Re-Gearing Cruisers
#1
Junior Member
Thread Starter
Re-Gearing Cruisers
Hi all, looking for some guidance as I'm a newb on modifying bicycles.
I have two 26" beach cruisers, a Firmstrong and Sixthreezero, both with shimano Nexus 3-speeds. My wife and I use them on the local paved trails, one bike with a kid seat and the other tows a 2-kid trailer. Yeah, we have 3 small kids though the 5 year old just did a 4.5 mile ride yesterday on a Strider pedal bike so her days in the trailer might be behind us once I upgrade her to something better. Anyway, we both use 1st gear 95% of the time, have never gone up into 3rd gear, and there's plenty times I'd love to have lower gearing for hills, sometimes even going flat I'd like lower gearing. We aren't commuting or trying to make great time, these bikes are just used for a leisurely day of riding with the family. My wife used to teach spinning classes and I used to mountain bike so we're used to a much faster cadence than the beach cruiser can offer especially when the trailer has 2 kids, water and maybe a picnic lunch. Sprockets are 40 tooth front and 18 tooth rear right now. I'd like to go down on the front sprocket, but I don't know how much is "enough" to make better use of the 3 speed without going too far.
So looking for guidance on the right tooth count to make a noticeable difference.
Second, how universal are these drive sprockets? What do I need to know to make sure what I buy fits my bikes (understanding I'll have to shorten the chain).
I have two 26" beach cruisers, a Firmstrong and Sixthreezero, both with shimano Nexus 3-speeds. My wife and I use them on the local paved trails, one bike with a kid seat and the other tows a 2-kid trailer. Yeah, we have 3 small kids though the 5 year old just did a 4.5 mile ride yesterday on a Strider pedal bike so her days in the trailer might be behind us once I upgrade her to something better. Anyway, we both use 1st gear 95% of the time, have never gone up into 3rd gear, and there's plenty times I'd love to have lower gearing for hills, sometimes even going flat I'd like lower gearing. We aren't commuting or trying to make great time, these bikes are just used for a leisurely day of riding with the family. My wife used to teach spinning classes and I used to mountain bike so we're used to a much faster cadence than the beach cruiser can offer especially when the trailer has 2 kids, water and maybe a picnic lunch. Sprockets are 40 tooth front and 18 tooth rear right now. I'd like to go down on the front sprocket, but I don't know how much is "enough" to make better use of the 3 speed without going too far.
So looking for guidance on the right tooth count to make a noticeable difference.
Second, how universal are these drive sprockets? What do I need to know to make sure what I buy fits my bikes (understanding I'll have to shorten the chain).
#2
Member
23 tooth Rear sprocket
Hi all, looking for some guidance as I'm a newb on modifying bicycles.
I have two 26" beach cruisers, a Firmstrong and Sixthreezero, both with shimano Nexus 3-speeds. My wife and I use them on the local paved trails, one bike with a kid seat and the other tows a 2-kid trailer. Yeah, we have 3 small kids though the 5 year old just did a 4.5 mile ride yesterday on a Strider pedal bike so her days in the trailer might be behind us once I upgrade her to something better. Anyway, we both use 1st gear 95% of the time, have never gone up into 3rd gear, and there's plenty times I'd love to have lower gearing for hills, sometimes even going flat I'd like lower gearing. We aren't commuting or trying to make great time, these bikes are just used for a leisurely day of riding with the family. My wife used to teach spinning classes and I used to mountain bike so we're used to a much faster cadence than the beach cruiser can offer especially when the trailer has 2 kids, water and maybe a picnic lunch. Sprockets are 40 tooth front and 18 tooth rear right now. I'd like to go down on the front sprocket, but I don't know how much is "enough" to make better use of the 3 speed without going too far.
So looking for guidance on the right tooth count to make a noticeable difference.
Second, how universal are these drive sprockets? What do I need to know to make sure what I buy fits my bikes (understanding I'll have to shorten the chain).
I have two 26" beach cruisers, a Firmstrong and Sixthreezero, both with shimano Nexus 3-speeds. My wife and I use them on the local paved trails, one bike with a kid seat and the other tows a 2-kid trailer. Yeah, we have 3 small kids though the 5 year old just did a 4.5 mile ride yesterday on a Strider pedal bike so her days in the trailer might be behind us once I upgrade her to something better. Anyway, we both use 1st gear 95% of the time, have never gone up into 3rd gear, and there's plenty times I'd love to have lower gearing for hills, sometimes even going flat I'd like lower gearing. We aren't commuting or trying to make great time, these bikes are just used for a leisurely day of riding with the family. My wife used to teach spinning classes and I used to mountain bike so we're used to a much faster cadence than the beach cruiser can offer especially when the trailer has 2 kids, water and maybe a picnic lunch. Sprockets are 40 tooth front and 18 tooth rear right now. I'd like to go down on the front sprocket, but I don't know how much is "enough" to make better use of the 3 speed without going too far.
So looking for guidance on the right tooth count to make a noticeable difference.
Second, how universal are these drive sprockets? What do I need to know to make sure what I buy fits my bikes (understanding I'll have to shorten the chain).
Last edited by Blues; 06-21-21 at 09:49 PM. Reason: grammer
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#3
Junior Member
Thread Starter
I don't think your chain ring is easily replaced. I would install a larger rear cog. Shimano makes an inexpensive 23T rear sprocket that will reduce your gearing almost a whole gear and is easy to install if you use "Circlip pliers". You can search for "SHIMANO SG-3C40 Nexus Sprocket (23T)". The product description says: "Shimano Alfine and nexus cogs work with either a 1/8 or 3/32 chain. Will also fit any 3 tabbed coaster brake or internally gear hub." You will need a new longer chain, too.
