Why are there no full DH casings with kevlar beads?
- Thread starter Udi
- Start date
Go look at a few different manufacturers weights on the exact same tires with steel vs kevlar bead. it's around 60g per tire. I'm not to blame if your reading comprehension fails you. My only fantasy is you pulling your head out of your ass.
The Tough Casing is fairly sturdy, I have nothing resembling a tear or a cut in them. The tread cap had a bunch of splits in them, all w/o a puncture; not-a-one in regards to knobby separation BTW.
The tread deteriorated quick front and rear - my main concern. My HRII did the same thing, but those things could not touch the sheer grip I had with these tires. Syntace W35MX rims on Hope Hubs. No ProCore (yet...)
To answer a few questions, no, EXO and SuperGravity are definitely not what I'm talking about here. Both make significant compromises in the casing compared to the full DH versions, thus will either increase the probability of pinchflats + rim damage, or require you to run higher pressure to avoid those things and sacrifice traction. I don't think Maxxis UST fits the description either because they add more weight in the casing - correct me if I'm wrong.
What I'm talking about is a 100% non-compromised DH casing (neither heavier nor lighter) with the steel bead traded for kevlar - no other changes. It's cool because it doesn't sacrifice performance for weight, and shouldn't sacrifice durability either if done correctly.
I appreciate the discussion though, unlike the hate-weenie posts from people who don't seem to realise that if small optimisations like these weren't constantly being made (or at least tried), their DH bikes would still weigh 21kg. I think the best weight savings are those which don't negatively affect performance or durability (eg. a Ti spring), hence my interest in the bead.
I'm more worried that @big-ted liked his post since I suspect he is from our time and thus has access to google. 60g per tyre is very plausible, and a quick search suggests savings from 50g (here) to 100g (here). That's a 100-200g saving in rotational mass per wheelset. Feel free to correct this data.
What I'm talking about is a 100% non-compromised DH casing (neither heavier nor lighter) with the steel bead traded for kevlar - no other changes. It's cool because it doesn't sacrifice performance for weight, and shouldn't sacrifice durability either if done correctly.
I appreciate the discussion though, unlike the hate-weenie posts from people who don't seem to realise that if small optimisations like these weren't constantly being made (or at least tried), their DH bikes would still weigh 21kg. I think the best weight savings are those which don't negatively affect performance or durability (eg. a Ti spring), hence my interest in the bead.
Gary is from the 1800s, his posts are written on parchment and sent by carrier pidgeon to a parchment2forum service where his writing is published to the intertron. What you're asking of him is a little unfair and likely impossible.
I'm more worried that @big-ted liked his post since I suspect he is from our time and thus has access to google. 60g per tyre is very plausible, and a quick search suggests savings from 50g (here) to 100g (here). That's a 100-200g saving in rotational mass per wheelset. Feel free to correct this data.
Data? Might as well just ask some random bloke down the pub.
I'm actually from the 1400s, My thoughts are written on silk underwear in the blood of virgins before being sent by Vampire Bat to a shaman who forwards my wisdom telepathically via a portal.
You have the scales and the tyres, Chop the steel bead out of one and be that dork Udi. It's why we love you. xx
I'm actually from the 1400s, My thoughts are written on silk underwear in the blood of virgins before being sent by Vampire Bat to a shaman who forwards my wisdom telepathically via a portal.
You have the scales and the tyres, Chop the steel bead out of one and be that dork Udi. It's why we love you. xx
You could probably just drill some speed holes in the wire beads.
I'm guessing at least 6grams right there.
I'm guessing at least 6grams right there.
Anyone know if you can get a Minion 26 / 2.5" DHF in this DoubleDown casing, and what the weight is?
Because the value compared to the regular DH-cased version of that tyre (1240g on average, I've weighed heaps ranging from 1220-1260g) would probably actually give a good indication of how durable the casing is - since we know roughly what the bead alone should save.
