Bontrager G5 Tire - First Look

Sep 11, 2012
by Mike Levy  
Bontrager unveils an all-new downhill tire developed by legendary tire designer Frank Stacy and the athletes of Trek World Racing, dubbed the G5. Proven by Trek World Racing’s Aaron Gwin throughout the 2012 World Cup calendar, the G5 blends Stacy’s knowledge of tread and compound design with the performance demands of the two-time-defending World Cup champion. Built specifically to maintain consistent, predictable traction at top speeds over the gnarliest of conditions, the G5 works best in loose terrain, regardless of whether its bone dry or pouring rain. Riders will instantly notice the new tire’s highly predictable nature when getting sideways through rough corners.
Bontrager G5 tire

Bontrager has invested an incredible amount of R and D in tire design in the last year and the G5 is a prime example of the huge payoff we're seeing from it,” said Frank Stacy. “Collaborating with Trek World Racing this year gave us the feedback of world-class athletes who can constantly push the tires to their limit, and are always searching for that little bit more.

Bontrager G5 tire

The G5 got its first win at the Fort William World Cup this year, when Gwin needed predictable cornering traction for the course’s notoriously varied terrain. After just one practice run on the new tread, Gwin kept the G5 prototype on his rear wheel for his race run and rode it all the way to the top step of the podium for his first win at the legendary World Cup track. He continued the G5 momentum, riding them on both the front and rear to wins at Mont Saint Anne and Windham.
bigquotesIt's not often that a company allows you to design a product exactly the way you want it. Bontrager gave me that opportunity with the new G5 tire and it turned out to be the best tire I have ever ridden. - Aaron Gwin

Bontrager G5 tire




We'll be reviewing Bontrager's new G5 downhill tire shortly, but in the meantime we sat down with the man behind the G5, tire engineer Frank Stacy, to pick his brain on tire design and rubber compound.


    What is the idea behind manufacturing the same tire out of different compounds?

Technically, two tires aren’t the “same” if they do not share compound. Other variables include casing material, bead material, as well as the rubber compound. When we develop a tire, we study its intended use and then determine the “spec” based on that intended use. A great example is the Bontrager XR4. The 26 x 2.2 Expert looks a lot like the 26 x 2.2 Team Issue, but they ride like two completely different tires. That’s because they are.


    We often see tires employ compound designations such as "50A", among others. What do these numbers actually mean, and how much of a difference is there between them?

Using 50A compound as an example: the “50” is the durometer, or rubber hardness. The higher the number, the harder the material. The “A” stands for A-Shore. Shore is a measuring scale developed by Albert F Shore, and is used by almost all tire manufacturers across multiple industries (bicycle, motorcycle, auto, etc.). There are twelve different scales, with A being used for softer rubbers like tires. Contrast that with D, which is used for things like skateboard wheels. The numbers in this system can be deceiving because, due to the nature of all tire manufacturing, a tire labeled a given durometer can vary up to +/- 3 durometer points based on the manufacturer’s formula. Formulating a tire compound involves carefully selecting the right proportions of four main ingredients. These are:

• Polymer. This is the rubber, but there are different types of rubber: natural, SBR, EPDM rubber... or even a mixture or all three.

• Oils. There are several types, but the type and percentage of oil depends on the tire’s intended use. Oil also has an effect on tread life and traction.

• Carbon Black. This is what makes the rubber black but it also adds strength, wear resistance and has an effect on traction. White carbon is used for coloured tires and does not have near the wear resistance of carbon black.

• Fillers. These are used to prevent cracking and increase ease of manufacturing.
Bontrager G5 tire

    How much effect will a tire's compound have on performance relative to tread design, casing, width, etc?

Rubber compound plays a key part in a tire’s overall performance, but it's only part of the recipe. It's a lot like making a cake... if you don’t get the proportions right, it won’t taste very good. That’s why it’s so difficult to judge a tire by one variable (tread design, weight, durometer), and one reason why the expertise embedded in every Bontrager tire results in a consistently incredible experience.


