Do tire inserts mean it's time to rethink tire design?

Masjo
Posts
247
Joined
11/25/2014
Location
Ancaster CA
11/16/2017 6:48am
Masjo wrote:
Building a tire with an integrated insert/tube, making specific rims for those tires, and somehow forcing the two together... Are we now basically talking about tubular...
Building a tire with an integrated insert/tube, making specific rims for those tires, and somehow forcing the two together...
Are we now basically talking about tubular mountain bike tires?
David.Max wrote:
Not really what I'm thinking, but I believe that I did see something along those lines in the coverage from one of the bike trade shows...
Not really what I'm thinking, but I believe that I did see something along those lines in the coverage from one of the bike trade shows once.

My first post was pretty long so I'll see if I can clarify what I'm thinking and pull out some of the main points.

At the moment this is definitely a performance focused idea, something for racing and other mission critical applications were traction and keeping air the tire are the highest priority. One of the things that really got me thinking about this is the frustration of seeing races at the highest level of our sport being decided by flat tires. If I was going to list priorities they would be:

1. Keeping air in the tire air
2. Ride quality/traction (as a very close 2cnd)
3. Weight
4. Price

I know those aren't everybody's priority, but from a racing perspective it makes sense.

The insert and the tire would still separate elements from each other, but the tire would be a squirmy, undamped mess if you rode it at low pressures without the insert.

Essentially this a a thought exercise. All tires are currently designed with the notion that they should be able to perform at high level without an insert. The insert is a new and significant structural element that was never taken into account in the original design of any tire that is currently on the market.

I'm asking what might be possible if a tire was specifically designed with the knowledge that an insert would be a part of the overall system of the wheel/tire? Right now the tire designer has to come up with a tire that is able to offer a significant degree of sidewall support, ride damping, and pinch flat protection. If the tire doesn't have to deal with those roles because they are being handled by the insert would that free up resources -i.e. material constraints and hence weight- that could then be redirected towards keeping air in the tire?

There are already a variety of ballistic materials that are used in tire construction. If we reconsider the design brief of the tire based on the use of an insert could we come up with something that is significantly more slash and puncture proof, while also offering an improved ride quality?
I understand you were not thinking of a tubular tire, but to me it sounds like maybe this is a design that already exists that could be modified to achieve your goals. The way I was thinking about it was three-fold:

1) Tubular tires are one piece, meaning that the insert would be a part of the rubber tire. Maybe that's not where we are at yet, but designing a tire to only be used with an insert is one step away from having both parts of these together.
2) The sidewalls could be made out of XYZ slash-resistant material. Since it's all one bonded piece, the tread, sidewall, and insert could all be made out of whatever material is most appropriate, and then stitched together. As a singular design, it could probably be lighter than if each piece were created separately, and the whole system would be engineered to work together - so sidewalls only have to be as strong as necessary with the insert and whatnot.
3) Tubular tires means tubular specific rims, but if a *gasp* standard for one came out that was designed with these in mind, then maybe a tire company and rim manufacturer could come together to optimize the rim profile to reduce the chance of pinch flats. If you are gluing the tire in place, who cares what the rim shape looks like? As long as it has a bit of a cup, the tire will stay on if the appropriate materials are used.

And yes, if you somehow managed to rip open your tubular tire on EWS race day, you are pretty f*#@ed. Maybe the pros will have to start carrying plugs, although I'm sure many already do. There also have been tubular mountain bike tires already, but just none with a specific insert as described.
This all relies on one tire manufacturer working with one rim manufacturer, which is probably a bit of a long shot unless a company does both (e.g. Bontrager), but it is a possible solution. Is it the only one? No. Is it a viable option? I do not know. Would I, a regular consumer with no EWS/UCI DH aspirations buy one? Heck no, that sounds like a lot of work. But look at cyclocross - they also appear to be a relatively small cycling discipline, and all those pros run tubulars, and some weekend warriors do too.

I think regardless of what the solution is going to be, it's not something that Maxxis, or Cushcore, or DT Swiss can solve themselves - it's going to require some sort of collaboration between all parties involved. The question is, who's already in business meetings together and is the new 'standard' going to be available for others to use or patented for the foreseeable future?
sspomer
Posts
6106
Joined
6/26/2009
Location
Boise, ID US
Fantasy
11/16/2017 7:38am Edited Date/Time 11/16/2017 7:40am
(edited) great discussion going on! PIA for sure but minnaar had tubular tires at sea otter (and maybe other races?) in 2012. not sure where this lead.


