I went from a 20" rear to a 700x35c, a major difference it was to me.
The 20", the rear bottom roller and chain hit many sidewalk edges when I would have to drop off or climb up on to go around pedestrians.
The tires were 20x1.5's and the lower roller's bottom edge was at the top of the rim in the gears I seemed to use most often making it about 2 inches off the ground, less when the tire deformed on an impact. It filled up with wet grass every time, stopping to pick it out was a pain.
The larger tire, the above issues were gone and it rolled so much better, small side walk cracks and side walk drop offs had so much LESS of an effect. The larger diameter helped keep the tire out of smaller holes and minimized the impact of small drop offs and bumps.
Gearing and speed, a very obvious difference. I could spin higher gear inches and acceleration was very much improved.
The better acceleration was IMO due to far less rolling resistance of the larger wheel.
Just my observed differences.
I must include the 20" rear was on the EZ-1 sx with my 20" front wheel mod, and the 700 rear was on the Sun Made Tour Easy SE
Both bikes had the same cassettes and chainrings as in number of teeth on the large chainring.
I could spin out all but the top gear on the EZ-1 and maintain for a given time
I could not spin out the top three gears on the Tour Easy due to the much greater upper gear Inches of the Tour Easy.
But I was spinning a taller gear inch than the top one on the EZ-1..
The EZ-1 top gear Inch was 83"
The Tour Easy tallest was 127"
The Expedition WILL be my choice and I will have one as soon as I can save up the coin to pay cash for one.
maybe next year XD
A quote from the Terra Trike site about 26" wheel upgrades:
One of our most popular trike upgrades, adding a 26" rear wheel to your trike gives you plenty of advantages, and looks pretty cool too! The larger wheel allows for greater maximum speeds (by increasing the gear inches) and faster acceleration. It also makes for a smoother ride, eliminating some of the road noise felt on rough bike paths or gravel roads. The 26" rear wheel works best for those who ride mostly bike baths or roads with a moderate amount of hill climbing.
For use on the Tour II, this upgrade requires a Dropout Extension. See our Recommended Products area below to order.
Last edited by osco53; 10-27-13 at 05:05 AM.