It's actually really hard to cut through tires, full DH casings and steel beads are pretty tough. I'm less concerned about the numerical saving and moreso think it's a place where there is dead weight (whatever amount that may be) and that it could be removed without any performance sacrifice. It'd be cool to knock the 'compromise-free' 60g (or whatever) out of the beads and run them a touch tighter if need be, it's one of the few places on a DH bike that isn't fully weight-optimised yet.
I'm still on 26" wheels and an alloy frame myself, so I'm going to make a tinfoil hat soon - that should be much easier to cut out than the tires.
Because the value compared to the regular DH-cased version of that tyre (1240g on average, I've weighed heaps ranging from 1220-1260g) would probably actually give a good indication of how durable the casing is - since we know roughly what the bead alone should save.
Haha you're a good sport. Maybe you're actually a time machine.
It's actually really hard to cut through tires, full DH casings and steel beads are pretty tough. I'm less concerned about the numerical saving and moreso think it's a place where there is dead weight (whatever amount that may be) and that it could be removed without any performance sacrifice. It'd be cool to knock the 'compromise-free' 60g (or whatever) out of the beads and run them a touch tighter if need be, it's one of the few places on a DH bike that isn't fully weight-optimised yet.
I'm still on 26" wheels and an alloy frame myself, so I'm going to make a tinfoil hat soon - that should be much easier to cut out than the tires.
How do you do that with the kevlar ones for a fair comparison though?
Winning the internet isn't that easy!
I think it's pretty easy to do what @MmmBones said and just compare mfg values for a wire and folding version of an identical tyre, it's really simple and something that actually exists in tires outside of dh-cased ones (obviously casing doesn't matter if we are just comparing bead weights, only that both tires use the same casing). I'm not sure why everyone is struggling with this concept so much - perhaps he can share some of the numbers he looked up so we can move on to the actual thread topic.
I actually agree with you in principle Udi. Of course there has to be a lighter alternative to steel for DH tyre beads. But having never ever felt a folding tyre with the same sidewall rigidity as it's wire bead counterpart I'd prefer the alternative not to be a floppy folding version. (some, especially lighter riders, may like the more supple sidewall, for DH I definitely don't).
Titanium is the obvious answer.
Yeah I agree - but that's because the casings are always compromised (by manufacturer choice), the loss of sidewall rigidity isn't because of the bead itself, the bead and rim act as a rigid body together in most scenarios to my knowledge regardless of material.
It's just the unfortunate coincidence that folding beads seem to be used on lighter tyres only (hence the flimsiness), but if you literally took a full DH-cased tyre with the equivalent of maxxis 2-ply sidewalls and swapped only the bead material I think it should work just as well. I'd be happy with non-folding like you say if that's required to get the same durability / resistance to being pulled off the rim. Just think it'd be cool to see more companies attempt it.
According to the Maxxis Tomahawk tire that is showing the weight listings in the DD casing, it will add about 195(1005 vs 810g) grams compared to the EXO in the 27.5x2.3 flavor, or about 185 grams (960 vs 775g) for the 26x2.3.
DD casing in not showing up in their specs yet for the Minion DHF, DHR2, or the HR2, but I would expect similar weight differences as the Tomahawk has. I would also doubt a 2.5 casing in 26 if they even make it in 26. Looks like most options are the 2.3/2.4 now.
-Brett
DD casing in not showing up in their specs yet for the Minion DHF, DHR2, or the HR2, but I would expect similar weight differences as the Tomahawk has. I would also doubt a 2.5 casing in 26 if they even make it in 26. Looks like most options are the 2.3/2.4 now.
-Brett
My data came from the Schwalbe website since they are easy to read and compare. The knobby Nic 26x2.1 performance dual compound in kevlar vs. steel bead weigh 550g/610g respectively.
Yeah. I know. which is why I doubt anywhere near a 60g saving is achievable per tyre and still retain that rigidity.
I don't have a clue how little an mtb kevlar bead on it's own is likely to weigh. never mind a fantasy reinforced/beefed up one. but I have felt the weight of plenty steel beads in the past. In both BMX and DH back in the 1400s we used to double up on tyres for strength/puncture durability at lower pressure by cutting the bead off a worn tyre and running the beadless tyre inside a good one. Rode DH for a few winters on Panaracer XC Spikes with this set up as DH mud tyres hadn't been invented yet.