11/16/2017 7:52am
I like this thread a ton.
Mountain biking was invented by people thinking about stuff after destroying the other stuff.
We are back on target.

I could see the inserts becoming "Tubes again" but more like "bad ass tubes" that don't have pinch resistance, more are simply impossible to pinch. these tubes would also "support" the tire in a way that previous tube designs never did.

ON a side note, i have been building ghetto tubeless setups for years, and they essentially create a "tubular" effect, and require me to ride with plugs, because i can plug a puncture or small rip and be on my way very easily.

the issue is integration at all levels, which will always cost more, always create internet ire, and ultimately, eventually, solve pesky problems.

IF we can make an insert designed integration, why can't we make a simply better tubeless tire? in my simple mind, i ask that all that weight go into a 175 dollar tire that is FRO. i would never run said tire all season on my little play bike, and it would be heavier butnot require inserts. but come race day, id be stoked. much like we did with old Minion 3c's: we saved them for the good stuff.
11/16/2017 7:58am
Masjo wrote:
I understand you were not thinking of a tubular tire, but to me it sounds like maybe this is a design that already exists that could...
I understand you were not thinking of a tubular tire, but to me it sounds like maybe this is a design that already exists that could be modified to achieve your goals. The way I was thinking about it was three-fold:

1) Tubular tires are one piece, meaning that the insert would be a part of the rubber tire. Maybe that's not where we are at yet, but designing a tire to only be used with an insert is one step away from having both parts of these together.
2) The sidewalls could be made out of XYZ slash-resistant material. Since it's all one bonded piece, the tread, sidewall, and insert could all be made out of whatever material is most appropriate, and then stitched together. As a singular design, it could probably be lighter than if each piece were created separately, and the whole system would be engineered to work together - so sidewalls only have to be as strong as necessary with the insert and whatnot.
3) Tubular tires means tubular specific rims, but if a *gasp* standard for one came out that was designed with these in mind, then maybe a tire company and rim manufacturer could come together to optimize the rim profile to reduce the chance of pinch flats. If you are gluing the tire in place, who cares what the rim shape looks like? As long as it has a bit of a cup, the tire will stay on if the appropriate materials are used.

And yes, if you somehow managed to rip open your tubular tire on EWS race day, you are pretty f*#@ed. Maybe the pros will have to start carrying plugs, although I'm sure many already do. There also have been tubular mountain bike tires already, but just none with a specific insert as described.
This all relies on one tire manufacturer working with one rim manufacturer, which is probably a bit of a long shot unless a company does both (e.g. Bontrager), but it is a possible solution. Is it the only one? No. Is it a viable option? I do not know. Would I, a regular consumer with no EWS/UCI DH aspirations buy one? Heck no, that sounds like a lot of work. But look at cyclocross - they also appear to be a relatively small cycling discipline, and all those pros run tubulars, and some weekend warriors do too.

I think regardless of what the solution is going to be, it's not something that Maxxis, or Cushcore, or DT Swiss can solve themselves - it's going to require some sort of collaboration between all parties involved. The question is, who's already in business meetings together and is the new 'standard' going to be available for others to use or patented for the foreseeable future?
Thanks for elaborating on your idea, it definitely makes more sense to me now and its another valid way of looking at the problem. More than anything I was really just trying to provoke discussion. New ways of doing things come about by talking about and trying a lot of ideas until we find something that works better than what we already have.

As a race only application what you are describing could have some real merits. It certainly hits on the integration aspect with everything being designed to work as a system and literally stuck together!

My concern is that it might be too costly and inconvenient even for top level race teams. Any kind of on site tire changes would be a thing of the past, and teams would simply have to have multiple wheel sets on hand glued up with different tires. That would be possible, but particularly when the races aren't in Europe space and shipping considerations do play a role, especially for the smaller teams.

If the tire and insert are fully bonded together that would make it that much more expensive when then tires wear out, although I suppose that could be gotten around with the re-treading idea I described above.

