New C4 rubber vs older C4 rubber

I’ve got a few pairs of newer Five Tens that I love, but the C4 rubber is not living up to the hype. Anyone know if Adidas actually changed the compound in the C4 rubber? Considering doing a resole with XS Edge instead. Love the shoes, but prefer my Vibram rubber.

Check out UnParrallel RH rubber. Resoled my shoes with it and was extremely pleased.

What exactly aren’t you happy with?  Wears too fast, doesn’t edge well, doesn’t smear well, doesn’t smedge well?   I have shoes with vibrant rubber that edge well but doesn’t friction as well as C4.   I think C4 is one of the best all around compounds even after Adidas took over.  I think Adidas is driving the climbing shoe side of the company into the ground but IMO the rubber has stayed pretty consistent.  Any shoes I’ve owned with Vibram I’ve resoled with C4 when it came time for new rubber.  I’ll have to give Unparalleled a shot one of these days if they ever make a high top. 

Kevin Mokracek wrote:

What exactly aren’t you happy with?  Wears too fast, doesn’t edge well, doesn’t smear well, doesn’t smedge well?   I have shoes with vibrant rubber that edge well but doesn’t friction as well as C4.   I think C4 is one of the best all around compounds even after Adidas took over.  I think Adidas is driving the climbing shoe side of the company into the ground but IMO the rubber has stayed pretty consistent.  Any shoes I’ve owned with Vibram I’ve resoled with C4 when it came time for new rubber.  I’ll have to give Unparalleled a shot one of these days if they ever make a high top. 

It’s peeling away super quickly. The edge is still there, but the rubber has started separating from the shoe in thin strips. Also, the edging is not as confidence inspiring as my Vibram shoes. I feel glued to tiny holds on my old TC Pros, but feel less glued on with my Five Tens. 

Alyssa Keene wrote:

Also, the edging is not as confidence inspiring as my Vibram shoes. I feel glued to tiny holds on my old TC Pros, but feel less glued on with my Five Tens. 

In that case you are comparing a much harder rubber (XS Edge) to a medium-stiffness rubber (C4). They're just going to have different performance and wear characteristics. One isn't necessarily better than another, they just are oriented to different situations. 

I'm a fan of C4. I feel like the most common Vibram rubber types represent specialist end members. The Edge rubber is pretty stiff; great for vert climbing in small footholds, but feels kind of dead on steeper terrain and polished rock. The Grip2 rubber is great on steep terrain and smooth rock, but is too soft to hold a small edge as well. 

C4 fits in the middle and is reasonably competent in most situations, which I like. It's my favorite rubber, with the Grip1 as a close second (another medium stiffness rubber). Both feel nicely balanced as all-arounders.  But these won't perform as well in on tiny edges as a harder rubber specialized to that.

I can't comment on old vs new C4 rubber. I've only used 5.10 shoes in the post Adidas era, so no comparison to the old stuff. I have no complaints about the current stuff though.

JCM wrote:

In that case you are comparing a much harder rubber (XS Edge) to a medium-stiffness rubber (C4). They're just going to have different performance and wear characteristics. One isn't necessarily better than another, they just are oriented to different situations. 

Good points! I was under the impression that C4 was their stiffest compound and most comparable to XS Edge. Would you say that XS Edge is the stiffest rubber compound out there?

Alyssa Keene wrote:

Good points! I was under the impression that C4 was their stiffest compound and most comparable to XS Edge. Would you say that XS Edge is the stiffest rubber compound out there?

Five Ten used to have a wide range of rubber compounds. Onyxx was their hard edging rubber, equivalent to Edge. C4 was the mid-range versatile rubber. Then they had HF as the soft rubber and Mi6 as the super soft rubber. In the recent era, it looks like they've dropped everything other than C4. Which if you are only going to have one rubber option, is the most versatile choice in that range. But the reduced range/options is a loss. This is probably the biggest change. It's not the C4 has necessarily changed, it's just unfortunately the only stealth option now. 

