26 vs 20 rear wheels
03-22-19 | 05:22 PM
#1
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26 vs 20 rear wheels
My wife and I are currently looking at buying recumbent trikes. A lbs owner told me they would travel at the same speed regardless of the size of the rear wheel with the gearing and cadence being the same . I do not believe that to be correct. I thought I would ask the "experts" here if that is the case.
Also, when choosing, which one would you prefer 26" or 20". From what I would think having all 3 wheels the same dia. would make it a better idea so when riding, you would only have to carry 1 size tube and tire if so inclined to take a tire along.
Currently looking at a Terra trike rover and similar Cattrike. Have also looked at recumbent rike tandems, but those look like would be a hassle to transport even more so than a recumbent trike.
Also, when choosing, which one would you prefer 26" or 20". From what I would think having all 3 wheels the same dia. would make it a better idea so when riding, you would only have to carry 1 size tube and tire if so inclined to take a tire along.
Currently looking at a Terra trike rover and similar Cattrike. Have also looked at recumbent rike tandems, but those look like would be a hassle to transport even more so than a recumbent trike.
03-22-19 | 05:53 PM
#2
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With the same gear and the same cadence the larger diameter wheel will make the trike go a longer way because of the diameter. It will be faster. However, being in a different gear or different cadence when riding together won't matter much. The only thing you will lose is high top speed from the larger wheel, and a lower first gear for hills with the smaller wheel. That probably doesn't matter either. The 20" wheels will accelerate a little better if everything else were the same. Also a very small thing. Smaller diameter wheels ride a little choppy as they drop in and out of low and high spots. I can feel it, some people can't or don't care. It's probably more important that the small wheel makes the whole trike shorter for transporting in a vehicle.
Decide by how they ride.
edit - I would pick the bigger wheel for a little smoother ride and better different tire selections available.
Decide by how they ride.
edit - I would pick the bigger wheel for a little smoother ride and better different tire selections available.
Last edited by 2manybikes; 03-22-19 at 06:02 PM.
03-23-19 | 06:31 AM
#3
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Having owned numerous trikes with varying wheel sizes, I can give my personal impressions.
First, the bigger the rear wheel, the faster the speed for the EXACT SAME chain ring/cassette cog combination. That’s just math and physics but both can achieve the same speeds by shifting gears
Now, since trike builders generally use the same cranksets and cassettes on their machines regardless of wheel size, for the same cadence, the larger rear wheel can achieve a higher top speed and the smaller rear wheel will yield a lower climbing speed.
Second, the small wheel will accelerate faster but the big wheel will “carry” the speed better.
Third, the big wheel will ride softer over bumps and cracks.
Lastly, big rear wheels make for a longer machine so harder to transport.
I currently ride a VTX with a big rear wheel and it rides like a Cadillac but definitely accelerates slower than my small speed trikes and it is long. On my small wheel machines, I mitigate the gearing difference with a larger front chainring.
Finally, average riding speeds are the same regardless of rear wheel size.
First, the bigger the rear wheel, the faster the speed for the EXACT SAME chain ring/cassette cog combination. That’s just math and physics but both can achieve the same speeds by shifting gears
Now, since trike builders generally use the same cranksets and cassettes on their machines regardless of wheel size, for the same cadence, the larger rear wheel can achieve a higher top speed and the smaller rear wheel will yield a lower climbing speed.
Second, the small wheel will accelerate faster but the big wheel will “carry” the speed better.
Third, the big wheel will ride softer over bumps and cracks.
Lastly, big rear wheels make for a longer machine so harder to transport.
I currently ride a VTX with a big rear wheel and it rides like a Cadillac but definitely accelerates slower than my small speed trikes and it is long. On my small wheel machines, I mitigate the gearing difference with a larger front chainring.
Finally, average riding speeds are the same regardless of rear wheel size.
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03-23-19 | 06:15 PM
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If you do the math, gearing a small wheel up to compensate for the smaller diameter will lose you a gear or two of range, too. Bottom line is, smaller wheels work well if you expect to go slow. If you're looking for speed, get the big wheels!
03-23-19 | 08:02 PM
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Thanks for all the quick replies. Part of our delima has been solved. My wife rode a Terra Trike Rover today and told me this is the one I want. She sat on a couple others and even without riding them, she said the Terra Trike was the one. She did ride the Rover around the lot and decided with the bike shop making the adjustments for the fit, she is happy and we brought it home. Even with the 20" wheels and the 330 rear hub , which was explained as a CVT for a bike, it makes things less complicated for her and we will see how much rides.