My biggest concern would be ripping tires off the the rim if they weren't glued properly. It does happen in cross from time to time and the leverage and moment of force being put on the rim/glue interface by a downhill bike, cornering on a high volume, low pressure tire at 50+ km/hr would be much higher than what cyclocross tubulars are exposed to. That said there are all kinds of incredible modern adhesives available, but that might make tire removal into even more of a nightmare than it already is for tubulars.

As much as I am thinking about this from a racer's perspective, I would hope to come up with something that could trickle down into the wider market eventually. That leads me to think that modular system where all the parts are designed to work together as a whole, would ultimately be superior to something that's fully integrated. But like you said, I don't know either.
11/16/2017 8:24am
sspomer wrote:
(edited) great discussion going on! PIA for sure but minnaar had tubular tires at sea otter (and maybe other races?) in 2012. not sure where this...
(edited) great discussion going on! PIA for sure but minnaar had tubular tires at sea otter (and maybe other races?) in 2012. not sure where this lead.


That's neat to see. Thanks for posting it. It would be great to be able to get some feedback from Minnaar or Marsh about how that worked for them. Based on the fact their not still using it I'm guessing that maybe it wasn't the end all be all...

Having dealt with tubulars a bit in cyclocross racing I'm reluctant to too that route. I can say that I would rather deal with installing an insert any day of the week, particularly on a rim that is designed to work well with it , than spend time gluing and stripping tubular tires!

One really interesting thing those picture seem to show is that the the tread is glued on to a lower portion which is then glued to the rim. That makes me think that maybe the re-treading idea that I mentioned earlier might be more practical that I imagined. Re-treaders could just stock a variety of treads in different compounds and and mixed compounds wouldn't be an issue. When its time to re-tread a tire it would just get a matter of grinding of the old tread until you got to the base material and then bonding the new tread in place. I would imagine that this could be easily accomplished with a little bit of specialized equipment to to apply even pressure to the casing and tread while heat curing and bonding the layers together...
11/16/2017 8:39am
I like this thread a ton. Mountain biking was invented by people thinking about stuff after destroying the other stuff. We are back on target. I...
I like this thread a ton.
Mountain biking was invented by people thinking about stuff after destroying the other stuff.
We are back on target.

I could see the inserts becoming "Tubes again" but more like "bad ass tubes" that don't have pinch resistance, more are simply impossible to pinch. these tubes would also "support" the tire in a way that previous tube designs never did.

ON a side note, i have been building ghetto tubeless setups for years, and they essentially create a "tubular" effect, and require me to ride with plugs, because i can plug a puncture or small rip and be on my way very easily.

the issue is integration at all levels, which will always cost more, always create internet ire, and ultimately, eventually, solve pesky problems.

IF we can make an insert designed integration, why can't we make a simply better tubeless tire? in my simple mind, i ask that all that weight go into a 175 dollar tire that is FRO. i would never run said tire all season on my little play bike, and it would be heavier butnot require inserts. but come race day, id be stoked. much like we did with old Minion 3c's: we saved them for the good stuff.
"IF we can make an insert designed integration, why can't we make a simply better tubeless tire? in my simple mind, i ask that all that weight go into a 175 dollar tire that is FRO. i would never run said tire all season on my little play bike, and it would be heavier butnot require inserts. but come race day, id be stoked. much like we did with old Minion 3c's: we saved them for the good stuff."

I'm not claiming to have all the answers, but it seems like inserts, and CushCore in particular, offer some real performance benefits that I'm not sure how we can achieve otherwise. If you look at what some of Jeff has described with regards to the way that inserts add progression, bottom out protection, and stability to a tire, that doesn't sound like something that I want to design out of the system. My perspective is much more a mater of looking at them as a missing element from tire/wheel design, and asking now that they are available how we can optimize wheels and tires to work with them.

Anyhow, I'm not trying to shoot down any ideas, I've definitely have my own thoughts about what might work best, but like I said above there's no way to know what would be best until we've tried and failed with a bunch of different approaches.

PS What do you mean when you said that your ghetto tubless setup created a tubular effect? I understand the idea behind ghetto tubeless, but its not something that I have ever done myself so I'm not that familiar with it.
Verbl Kint
Posts
590
Joined
9/13/2013
Location
Quezon City PH
11/16/2017 9:40am
I wonder who would come up with an integrated mtb wheel system first, a tire manufacturer or a rim manufacturer?

