chaadster

Knobbies vs. slicks?

Cargo or kids?

dirt vs. pavement?

wider or narrower?


These are the questions that are concerning me right now as I prepare my Tanjor Aero for another season. It's mostly hauling kids, but I've got what are probably 15yr old BMX style small-knob tires on it, and I'm wondering if there's any problem with running slicks, the thinking being that they'll roll faster.

I mean, trailer tires don't need traction, per se, do they?

Also, will the kids howl in pain if I go from a 20x1.75 to 20x1.25 or even 1.10? Does tire width have a noticeable impact when pulling a trailer? I keep the 1.75s at 60psi now, so I don't imagine a 1.25 at 100psi will make much difference, but I want to get some more informed opinions before I decide.

Thanks in advance!

Chaad

hopperja

Chaad, my 2 cents...

I'm not sure why you'd want narrower tires. Pulling a trailer is generally not the most efficienty cycling discipline. Your speed/pace is going to be drastically hindered by the trailer, particularly if it has any surface area for the wind to catch (ie, containers or fabric cover). Narrow tires are likely to offer negligible advantage.

Higher pressure tires would probably give you more gains in efficiency. However, they are not going to make pulling a loaded trailer easy. I doubt I'd notice a difference between 60 and 80 psi.

Personally, I run my trailers at 40 psi, loaded or unloaded. I run my bike tires (except my trail bike) at 60-65psi. I find those pressures to a nice compromise between efficiency and comfort.

prathmann

What's the total weight of this trailer plus kids and other items inside? The reason you run 100 psi with narrow bike tires (or 60 psi with 1.75" tires) is because you've got a total load of around 175 lbs or so and need that much pressure to avoid pinch flats. Trailers are usually much more lightly loaded and should be run with less pressure. Otherwise they'll have a harsh ride and the tires will tend to bounce when hitting bumps making the ride even worse.

For best efficiency get some tires with minimal tread pattern (slicks should be fine) and a soft, compliant sidewall so little energy is lost when it flexes (it'll also give a smoother ride to the kids). If they have those characteristics the width won't matter much and you may as well use some fairly wide ones so they'll ride more smoothly over rough pavement areas.

chaadster

Thanks for the replies hopperja and prathmann.

I know there are lots of variables, but it sounds like it's fair to conclude that in general, there's really little to be gained by trying to fine tune the tire selection for efficiency too much.

To answer prathmann's question, and to be a little more specific, I was hauling about 100lbs worth of kids in what's probably a 25lb trailer the other day when I got to thinking about this. I felt as though there was drag on the trailer tires, which are 20x1.75 with that old school BMX knobby pattern, at about 60psi. Just as often, however, I'm pulling 1 kid at half that weight, but whatever the load, almost always on paved, but rough, road.

I should probably do a little experimenting first with tire pressures on what I've got, and then just replace them with whatever I can afford. I'd forgotten how much a quality 20" can cost, between $20 and $45! I like to pull the trailer pretty fast-- maybe 13mph average, 20mph max-- so efficiency in the tires is welcome, but it's really just a trailer, and I'm not keen to dropping $100 bucks on rubber.

I'll try to find some fairly lightweight slick/grooved tires and ditch the knobbies, though. Those are unnecessary and just contribute to drag, right?

The perennial and ultimate solution: get stronger legs!

Rockfish

The other criteria I'd look for is flat protection. For one, you are probably pretty used to avoiding sharp stuff with your bike tires, but your trailer tires don't follow that same path (and you can't see the trailer tires) so you are much more likely to run things over with your trailer. In addition, emptying your cargo or kid on the side of the road to fix a trailer flat is really not fun!

As for efficiency, start with smoother. Knobs are a killer. After that, I'd suggest wider and softer for trailers.

chaadster

I hear you on the flat protection! A flat this winter was a big PITA, and is one of the reasons I'm looking to replace; they're old.

I think I've decided to go with a pair of Tioga Powerblock S-type tires. They've got some tread on the shoulders, but the 1.95 weighs only 310g, so with a moderate amount of psi, I'm thinking it should roll up on the smooth center ridge. We'll see.

Sirrus Rider

I may point out that many kiddie trailers come with rims that don't handle high pressure. IRC my Burley only handles 60lbs. I've got TIOGA Comp Pool TA's on there right now that are rated to 90lbs and the first time I put them up to that pressure things nearly got exciting as the beads popped out and the tubes were exposed and ready to blow.

I may point out that at 25psi the Comp Pool TA have some nice float for both kids and cargo.

chaadster

I've been rolling 60psi successfully, but how can I tell what the rim can handle? Mine are only marked Kin Lin and the 20x1.75 size, but I think they're a pretty respectable rim builder. Can I examine the rim and tell?