Yeah. I really am that old son.
No, the rigidity comes from the casing (not the bead) - and the 60g quoted is the saving between tyres using the same casing - see the post above yours. That is the difference in the bead alone, so it's a practically useful value. The bead only needs reinforcement if you're ripping/stretching tyres off rims under cornering but I haven't managed that on the EXOs (on trailbike) yet anyway so I doubt much if any change is necessary when porting that bead over to a full DH tyre.
I'm not sure how true the rest of your post is but it made me smile anyway. The 1400s sound like a blast.
I just did some reading up on Vittoria Graphene tires and it sounds like they have many benefits that would improve aggressive MTB tires in terms of grip, rolling resistance, durability and weight. Reviews are just starting to come around: http://www.outsideonline.com/2028771/vittoria-mezcal-g-tires-review
it's all true dude. the UK DH scene was a pretty pikey place back then.
One thing you're missing.. even the rubber that surrounds a steel bead is more substantial than the material covering any kevlar bead. This. along with the more rigid bead can only really add rigidity to the structure of the tyre over using the kevlar equivalent. no?
One thing you're missing.. even the rubber that surrounds a steel bead is more substantial than the material covering any kevlar bead. This. along with the more rigid bead can only really add rigidity to the structure of the tyre over using the kevlar equivalent. no?
You seriously believe Schwalbe's weight claims? They differ by 100 g for the same model/size (=identical) tire and never match their claimed weight.
No, that's why I chose tires with little rubber as an example. I have never found a tire that weighs exactly what the manufacturer publishes and when I rode schwalbe's I weighed them all and the smaller single-ply's were the most consistent. This difference in weight between steel and kevlar beads is consistent throughout the range of tires they offer.
3 diameter options, and 2 rubber compounds for each. The casings are the same, and weights are about the same for both tread compounds.The list I'm looking at has 5 different models to choose from.
That's the Wild RockR, not the Wild RockR 2. Completely different, and much worse tread pattern.I'll
I love the WTB TCS Tough casings. I've been using the 2.5" Breakout on my enduro bike all season. It's not quite a DH tire but plenty burly and I haven't had a problem doing many runs down DH courses at resorts on my Nomad at speeds that would probably win any amateur DH race.
Unfortunatly what Udi is asking for doesn't exist but WTB TCS Tough, Schwalbe Supergravity, and Maxxis Double Down are as close as we'll get until World Cup racers start asking for kevlar beads.
I think my puncture experience with EXOs has been about the same as your's but when those punctures cost me races they're unacceptable. Also, I had to run 28-29psi front and 33-34 rear to avoid rim crunching bottom outs. The WTB TCS Tough Breakouts went all season without a puncture and I ran 23-24 front, 27-28 rear and got way more traction with only a couple maybe rim hits that left no sign. Totally worth the weight gain.
I have their new mud DH/Enduro tire but haven't had to use it yet (I have used their new XC tire and it's the best XC tire I've ever felt). I'm friends with their new tire designer. He used to work for Maxxis. He told me this tire has a full DH casing and it has kevlar beads. But the tread really is for mud or soft soil only.
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Maybe it did? Intense tires made those dual ply foldable DH tires. They still were not light, but the kevlar bead got their weights down to normal levels at least. I love(d) those 909 and Intruders.
You totally contradicted yourself and I want to try that tire. The Jafaki? Please suggest to your friend a combination of a few Vittoria tire names for his next design: Peyote Booze Tattoo has a nice ring dontchathink?
Yes, the Jafaki. It supposedly is a full DH casing but that's just going by what he told me, Vittoria doesn't have other DH tires to compare it to so we'll have to take his word that it's beefier than Supergravity, TCS Tough, ect. The impression I had was that it's marketed to the enduro crowd and the DH casing is to make up for the narrow width and provide protection from the hidden sharp things we find under the mud sometimes. The real limitation that keeps me from considering this as an option for Udi is that it's a mud tire, only 2.35", and not for everyday use. Now if they'd put a more all around tread on a 2.5" version of that carcass perhaps it would be the most viable option available. It did feel like a DH casing when I had to roll them up and stuff'em in my luggage.
