Switching from a 20 inch rear tire to a 24 on a trike

[michaelmac]

Hi
couple of weeks ago I posted about changing my chainring to get more speed. This led to a discussion about the different ways to accomplish what I wanted to do. Which was increase my speed from around 11 or 12 miles an hour to the 15 mile an hour and at the cadence of 60 RPM. There was discussion about chain ring, the rear cassette and changing the rear tire from 20 to 24 inch. The Result of comparing these thing seem to indicate that changing the tire size would give me the most increase in speed.???
So, I have done some research into changing the rear tire and keeping everything else same. It seems like it's probably doable? So, question I now have is,,,,,, can I change just the rear wheel, to 24 inch,,,,,, this would be my preference or do I need to change all three wheels? Are there safety and mechanical reasons to not just change the rear wheel. Or are there other consideration.
Thanks in advance for opinions and help
Michael

 

[phoenixtoohot]

I changed the rear tire on a TerraTrike, non electric, from 20 to 24 inch, and it made negligible difference on speed. The downside is that it lowered the nose enough that pedal strike on the pavement became a problem.

 

[rich c]

You've checked the physical clearances? The chain stays are long enough?

 

[steve marino]

Not sure if my math is right, but if you had gone from a 20" tire to one that was 22", you would have increased the diameter by 10%. Double that because you went to a 24" tire and you get an increase in diameter of 20%. Figuring that you were getting 12 mph w/ the 20" tires, you should be able to get 14.4 mph w/ the 24" tires. This is probably all wrong, but I think the numbers still sorta make sense. Figure another 1 or 2 extra mph. You'd have to go to 26" tires to see much of a difference, but then the bike would be a lot harder to pedal up to speed if it's a single speed.

No, you wouldn't need to change all three wheels, you wouldn't even need to change two, but the bike would handle "somewhat" differently w/ different size wheels on each side (and your coffee would slosh out of your cup if your cupholder was mounted on the handlebars). Race cars that race on ovals sometimes have two different size tires on each side due to the centrifugal forces on an oval at high speed. You probably don't have to worry about that on your trike :]

If you want it to go faster, just put an electric motor and a battery in the rear rack. I saw a trike in Florida like that, and it would really go!

 

[michaelmac]

I changed the rear tire on a TerraTrike, non electric, from 20 to 24 inch, and it made negligible difference on speed. The downside is that it lowered the nose enough that pedal strike on the pavement became a problem.

hi
okay, so now I'm confused ,,,, which is not surprising I'm confused a lot.
During the discussion of my original post,,,,,, the reason that I had decided to go to the 24 inch wheel is that as Steve M points out it is a 20% increase. Assuming that his math and my math and the math from my previous discussions were correct. So, I'm wondering where we're going wrong? It sure seems like you should have had a 20% increase if you were pedling at the same rpm's,,,, in the same gear? There has to be something I'm missing here, can you help,?
Thanks
Michael

 

[Lightning P38]

Hi
couple of weeks ago I posted about changing my chainring to get more speed. This led to a discussion about the different ways to accomplish what I wanted to do. Which was increase my speed from around 11 or 12 miles an hour to the 15 mile an hour and at the cadence of 60 RPM. There was discussion about chain ring, the rear cassette and changing the rear tire from 20 to 24 inch. The Result of comparing these thing seem to indicate that changing the tire size would give me the most increase in speed.???
So, I have done some research into changing the rear tire and keeping everything else same. It seems like it's probably doable? So, question I now have is,,,,,, can I change just the rear wheel, to 24 inch,,,,,, this would be my preference or do I need to change all three wheels? Are there safety and mechanical reasons to not just change the rear wheel. Or are there other consideration.
Thanks in advance for opinions and help
Michael

Why not just shift up a gear or two to get more speed?

 

[michaelmac]

Why not just shift up a gear or two to get more speed?

In my highest gear at 60 RPMs I'm only getting about 11 or 12 miles an hour. I would like to get at least 15 miles per. I picked 60 RPMs because according to Google that is what most recreational riders pedal at comfortably. I'm not really sure what RPMs I am going at when I get the 11 or 12 mph, but it doesn't seem like peddling faster helps any. So for the sake of consistency I'm using 60 RPMs.
Thanks for the reply
Michael

 

[terry28613]

In my highest gear at 60 RPMs I'm only getting about 11 or 12 miles an hour. I would like to get at least 15 miles per. I picked 60 RPMs because according to Google that is what most recreational riders pedal at comfortably. I'm not really sure what RPMs I am going at when I get the 11 or 12 mph, but it doesn't seem like peddling faster helps any. So for the sake of consistency I'm using 60 RPMs.
Thanks for the reply
Michael

I just joined and was thinking of a 24 inch rear wheel and heel strike may become a problem. I am considering the 10 speed so I can get the 11 36 cassette. I am concerned with the derailer but I can consistently go 15-17 on flat smooth surface. I am pedaling pretty fast though.

 

[Lightning P38]

In my highest gear at 60 RPMs I'm only getting about 11 or 12 miles an hour. I would like to get at least 15 miles per. I picked 60 RPMs because according to Google that is what most recreational riders pedal at comfortably. I'm not really sure what RPMs I am going at when I get the 11 or 12 mph, but it doesn't seem like peddling faster helps any. So for the sake of consistency I'm using 60 RPMs.
Thanks for the reply
Michael

i think your easiest solution is to put a bigger gear ring on the bottom bracket. Have a bike shop do it for you, if you need help to do it. I am assuming you only have one gear on the front.


They will know how big a ring to put on....talk with them to see what they think would work.