    How does rubber rebound speed relate to how soft or hard the compound is?

Again, this depends greatly on a tire’s intended use. Typically, DH tires use a very slow rebound formula to reduce deflection on high speed terrain. The downside is that the slow rebound rubber typically means higher rolling resistance and faster wear. Harder compounds typically roll faster and last longer but can have less traction on some terrain. Bontrager has two new rubber compounds that have bridged the gap between slow rebound and fast rolling. These new compounds are found in our Team Issue XR1, 29-1, XR4, and 29-4 tires.


    Is this something that the average rider can benefit from, or does one need to ride at a pro level to experience it?

While Bontrager tires are developed with professional athletes, we also test extensively at other levels of rider ability. We also test on different types of terrain, in both wet and dry, and everywhere in between. Testing at the professional level is crucial because those riders can push the tires beyond the limits of most people. The average rider can’t tear a tire apart in an afternoon, but Aaron Gwin certainly can. This level of expertise and development certainly benefits the average rider. Although the average rider doesn’t ride even close to that hard, he or she ends up benefitting greatly in areas like rolling resistance, wet traction, and puncture resistance.

    Does tread design have an effect of a designer's compound choice?

Yes, especially in terms of overall knob dimension (height, width and depth). If you’re intending to use a very soft rubber compound, you'll need to support the knobs by design otherwise they will tend to flex easily. Or if you’re intending to use a harder compound, you can minimize the overall knob dimensions.


    What is the purpose of a tire using multiple compounds?

There are several options for multiple compounds. The most common is the dual compound where you have a harder rubber in the center that rolls faster and wears longer, with a softer rubber on the shoulder knob for higher cornering traction. Typically there is a 5 - 10 point difference in rubber durometer, center to shoulder. Bontrager Team Issue XR1, 29-1, XR4, and 29-4 tires use this technology.

www.bontrager.com


101 Comments

  • 79 1
 Can we get more of these articles up? Us nerds like them =)
  • 7 0
 CST make these tires as per Bontrager specs, just like they do for Maxxis and Specialized tires as well....
Thats why they kinda look like the Minion, as does the Spec tires...

I think they look solid and I too like the tech jibberish to support their claims.
Its all down to the subtle changes in the desired spec.
Compound
Sidewall Cassing
Knob Size, Ramping Angles and positioning

www.csttires.com
  • 2 0
 CST is the parent company of Maxxis
  • 1 0
 CST also makes Kenda iirc. Their first foray into the MTB tire market under the CST name had a bunch of duplicate models that looked exactly the same as Kenda models.
  • 4 0
 Hmm, I'm pretty sure Kenda is its own company, but I could be wrong
  • 1 0
 This got me stoked, I'd love to get my paws on G4s but here in germany there dont seem to be any. Now theres this mad G5 thats got me even more stoked!
  • 2 0
 how much is this?
  • 4 0
 It's weird that CST makes all these tires for high-profile companies with solid reputations yet their advertisements (in BIKE Magazine, for instance) absolutely look like dogmeat. They are just garbage. Their marketing people really ought to be replaced. It appears that they buy stock images and try to keep the copy to a minimum. I'm not necessarily going to be swayed by an ad for tires - I generally know what I like - but BIKE has so many great pics and photographers and articles, bad content like CST ads really stands out.

Maybe I *would* buy CST tires knowing that they're made by a big factory that is used by the big S and Maxxis etc.
  • 2 0
 Cheng Shin Rubber makes tires specifically for Maxxis and Cheng Shin Tires (CST). I don't know about Kenda, but I would not be surprised to know that they actually do own them, or Kenda's patents on their tire designs we're bought off by CST allowing them to copy them perfectly. That being said the designer for Specialized's tires used to work at Maxxis, so nobody should be surprised as to why Specialized's tires look almost exactly likes Maxxis.

