What Are Hookless Bicycle Rims?
7 Things You Need To Know.
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00:00 If you've kept up with the latest wheel releases, then you've probably noticed one thing.
00:05 Hookless rims. They seem to be everywhere, but what are they?
00:09 Well, this piece of technology is relatively new to the road and gravel market.
00:14 And what benefits does it bestow to the user? And what potential negatives are there?
00:18 Well, today and in this video, I'm going to tell you seven things
00:21 that you absolutely have to know about hookless rims.
00:25 [Music]
00:30 I quickly need to step back in time. You see, in 1970, Mavic released its Module E rim.
00:37 A rim that was certifiably a game changer in the world of cycling.
00:43 You see, before that rim existed, the only choice for racing was tubular tyres,
00:48 wherein you glue a tub, a tubular tyre, onto a rim.
00:51 For every other type of cycling, there was something called wire-on tyres.
00:55 But these tended to be heavy and quite slow.
00:58 The difference with the Module E was it incorporated a hook,
01:02 which allowed it to capture a lighter, foldable beaded type of tyre,
01:06 and prevented it from blowing off at high pressures.
01:09 Ever since then, that has been the most commonly used form of rim for bicycles.
01:14 But now, we're starting to see more and more hookless rims.
01:18 [Music]
01:25 Put simply, and as the name suggests, a hookless rim is a rim without the hook
01:30 that would usually capture the bead of a tyre.
01:33 If you look at a profile, you'll see that it lacks a hook
01:35 at the top of the sidewalls of the rim, and instead, it is completely vertical.
01:41 Now, this means a couple of things that are quite important that you need to know.
01:45 The first one is that you cannot use clincher tyres.
01:48 This is a tubeless-only setup.
01:50 That's not to say that you can't run tubes.
01:52 For example, if you had a catastrophic puncture, you absolutely could,
01:56 but you could not change the tyres to a clincher version.
01:59 Even more confusingly, hookless rims aren't actually compatible
02:03 with all tubeless tyres on the market.
02:06 And I'll come into that a little bit more later on in this video.
02:09 [Music]
02:16 Cycling is lagging and not leading when it comes to hookless rims.
02:20 In fact, it has taken from about the 1970s until now for cycling,
02:25 especially road cycling, to catch up with other pneumatic forms of transport.
02:30 Mountain bikes have used hookless rims for a little while now,
02:33 but road cycling has sorely lagged behind.
02:36 However, that does seem to be changing, and although they're hardly universal yet,
02:41 there are a lot of notable brands putting quite a lot of time and energy
02:45 into developing hookless rims for the road and gravel market.
02:48 These include Enve, Zipp, Kadex, the sister company to Giant,
02:52 and Giant themselves, all of whom are putting money into hookless rims.
02:56 And today I'm using Giant's SLR1 wheel to perfectly demonstrate
03:00 exactly what hookless rims are, and what all of these brands are espousing
03:04 when they say it bestows a lot of benefits to the user.
03:07 [Music]
03:14 I'll start by explaining exactly what the hook is,
03:17 and it's pretty self-explanatory.
03:19 The hook is part of the rim profile that captures the tyre's bead
03:23 and prevents it from blowing off when inflated.
03:26 On hooked rims, if you feel the side of the rims there,
03:31 you'll naturally feel a little lip at the top,
03:33 and that is exactly what we're referring to when we talk about a hook.
03:37 Meanwhile, on these hookless rims, you'll notice, if you can see up close,
03:42 that the rim profile is completely straight with vertical sides,
03:46 and that's where they're lacking the hook.
03:48 Now, in the early days of tubeless mountain biking setup,
03:53 it wasn't uncommon for riders to experience something called burping.
03:58 Burping was the sudden and unexpected loss of pressure
04:01 between the tyre and the rim wall.
04:04 Now, this could happen for numerous reasons.
04:05 It might be that the tyre bead wasn't stiff enough,
04:08 or that the pairing between the tyre and the rim wasn't quite right,
04:12 and air was able to escape.
04:14 Ease away, imagining burping happening on a road bike is absolutely terrifying.
