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-   -   Which front chainring should I use on my Juiced bike Rip Current S? (https://www.bikeforums.net/showthread.php?t=1185286)

sumbikerguy123 10-08-19 05:26 AM

Which front chainring should I use on my Juiced bike Rip Current S?
 
I have a Juiced bike Rip Current S. The front chain ring is a 52 tooth ring. When I get to 25mph+ I feel like I am over pedaling. So I want to put a larger tooth front chain ring on it. I'm looking for suggestions on which chain ring to use...53-54-55 or ?

And a online place to buy the chain ring? Juiced tells me I the bolt pattern/size you need for the sprocket is 130 mm.

Tires are 26 X 4.0 fat tires. 9 Speed Shimano Cassette Drivetrain.

I live in Florida, so it's mostly flat roads and occasional highway overpass to go over.

I use the smallest gear in the back 99% of the time. Unless I have my bags filled with groceries in the back and I am going over a overpass. Then I will drop the rear gear down one.

Any advice is appreciated, thanks, Bill.

trailangel 10-08-19 08:05 AM

I wouldn't do this. You haven't provided what size tires, rims and what you highest cassette gear is. Website says 9 speed cassette, so your high gear is 11 tooth. With a 52 in front and 11 in the rear, with 4 inch tires, I'm guessing this is already a 120 inch gear..... What is your crank RPM at 25 mph?
I suggest learning to spin your crank.

cat0020 10-08-19 08:15 AM

How often are you pedaling at 25+ mph?

Do you sustain that speed over long distance?

sumbikerguy123 10-08-19 08:19 PM


Originally Posted by trailangel (Post 21154867)
I wouldn't do this. You haven't provided what size tires, rims and what you highest cassette gear is. Website says 9 speed cassette, so your high gear is 11 tooth. With a 52 in front and 11 in the rear, with 4 inch tires, I'm guessing this is already a 120 inch gear..... What is your crank RPM at 25 mph?
I suggest learning to spin your crank.

R. I edited my OP with more info.

What is your crank RPM at 25 mph?...........................R. I have no idea? Just know I am over pedaling and could use a larger front chain ring. Just not sure which one would be best for me?

I suggest learning to spin your crank.................................R. IDK what this means?

I'm guessing this is already a 120 inch gear................................R. IDK what this means either?

sumbikerguy123 10-08-19 08:49 PM


Originally Posted by cat0020 (Post 21154875)
How often are you pedaling at 25+ mph?

R. Don't know how to answer your question other that the fact I am pedaling too fast or over pedaling. And need a larger front sprocket than the 52tooth chain ring I have.

Do you sustain that speed over long distance?

R. Yes, when I am doing stuff around town. Traveling to the gym or food shopping. Pretty much straight line non-stop pedaling for 5-10 miles. A few lights, approximately 15-30 minutes non-stop pedaling. Top speed is 28-32mph depending on wind, charge and load I'm carrying.

2old 10-08-19 11:28 PM

You can ascertain your crank rpm with a stopwatch (or any watch with a "second hand"), then calculate speed (or use speed to calculate your rpm); measure the outside tire diameter, and use pi (3.1416), gear ratio (apparently 52/11 in your tallest gear), 60 minutes in an hour, 12" in a foot and 5280' in a mile. If you can't figure out the formula, just ask. Also, if you go from 52 teeth to 53, your cadence will be reduced by less than two rpm (crank revolutions per minute).

cat0020 10-09-19 07:23 AM


Originally Posted by sumbikerguy123 (Post 21155947)
R. Yes, when I am doing stuff around town. Traveling to the gym or food shopping. Pretty much straight line non-stop pedaling for 5-10 miles. A few lights, approximately 15-30 minutes non-stop pedaling. Top speed is 28-32mph depending on wind, charge and load I'm carrying.

If you travel 5 miles in 15 min.. that's averaging about 23 mph
If you travel 10 miles in 30 min, that's averaging 30 mph.
Hitting a pothole or avoiding hazards at those speeds can be tricky.

If OEM chainring is a 52T, and you are in the smallest cog (12 or 14T) you should be cruising along at decent speed.
You could try a 54 or 56T, but likely you will lose some climbing ability when pedaling.
But if your riding doesn't involve much hills, losing climbing ability shouldn't be a concern.
I would be more worried about hitting a pothole at 30 mph.

sumbikerguy123 10-09-19 07:35 AM

But if your riding doesn't involve much hills, losing climbing ability shouldn't be a concern...............R. No hills in S. Florida. Except for a few bridges.

You could try a 54 or 56T, but likely you will lose some climbing ability when pedaling.

R. I use the 9th gear 99% of the time so I can always shift down 8 more gears if need be. Pretty flat here in S. Florida except for overpasses.

I would be more worried about hitting a pothole at 30 mph.

R. There are no potholes on the roads bike lanes I use. But agree it wouldn't be fun hitting a pothole on a bike. Maybe in the Northeast there are more potholes for sure. But not in my area.

Thanks for the advice.

sumbikerguy123 10-09-19 07:38 AM


Originally Posted by 2old (Post 21156060)
You can ascertain your crank rpm with a stopwatch (or any watch with a "second hand"), then calculate speed (or use speed to calculate your rpm); measure the outside tire diameter, and use pi (3.1416), gear ratio (apparently 52/11 in your tallest gear), 60 minutes in an hour, 12" in a foot and 5280' in a mile. If you can't figure out the formula, just ask. Also, if you go from 52 teeth to 53, your cadence will be reduced by less than two rpm (crank revolutions per minute).

R. Thanks for the info, but when it comes to math I'm clueless. Would you suggest a 53, 54, 55 or ? I'm guessing a 54 T ring?

2old 10-09-19 10:23 AM

Assuming the diameter of your 26" X 4" tire is 28"; your chainring is 52 teeth and smallest cog is 11 teeth.
Speed = RPM (how fast you're pedaling in revolutions per minute) X 52/11 X 3.1416 (Pi) X 60 (minutes in an hour) divided by 12 (inches in a foot) and 5280 (feet in a mile)
So: 30 mph means that you are pedaling 76.2 RPM (crank rotations per minute); changing to 54 teeth would reduce your pedaling speed to 73.4 RPM (IMO, minimally, which is why others have said "learn to spin", that is pedal faster). Alternatively, go to the biggest chainring that won't interfere with the right chainstay. 60 teeth at 76.2 RPM would be about 35 mph.


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