As for Trek, the idea behind the design is pretty simple, take an already existing and well renowned design, and improve it the way You want it. Really like the look of this tire, and definitely love the whole tech/geek info that they're letting out here. That being said, I wouldn't put them on my bike unless I actually bought a Trek, but it's good to see them try to innovate and make a good product.
  • 2 4
 There are many tire sweat-shops. Mostly Malaysia, Indonesia, China. Mostly the ultra cheap variety. Cheng Shin gets specs from the marketing outfits like Spec, Bontrager, Intense etc. Development happens at CST. They are capable of doing knockoffs and lookalike but not original stuff, Kenda comes to mind. Maxxis highend stuff like the Minion derivatives owes to motorcycle engineers. This is why its good. Schwalbe and Conti do their own thing. Not that great and both have their plants in Indonesia. Tires are not really patentworthy anymore. So no buy offs. Oh and thanks to Kenda I spent 3 hours in ER last sunday. THis knockoff has very little threshold. Just not like a Minion. In my eyes a design fault.
  • 4 1
 knob size...*sn*gger*
  • 1 0
 I totally agree. This was an awesome write up. I love reading about the technology behind the bike parts we enjoy.
  • 1 0
 the price?.... ah who cares anyways, the bike is already a few grand, how much bigger of a hole could i put in my wallet anyways
  • 1 0
 Bontrager tires are priced very affordably compared to a brand like Maxxis.
  • 1 0
 There not trippin. They got maxxis an shit. They can care less
  • 23 0
 Sick minion butcher highroller!!
  • 4 5
 totally a minion butcher high roller. the best features of all three in one tire. i'd rather just get a minion, butcher, or high roller though
  • 6 4
 If you're loaded with money, go with Maxxis. If you're not, just like the majority of us, buy a G4 or G5. I've ridden Minion 3C all my life til this year. I switched to the G4s and not only do they roll faster than the Minion 3Cs, they have better sidewall grip in rocky corners, cost almost half as much, and last much long (the center knobs stay intact) on DH trails then any Maxxis I've ever owned; And I've owned many.

Cuban, I dare you to pick up a pair of these tires and see if you have the same experience! And with the money you save, treat yourself out to a couple nights at In-n-Out burger.
  • 2 1
 love in n out
  • 1 0
 Just a thought, but... if they roll faster and last longer then they're made of a higher density rubber compound (assumed because the center row is so similar to a Minion/butcher) which means they won't be as tacky on slippery surfaces. Right?
  • 2 1
 @dingo-dave nah, they have similar tread patterns, but if you look at them in person they have different block heights and width and lengths. plus the spacing is different. the more open the spacing the better in rocks and mud (look at mud spikes and how open they are) this tire is meant for rocks, shale, mud, and the shittiest surfaces you can find. the G4 is a fast more DHF type tire, tighter knob grouping, more ramping.
  • 3 0
 Thanks for the clarification... 2 years later
  • 1 1
 welcome
  • 9 3
 Gwin was smoking everyone last year on Maxxis High Rollers, they are much closer this year on when Gwin has been on the Bontrager G4/5.
Vote with performance I say....
Saying that, I use MM's because they are good for most conditions.
  • 2 0
 i doubt the difference is the just the tires though...but...lets wait to see what hes riding next year...highrollers are surely suffice til then
  • 7 0
 I honestly doubt it was down to tyres as a lot of the competition was probably running the same tyres as them as well.

And it wasn't close in val di sole , remember.?
  • 1 0
 now there is clarity, i thought Gwin was sponsored by maxxis, i must have missed that memo
  • 1 1
 Gwin doesn't even use these tyres in competition does he? They should refer to it as "The tyre Gwin uses for photoshoots".
  • 1 0
 Yes he does , I doubt he has a contract with Bontrager saying photoshoots only , no racing.
  • 1 0
 I doubt it too, but I'm pretty sure I haven't seen him using any tyres other than Maxxis in races. Obviously he thinks winning is more important than using an inferior product you get paid to use. I agree with him.
  • 1 0
 the only race he switched to minnions was ft. william when he crashed twice in qualifying. i believe he mentioned something about a switch in tires causing some issues with that. and his contract allows him to use any tire he wants at his discration, pretty sure he used the G5's all year though.
  • 1 0
 The Minion and Bonty look the same to me anyway in the tread. The writing in that first picture is on the rim, not the tyre, and in all the shots with Bontrager on the tyre, so what? How hard would it be to put those stickers on a Minion?

