Caliwild

Hi,


Looking for suggestions for a 40c tire for my Jamis Renegade Exploit. I'm in Southern California so our gravel is more like dirt over hardpack (obviously dry conditions). I need something that will ride decent on the pavement, since I'll be riding to the trail (I won't be doing any hardcore mountain bike trails). The Maxxis Rambler, WTB Nano and Panaracer Gravelking come to mind. Challenge has some decent tires on their site too, as well as Soma. I wonder if a 42 Soma Cazadero would fit in the rear? Anyway, just looking for recent experience/suggestions... Thanks in advance.

shoota 

I haven't used the Rambler yet but since it's basically a 38mm tire you can compare it to other 38mm tires. I have the 40mm GKs on mine and they are more like 42-43mm on my rims. I can whole heartedly recommend them as a tire though. I'd get the 35 or 38mm GKs though. The other tire that I know of that is in the same class is the Bontrager CXO team. They set up tubeless really nicely and also perform well on pavement. But the GK is the toughest of the three and only slightly heavier. You won't be disappointed by it.

edit: The Cazadero will fit but is likely way overkill for your riding. Tubeless is key as well. I'm guessing you guys have goatheads out there..

shoota 

That being said it's really too bad Jamis cheaped out and specced our bikes with a crappy non-tubeless 30TPI 36mm Clement MSO. That would have been the perfect tire for you if it was the quality tubeless version.

edit: Others you should look at: MSO 36mm TR, Schwalbe G-One, Vittoria Terreno Dry

Caliwild

Thanks, guys. The Panaracer does look good... So no real benefit of going up to 40s? 38s are ok? I'm a roadie so no idea how wide is good on gravel...

shoota 

Let's just say that I ride in about the worst gravel there is and I'm thinking about going down a size from my GK 40s.

justin1138

I use a Nano(f)/Ramber(r) combo, and like it quite a bit. The Nano up front gives a little more cornering tread + I only needed to replace one tire when I got the Rambler. Off road these are nice tires. Lower pressures give a good amount of squish, which helps with the traction and soaking up the rough stuff. On pavement, they're just okay IMO. If the pressure is low for off road fun, they feel very sluggish on road. Especially going up hill.

shoota 

That sounds about right. If I were the OP and riding a lot of pavement and hard pack I'd be looking at something in the ~35mm range with minimal tread and light weight.

shoota 

The Schwalbe G-Ones look amazing. Merlin has them for $45, really tempting.

HTupolev

It... depends.

The primary purpose of high width is to allow tires to function better (better rolling resistance, not bottoming out against the rim when hitting bumps, minimizing sidewall exposure to the riding surface) at lower pressures.

Pumping the tire softer is useful for a few main purposes:
1-Suspension. If a tire is pumped stiff, rather than deforming around surface irregularities, it can transmit deflection to the rest of the bike, which is a big waste of energy (not to mention uncomfortable). The rougher the surface, the squishier the tire needs to be to perform well. This is why tires used on the polished wooden surfaces of indoor velodromes tend to be narrower than those used in outdoor road races; tires used on indoor velodromes can be pumped very stiff before suspension becomes an issue. Note that because good suspension performance means the tire is making more consistent contact with the ground (versus chattering off it), it can also improve handling.
2-Float. Unlike paved roads, gravel surfaces can be loose. If the loose stuff is deep, tires may "sink" into it, which can result in a big loss of performance and draggy handling. A squishier tire distributes the weight of the bike+rider over a wider contact patch; the lower pressure in the tire corresponds to the tire pushing with less pressure against the loose surface. The loose surface is thus less likely to give way, helping the tire "float" over it, rather than "sink."

On the other hand, there are a few cases where a stiffer tire is sometimes preferable. Most notably, cyclocross racers have noticed that in some muddy circumstances, it can help to use a narrower higher-pressure tire to cut into the mud and bite into more sure-footed surfaces below.

But all these things depend on complex particulars of the surface. Some surfaces called "gravel" are just fine on 23mm tires at 110PSI, and some are sloppy and uncomfortable on anything other than a fatbike. One time I even rode to a trail that someone had described as "pea gravel", and to my amazement, "pea gravel" turned out to be a rather strange phrasing of "clumpy sand underneath 3 inches of water."

How much width you want depends on other factors, too. Tires at a given squishiness deform more under heavier riders, so heavier riders may want to go wider than lighter riders to ensure good rolling performance and minimize the risk of bottoming the tire out. Tubed clinchers are more prone to pinch flats than tubeless or tubular tires in the event of the tire bottoming out, so the narrower the tire, the more benefit to using something other than tubed clincher. Different tires have different performance characteristics at different squishinesses; supple high-performance tires may perform very well even when squishy, while bombproof tires may need lower PSI to achieve a given squishiness, and may roll worse at a like-for-like squishiness.