#4
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Regardless, You need larger tooth counts on the back or smaller tooth counts on the front to make pedaling easier for climbing. But the lower the gear ratio, the slower you will be going per turn of the crank.
Whether or not you can easily solve your issues depends on what bike you have and it's components.
Or maybe you did.... I must be hallucinating again. <grin> And how the heck did I get in here?
Not that I don't like beach cruisers. I just don't have one right now. But I've been trying to convince the spouse that she'd like one.
Last edited by Iride01; 06-22-21 at 03:03 PM.
#5
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A lot of bike stuff is proprietary and not cross-compatible - but not three-speed hub sprockets. Shimano and SRAM [Sachs (Fichtel&Sachs)] and Sturmey-Archer (since 1903!) sprockets all fit. Given the COVID bike part shortages, take what you can get!
Sturmey offers a 24T.
Sturmey offers a 24T.
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#6
Junior Member
Thread Starter
I don't think your chain ring is easily replaced. I would install a larger rear cog. Shimano makes an inexpensive 23T rear sprocket that will reduce your gearing almost a whole gear and is easy to install if you use "Circlip pliers". You can search for "SHIMANO SG-3C40 Nexus Sprocket (23T)". The product description says: "Shimano Alfine and nexus cogs work with either a 1/8 or 3/32 chain. Will also fit any 3 tabbed coaster brake or internally gear hub." You will need a new longer chain, too.
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Gear ratios are simple enough to switch to your liking. As mentioned, the SRAM, Shimano and the, Sturmey Archer use the same cogs so that is a plus.
You can either make it easier to pedal by reducing teeth on the Sprocket, or by adding teeth on the cog.
That is for over-all pedal easiness, each gear will be equally easier.
I'm quite familiar with the Sturmey Archer hubs and not so much with the Shimano but the old Sturmey hubs (before 2010) use 2nd gear as the 1:1 direct drive. 3rd gear is 33% higher and 1st is 25% lower. For the Sturmey, that makes it easy to have two cruising gears and a granny for hills.
Im not sure if the Shimano is set-up that way. When Sturmey was bought in 09/10, the hubs were changed to 1st being direct drive which messes things up a bit for gearing changes.
There is a math formula for getting the correct gearing.
Front sprocket teeth divided by rear cog teeth times net tire height. (net is 1/4" less that standing tire height).
This will give a number that is called inch feet.
Industry normal for 1st gear is usually somewhere in the 50's I personally like +/- 58 i.f for first gear. Somebody pulling something or carrying weight may want a lower 1st.
Consider that the i.f. numbers for an average Schwinn 3spd with a 26" tire are 1st=50, 2nd= 67 and 3rd= 89. (using a 46t front, 18t rear)
Since the rear is usually the gear to change, you just plug in different rear cog tooth numbers until you get what you want.
I have a 3spd on a Schwinn lightweight frame using 27" tires. I use 2nd as the primary riding gear and 1st as a granny for hills, 3rd will get me around 20 mph with an easy gait. The formula was 48 teeth front sprocket divided by 22 teeth rear cog times by 27.25
That gives me a 2nd gear primary riding gear of 59.5. A first gear 25% higher of 44.6 which is a good granny number and 79.3 for third being 33% lower than 2nd.
I also have a 2 speed that is geared for me the same way.
Front sprocket 39, rear cog 19, tire 27.5"
That comes out to 55.9 for 1st and 74.5 for 2nd. Right in that sweet spot.
So Im not sure of the steps in a Shimano hub but the gear juggling is the same.
You can either make it easier to pedal by reducing teeth on the Sprocket, or by adding teeth on the cog.
That is for over-all pedal easiness, each gear will be equally easier.
I'm quite familiar with the Sturmey Archer hubs and not so much with the Shimano but the old Sturmey hubs (before 2010) use 2nd gear as the 1:1 direct drive. 3rd gear is 33% higher and 1st is 25% lower. For the Sturmey, that makes it easy to have two cruising gears and a granny for hills.
Im not sure if the Shimano is set-up that way. When Sturmey was bought in 09/10, the hubs were changed to 1st being direct drive which messes things up a bit for gearing changes.
There is a math formula for getting the correct gearing.
Front sprocket teeth divided by rear cog teeth times net tire height. (net is 1/4" less that standing tire height).
This will give a number that is called inch feet.
Industry normal for 1st gear is usually somewhere in the 50's I personally like +/- 58 i.f for first gear. Somebody pulling something or carrying weight may want a lower 1st.
Consider that the i.f. numbers for an average Schwinn 3spd with a 26" tire are 1st=50, 2nd= 67 and 3rd= 89. (using a 46t front, 18t rear)
Since the rear is usually the gear to change, you just plug in different rear cog tooth numbers until you get what you want.
I have a 3spd on a Schwinn lightweight frame using 27" tires. I use 2nd as the primary riding gear and 1st as a granny for hills, 3rd will get me around 20 mph with an easy gait. The formula was 48 teeth front sprocket divided by 22 teeth rear cog times by 27.25
That gives me a 2nd gear primary riding gear of 59.5. A first gear 25% higher of 44.6 which is a good granny number and 79.3 for third being 33% lower than 2nd.
I also have a 2 speed that is geared for me the same way.
Front sprocket 39, rear cog 19, tire 27.5"
That comes out to 55.9 for 1st and 74.5 for 2nd. Right in that sweet spot.
So Im not sure of the steps in a Shimano hub but the gear juggling is the same.
Last edited by macstuff; 08-26-21 at 02:46 PM.