Even if this tyre is good, that's because it's exactly the same as the Minion they copied it off.

It means nothing to me, I don't care what he uses, but I think he uses Minions all the time.
  • 1 0
 And the marketing hype is a joke. If you read through that list of notable features, it sounds like it's the perfect tyre for all conditions. I'm surprised they didn't claim it's great on ice too, and maybe even greased poles!
  • 2 0
 The bonty uses a 50A compound unless I am mistaken (I know it 50A in the text but never says the Bonty is a 50A)
50A is not great for the rocks in Norway, a little like 3C does not work great here/there either, hence whey Brits use super tackies (42A) still.
The Minion ST and HR ST are over 10 years old, amazing how good they still are all these years later.
I am a MM convert, but only because they are good for all but the deep mud.
  • 7 0
 Looks like a minion to me. must be good!
  • 3 0
 as long as they keep me rubber side down and they aren't extortionately priced then i dont mind i think only the top % of riders wil be able to feel the difference between these and something like the DHF, Butcher, Kaiser (self cleaning angled edges) GO AWAY its rubber! itll still flick a load of cr** at my face and itll grip most of the time go show the XC guys your research!

Yep, go neg prob me
  • 3 1
 The tire's knob shape and placement is the most crucial aspect of how a tire works. Sadly, this is the part that gets noticed last. In MX racing, a tire designed for a specific terrain type usually works well for its intended purposes and not really that good on other terrain. In dh mountain biking, most tire "engineers" still design tires without much thought to terrain types, front/rear wheel braking, corner braking, etc. If the tire has pretty knobs, combined with a lot of dumb luck, it will sell.
  • 2 0
 exactly my point they are still coning people into buying tires which are apparently much better where in fact they should be designing front and rear specific tires, as they encounter different conditions
  • 1 0
 Yes!! This guy ^ gets it
  • 3 0
 Everyone keeps talking about Maxxis but it was the Michelin DH Comp that everyone wanted and was copied from back in the day. That's what really started all this and that's what Nico rode...
  • 1 0
 youre right - the DHcomp 24 was the original HotS design also. i rocked those til they were discontinued. DH24 still one of the best tires around. this design eventually evolved into the Minion DHR.
  • 6 1
 I see nothing here that surpasses that of a minion, buy a minion
  • 2 0
 Good to have another intermediate tyre to try out , glad companys are making good allround tyres. Looks like these might challenge my MuddyMarys as the best allrounder I have used.
  • 4 0
 Agreed def looks like a minion, not a bad thing but why not just buy a minion?
  • 1 0
 Because Minion 3Cs are like $95, and these are probably $60-70. I've got to say here that the Specialized Butcher SX is a phenomenal tire as well. Also a Minion clone, and priced at about $65. There is no reason to buy a Minion at this point when it's $20-30 more than the clones, which work just as well for 90% of us.
  • 1 0
 Going on my experiences with the new XR4 these should be awesome. cant really comment on the whole "minion" copy opinion only to say that as stacy says, the compound can make a hell of a difference. Old xr4 vs new XR4 are worlds apart this is massively due to the tread pattern im sure but the compound seems noticeably different to my untrained eyes and hands. the new XR4 is far more controlled. so long as the price is right i cant wait to give these puppies a go for summer DH. Never gonna give up swampies in the winter tho
  • 1 0
 Completely agree on the XR4 change! Old one was a pile of cr*p ! New ones work a treat!