The drawbacks of going wider, besides clearance:
1-Wider tires tend to be heavier.
2-Aerodynamics. On non-aero setups this is unpredictable and I personally don't think it's something to worry about that much, but, you'd completely throw away the benefits of something like an ENVE 4.5 AR rim if you stuck a >30mm tire on it.

As far as 38mm vs 40mm... that's a tiny difference, and not something I'd worry about either way. Other aspects of the tire's construction are going to be vastly more important that a 5% width change.
If you're on decent hardpack, you could probably go narrower, too. Or, if you're unsure, it's often a good idea to err wide. It'll probably work out fine either way. Whatever.

justin1138

+1

currently I have 32s on for more pavement use. Over the same off road terrain, it just means picking the line a bit more carefully and a little less aggressive cornering.

Caliwild

Wow, thanks for the info. Much obliged... So, perhaps I should go with 35 or 38s then based on everyone's responses... Can I get away with something like the Compass tires which don't have aggressive tread? Maybe like the Barlow Pass? https://www.compasscycle.com/shop/co...8-barlow-pass/


Or should I get something with a bit more tread? Thanks.

Lazyass

I have Pasela PT 35's, they come in a lot of sizes. I got them on last week and they're great on pavement and worked fine on the light gravel/hardpacked sand roads I hit. The folding bead version is pretty light and they have soft sidewalls so they ride smooth.




This is what 35's look like. That's about as big as my bike will fit but I really don't need anything bigger.

tangerineowl

You'd be fine using Compass file-treads on your road conditions.

HTupolev

The function of knobs is to bite into surfaces and grab/hook into them. If you're on muddy and clumpy stuff, knobs can definitely aid in traction. For most dry and rocky gravel, they don't seem to make much difference in my experience.

I use Rat Trap Pass Extralights on my gravel bike, and love them. They don't feel disadvantaged on our gravel roads, and when rides hit the pavement, they perform like the road tires that they are; the width ironically might be helping with that, as it means that their rolling resistance doesn't take much of a hit at all from being set to squishy gravel pressures.

Based on how you describe your gravel, I'd guess that wide road tires such as Compass would be fine.

Be aware that Compass tires have no explicit puncture protection features. That's not to say they're necessarily doomed to flat constantly; I've never flatted mine off pavement, and my only two punctures have been on very filthy winter roads. But, if you try to do something like ride them with an inner tube in goathead territory, you might be in for a bad time.

Cyclist0108

I use two sets of 40mm. Clement MSO 120 TPI for what you describe, and WTB nanos for when I want to go mountain-biking with my road bike. The Clements are ok on the road. The nanos are a bit of a drag on road, but transformative off-road.

CliffordK

Do you have problems with goatheads on your back roads?

Caliwild

Not really... although I've experienced them on a few trails south of here.

Caliwild

Other than comfort, is there a big advantage to the 120 tpi vs. the 60 tpi version of that Clement MSO? Thanks

gregf83 

I just bought 3 from Merlin for $29ea.
Excellent tires.

CliffordK

Ok,

In another topic there was the discussion about goatheads, and the suggestion of thicker the better, for example the Michelin Protek Cross Max which is an absolutely massive tire.

https://www.biketiresdirect.com/prod...-max-700c-tire

But, without that exposure, I'd probably choose something a bit lighter.

Caliwild

Narrowing down my choices. The Challenge Gravel Grinder 120 TPI sounds good... I've had great luck with Challenge tires on my road bikes. Anyone have experience with this one?

Cyclist0108

They wear out faster and are more expensive.

Lazyass

I wouldn't want to ride those on pavement, especially cornering. And I doubt that tread would last long unless you're off road most of the time. I'd probably wear the centers smooth in a month.

Caliwild

Thanks... that makes sense. I contacted Jamis directly and here's what they said: "We haven’t had any feedback about 40c tires not fitting the Renegade Exploit - the frame/fork should clear up to a 42 (and even650x47). Most of us at Jamis use the Clement X’Plor MSO 700x40 on the bike, but there are a number of excellent tires out there in that size right now."


Sorry for all the questions... One more: Would you go with the Compass Barlow Pass or the Clement X'Plor MSO? I know, completely different tread but trying to figure out this new world of gravel/dirt!

shoota 

Not the same ones though.