Comparing with the Vibram rubbers, Edge is notably stiffer than C4. Grip 2 is softer than C4. Grip 1 (which is still used by Tenaya) is pretty close to C4. Another rubber pretty close to C4 in the medium-range is Trax SAS. I find C4 is my favorite of the mid-range rubbers, but that might just be placebo. They're pretty similar.

Edge is definitely one of the stiffest options in the market now, but I'm not sure if it is the absolute stiffest. I haven't tried all of them. There's also Trax XE, which is the Evolv stiff rubber. There may be others from UP or Butura or someone else; I haven't really followed those.

Overall, I think climbers get way too caught up in saying "this rubber sucks, this other rubber is better." Or just generarically describing a rubber compound as "sticky" with no situational context. This is pretty unhelpful. I think most modern rubber compounds are pretty good, but their relative performance is situationally dependent based on hold type, rock texture, temperature, climber weight, and personal preference. One rubber may be much better than another for the climbing you do, but it's about figuring out the situational details that work for you.

For instance, I have 2 pairs of TC Pros. One is my larger pair and has the original Edge rubber. I use this in warm weather when my feet are bigger (hence larger size) and since in warm temps you want the harder rubber. Then I have a pair that is a half size smaller and resoled with C4, that I use in cold weather. They both perform great in their respective use cases. C4 at 40 degrees feels pretty similar to how Edge feels at 75 degrees.

 It's possible that the rock and conditions that OP has been climbing in SoCal (rough granite; warm temps) favors harder rubber like Edge. C4 gets really soft in the heat.

JCM wrote:

Five Ten used to have a wide range of rubber compounds. Onyxx was their hard edging rubber, equivalent to Edge. C4 was the mid-range versatile rubber. Then they had HF as the soft rubber and Mi6 as the super soft rubber. In the recent era, it looks like they've dropped everything other than C4. Which if you are only going to have one rubber option, is the most versatile choice in that range. But the reduced range/options is a loss. This is probably the biggest change. It's not the C4 has necessarily changed, it's just unfortunately the only stealth option now. 

Comparing with the Vibram rubbers, Edge is notably stiffer than C4. Grip 2 is softer than C4. Grip 1 (which is still used by Tenaya) is pretty close to C4. Another rubber pretty close to C4 in the medium-range is Trax SAS. I find C4 is my favorite of the mid-range rubbers, but that might just be placebo. They're pretty similar.

Edge is definitely one of the stiffest options in the market now, but I'm not sure if it is the absolute stiffest. I haven't tried all of them. There's also Trax XE, which is the Evolv stiff rubber. There may be others from UP or Butura or someone else; I haven't really followed those.

Overall, I think climbers get way too caught up in saying "this rubber sucks, this other rubber is better." Or just generarically describing a rubber compound as "sticky" with no situational context. This is pretty unhelpful. I think most modern rubber compounds are pretty good, but their relative performance is situationally dependent based on hold type, rock texture, temperature, climber weight, and personal preference. One rubber may be much better than another for the climbing you do, but it's about figuring out the situational details that work for you.

For instance, I have 2 pairs of TC Pros. One is my larger pair and has the original Edge rubber. I use this in warm weather when my feet are bigger (hence larger size) and since in warm temps you want the harder rubber. Then I have a pair that is a half size smaller and resoled with C4, that I use in cold weather. They both perform great in their respective use cases. C4 at 40 degrees feels pretty similar to how Edge feels at 75 degrees.

 It's possible that the rock and conditions that OP has been climbing in SoCal (rough granite; warm temps) favors harder rubber like Edge. C4 gets really soft in the heat.

This was so incredibly helpful. Thank you for writing it all out and explaining it in so much detail. I’ll agree with you that I feel most frustrated with my C4 shoes when it’s hot out (which it has been lately). Never even considered that as a factor! Anyways, thank you again for your insight- it was very helpful!

