The Pearl Izumi Tri Fly III got a complete makeover, and the Tr iFly IV is the result.
The Tri Fly III had 2 closure straps with the large one, on top, offset, and it closed from the lateral side of the foot to the inside of the foot. This closure style helps prevent the chain interfering with the strap when the shoes are already mounted on the pedals in T1. Although it’s a very common way to affix straps on a tri-specific cycle shoe there seems to be a trend to abandon this for the original mounting method you see in this shoe.
The Tri Fly IV is similar to the Scott tri shoes and the Specialized Trivent, in that the largest strap closes from the inside out. Due to the way the strap is placed on the shoe there is no way that it will interfere with the chain even when the shoes are mounted on the pedals. I always preferred this way of closing the shoe since it felt more natural on my foot. It also seems to give me extra support in my arch.
Another feature which got a makeover is the heel loop. The loop on the III was made from knitted nylon and a little on the small side when you need to close it in a hurry. On the IV it’s made of synthetic leather which is a little more stiff and solid, so it stands straight up. It’s also a little bigger, so it’s easier to grab when you’re going full throttle.
The mesh on the upper is great, and it’s a well vented shoe, but for those whose feet get cold, or those living in areas with cooler weather, that might be a drawback. The shoe is built with an open forefoot upper in contrast to some other new models reviewed earlier this year, like the Scott and the Lake shoes.
Another improvement is the heel cup. It’s not that the one in the III was bad, not at all. But the support of the heel cup in the IV is just a bit better. It feels slightly narrower and it’s also a bit stiffer. On the flip side, if you are the rider with a beefy heel you might find the IV a bit too narrow.
The fit of the complete shoe is on the narrow side, heel-to-forefoot. It’s for sure not made for athletes with wide feet. This not good nor bad, it’s just how it is. The upper is made with almost no seams at all so very suitable for riding without socks.
The insole on the IV is unchanged from the III: good quality and already made with a metatarsal pad. But I still find it disappointing that Pearl Izumi doesn’t deliver this shoes with their great 1:1 insoles, where you can adjust varus/valgus forefoot angle and the arch support to your personal needs. I think they miss an opportunity here to get to a maximum level of service to the customer.
As in the III, the IV is available in two ways: a cheaper, nylon/fiberglass sole version, at $125, and a more expensive, but certainly not too expensive ($180), carbon sole version (orange). The carbon sole version is, of course, the stiffer one. However I’ve ridden them both and I wonder how many athletes really can tell the difference between those two models.
What’s also not changed is that in the non-carbon sole model you can mount your SPD MTB cleats. Nice if you want to press them into secondary service as a spinning bike shoe. This option is not available on the carbon sole version.
Both non-carbon and carbon versions are made in mens and womens specific sizes and colors (women's adjacent in white). And if you want to buy these online make sure you go a full size larger than your running shoe size because they tend to fit really small.
Overall they are both really great shoes that will appeal to a lot of customers.