11/16/2017 11:29am
So the inserts work well, but are too heavy. What if the tires incorporate the foam to the walls (less material) and also design a most clever way to instal a tubeless... the rim tape, the hole and the valve looks as a temporal solution.
Masjo
Posts
247
Joined
11/25/2014
Location
Ancaster CA
11/16/2017 12:00pm
So the inserts work well, but are too heavy. What if the tires incorporate the foam to the walls (less material) and also design a most...
So the inserts work well, but are too heavy. What if the tires incorporate the foam to the walls (less material) and also design a most clever way to instal a tubeless... the rim tape, the hole and the valve looks as a temporal solution.
If a rim were truly designed with a insert/liner in mind, then maybe you wouldn't need tubeless tape? If the fit works well enough, it could be airtight with the right material. Then the tire needs to be designed with this in mind - and we are again back at who would do it first?
Does anyone know of any tire/rim manufacturers that are under the same parent company? The only one I know of that does both is Trek/Bontrager or Specialized/Roval.
As another commenter mentioned, I do not think the general internet would appreciate another new 'standard' especially if, say, Trek created a proprietary system or held an exclusivity agreement for a while a la the new Thru-Shaft bikes and shocks. I don't think Trek or Specialized necessarily have enough tire selection or distribution volume to have their bikes only able to run just their wheels and tires. This sounds like something everyone, or almost everyone, would have to agree on. It could happen, considering we did something similar with Metric shocks.
slimshady
Posts
146
Joined
9/16/2011
Location
AR
11/16/2017 12:21pm
I still think the rim profile needs to change. We are basically using a wider version of something designed to be ridden in roads or gravel, with narrower tires, higher pressures and significantly smaller lateral loads. The MTB tires and rims should address our sport's characteristics and do away with their road heritage.
11/16/2017 2:17pm Edited Date/Time 11/16/2017 2:17pm
My ghetto tubeless set ups use a split open inner tube and a traditional rim strip. once the set up is locked on the bead the old tube flapper doohickey is adhered to the brand new tire using the sealant. if i use a ton of sealant i have noticed significant lack of burps: when i roll the tire ( and i roll many tubeless set ups including ust, i am 6-4 and weigh about 220 in training mode-195 after fighting off dad bod) the inner flapper goes with it and i never lose air. the tubeless tires and rims just make the capturing of the flap that much tighter and snappy. Its brilliant and yet, rim strikes at really really really low pressures still threaten to damage the rim, BUT a damaged rim still holds air fine, because the dried up sealant is making the set up act "tubular" ( which i now yell when im getting rowdy....) TUBULAR DUDE!

I would love to see a three part system where:
1. the tires are tubeless.
2. the insert is a bead locker that actually locks the bead.
3. the rims are made to not destroy the tires, and work in conjunction with the insert

your idea has mad merit.
is the Pro Core not doing this? what if we had a rim that was Pro Core specific?

Are the wheels the actual problem here?
Masjo
Posts
247
Joined
11/25/2014
Location
Ancaster CA
11/16/2017 7:23pm
My ghetto tubeless set ups use a split open inner tube and a traditional rim strip. once the set up is locked on the bead the...
My ghetto tubeless set ups use a split open inner tube and a traditional rim strip. once the set up is locked on the bead the old tube flapper doohickey is adhered to the brand new tire using the sealant. if i use a ton of sealant i have noticed significant lack of burps: when i roll the tire ( and i roll many tubeless set ups including ust, i am 6-4 and weigh about 220 in training mode-195 after fighting off dad bod) the inner flapper goes with it and i never lose air. the tubeless tires and rims just make the capturing of the flap that much tighter and snappy. Its brilliant and yet, rim strikes at really really really low pressures still threaten to damage the rim, BUT a damaged rim still holds air fine, because the dried up sealant is making the set up act "tubular" ( which i now yell when im getting rowdy....) TUBULAR DUDE!

I would love to see a three part system where:
1. the tires are tubeless.
2. the insert is a bead locker that actually locks the bead.
3. the rims are made to not destroy the tires, and work in conjunction with the insert

your idea has mad merit.
is the Pro Core not doing this? what if we had a rim that was Pro Core specific?