As some context (and someone please correct me if i am wrong), from what i have read and been told, the C4 rubber compound changed when 5.10 was absorbed by Adidas. I used to have several pre-adidas shoes and loved them. the rubber lasted forever and i only had problems with the heel loops breaking. Once Adidas got a hold of them, they pushed manufacturing over to asia and the quality (and rubber compound) tanked. i had a pair of the new hiangles and they delaminated within several weeks compared to my old hiangles that lasted almost a year of daily climbing.

Once Adidas moved over seas, the old factory was taken over by a company called Unparallel and they make many of the same shoe styles as 5.10 (See the UpMocc vs the Moccasym) and they are rumored to be using the old C4 compound because a bunch of the old 5.10 engineers are now with Unparallel. 

So TLDR: rubber changed when 5.10 was bought out and now i am no longer a fan...  

Nick A wrote:

As some context (and someone please correct me if i am wrong), from what i have read and been told, the C4 rubber compound changed when 5.10 was absorbed by Adidas. I used to have several pre-adidas shoes and loved them. the rubber lasted forever and i only had problems with the heel loops breaking. Once Adidas got a hold of them, they pushed manufacturing over to asia and the quality (and rubber compound) tanked. i had a pair of the new hiangles and they delaminated within several weeks compared to my old hiangles that lasted almost a year of daily climbing.

Delamination indicates a glue issue, not a rubber issue. Still a bummer, and potentially indicating a decline in manufacturing quality, but that doesn't indicate anything about the rubber.

My hypothesis: Stealth rubber is falling victim to it's own mythology. There was a time 20-30 years ago when Stealth was actually probably the best rubber available (the others have since caught up). 5.10 capitalized hard on this, heavily advertising on the superiority of their rubber. This built up a myth of it having near-magical properties. I think what happened was that when Adidas bought 5.10, climbers were dubious and stopped believing in that myth. And when in the reality the rubber did not have the superiority people previously believed in, they wondered if it had changed.

It's a good shoe rubber. But so are (most of) the rest of them. None of them have magical properties. Some are better in different situations though.

JCM wrote:

Delamination indicates a glue issue, not a rubber issue. Still a bummer, and potentially indicating a decline in manufacturing quality, but that doesn't indicate anything about the rubber.

My hypothesis: Stealth rubber is falling victim to it's own mythology. There was a time 20-30 years ago when Stealth was actually probably the best rubber available (the others have since caught up). 5.10 capitalized hard on this, heavily advertising on the superiority of their rubber. This built up a myth of it having near-magical properties. I think what happened was that when Adidas bought 5.10, climbers were dubious and stopped believing in that myth. And when in the reality the rubber did not have the superiority people previously believed in, they wondered if it had changed.

It's a good shoe rubber. But so are the rest of them. None of them have magical properties. Some are better in different situations though.

Im sorry i didnt clarify better. Not only did the shoe delaminate but the rubber wore down much faster. I got about 4-5 months out of the new post adidas shoes compared to about a year in the pre-adidas ones. and i used the post adidas ones later in my climbing career so one would think (and hope) my footwork didnt magically get absolutely horrible. The compound changed for sure and it not what it used to be. 

FYI adidas owns the name to stealth, not the compound. They pay for the use of the formulation and its the same as it ever was.
Supposedly RH is C4.

My understanding, like Mr Rogers and others, was that Adidas could only buy the name of the Stealth rubber and they do not own, or maybe even know, the original formula for the rubber. The only person who knows the original formula is the engineer/designer with ran 5.10 (can't remember the name) and who opened UP when 5.10 was bought out.

