Saturday, October 9, 2010

Tires and tubes and rims, oh my!

First, the UCI is stupid. Its not like you should expect anything different, but I am just pointing this out because of their decree that no CX tire shall be greater in width than:

"1.3.018 Wheels of the bicycle may vary in diameter between 70 cm maximum and 55 cm minimum, including the tire.
For the cyclo-cross bicycle the width of the tire (MEASURED BETWEEN THE WIDEST PARTS) shall not exceed 33mm and it may not incorporate any form of spike or stud."

The average rider will gain more from wider tires than more advanced riders regardless of whether they are tubular, tubeless, or tubed clinchers. Tire volume allows a rider to utilize a wider range of tire pressures. The voluminous nature of tires is a factor of several things, but I am just going to focus on rims and tire size.

See below

On the left is a 40c Michelin Transworld sprint mounted on ZTR 355 rim(19mm wide), and on the right is the same tire mounted on a Ritchey Pro rim (17mm wide). Even a 2mm increase in rim width creates a tire that is substantially more voluminous with a broader tread profile.

Now lets look a a more realistic CX tire selection, Hutchison Bulldogs 34mm

The ZTR 355 rim is on the left, and Mavic Open Pro is on the right. Visually the results are not as stunning as with the 40c tires, but you can definitely see that the ZTR creates a tire profile that is less rounded and more boxy. This boxy profile is essential if you decide to run lower pressure (<30psi) style="color: rgb(255, 0, 0);">
Late edit: I am not hating on anyones wheels, I just wrote the below statement in regards to a recent velonews article
that totally ignored the impact that Stans has had on CX tubeless
Road tubeless wheelsets: maybe its because I do not own a road bike, but I have never really gotten the big deal over Shimano's Ultegra(~$650) and DuraAce (~$1100) tubeless wheelsets or the Mavic Kysriums for tubeless use in CX. They are (in my mind) over priced and will never allow you to run pressures as low as I could run with a Stans ZTR rim. I do not doubt that they are awesome for road, but for the same pricepoint I could have ZTR 355's laced to Chris King Hubs (32 spokes with DT Revolutions). With the left over money (compared to DuraAce) I would buy a set of Mud tires (Michelin Mud2's) and a all around set of tires (Hutchison Bulldogs). If you already own a set for on the road, then I can see the utility of using them for CX, but buying them solely for CX doesn't make sense to me.
I actually just commissioned a new set of gravel/CX wheels. Big Poppi's is lacing me up a set of the new Stans Alpha 340 to Chris Kings. I have had the hubs for a while, but was waiting on stans to bring another round of rims out of manufacturing. The Alpha 340's are a narrower rim than the 355's so I am reserving judgement until I get to play with them.
As an aside, one of my all time favorite CX tires was the dirt cheap IRC Mythos CX Slick (I last bought a set at Capp's in Topeka for ~$30 for a pair). They were a super durable tire that lasted through CX season and gravel season. I actually won the 2008 Dirty Kanza SS on those tires. I haven't seen these tires in at least a year.
FYI: Big tires are not light, but neither are tubes.
Bontrager tube

Michelin Transworld Sprint 40mm

Hutch Bulldog


Noah Marcus said...

I'm glad someone thinks about this stuff, because I certainly don't.

Joshua Stamper said...

You should be thinking about heart conditions and physiology

Mike Miles said...

Josh, the reason I run Dura Ace wheels (not set up tubeless since the continuously burp air) is because I paid <400 for them. I have no doubt your ZTR's are better wheels.

Joshua Stamper said...

@Mike, sounds like you made off like a bandit then! I was actually referencing a recent Velonews article that espoused that shimano tubeless wheels were the cats pajamas

Have you tried the DA wheels with hutch tires or just other non-tubeless tires? I got a spare pair of hutch's if you want to play with them