Are the wheels the actual problem here?
I think this is certainly the way to go, but the question is how to design the rim so it doesn't fatally strike the tire? Not to keep beating the horse, but if the tire and insert were a single package that were glued/bonded in some way to the rim, you could in theory design a rim without sidewalls, or at least very small ones. I have no idea how that would play into the feel of the tire, but it seems like the bead is possibly not that important as long as the sidewalls are secured to something.
TEAMROBOT
Posts
1391
Joined
9/2/2009
Location
Los Angeles, CA US
Fantasy
11/16/2017 7:29pm
grinch wrote:
This conversation seems very dh centric. If you can make the rim without a thin sidewall why wouldn’t you? Dh included. We’ve seen EWS bikes go...
This conversation seems very dh centric. If you can make the rim without a thin sidewall why wouldn’t you? Dh included. We’ve seen EWS bikes go from exo to dd weight tires to full dh tires and using full inserts(cushcore not huck Norris) all to prevent flats , for the most part(yes they ride better with inserts as well), and flats are still deciding races. No one I now rides a trail bike with dh tires and cushcore. I’ve settled on 1000g tires with huck Norris and a bit more air than I’d prefer. Huck Norris is cut to shit from the rim sidewall but it works. It’d probably be fine without the rim sidewall profile. I only use my set up as an example , it can be applied to lighter xc or heavier dh
I agree with Grinch, this conversation is very DH and more importantly pro-centric. For the average rider on their home trails, 1300g tires, 300g inserts, etc are totally unnecessary. Even at 190 pounds he seems to make due with 1000 g tires, so Grinch... be happy that you can run those

As someone who was kinda fast once, I still regularly turn 1000g and EXO tires into garbage, I ruin rims, and my tires generally squirm all over the place at lower pressures. This leads me to want DH tires on my trail bike, but those too feel like garbage. Jeff's comparison is right on, the DH tire rides like a coil- it's linear. A trail bike sees lower speeds and smaller bumps, so DH tires feel WAAAY too stiff at low speeds. If I let some air out to feel marginally better at low speeds, it folds all to hell or flats at high speeds in turns and on rocks. This means that DH tires are only tolerable on trail bikes as rear tires.

Unfortunately, front and rear inserts are a joke of an idea for anything less than EWS racing: I know they'll save me some flats, but 600g of extra rotating weight? Unless you're one of the tip top guys fighting week in/week out for overall series points, it makes no sense to constantly slow yourself down with heavy ass slow ass wheels. You'll run lighter wheels and gamble.

I see a lot of people running a rear only insert- this seems like the best solution we currently have. DD tires and a rear insert, maybe a front Huck Norris. But even then, it's easy to cut the tread on a DD with a nice sharp rock. Gwin obviously cut his tread on a downhill tire. What I'm trying to say is there's currently no good solution, only a series of compromises that sorta work. Pick your poison.
tims5377
Posts
4
Joined
5/20/2014
Location
Rochester, NY US
11/17/2017 5:49am
This is a great discussion. It is making me think of a multiple chamber tire, where there are two zones that can be inflated to different pressures. I'm just going to powerpoint engineer this cause it'll be easier... be back in a minute...

OK, so I realize now, that I just designed pro core! My thought is to actually integrate that into the tire, so a flexible piece of rubber - similar to inner tube material - is low, closeish to the bead yet still above the rim interface. This can be pressurized high to avoid pinches but the remainder of the tire can be set to a riding pressure. It essentially is a bottom out bumper.

