Gear Inches Question: 28.3 v 27

[timacn]

I'm thinking about getting an ebike and wondering about gear inches. On bikes with multiple gears, I tend to use far fewer combinations than I have available. I also like to have one "easy" combo available for hills, particularly as I'm getting older. I was wondering about the differences between a low gear combo using a 50/34 crank and a Shimano 105 11-34 cluster and a combo of a 44t crank and a 11-42 cluster. According to Sheldon Brown, if I computed it right, the lowest gear combo between the two is 34/34 (approximately 27 gear inches) on the first bike and 44/34 (approximately 28.3 gear inches) on the second bike. Is a combo of 27 gear inches versus 28.3 gear inches a big deal? I think I would prefer an 11 speed to a 22 speed if the difference between those two low gear combos is not a big deal. (By the way, I am comparing a Cannondale Synapse Neo 1 to a Cannondale Synapse Neo SE here.)

Thanks for your help. (Please forgive any stupidity in the question. This is new ground for me)

 

[Nova Haibike]

The difference in low gear is not significant, but there is a significant difference in the wheels between the two bikes. You should ride them if you can.

 

[timacn]

Thanks, NH. Unfortunately, I can't ride them as there are none available locally in shops. I do have a Topstone 105 with 650 tires and I like them, so long as they are inflated to the max. Otherwise, they are "squishy" and tend to roll weirdly when turning.

 

[Sierratim]

@timacn , as it seems you might know (since you've mentioned Sheldon Brown), 'Gear Inches' is the ratio of the tooth count for the chain ring and cassette cog, multiplied by the diameter of the tire being driven. It's related to the distance the bike would move with the selected gearing combination during one rotation of the cranks (multiple by Pi to get the actual distance). In this sense the difference between 27 & 28.3 gear-inches is going to be hard to notice being just (28.3-27)*Pi = 4 inches per crank rotation. Unless you ride in very steep terrain this shouldn't be a big deal.

The bikes you mention do have different wheels and tires. When I enter the actual wheel/tire sizes into Sheldon Brown's calculator I get just about the gear inch result for both bikes. In other words, these bikes will cover the same distance in one pedal stroke when they are in their lowest gears.

My ebike has a 1x front chain ring. I'm liking it a lot for the simplicity.

 

[timacn]

Thanks, Sierratim! Appreciate the insights.

 

[NH-Senior-Gal]

I'm thinking about getting an ebike and wondering about gear inches. On bikes with multiple gears, I tend to use far fewer combinations than I have available. I also like to have one "easy" combo available for hills, particularly as I'm getting older. I was wondering about the differences between a low gear combo using a 50/34 crank and a Shimano 105 11-34 cluster and a combo of a 44t crank and a 11-42 cluster. According to Sheldon Brown, if I computed it right, the lowest gear combo between the two is 34/34 (approximately 27 gear inches) on the first bike and 44/34 (approximately 28.3 gear inches) on the second bike. Is a combo of 27 gear inches versus 28.3 gear inches a big deal? I think I would prefer an 11 speed to a 22 speed if the difference between those two low gear combos is not a big deal. (By the way, I am comparing a Cannondale Synapse Neo 1 to a Cannondale Synapse Neo SE here.)

Thanks for your help. (Please forgive any stupidity in the question. This is new ground for me)

Hi again timacn, I think the big difference between the two bikes that you are considering is the terrain / road surface you will be mostly riding on. Although the lowest gear on both bikes is similar, the high gear is higher on the Neo 1 with the 50 tooth chainring, vs the Neo SE which has the 44 tooth chainring. I think the manufacturer is assuming that you will ride mostly paved roads on the Neo 1 and want to be zipping right along on a gentle paved downhill. They may also be thinking that the Neo SE (which is designed as a 'gravel' bike) doesn't need the high gear because they are assuming you won't be needing really high gears even downhill on gravel. You might feel a little "spun out" on a gentle paved downhill on the Neo SE if you want to rush along, but then again, maybe you don't mind that limitation, or perhaps you are a good 'spinner'.
As a note, most people don't pay as much attention to gearing as I do because they are generally much stronger than I am. I have never been very strong, so I have always changed my bike's gearing to give me the low gears I want; and I don't mind giving up the high gears since I am usually not in a hurry. Coasting is OK
Good luck in finding the right bike for you. I think you are on the right path to ask a lot of questions.
Brenda

 

[timacn]

Thanks, Sierratim! Appreciate the insights.

