Tuesday, April 26, 2011

Shopping for tires

Tire fitment can get insane. Different companies make different sizes but call them the same. There's other conflicts make it difficult to match tires with rims. Then came the ETRTO system which is the universal sizing.

More info here:

Sheldon, the god of bicycle resources states, "A general guideline is that the tire width should be between 1.45/2.0 x the inner rim width."

My inner rim width is 22mm as noted here in the photo. The second number? That's the diameter of the bead set.

Now what on Earth is a bead set diameter, BSD? Here you go!

A 16" rim can have a BSD of any of the following:


Though they're all named "16 inch" tires, they're not all compatible. Confusing eh? So what does 16" actually mean? Absolutely nothing. It's the ETRTO numbers that matter.

So what fits my new KMX spoked rim? Some smart guy named Georg (yes, there's no e) Boeger made a chart and I can basically have any tire that's 37-50mm. My current Big Apple tires are 50mm so it'll work, but it's on the wide side of the scale.

This means Kojak tires will NOT fit. Boo!

It looks like someone put together a list here already, but it's old. Here's a new list I made before finding that one:
- Big Apples
- Marathon Racer HS 366
- Marathon HS 420
- Primo Comet

The new wheels are definitely more narrow. The BSD may actually be the same, but the overall depth of it is fairly significant. I don't think my 1.75-2.125" tube will work. I tried and it's too big.

After searching for smaller tubes, I couldn't find any. That could only mean one thing. I was wrong! It kept at it and it works!

The Primo Comet is back in the picture. Although I passed on it the first time around and eventually had bought the Big Apples, I'm turning towards the Primo Comet again b/c they're thin race tires. I've had a good experience with Ebikestop when I bought a chain ring from them. At $15.95/tire, it would be worth trying.

Mike is surprising me with some discontinued Schwalbe Speziel tires. If they work right, then I won't need the Primo Comets, but it's good to know I have a back up tire choice.

UPDATE: 5/1/11
The BROL members posted some reviews of the Primo Comets and they supposedly may not be all that puncture resistant - that worries me. Although the Primo's may be good for a neighborhood ride and may be superfast for asphalt, I'm not going to use it for the ALC.

I've been thinking further about the Schwalbe Marathon Racers and I'm strongly considering using these for the front two 16" tires. The durability rating is the same as the BA's which I guess means treadwear. The Protection rating however is lower than the BA's but still high.

I just noticed that the Marathon Racers have the same specs as the oh-so-loved-by Catrike Kojaks (the ones that don't fit on my rims). Looks to be the perfect alternative.

UPDATE: 5/3/11
In addition to my research on the tires through BROL member responses and info available on the net, I wanted to call up Schwalbe themselves to see what they had to say about my choice between the Marathon Racers and Big Apples.

Schwalbe picked up my line in one ring! No call tree menu or anything. Wow, great service. The guy who picked up was a bit difficult to hear, but the main response when asking about the two tires for a touring ride, he said the BA's were never meant to be a touring tire. He didn't have any concerns about using Marathon Racers.

I wasn't quite satisfied with the answer, so I called up Schwalbe again hoping for a different rep. Ben, a different guy picked up and he was much more articulate. I asked him to compare the Marathon Racers and Big Apples. He said the Marathon Racers would have less rolling resistance and weigh less but have the same puncture resistance as the BA's. I gave him a curve ball and asked about the City Jet's that I'll soon be getting from Mike. Ben said that the Marathon Racers are an improvement over the City Jets. Lighter, stronger and better rolling resistance. Looks like I have my answer! The City Jets will be perfect for a backup tire for the trip and as a local casual rides. The City Jets from what I understand are a lot smaller so they'll fit into my duffel bag for the trip more easily.

I just set myself back $141.34 for two 305mm Schwalbe Marathon Racers, one folding bead 406mm Marathon Racer for the rear and the Catrike universal flag mount. Ouch! I'm asking about the pricing for the two 16" ones b/c $39.95's pretty pricey for such a tiny tire, especially when the 20" non-folding version is on sale for $25.

UPDATE: 5/6/11
I bought the Schwalbe Marathon Racer tire for the rear. It's the folding version.

This thing compacts pretty small! It'll definitely fit in the duffel bag for the trip, but probably not my trike bag. I'm tempted to install this but I really need the puncture resistance of the Big Apple. Swapping tires or even repairing a tube on the rear is a pain.


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