I also found this and thought it was very interesting and quite pertinent (albeit heavy):
https://google.com/patents/US2196814


Masjo
Posts
247
Joined
11/25/2014
Location
Ancaster CA
11/17/2017 7:11am
grinch wrote:
This conversation seems very dh centric. If you can make the rim without a thin sidewall why wouldn’t you? Dh included. We’ve seen EWS bikes go...
This conversation seems very dh centric. If you can make the rim without a thin sidewall why wouldn’t you? Dh included. We’ve seen EWS bikes go from exo to dd weight tires to full dh tires and using full inserts(cushcore not huck Norris) all to prevent flats , for the most part(yes they ride better with inserts as well), and flats are still deciding races. No one I now rides a trail bike with dh tires and cushcore. I’ve settled on 1000g tires with huck Norris and a bit more air than I’d prefer. Huck Norris is cut to shit from the rim sidewall but it works. It’d probably be fine without the rim sidewall profile. I only use my set up as an example , it can be applied to lighter xc or heavier dh
TEAMROBOT wrote:
I agree with Grinch, this conversation is very DH and more importantly pro-centric. For the average rider on their home trails, 1300g tires, 300g inserts, etc...
I agree with Grinch, this conversation is very DH and more importantly pro-centric. For the average rider on their home trails, 1300g tires, 300g inserts, etc are totally unnecessary. Even at 190 pounds he seems to make due with 1000 g tires, so Grinch... be happy that you can run those

As someone who was kinda fast once, I still regularly turn 1000g and EXO tires into garbage, I ruin rims, and my tires generally squirm all over the place at lower pressures. This leads me to want DH tires on my trail bike, but those too feel like garbage. Jeff's comparison is right on, the DH tire rides like a coil- it's linear. A trail bike sees lower speeds and smaller bumps, so DH tires feel WAAAY too stiff at low speeds. If I let some air out to feel marginally better at low speeds, it folds all to hell or flats at high speeds in turns and on rocks. This means that DH tires are only tolerable on trail bikes as rear tires.

Unfortunately, front and rear inserts are a joke of an idea for anything less than EWS racing: I know they'll save me some flats, but 600g of extra rotating weight? Unless you're one of the tip top guys fighting week in/week out for overall series points, it makes no sense to constantly slow yourself down with heavy ass slow ass wheels. You'll run lighter wheels and gamble.

I see a lot of people running a rear only insert- this seems like the best solution we currently have. DD tires and a rear insert, maybe a front Huck Norris. But even then, it's easy to cut the tread on a DD with a nice sharp rock. Gwin obviously cut his tread on a downhill tire. What I'm trying to say is there's currently no good solution, only a series of compromises that sorta work. Pick your poison.
While this is very centered toward DH and EWS, that is where the problem lies - races being decided by mechanical failures versus 'skill' of the athlete. Now, part of the 'skill' is to avoid getting flats, but we don't want that in our races.
I'm going to beat the dead horse that is my tubular tire remark, but pretty much only cyclocross pros run tubulars, with only dedicated amateurs and those with enough money/time getting them otherwise. If I get a flat on a ride with friends, I'll just hold them up a bit and we have a chance to talk or grab a drink. I agree that not many people would want to pay extra money for a dedicated and expensive rim/tire setup to get rid of a potential, low-impact problem.
Eventually, sure, there may be a 'cheaper', 'uncuttable/unpinchable/unleakable' tire, but we're trying to specifically solve a 'big' racing problem, and the comparable issue for the average consumer just doesn't matter that much.
jeff.brines
Posts
1225
Joined
8/29/2010
Location
Grand Junction, CO US
11/17/2017 7:21am Edited Date/Time 11/17/2017 7:23am
TEAMROBOT wrote:
I agree with Grinch, this conversation is very DH and more importantly pro-centric. For the average rider on their home trails, 1300g tires, 300g inserts, etc...
I agree with Grinch, this conversation is very DH and more importantly pro-centric. For the average rider on their home trails, 1300g tires, 300g inserts, etc are totally unnecessary. Even at 190 pounds he seems to make due with 1000 g tires, so Grinch... be happy that you can run those

As someone who was kinda fast once, I still regularly turn 1000g and EXO tires into garbage, I ruin rims, and my tires generally squirm all over the place at lower pressures. This leads me to want DH tires on my trail bike, but those too feel like garbage. Jeff's comparison is right on, the DH tire rides like a coil- it's linear. A trail bike sees lower speeds and smaller bumps, so DH tires feel WAAAY too stiff at low speeds. If I let some air out to feel marginally better at low speeds, it folds all to hell or flats at high speeds in turns and on rocks. This means that DH tires are only tolerable on trail bikes as rear tires.