As do my Hans Dampfs actually...
  • 1 0
 I would like to see this tread available in a lighter casing/faster rolling compounds for those of us who don't live in a place to do DH but want an aggressive trail tire that doesn't require twice the effort to pedal around. I'm running the XR4 Team right now and it is a good tire, but I could go for a little more bite around the edges.
  • 1 0
 This is definitely not far off the Maxxiz Minion DHR2 which is a great tire front and rear. The blocky knobs hol well under hard cornering and the braking traction is phenomenal. I wouldn't mind hitting Whistler with a G5 to test it out.
  • 7 6
 made by Maxxis.

This is the first time in mtb tire history that a tire "designer" has used some science to back up a design, other than "oh that'll look good on the shelf" (Maxxis prior to the HR2 and DHR2)
  • 3 0
 Even the G4 looks like a Minnion tire, I always wondered if it was a copy or rebranded.
  • 2 0
 what makes you think Maxxis operates like that ?
They have been making offroad tyres for many vehicles for decades ... I'm sure they do more than go ' hey that looks grarly produce that tyre now ! ' ...
  • 1 0
 Ritchey markets their tires with a bit of science as well. they just dont have a huge mtn bike market.
  • 5 12
flag Protour (Sep 11, 2012 at 12:35) (Below Threshold)
 I would hate to own it just cause it says Bontrager on it, and no other in -house parts brand has less credibility or as bad of a reputation. And Keith Bontrager is a douchebag, hes the guy who thought the URT suspension design was the best design, so why would you want any affiliation with him?

It looks decent, so the Bontrager engineers must not have been
involved with anything but the logo design. Hopefully Trek just asked Maxxis to design a tire for them and said "sorry, but we can't be a part of this project cause we know from experience we suck at all things except frames."
  • 8 1
 I designed the HR2, so I pretty much have first hand knowledge of how and by whom these tires are designed. As in, let's make the knobs look pretty so they'll sell, not much to do with actual thought to specific types of riding and how the tire's knobs should perform. Like the HR1 was designed to serve a purpose, it just had some questionable design flaws that forgot about braking in DH applications. Motorsports are different, they actually use science to design and test those tires, especially MX tires. But even then you can ask what was your thinking behind that knob shape and be left with a made up answer. This Trek tire looks like a very good rear tire, but I would bet my house on it being very drifty up front.
  • 4 5
 That was Scot Nicol that thought the URT was the best design, not Keith Bontrager. Sorry Keith, you have made some good contributions to the industry before you sold out to Trek and destroyed your good name.

Good thing I'm a born-again Christian, repentance comes easy.

Didn't Gwin crash in his qualifier at Ft William and blame it on tire choice? And here it says the tire he rode on the front in the qualifier was the Bontrager, and that he changed to something else for the final. Funny they would
mention that in their big introduction of this tire.
  • 2 0
 @Protour: I'm sure there were quite a few people back in the day that believed in the URT, but you're probably wanting to evoke the name of John Castellano - father of Sweet Spot.

All of this has absolutely nothing to do with KB (or more directly: Frank Stacey), btw.
  • 2 0
 I agree with the good DrSanchez, not a good front tire, at least not in the loose stuff.
  • 3 1
 I also like his honesty in talking about how tires are designed. Face it, MTB tires are pretty subjective, unless you are talking about pure mud or solid hard pack. A tire might be great on one part of a course and not so good on another part where conditions are slightly different. Some tires might be great on flat corners but bad on off-camber turns. Gwin could win on Kenda's, Michelins, Specialized, or Schwalbe's. It's mainly a matter of getting used to your tires and getting a feel for their limits.
  • 1 0
 Hey Doc, Nice job on the HR2. sweet tire! The DHR2 is pretty dope too..

