Originally Posted by
FixedFiend626
I have a road triple (52/42/30) that came on my touring bike and have since realised the 52t outer ring is slightly overkill, only time it gets used is with a heavy tailwind. Curious as to what the minimum difference between teeth count is. Would 46t be too small? Any more than a 48 and would make more sense to just replace the crankset. any advice appreciated, thanks.
You didn't mention what cassette tooth counts you use, and how many cogs in the cassette.
A 46 and a 42 would only be about a 1 to 1.5 cog shift. For instance,at 85 rpm:
the
46-19 is 16.1 mph, between
the 42-17 at 16.5 mph, and
the 42-18 at 15.6 mph.
So the middle 42 and large 46 would be pretty much interchangeable.
I'd suggest a 39 middle instead of your 42, and keep the 52 for those occasional long gradual downhills or big tailwinds. My 39-12 gear is good up to the low 20 mph range, so I'm rarely shifting to my 52.
It will lower the middle gear's mph range by about 1 mph, a little more at faster speeds.
It's about 7% easier.
It depends on your typical cadences and road speeds, of course.
EDIT--and touring with a load needs lower gears than this.
I
mentioned my 11-speed 12-25 cassette with my 52-39-39 in another recent thread. I only use the 52 on mile or more downhills.