Unfortunately, front and rear inserts are a joke of an idea for anything less than EWS racing: I know they'll save me some flats, but 600g of extra rotating weight? Unless you're one of the tip top guys fighting week in/week out for overall series points, it makes no sense to constantly slow yourself down with heavy ass slow ass wheels. You'll run lighter wheels and gamble.

I see a lot of people running a rear only insert- this seems like the best solution we currently have. DD tires and a rear insert, maybe a front Huck Norris. But even then, it's easy to cut the tread on a DD with a nice sharp rock. Gwin obviously cut his tread on a downhill tire. What I'm trying to say is there's currently no good solution, only a series of compromises that sorta work. Pick your poison.
Just some food for thought, even though I largely agree with you. (or wait, robots don't eat food, and certainly don't need any sort of sustenance for thought. Hmmmm....)

600 grams of rotating weight does suck for normal trail riding. No two ways about it. There is a reason I took Cushcore out of my last test bike as racing and bike park became less the focus and trail riding more the focus.

That said, in a race environment, I'd *gladly* take the weight. But maybe that's because my strength is I'm stronger on the gas and my weakness being trusting my bike in corners (EG: Jeff is a lame bike rider). I also struggle with arm pump. This product in the front wheel, specifically, helped me hold better speed through corners while taking the sting off a lot of the trail chatter. I don't care how "big" of a race (meaning how much climbing I have to do), I'm going Cushcore or similar next season anytime cornering speed is rewarded.

Next year I'll be a spoiled little bike dork and have two wheelsets. Same tires. One with cushcore, one without. When I'm shuttling, going to the bike park, racing or really looking to get after it going downhill I will no-doubt go with the insert based system. After work trail riding, racing light, going for uber long rides, sans-insert wheelset.

The Huck Norris system is cool, but I'm not nearly as interested in this style of system as it doesn't offer any ride-quality benefit, which is more than half of what I'm after with these systems. Put another way, like Sponsel, I have to run higher-than-I'd-like pressure without a sidewall supported insert. As a result, I have very few flats from pinging my rims, at least outside race environments when I'm not "trying harder than I can".





Dave_Camp
Posts
460
Joined
8/25/2009
Location
CO US
11/17/2017 8:56am
I'd like to see at least an option for heavier tires made of normal cheap materials. 1500 gram tire with normal rubber (not sticky DH rubber) would be pretty indestructible on the trail bike, roll fast enough and not wear out too quickly. Pressure could be run lower because you can't pinch flat it.

Just where I'm coming from- my cheap moto rear tire weighs 16lbs and costs $65 retail, does not flat unless you do something really! bad. No special design needed- just more rubber.


I can pony up for $100 MTB tires when racing, but stuff is getting spendy.
dstucki
Posts
11
Joined
7/8/2013
Location
Durango, CO US
11/17/2017 9:15am
This discussion is awesome. I want to steer everyone's ideas in a slightly different direction, though. Tire inserts already exist, but their purpose is to protect the tire from an impact where the casing is punctured by direct force on the rim. Essentially a tubeless pinch flat. These inserts exist mostly due to flaws in rim design, not necessarily tire design, with the exception of how the tire is mounted to the rim.

That said, gluing tires is pretty damn archaic by my math, and there is a reason why Syndicate never ran tubulars for prominent races. I'd be willing to bet that tubeless will begin to take over the cyclocross scene in the near future as well. You also have to consider these are the types of people who intentionally ride bike with skinny tires and drop bars in the mud, dirt, grass, and sand... bike conservatives, who make rules that hinder the advancement of the sport, i.e. 33c tires and 46mm wide bars, etc. There has got to be something better... and I'm not talking about Tufo's Tubular Clinchers: http://www.tufo.com/en/tubular-clincher/

Pinch flats are not something we regularly see with alloy rims because as mentioned above, alloy rims typically bend. We all know through the history of DH racing that there used to be rims, such as the Mavic DeeMax that were too hard, and cut tires or flatted tubes instead of denting. This issue has resurfaced with the assimilation of carbon rims in MTB. Your rim either breaks or cuts your tire on a significant impact. Both scenarios are less than ideal. To me, this still seems more like a rim issue than a tire issue. Having tested the majority of tire inserts on the market, I will say that some work, some are total gimmicks, and others offer other benefits than just rim protection. Schwalbe's Pro Core allows the rider to more or less fine tune the spring rate of their tire and also acts as an internal bead locker. ENVE's rim strip is pretty damn awesome... going on two years without a single pinch flat on EXO casing tires. (I'm 6'5" and 200lbs, break a lot of shit and flat all the time). Again, I think all of these fixes are more rim-related than tire related.

