Tubeless tire exploded off hookless rim

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mattr
Posts: 4671
Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

jencvo wrote:
Fri Mar 01, 2019 2:58 pm
I'm just wondering the whole tire + rim combination, if for example hitting a big pothole could do repeat this (though I've hit that before and had no problems).
yeah. You've stretched a 622mm diameter loop of cord, which is absolutely dependant on having virtually no give in it at all, over the top of a ~630mm diameter rim wall. You'll have stretched the actual cord by at least 10mm on its circumference. The cord will also have moved within the tyre sidewall. Maybe damaging it.

Unless it was seated really badly before it popped (i.e. massively off concentric to the rim) it's probably just waiting to blow off again. Probably when the pressure spikes.

When you hit a pothole or something, or maybe when you are really pressing hard into a curve......

Hope it's a rear.

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Jugi
Posts: 678
Joined: Sun Jun 24, 2018 8:10 am

by Jugi


Calnago wrote: But I’d still like to know the advantages of hookless, regardless. Just cuz.
Anyone?
When hookless arrived for MTB, the most marketed feature was increased impact strength at the rim's edge. So lower risk of damaging a rim when running lower tire pressures. Tire's snake bite risk doesn't go away with hookless but tires are a lot easier to replace than rims.

So, simplified structure (carbon is not good for fishing hooks or any other hook) yields higher strength, lower weight and cheaper manufacturing process. Tire retention doesn't matter, as the whole idea is to use wider tires with lower pressures.

In my opinion hookless rims are not suited for road cycling, but because of this "gravel" thing people with moustache seem to be into, there seems to be a need for "a road cycling wheelset" with wide hookless rims.

MikeD
Posts: 1000
Joined: Thu Dec 11, 2014 9:55 pm

by MikeD

Jugi wrote:
Calnago wrote: But I’d still like to know the advantages of hookless, regardless. Just cuz.
Anyone?
When hookless arrived for MTB, the most marketed feature was increased impact strength at the rim's edge. So lower risk of damaging a rim when running lower tire pressures. Tire's snake bite risk doesn't go away with hookless but tires are a lot easier to replace than rims.

So, simplified structure (carbon is not good for fishing hooks or any other hook) yields higher strength, lower weight and cheaper manufacturing process. Tire retention doesn't matter, as the whole idea is to use wider tires with lower pressures.

In my opinion hookless rims are not suited for road cycling, but because of this "gravel" thing people with moustache seem to be into, there seems to be a need for "a road cycling wheelset" with wide hookless rims.
It probably went like this at company XYZ:

Production guy: I'm having a devil of a time forming a hook on these carbon rims, getting a lot of rejects.

Company noob: Why are there rim hooks anyway?

Production guy: it would be nice if we didn't have to form the hook.

Marketing guy: Hey, you're onto something there. I can spin this so we can say it's lighter and stronger, you know, for bashing off rocks and such. Well call it "hookless." People will think they're better than hooked rims. It's a "win-win" situation. We'll sell a lot of product.

Quality guy: I hope nobody puts high pressure tires on these rims. The tire could come off.

Company lawyer: We'll put a maximum pressure rating on them. That should absolve us of any liability.

Company noob: Oh, that's why rims have hooks.

Marketing guy: Promote that guy!

The rest is history...

noelnoel
Posts: 12
Joined: Tue Oct 27, 2020 10:06 am

by noelnoel

Calnago wrote:
Fri Mar 01, 2019 9:18 pm
So what is the advantage of “hookless” rims as they don’t seem to hold the tire as well as a hooked rim can. With all these caveats about pressure limits etc, there must be some great advantage that outweighs the possibility that your tire has a greater chance of blowing off the rim, but I don’t know what it is? Speaking about road use here. I generally don’t run tires large enough to even approach using only 60lbs of pressure, apart from my fully loaded touring bike with 32’s, so I’m just looking to understand the whole hookless thing a bit better.
They are cheaper to make so the bike cycling companies make more money. Lol 2 x moulds gluesd together. hokked rims require 3 moulds. lol

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