I am still out to lunch, so to speak. I don't want to give up my Speicalized Roubaix for a trike just yet. Gonna wait and see what happens and how hard it is for us to ride sort of together. A trike is in the future, I am sure. Just need to make up my mind which one.
I am still out to lunch, so to speak. I don't want to give up my Speicalized Roubaix for a trike just yet. Gonna wait and see what happens and how hard it is for us to ride sort of together. A trike is in the future, I am sure. Just need to make up my mind which one.
03-24-19 | 08:06 AM
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Thought I would share, though you have already purchased.
Some manufacturers use Shimano's Capreo hub and cassette for 20" wheels. This system uses 9-10-11-13 tooth cogs on the small side, which effectively gears the bike/trike in a way that compensates for the smaller wheels. It also means that you should not consider gearing to be a big factor in what wheel size you use.
Some manufacturers use Shimano's Capreo hub and cassette for 20" wheels. This system uses 9-10-11-13 tooth cogs on the small side, which effectively gears the bike/trike in a way that compensates for the smaller wheels. It also means that you should not consider gearing to be a big factor in what wheel size you use.
03-24-19 | 08:41 AM
#8
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Some manufacturers use Shimano's Capreo hub and cassette for 20" wheels. This system uses 9-10-11-13 tooth cogs on the small side, which effectively gears the bike/trike in a way that compensates for the smaller wheels. It also means that you should not consider gearing to be a big factor in what wheel size you use.
03-24-19 | 09:37 AM
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And, isn’t the Capreo limited to 9 speed?
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03-24-19 | 09:45 AM
#10
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Thanks for all the quick replies. Part of our delima has been solved. My wife rode a Terra Trike Rover today and told me this is the one I want. She sat on a couple others and even without riding them, she said the Terra Trike was the one. She did ride the Rover around the lot and decided with the bike shop making the adjustments for the fit, she is happy and we brought it home. Even with the 20" wheels and the 330 rear hub , which was explained as a CVT for a bike, it makes things less complicated for her and we will see how much rides.
I am still out to lunch, so to speak. I don't want to give up my Speicalized Roubaix for a trike just yet. Gonna wait and see what happens and how hard it is for us to ride sort of together. A trike is in the future, I am sure. Just need to make up my mind which one.
I am still out to lunch, so to speak. I don't want to give up my Speicalized Roubaix for a trike just yet. Gonna wait and see what happens and how hard it is for us to ride sort of together. A trike is in the future, I am sure. Just need to make up my mind which one.
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03-24-19 | 11:44 AM
#11
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Not quite true. Cogs smaller than 13 teeth suffer progressively more efficiency loss and higher wear. Also, you're talking about getting a one-of-a-kind hub and cassette. So they're harder to drive, more expensive to replace, and you replace them more often. Again, that only matters if you expect to go fast enough that you need gears over 80" or so. Slower than that and you don't need to normalize the gearing.
I posted so that the OP would be aware of the Capreo, but (and I hadn't thought about this before your comment) it would be nuts to acquire one for 20" wheels. Maybe 16" wheels, though.
I believe there is a 10 speed version now.
03-24-19 | 12:07 PM
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Define gearing for me. If you are looking for the correct answer that's significant.
I'm thinking the other responders are referring to the same number of sprocket teeth as being the same gearing. If that's your definition of gearing, they are right. A larger wheel will definitely go faster.
Traditionally, bicycle gearing has used the concept of "gear inches". Gear inches = chainring teeth divided by rear cog teeth times wheel diameter in inches. That adjusts for wheel size so, just as your mechanic said, equal gearing will produce equal speed.
The elephant in the room when discussing bicycle speed is the motor. If you were to put a Ferrari transmission into a Yugo do you think it would go 150 MPH? Of course not because the Yugo doesn't produce enough power. Bicycles are the same. Once you get over about 15 MPH, most of your energy is going to overcome air resistance. You need power to do that regardless of your bike's wheel size or gearing.
I'm thinking the other responders are referring to the same number of sprocket teeth as being the same gearing. If that's your definition of gearing, they are right. A larger wheel will definitely go faster.
Traditionally, bicycle gearing has used the concept of "gear inches". Gear inches = chainring teeth divided by rear cog teeth times wheel diameter in inches. That adjusts for wheel size so, just as your mechanic said, equal gearing will produce equal speed.