Hi again timacn, I think the big difference between the two bikes that you are considering is the terrain / road surface you will be mostly riding on. Although the lowest gear on both bikes is similar, the high gear is higher on the Neo 1 with the 50 tooth chainring, vs the Neo SE which has the 44 tooth chainring. I think the manufacturer is assuming that you will ride mostly paved roads on the Neo 1 and want to be zipping right along on a gentle paved downhill. They may also be thinking that the Neo SE (which is designed as a 'gravel' bike) doesn't need the high gear because they are assuming you won't be needing really high gears even downhill on gravel. You might feel a little "spun out" on a gentle paved downhill on the Neo SE if you want to rush along, but then again, maybe you don't mind that limitation, or perhaps you are a good 'spinner'.
As a note, most people don't pay as much attention to gearing as I do because they are generally much stronger than I am. I have never been very strong, so I have always changed my bike's gearing to give me the low gears I want; and I don't mind giving up the high gears since I am usually not in a hurry. Coasting is OK
Good luck in finding the right bike for you. I think you are on the right path to ask a lot of questions.
Brenda

Hey Brenda. Thanks for your input. (I was thinking of your earlier post when I asked my new questions.) So: I am torn between the Synapse Neo 1 and the Synapse Neo SE. Since covid, I've been doing very little outside biking, mostly indoors on trainers. I have dream visions of things like riding bike paths in Acadia National Park and cinder topped bike paths and canal routes. The Neo 1's high gears would be nice to have and if the stock tires on the Neo 1 are good for light gravel, that might be the smart way to go. I do like paved country roads, but while riding a bike many years ago I was hit by a car and don't like to share the road with automobiles too much, especially with the advent of texting. Bike paths and rail trails are much safer.

 

[NH-Senior-Gal]

Hi,
It sounds like you will be leaning toward the Neo SE. It will be great on the roads and trails you like most. For both bikes the range is awesome!
I ride mostly paved roads with friends; dirt roads and cinder trails just occasionally, so the Neo 1 is perfect for me. If I wanted to ride the roads and trails like you prefer, I would have chosen the Neo SE. AND, it's a cool color!
And Acadia carriage roads are great -- you will love to bike there.
Good luck!
Brenda

 

[timacn]

Thanks, Brenda. Did you ever take your Neo 1 on Acadia carriage roads? If so, how did it work out?

 

[NH-Senior-Gal]

Thanks, Brenda. Did you ever take your Neo 1 on Acadia carriage roads? If so, how did it work out?

No, I did not ride the trails with the Neo 1. It was years ago (1992?) and we had our skinny-tire road bikes with us. We rented Cannondale! mountain bikes to do the carriage roads. Even though the roads are well maintained, I think I would like the Neo SE on those roads better than the Neo 1. When you get there, pay attention to all the bridge designs; I think they are all different. Here's a picture of one of the roads (grabbed from the web) that has a nice view.

 

[timacn]

Thanks, Brenda. Great picture of a nice looking trail.
And thanks as well for the good bike advice.
Maybe after the vaccine I'll check it out.

 

[NH-Senior-Gal]

We are also waiting for the vaccine! But we have been riding by ourselves and try not to interact with other people. That's working our well, though we are somewhat limited by the availablilty of...porta-pots... Some parks have taken away their porta-pots and we don't want to go into gas stations, stores or restaurants. Usually we just use the "green rooms" along our route.
Now that the weather has moved toward winter, we will be moving our bike riding into the basement. Sigh...

 

[timacn]

Porta pots probably aren't real great either in terms of covid transmission.

 

[NH-Senior-Gal]

Porta pots probably aren't real great either in terms of covid transmission.

That's why we prefer 'green rooms'. When we use porta-pots, we use a LOT of hand sanitizer and try to sanitize everything we can 'before' and 'after'. A coronavirus vaccine will be most welcome!

 

[timacn]

In re: Synapse Neo 1 Wheels: as Carson Jones kindly pointed out to me, the other option is to get a pair of 650b tires for the Neo 1 and use them when contemplating a "gravel focused" ride.

 

[NH-Senior-Gal]

Regarding different tires for the Neo 1: A while ago I talked with my Local Bike Shop (LBS) and they said that the Neo1 has enough clearance for 40mm tires. The Neo 1 takes 700c tires, so 650b tires won't work, but you can get a wider and more knobby 700c tire for the Neo1.
Here are a couple I found online:
The 40mm WTB Byway TCS 700c Gravel Tire which has a smooth center tread good for pavement and small knobbies at the side to help in dirt and gravel. When I look at the specs it appears that the Neo SE has this tire in 47mm.
Another one I found which looks more tuned for gravel roads is the Maxxis Rambler 700c Gravel Tire available in (38mm or 40mm) which has small knobbies on the whole contact surface and looks like it would be at home on dirt and gravel.
Thanks for the inspiration to do some research on tires. My tires are looking a bit worn after 2200 miles and I probably will replace them at the beginning of next season. If you get the Neo 1 be sure that any spare tires you get are "tubeless ready" because the rims are also tubeless ready. Regular tires that are not tubeless ready won't work (or so I've heard...)
Good luck in zeroing in on your bike choice.
Brenda

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[timacn]

Once again, thanks for the great information, Brenda! Very helpful.