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I have a tomahawk dd in hand. 1030g for the 27.5 that's in the packaging. 50g lighter than a Michelin wild gripr2 in the same size (still in package, but the cardboard is a little more substantial).
I suspect the difference to be from packaging and the fact that the Michelin has more meat in the tread department.
As far as feel, they are both pretty burly casings but the dd is the closest I've ever felt to a wire bead in a folder. Not only is the bead substantial, but it seems they added some rubber to the base of the sidewall as well.
I haven't ridden the dd yet, but the reinforced Michelins have been good so far and have been bottomed out on a rock on carbon rims without flatting. I also have a few days of dh on the vigilante tough high grip on the back of my tr500. It has been the meat in a rim/rock sandwich as well without flatting.
So my opinion in the three casings in terms of toughness are dd>Michelin reinforced >wtb tough.
I suspect the difference to be from packaging and the fact that the Michelin has more meat in the tread department.
As far as feel, they are both pretty burly casings but the dd is the closest I've ever felt to a wire bead in a folder. Not only is the bead substantial, but it seems they added some rubber to the base of the sidewall as well.
I haven't ridden the dd yet, but the reinforced Michelins have been good so far and have been bottomed out on a rock on carbon rims without flatting. I also have a few days of dh on the vigilante tough high grip on the back of my tr500. It has been the meat in a rim/rock sandwich as well without flatting.
So my opinion in the three casings in terms of toughness are dd>Michelin reinforced >wtb tough.
Someone at Special-Ed read your question, @Udi
http://www.vitalmtb.com/photos/features/Enduro-World-Series-Race-Action-from-Corral-Chile,9947/Slideshow,0/sspomer,2 Pic 24 of 33
Edit: http://www.vitalmtb.com/photos/features/PIT-BITS-Enduro-World-Series-Corral-Chile,9941/Curtis-Keenes-Prototype-Specialized-Tire,103233/sspomer,2# Pic 1
http://www.vitalmtb.com/photos/features/Enduro-World-Series-Race-Action-from-Corral-Chile,9947/Slideshow,0/sspomer,2 Pic 24 of 33
Edit: http://www.vitalmtb.com/photos/features/PIT-BITS-Enduro-World-Series-Corral-Chile,9941/Curtis-Keenes-Prototype-Specialized-Tire,103233/sspomer,2# Pic 1
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Forgot about this thread, but I ran an SG Magic Mary front (650b) for over a month in Queenstown this year with no issues, complete with fairly low pressure (~22psi) and plenty of rock hits - enough to hear pinging noises. Expected flats but didn't get any.
It was a borrowed tyre but after the positive experience I just bought my own and am running it currently, very happy.
Wouldn't use one on the rear, but works well on the front and isn't particularly light for whatever it's worth (1140g, only ~150g off full DH casing weight). I'm pretty sure it actually is the closest thing you can get to a full DH casing with a kevlar bead.
The downside is that the weight was a bit over the claim, and therefore it's not really a big weight saving. Probably why it works.
It was a borrowed tyre but after the positive experience I just bought my own and am running it currently, very happy.
Wouldn't use one on the rear, but works well on the front and isn't particularly light for whatever it's worth (1140g, only ~150g off full DH casing weight). I'm pretty sure it actually is the closest thing you can get to a full DH casing with a kevlar bead.
The downside is that the weight was a bit over the claim, and therefore it's not really a big weight saving. Probably why it works.
I actually saved 100g over my old one and performance seems similar so far, that was the whole point of this thread (i.e. bead material doesn't really affect performance but casing does).
Luckily for me, the matching (except full DH casing) rear I bought was a ludicrous 140g over their claimed weight, so I gained back my saving in a very roundabout way.
WTF Schwalbe. Thanks for nothing.