So, is the new Maxxis 2.4" case the same as the old 2.5" case?
they just adjusted the number spec down to more closely meet the actual size? They sure look similar. the old 2.5"s were small!
  • 2 1
 No idea, I don't deal with Maxxis anymore. Too many "engineers" with fragile egos over there.
  • 1 0
 the new 2.4" new casing is bigger than the 2.5" old casing.
  • 2 0
 So what they did here is make a tire close enough to a minion, so that gwinny can rock minions and paint bontrager on the side.
  • 3 0
 I think its funny that there's a maxxis minon dhr2 ad at the top of my page
  • 4 1
 Panaracer Smoke and Darts are still the best tires ever. need DH width version
  • 4 0
 No we need WTB Velociraptor DH.
  • 1 0
 Hutchison Coyote. And Onza Porcs for looks.
  • 1 0
 Wow dude I didn't think anyone would remember the coyote. Best rear tyre I ever had. I was only about 13 or 14 when I had them on my old Kona Stuff, they gripped like a wilder beast, especially in climbs, and they lasted for ages!
  • 1 0
 Well if there anything like the g4s Im running just now, there grippier than minions imo... MUCH better grip than high rollers. cheaper too. be a bit more open minded n give em a try folks. Smile
  • 2 0
 Most modern tire designs share many similarities. A different downhill tire will not make a non-pro a better rider. Practice will make you a better rider.
  • 3 0
 conti all the way , nobody gives them credit
  • 1 0
 This guy knows what's up. I tried the bontrager G4 and they were the worst dh tire I've ever used. Brutal cornering traction and utterly unpredictable. When they give, they're gone. I have Minion DHF 3C's right now because conti's had sold out locally. As soon as these minions wear out I'm going back to conti for good. Minion's just don't compare to the traction a rain king or der kaiser will give you. I get the impression that most people who love their minions haven't compared them with a leading contender (rain king, muddy mary, etc). I get that, it's so expensive to experiment with tire choice.
  • 1 0
 Your last sentence is exactly why I stick with Maxxis. I read what you say, but each time I try something different I get burned.

Forget test bikes, I want a shop with test tires. Or just ONE tire will do - shove it on the front and if I start washing out/understeering where I didn't before, then I know it's crap.
  • 1 0
 i'd like someone to test a tread similar to this/minions with a clearer defined upside down "Y" like tread, and share some results, only on the so called "A-A, A1" sections.
  • 1 0
 it all seemed cool until I read this: "and one reason why the expertise embedded in every Bontrager tire results in a consistently incredible experience."
  • 1 0
 Yeah they should not be promoting their new tires based on the performance history of their old ones, because quite frankly, they have sucked.
  • 3 1
 "we used a super tyre expert with extra science and made a minion"
  • 2 0
 thoughts on conti anyone ??
  • 1 0
 Yes, No.
  • 1 0
 Best available. It's weird to me that the Atherton's seem to ride a prototype that's not out yet, as the der baron and der kaiser are both outstanding. One thing the der barons suffer from is rolling resistance, which probably matters more to them than me.
  • 1 0
 Another Minion Derivat??? Why not ride the Original??
Nothing to look here I guess :°
  • 2 0
 I still say KENDA nevegal Tomac series ftw ! ! !
  • 2 0
 Nevegals are so much better in the loose stuff.
  • 1 0
 And Cali has some really loose stuff since the rain hates us Frown
  • 1 0
 Well the only way to know if they re good tire is buy them and try it.i think it gonna be my next purchase.
  • 1 0
 a mix of a minion and a Hig roller! seems good to me
  • 1 0
 looks like a trek. (yesssSSSSS!)
  • 1 0
 these tires are like Rob Warners ass...shitt
  • 1 0
 looks good
  • 3 3
 exact copy of a continental der kaiser. well done bonty!!!
  • 2 1
 as well as a minion DHF and specialized Butcher
  • 2 0
 The first thing that came to my mind was a DHF.
  • 1 0
 price?
  • 1 0
 minion dhr2 haha
  • 1 0
 looks very nice!
  • 1 0
 looks dialed
  • 1 0
 Tubeless? Weight?
  • 1 0
 gwins a fool
  • 1 0
 Nice high rollin minion!
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