The elephant in the room when discussing bicycle speed is the motor. If you were to put a Ferrari transmission into a Yugo do you think it would go 150 MPH? Of course not because the Yugo doesn't produce enough power. Bicycles are the same. Once you get over about 15 MPH, most of your energy is going to overcome air resistance. You need power to do that regardless of your bike's wheel size or gearing.
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03-24-19 | 04:47 PM
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03-24-19 | 04:59 PM
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Thanks for all the comments. We have made the deal and brought the trike home. Wife has a smile on her face. I have transferred the lights and cat eye over to the trike from her df bicycle. We are going to give it a go in the morning as today is church day and not enough time .
From what the guy at the bike shop told me the rover with the n330 hub is really a cvt for a bicycle. He showed me a chart on gear inches where this hub will give her the capabilities of relative fast rides, if she so chooses. I doubt that. She is more a lazy days rider and likes to look around. Her fear of falling seems to have been the biggest feature holding her back before. Only time will tell.
I plan on using the short rides she does as a warm up for me to go off on my longer, faster rides by myself. A bent bike does not appeal to me, although I have never ridden one.
From what the guy at the bike shop told me the rover with the n330 hub is really a cvt for a bicycle. He showed me a chart on gear inches where this hub will give her the capabilities of relative fast rides, if she so chooses. I doubt that. She is more a lazy days rider and likes to look around. Her fear of falling seems to have been the biggest feature holding her back before. Only time will tell.
I plan on using the short rides she does as a warm up for me to go off on my longer, faster rides by myself. A bent bike does not appeal to me, although I have never ridden one.
03-24-19 | 08:37 PM
#15
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Hope your wife enjoys riding her Rover and that you continue to enjoy your Roubaix. 
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03-26-19 | 09:17 AM
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Hmmm. Here's an idea. It's not original either. O.p.'s wife has her TTR and likes it. Good. However, Specialized Roubaix and TTR probably cannot play nice together! If and when DH gets his trike will he also get a TTR or will he get something more ... spirited? Why not give the Mrs. an e-assist so the innate differences in horsepower (figurative) AND the differences in hardware, are equalized? Short of getting a tandem there really isn't a better way to allow people of different strengths or that have different vehicles to really ride together without the stronger rider loafing along well below an energy output that is satisfying.
03-28-19 | 02:07 PM
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I have been looking at a Gran Tourisimo from TT. It would work for when we ride together at the same speeds, but would offer me the ability to go further and faster when the desire hits me. Only time will tell if she continues to ride it often. Not going to buy myself one if it not needed to ride together. Thanks again for the responses.
04-14-19 | 06:07 AM
#19
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As I have mentioned before I put on the 26" upgrade on my Terratrike. The main reason was to get the RD and chain further up out of the dirt. In some gears the RD tension wheel and chain are not much more than an inch off the ground with a 20" rear wheel. Being that low it just has to pick up a lot of dirt and grit and cause power train wear.
And yes I did change the rear cluster to 11-34.
And yes I did change the rear cluster to 11-34.
Last edited by rydabent; 04-17-19 at 09:41 AM.
05-17-19 | 03:19 PM
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I have a pair of 16 3/8 on the front (almost 18in) and a 24in on the rear, and I can say that combo is good enough for comfort but it understeers on the little Brompton front wheels. I blame the Marathon tyres on them, and I'm looking at putting fatter tyres on 18s (can't get them for the 16 3/8s).
I don't know how people use big wheels on the front. My turning circle will suffer with Big Apples on 18s and I can only just get it through a doorway.
I don't know how people use big wheels on the front. My turning circle will suffer with Big Apples on 18s and I can only just get it through a doorway.
07-13-19 | 03:48 AM
#23
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I have a ICE Adventure with 20” wheels all the way around that I put SchwalbeBigApple 2.0 in the rear and 2.15 in the front, it turns just fine.
Last edited by tim24k; 07-13-19 at 03:52 AM.
12-29-19 | 08:23 AM
#24
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Unless you change the rear wheel size as I did, the mfg will equip the bike or trike with appropriate gearing.
Not only does the 26 inch rear wheel get the RD further up out of the dirt, IMO it just makes the trikes look better for what that is worth.
Not only does the 26 inch rear wheel get the RD further up out of the dirt, IMO it just makes the trikes look better for what that is worth.