Likely Adidas' formula is no longer C4 and the rubber at UP is. From another thread about 5.10/UP connections, someone got a response from UP saying 

"Thanks for your interests toward UP (UnParallel) and UP was not split but UP was ex-team for 5.10 all most for 2 decades. After Adidas decided to leave out of USA to China for production and to Germany for operation, all ex-colleagues have launched UP  with all same stuffs, such as factory and original rubber compounds, so on."

Ian Lauer wrote:

My understanding, like Mr Rogers and others, was that Adidas could only buy the name of the Stealth rubber and they do not own, or maybe even know, the original formula for the rubber. The only person who knows the original formula is the engineer/designer with ran 5.10 (can't remember the name) and who opened UP when 5.10 was bought out.

Likely Adidas' formula is no longer C4 and the rubber at UP is 

Charles was still involved with Five Ten for a time after he sold it to Adidas so I am sure Adidas has the same C4 compound.  Climbing rubber is the big secret these days that it used to be back in the Boreal, Vertical days.  I am sure its pretty easy for chemists to reproduce the compounds these days.

Another hypothesis: rubber manufacturing is finicky and sometimes a "bad batch" happens. This is reported to occur with Vibram rubber also. One reasonably likely scenario is that even if the original C4 formula has not changed, the quality control could have suffered with the manufacturing move to China (a common scenario). So perhaps the good batches are the same as ever, but the consistency has dropped and bad batches happen more often than they used to.

This could explain the differing reports. All the C4 rubber I've used in the last 5 years (on new 5.10 shoes and on other shoes resoled with C4) has been great; no complaints. It holds up well and performs as expected.  But perhaps I've just gotten lucky and gotten good batches, whereas Nick A's negative experience was because he got a bad batch.

I have no definitive evidence for this hypothesis, but it does seem to fit the observations.

If this drop in QC is true, that is an issue worth noting if thinking about buying 5.10 shoes or resoling with C4.  But again, just speculation at this point.

Back when I started climbing, C4 was the rubber of choice. Later I switched to LaSportiva. A couple years ago I had my TC Pros resoled with C4, they sucked! Last year I had them resoled with RH and I love them. Slightly softer than the original XS-Edge but they edge well and smear amazing. The XS is still better at standing on dimes.

A buddy of mine resoled a pair of Crawes with UP-RH and he was amazed at how much better they climbed face.

All anecdotal but ... 

Kevin Mokracek wrote:

Charles was still involved with Five Ten for a time after he sold it to Adidas so I am sure Adidas has the same C4 compound.  Climbing rubber is the big secret these days that it used to be back in the Boreal, Vertical days.  I am sure its pretty easy for chemists to reproduce the compounds these days.

Correction to what I said, Adidas bought the name and very well probably has the formula, however they only have exclusive use to the name, not the formula

I had a pair of the yellow Quantum Velcro, loved them in and outside. Got another pair after they moved manufacturing to China, one was 1/4 size smaller than the other, and the rubber was so slick I was slipping off everything in and outside. Got rid of them. Then a bit later got a pair of new white HiAngles and they were the stickeyist pair of shoes I've ever worn. I'd set them on the carpet and they'd pick up all the cat hair lol. Either they put cheaper rubber on the lower end shoes now, or the batch quality is all over the map imo. 

JCM wrote:

But perhaps I've just gotten lucky and gotten good batches, whereas Nick A's negative experience was because he got a bad batch.

I would honestly believe this. i bet they had a time during the transfer period that was just not up to the normal standard because of all of the moving and transfer of knowledge. And maybe QC just isn't what it is anymore once the company changed hands? no idea but all i know is that the rubber changed and im not a fan of the new stuff... maybe in the future i will try again!

Woah, that’s really interesting that Grip2 and Edge are so similar by the provided metrics.

My personal gripe is with Trax SAS right now. Good traction, but comes off in a shoe width smear on my newly made wood holds.

John Clark wrote:

Woah, that’s really interesting that Grip2 and Edge are so similar by the provided metrics

It also appears as though Grip is softer, thus potentially higher performing than Grip2.