcolor: transparent"]50[/TD]
[TD="class: xl65, width: 64, bgcolor: transparent"]MPH (75 rpm)[/TD]
[/TR]
[TR]
[TD="class: xl65, width: 64, bgcolor: transparent"]15[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"][/TD]
[TD="class: xl67, bgcolor: transparent"][/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"]88[/TD]
[TD="class: xl67, bgcolor: transparent"]19.6[/TD]
[/TR]
[TR]
[TD="class: xl65, width: 64, bgcolor: transparent"]16[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"][/TD]
[TD="class: xl67, bgcolor: transparent"][/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"]83[/TD]
[TD="class: xl67, bgcolor: transparent"]18.4[/TD]
[/TR]
[TR]
[TD="class: xl65, width: 64, bgcolor: transparent"]17[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"][/TD]
[TD="class: xl67, bgcolor: transparent"][/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"]78[/TD]
[TD="class: xl67, bgcolor: transparent"]17.3[/TD]
[/TR]
[TR]
[TD="class: xl65, width: 64, bgcolor: transparent"]18[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"]50[/TD]
[TD="class: xl67, bgcolor: transparent"]11.1[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"]74[/TD]
[TD="class: xl67, bgcolor: transparent"]16.4[/TD]
[/TR]
[TR]
[TD="class: xl65, width: 64, bgcolor: transparent"]19[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"]47[/TD]
[TD="class: xl67, bgcolor: transparent"]10.6[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"]70[/TD]
[TD="class: xl67, bgcolor: transparent"]15.5[/TD]
[/TR]
[TR]
[TD="class: xl65, width: 64, bgcolor: transparent"]20[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"]45[/TD]
[TD="class: xl67, bgcolor: transparent"]10.0[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"]66[/TD]
[TD="class: xl67, bgcolor: transparent"]14.7[/TD]
[/TR]
[TR]
[TD="class: xl65, width: 64, bgcolor: transparent"]22[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"]41[/TD]
[TD="class: xl67, bgcolor: transparent"]9.1[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"]60[/TD]
[TD="class: xl67, bgcolor: transparent"]13.4[/TD]
[/TR]
[TR]
[TD="class: xl65, width: 64, bgcolor: transparent"]24[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"]38[/TD]
[TD="class: xl67, bgcolor: transparent"]8.4[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"]55[/TD]
[TD="class: xl67, bgcolor: transparent"]12.2[/TD]
[/TR]
[TR]
[TD="class: xl65, width: 64, bgcolor: transparent"]26[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"]35[/TD]
[TD="class: xl67, bgcolor: transparent"]7.7[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"][/TD]
[TD="class: xl67, bgcolor: transparent"][/TD]
[/TR]
[TR]
[TD="class: xl65, width: 64, bgcolor: transparent"]30[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"]30[/TD]
[TD="class: xl67, bgcolor: transparent"]6.7[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"][/TD]
[TD="class: xl67, bgcolor: transparent"][/TD]
[/TR]
[TR]
[TD="class: xl65, width: 64, bgcolor: transparent"]34[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"]27[/TD]
[TD="class: xl67, bgcolor: transparent"]5.9[/TD]
[TD="class: xl66, width: 64, bgcolor: transparent"][/TD]
[TD="class: xl67, bgcolor: transparent"][/TD]
[/TR]
[/TABLE]
McBTC bring up an aspect of gearing that is very interesting to ME. I have always wondered about the preponderance of cogs at the high end of gearing. I understand that with fewer teeth, the percentage of change is greater (with only one tooth difference) but I am wondering if something in a 13-32 is readily available. Any thoughts? (Do we need a new thread of this -or- can someone link me to an existing thread that covers this?)
Thanks
Houseboy522 is offline  
Reply
0