04:19 Now, proponents of hookless rims actually say
04:23 it's a much safer way to have a tubeless setup.
04:26 And that might seem strange, because you're literally removing the hook,
04:29 the thing that was designed for years to keep tyres in place.
04:33 However, Zipp have done a lot of research into this,
04:36 and have found that the pressure required to blow a tyre off a hooked rim
04:40 and a hookless rim is actually very similar.
04:43 As another example, Enve say that by removing the hook from hookless rims,
04:48 brands can actually make sure that the bead seat diameter of the rim
04:51 is accurate and consistent the whole way round,
04:54 allowing for a better pairing between the tyre and the rim.
04:58 Now, this leads neatly onto another aspect
05:00 that brands are keen to push when it comes to hookless rims,
05:03 that is superior manufacturing.
05:06 Proponents of hookless rims are keen to talk about their simpler,
05:10 but superior manufacturing process.
05:12 Zipp, for example, told us that hookless rims allow better carbon compaction,
05:16 better resin distribution throughout the rim,
05:18 more accurate bead seat diameters,
05:21 and ultimately, less scrap and less waste.
05:25 To help demonstrate this point,
05:26 I'm going to talk a little bit about rim manufacturing,
05:30 but I'll keep it short and simple.
05:31 So, to help demonstrate this point,
05:33 I'm going to talk a little bit about rim manufacturing,
05:36 but I'll keep it brief because it can be a bit complicated.
05:40 But in short, with hooked rims,
05:42 brands use a silicon mandrel to mould the tyre bed cavity.
05:46 Now, that silicon mandrel is quite soft and can only be used once
05:50 and then it needs to be thrown away.
05:53 However, with hookless rims,
05:55 brands can use a steel mandrel to mould that tyre bed cavity
05:59 and get more uses out of that because it's much harder.
06:01 That's not the only benefit either.
06:03 A steel mandrel allows them to create more accurate
06:06 and more consistent tyre bed diameters,
06:09 allowing for a better pairing between the tyre and the rim.
06:13 The other manufacturing benefit of hookless rims
06:15 is that you can get a better distribution of resin in the rim.
06:19 Now, this not only allows you to create a better interface
06:22 between the tyre and the rim,
06:23 which is obviously incredibly important,
06:25 it also, crucially, allows you to drop the weight of the wheel.
06:29 However, that's not the only thing you drop with hookless rims.
06:32 Brands are also keen to state
06:33 that they are ultimately cheaper for the consumer
06:36 because of these more efficient manufacturing processes.
06:39 Now, Zipp are very keen to state
06:41 that their new 303 Firecrest wheels are 300 grams lighter
06:46 than the old model because they have moved to a hookless design
06:49 and also they are 30% cheaper than those old models as well.
06:54 Of course, inevitably, there will be those that say
06:57 the drive behind hookless
06:59 isn't because of performance reasons for the user,
07:01 but actually because of cheaper manufacturing costs for the brands.
07:04 And they might well be right.
07:06 It's still a little early to tell,
07:08 but it will be really interesting to see in the future
07:11 as hookless rims become more available
07:13 and more common on the cycling market,
07:15 where the prices really do go down for the end user.
07:19 [Music]
07:25 Until very recently,
07:26 if you'd asked me what the widest internal rim widths
07:29 I'd expect to see on a wheel,
07:30 I'd have told you 21mm.
07:32 That was usual for both Zipp, Enve, Hunt.
07:35 All of these wheel manufacturers had internal rim widths
07:37 that were that wide.
07:38 However, with their latest releases,
07:40 both Zipp and Enve have wheels
07:42 which have internal rim widths of 23 and 25mm.
07:47 But why have they done this?
07:49 Well, it all comes down to the shape of the tyre.
07:52 You see, on a hookless rim,
07:54 the tyre side will sit further apart
07:56 because they're not being pulled inward by the hook.
07:59 If previously you'd put a wide tyre
08:00 on a rim with a narrow internal rim width,
08:02 you'd have got a bulbous shape to your tyre
08:04 and it would have looked like a mushroom
08:06 coming off the top of the rim.
