i don't know if it's necessary for me to mention this, but i don't think breaking a rim in this fashion is a function of hookless 5 bar limits. i think it's more likely because the ideal pressure for this wheel during, say, strade bianchi is much lower. maybe 45 to 55psi depending on the tire. whether hooked or hookless i don't know that a lot of folks realize how hard the ride would be if you ran 5 bar in a 28mm tire on a 25mm internal width rim. i've ridden parts of the strade bianchi's typical route and that would be a terribly high pressure to ride on the gravel roads that i was on. it's not that 72psi isnt high enough to prevent a rim strike; it's that 45 or 50psi might be the ideal pressure and the downside is the possibility of a rim strike.

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Dan Empfield
aka Slowman

Not replying to you in particular.

Not long ago a bike shop had to stock tubulars and clinchers in a variety of sizes. Then tubeless clinchers appeared. Then hookless clinchers. Sizes went from 2-3 widths to at least half a dozen. So the number of SKUs a bike-shop has to keep in order to satisfy its customers has more than tripled in a short number of years. Related to this, see Trek's announcement about slashing costs, being the reduction of SKUs by 40% a large part of the reduction.

Then, bike-shops are not schooled by the manufacturers nor is the labelling clear enough relative to the risks taken by modern cyclists. I've had tubeless clinchers mounted by bike-shops in hookless rims and I myself have ridden hooked wheels above the recommended pressure, because I was not aware there was a difference.

Are the above downsides justified by a potential reduction in a handful of grams, maybe 100 dollars and no proven performance gains?

My conclusion is no. This is due to the planned obsolescence dynamics of the cycling industry combined with an era of peak performance. i.e. It has become exponentially difficult to provide marginal gains for the consumer at the cost of making the life of the cyclists significantly more complex. And in the particular case of hookless, potentially more dangerous.

As an aside, some of the recent "innovations" have been detrimental to the "inventors". As an example, making a good braking track for a carbon wheel was difficult and differential. It put Zipp, HED and others well above the rest. Come rim brakes, it becomes much more difficult to justify the price difference between a Zipp rim or a Chinese open mould. Maybe that is the reason they are introducing hookless, to increase the gap again...

+1 to the tyre stock the LBS has to have on hand, and in reality is now another factor that means even as someone that tries really hard to use my LBS over mail order, it's impossible with tyres. They just do not stock them. I was trying to get some 28mm non tubeless 6 months ago, vittoria or conti, and there were non at all in stock in the town.

But back to the cracked rim. We're in some parallel universe where the marketing team is putting out images to prove that a stone small enough to have been missed as he approached can result in the rim being smashed at less than 50kph. So they are saying that buy their rims and pray every time you are descending?

Note that I managed to ding a zipp course 30 hitting a stone on a descent a few years ago and that did cause front tyre blowout, 58kph, in a narrow shoulder with 100kph trucks beside. That was unpleasant and as well as a new tyre and tube, also needed replacement of my shorts. But I was able to get the rim back and 20,000km later its still fine. So I do get that accidents happen, but that's an expensive loss if it happens to you as a consumer.

Did you check to see if they had any downtube friction shifters too? :)

And then gravel comes along and really ruins it for retailers. I mean, oh my gosh, they might have to stock 4-5 different types of bikes to sell — the madness!

;-) Good point, well made. For the record I have 2 spare new in box 9 speed ultegra chains for when I need them, been holding them since Chain reaction accidentally sent me a double order of 3 (ie total 6) in 2007 and I negotiated a very good discount in place of them paying the postage back.

But seriously, 5ish years ago then stocking 23 or 25mm widths of clinchers, covered 90% of market, so stock 4 brands in each for choice of budget/use case was 8 items to carry. Now, it's 25, 28, 32 at least, tubed, tubeless hooked, and now hookless. So even with a single tyre choice that's 12.

Don't have to - raced/crashed with them for years - never broke or wore out AND worked with anything attached to the other end of the cable. Then came the first successful index shifting system - Shimano SIS - and the beginning of the proprietary group mentality, from a company that would go on to dominate the industry.

Nowadays the mechanical shifting is software locked to stop it from being used interchangably on 10/11/12 speed. You can update the software via bluetooth from your phone, but the functionality to use it with any other run of components is artificially locked. Planned obsolescence.

where you wrote mechanical did you mean electronic?

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Dan Empfield
aka Slowman

Are we talking nominal width or measured width?

I have a set of Conti 5000 S TR 32mm on HED gravel wheels (25mm internal, hooked). They measure 36mm.

A set of the same tires, 28mm wide, on HED Ardennes rims (21mm internal, hooked), measure 31mm. 25mm tires measure out to 28. And, 23mm Vittoria Speed G tires measure out to 26mm. The same tires in 25mm measure out to 27-28mm.

If we're concerning ourselves with tire width and its impact on aero, I would think measured width is far more important.

Yes I did, my bad.

No, you were right the first time.

"Our dog shared the WiFi password with the 70s steel bike" is a perfectly legitimate explanation for the new Super Record groupset on the credit card statement.

My #1 question about tire "techs":

HOW DO YOU CHANGE A FIELD FLAT?


I picked clinchers over tubulars because of the cost, field change annoyance, and the fact rolling resistance was only better with cement-grade glue from what I recall.

I ignored tubeless, but I wouldn't mind someone to explain that as well.

I hear "sealant" which to me sounds like "big PITA or impossible field change"

I bike in the midwest, and cell phone coverage for a lot of the fun stuff is often a no go, even in this day and age.