All of that aside, I am curious to spark some ideas about alternatives to air. All systems currently available are centered around using air, or another type of gas (nitrogen), to inflate the tire. This is the system's achilles. What are your ideas for the coil spring of tires? What about something like this: https://www.youtube.com/watch?v=OIzDu482mME

Eliminating air from the equation also eliminates other issues such as leaky tubeless valves, sealant, and tubeless tape.

P.S. I think re-treading could be a sweet idea... Buy a nice set of tires, and send them in to get some fresh tread when they wear out. Much less disposable, and we all know our industry could jump leaps and bounds in the sustainability department.
JLBThreee
Posts
1
Joined
11/16/2017
Location
Matthews, NC US
11/17/2017 2:01pm Edited Date/Time 11/17/2017 2:02pm
@dstucki - I share your exact same opinion. Why not ditch air all-together? I came from an offroad R/C background which used foam in place of air. With the sticky tires and soft rubber they use, air just doesn't make sense. With this thought in mind, I think we could easily develop a lightweight foam and tire system that could support our mountain bike need. To reduce weight, you could play with material, density, cutouts etc... I've attached a photo of a common R/C tire below. Note the ribs and other features on the ID and OD of the foam. All used to control the damping/pressure of the tire.

To add to this thought, our our current tires have an additional feature that is often not overlooked...they need to hold the forces due to pressure. Hence the max PSI rating for all tires. If you can eliminate the requirement of holding pressure, you could likely save weight on the tire carcass as well.

There are likely a bunch of haters out there that don't see the benefit, but I think a properly designed system would be better all-around (wheels, tires, and inserts). Possibly lighter depending on tire and rim construction. Imagine a day when you can keep riding after a gnarly sidewall tear...simply slap some duct tape on it to keep the dirt out and keep riding. HAHA No more leaky sealant and flat tire headaches. Heck, I'd take a weight penalty to say goodbye to flats.

SlicedAsiago
Posts
1
Joined
9/9/2017
Location
Washington, DC US
11/19/2017 12:40pm
So I guess running a slightly higher psi is out of the question for everyone?
Big Bird
Posts
2292
Joined
2/1/2011
Location
Oceano, CA US
11/20/2017 7:19pm
@JLBThreee I like your idea. How about using current rim and tire tech, But develop a liquid that could be introduced at pressure through a tubeless valve stem that would foam up to fill the tire. The feel of the tire, like we currently adjust air pressure to regulate, could depend perhaps on the composition of the foam solution making larger or smaller bubbles. Or perhaps it could vary with the amount of pressure that it's pumped in at?

And @SlicedAsiago Yeah, that's what I've always done. I hate the feel of a low pressure "Grippy" tire. I ride on rails!
11/21/2017 1:59am
Tire inserts mean to rethink what rim you are using and how your suspension is set up.
Fred_Pop
Posts
222
Joined
11/26/2017
Location
FR
11/30/2017 5:33am
I used to run Schwalbe supergravity tires with tubes a while back and was quite happy with that setup. It was an improvement weight wise compared to full on DH tires. Then 2 years ago I made the switch to singleply tires with procore setup. I managed to lose even more weight, still retained the flat proofness and got loads more grip because of the lower pressure I could run. The downside is that the singleply tires are more fragile so I did manage to slice one this year. I think kevlar sidewalls would solve the slicing/tearing issue. As for a new tire system so we don't have to deal with inserts I think that would be great. I think holding the tire on the rim even if you flat is a nice feature of procore so it would be something I would incorporate. Perhaps a special rimstrip you could tighten that would keep the tire on the rim.
Foam in the sidewalls with kevlar could be an idea to provide the damping and the protection needed.
The alternative is to integrate the insert directly into the rim like the old THE eliminator rim:
https://www.ebay.com/itm/T-H-E-Eliminator-26in-32-hole-rims-Made-by-Tob…

Post a reply to: Do tire inserts mean it's time to rethink tire design?

The Latest