08:08 Now, that interface between tyre and the wheel
08:10 has long been the subject of study for aerodynamicists,
08:14 who all say that a flush interface,
08:17 so one that sits neatly, the rim into the tyre,
08:20 and not a bulbous shape, is much more aerodynamic.
08:22 What's more, because those sidewalls are further apart,
08:26 you're able to run your tyres at lower pressures.
08:29 This not only creates a more comfortable bike ride,
08:31 but also has been proven to make the bike faster.
08:35 Zipp say that on a smooth asphalt road,
08:38 a wider tyre can expect to save between 3 to 5 watts,
08:41 up to 40 watts on a rougher surface.
08:44 Now, of course, not all riders are going to want to go
08:47 for wider tyres, but if you look at the recent trend
08:50 of GC bikes and the sort of top-end race bikes
08:53 on the World Tour, you'll definitely see
08:55 that there is a trend towards wider tyres on fast bikes.
08:58 The reason you might be limited in tyres
09:07 for your hookless rims is ultimately due
09:09 to the lack of standards around them.
09:12 Basically, the rate of change on hookless rims
09:15 and tubeless tyres have gone so quickly
09:18 that the two governing bodies, the ETRTO,
09:20 that's the European one, and the ISO,
09:22 the international one, are yet to be able to sign it off.
09:25 They have fears that high pressures might blow
09:28 the tyre off the rim, and it's not something
09:30 they've experienced yet, because mountain biking,
09:32 where hookless rims have been used the most,
09:35 tend to run their pressures much, much lower
09:37 than we would on the road.
09:38 However, with road and gravel companies,
09:42 using that technology for mountain biking,
09:44 they've been pushing the rate of change
09:46 in hookless rims much faster than those two
09:49 governing bodies can keep up.
09:51 For this reason, it has been left to rim
09:54 and tyre companies to work out which tyres
09:56 are compatible with which rims,
09:58 and most of this legwork is being done
10:00 by wheel manufacturers.
10:02 For example, Giant told us that they're working
10:04 really closely with tyre brands
10:06 in their testing protocols, which involves
10:08 inflating a tyre to 1.5, the maximum pressure standards,
10:12 to see if it will blow off the rim.
10:14 Now, if you look at Zipp, Enve, and Giant's websites,
10:17 all of them have lists of tyres which are compatible
10:20 with their rims, but some of them are smaller than others.
10:23 For example, Zipp only lists five brands
10:25 that it feels are compatible with its rims,
10:28 whereas Enve and Giant list a little more.
10:30 It's all a little bit murky and quite confusing
10:34 at the moment, and not unlike the Wild West, really.
10:37 But as the pace of change increases
10:39 and the steady march of technology carries on,
10:42 expect to see tyre brands and rim manufacturers
10:45 working together to create more compatible products.
10:48 Early adopters of the tubeless setup
10:57 will no doubt welcome hookless rims
10:59 and the better interface between tyres and rims
11:02 that it offers, and therefore a more secure setup.
11:04 However, as we know from our comment section,
11:07 not everybody wants to set up their tyres tubeless,
11:10 and there will be those that are saying
11:12 there's no demand for hookless rims
11:14 and that it's not necessary in the road market.
11:17 Now, it does feel important to say that
11:18 at the time of filming, neither Continental nor Vittoria,
11:22 two of the biggest tyre manufacturers in the world,
11:25 say that their tyres are compatible with hookless rims.
11:29 I'd hazard that it will take a couple more
11:31 of the big-name tyre brands to get involved,
11:33 and ultimately for ETRTO and ISO to get involved
11:37 and to set some standards,
11:38 but the upshot for the end user
11:40 could be better value and lighter wheels.
11:42 So there you go, seven things that you have to know
11:47 about hookless rims, a new technology
11:50 for the road and gravel market,
11:52 but one that seems to be advancing at quite a pace.
11:55 If you have any questions about these new type of rims,
11:58 then please do leave them in the comment section below,
12:00 and I'll do my best to answer them.
12:01 And if you have found this video helpful,
12:03 do give us a thumbs up and subscribe to the channel.
12:06 It really does help us out.
12:08 Now, I'll be back soon with some more great tech content,
12:12 and I'll see you then.