Here we go...bicyclerollingresistance.com finally tests the Compass Bon Jon Pass

[Jan Heine]

Originally Posted by rain dogs

Can you comment on what "low pressure" is in your mind. I know that varies on volume (larger volume, lower pressure) but when we had a subscription to BQ, you've written and seemingly endorsed regularly riding at pressure close to the sidewalls collapsing in corners???

The main issue is braking performance. When you brake hard, you have all your weight on the front wheel, and you don't want the tire to collapse. That is also why the old advice of running your front tire lower doesn't make sense. These days, I run my 42s at about 35-40 psi on the road. I haven't ridden 25s in a long time, but I recall that the Open CX felt best at around 85 psi...

Jan Heine
Founder
Compass Cycles
www.compasscycle.com

[xnetter]

Originally Posted by tuscanyswe

Mine either. Very good puncture resistance actually.

My experience as well. I used to ride them daily on my urban commute and very few flats, even when I knew I had ridden over broken glass.

KJ

[ripvanrando]

Originally Posted by benb

The more interesting take aways from this for me are the puncture notes I guess.

I've been semi-scared to try these as I was on a group ride where someone had a horrific time with these tires. It was a road ride, no gravel or anything that would have been a torture test for a tire, and the rider with the Bon Jons flatted so much the entire group's tube supply came into concern. It was absolutely ridiculous. It was winter weather, and the group showed a really strong and great concern for the rider who was in trouble but the tires were really scary. Literally everyone in the group had taken a turn inspecting the tires looking for a hidden sharp object that was causing the repeated flats by the end of the ride. This was a group of really seasoned riders and no one could figure it out.

According to these tests the Bon Jon Pass tires have thinner tread than all but the most crazy "race day" road clinchers, that seems odd for a gravel tire. (E.x. the Specialized Turbo Cotton is slightly thicker.)

I have a set of Panaracer Gravel King 32c tires on my "gravel bike", they're a good tire but for our local definition of "gravel" they aren't terribly great. They're a good "bad road" tire for me, but the traction just isn't there for cornering off pavement.

One other thing I notice about these tests is he's testing the tire to a 42.5kg load. If you're like me and you take Jan's tire pressure chart as a religious thing you're going to have the front tire pretty low. And these tests show more rolling resistance at the lower pressures. But for the front tire the load is not likely to be 40kg+ for most of us.

I'm relatively large for a rider who is in shape & I have a tank like gravel/touring bike and I still don't exceed 40kg load on the front tire.

I ran them at 40-45 psi tubeless in front but changed to tubes because I got tired of pumping them up twice per day. Not one flat in about 4500 miles and there is still a decent amount of tread still there.

The rear would blow off at 60 psi tubeless, so, I ran them 60-70 psi with tubes but the casings of both ruptured spectacularly. Both. I am heavy....around 185-190 at the time.

Bicycle rolling resistance is spot on with respect to puncture and rolling resistance. I'd be more confident rolling around on 185gm Silk pistas.

[MrStevens]

Originally Posted by echappist

No. Unless if the TT is held on gravel roads

Its width leads to nontrivial aero penalty, and its rolling resistance isnt great compared to the truly fast tires

That certainly was my "seat-of-the-pants" experience when I TTed on them. No gravel sections though ; )
http://jeffsbike.blogspot.co.nz/2018...st-is-fat.html

[Ciavete]

Rode on these from San Francisco to San Diego for a charity ride. 600+ miles, 7 days. On a steel bike, of course!

Plus: Felt like I was cruising down the coast in a Lincoln Continental. I could have taken a nap on the bike (and sometimes almost did).

Minus: Four flats in 7 days. Fortunately the excellent ride crew was always nearby.

[rodney]

Originally Posted by Ciavete

Rode on these from San Francisco to San Diego for a charity ride. 600+ miles, 7 days. On a steel bike, of course!

Plus: Felt like I was cruising down the coast in a Lincoln Continental. I could have taken a nap on the bike (and sometimes almost did).

Minus: Four flats in 7 days. Fortunately the excellent ride crew was always nearby.

I'm curious. Tubes or tubeless? Extralight or regular? What sealant if any? I have bon jon EL in black on order. they will be set up tubeless. Going on a trek domane.

[Ciavete]

Originally Posted by rodney

I'm curious. Tubes or tubeless? Extralight or regular? What sealant if any? I have bon jon EL in black on order. they will be set up tubeless. Going on a trek domane.

Tubes. Extralight. Fantastic ride; maybe I was just unlucky. I'm certainly not giving up on them yet. Wish you well with yours!

[m4rk540]

Originally Posted by Ciavete

Rode on these from San Francisco to San Diego for a charity ride. 600+ miles, 7 days. On a steel bike, of course!

Plus: Felt like I was cruising down the coast in a Lincoln Continental. I could have taken a nap on the bike (and sometimes almost did).

Minus: Four flats in 7 days. Fortunately the excellent ride crew was always nearby.

Were you riding without a pump and tube or did you puncture multiple times on a single stretch?

[Ciavete]

Originally Posted by m4rk540

Were you riding without a pump and tube or did you puncture multiple times on a single stretch?

Rode with a pump & spare tubes. Flats were spread out over 7 day route.

[rodney]

Thanks for the feedback Ciavete.

[Ciavete]

Originally Posted by rodney

Thanks for the feedback Ciavete.

Sure thing. Paceline has helped me raise hundreds of dollars for charity; always grateful.

[rodney]

After 3 or 4 hundred miles on my Bon Jon ELs set up tubeless, I can positively say that I will not be going back to normal tires. After a couple of days of slow leaks the sealant did its trick and zero air loss. These tires are super smooth, easy rolling, fast, and no flats. Makes my bike much more enjoyable to ride. Most of my riding is on crappy pavement littered with debris and broken glass. Customer service is alive and well at compass tire. I'll be buying more.

[wallymann]

what about the roller being made of smooth/polished metal? that tire-road interface is nothing like what you'd see with smooth asphalt, much less the coarse stuff we experience in the real world. asphalt interactions with rubber, thus rolling resistance, must be massively different! this drum testing seems wack across the board.

[sailorboy]

Originally Posted by Jan Heine

The needle puncture resistance test isn't used much any longer. It's a static test that assumes you stop on the object. In the real world, rolling over a sharp object is a dynamic process, and many factors influence whether a sharp object punctures the tire. Most important is tire pressure: Lower pressure let’s the tire deform around the sharp object, rather than being flicking it up so it can puncture the tire.

However, there is little doubt that high-performance tires, including Compass tires, are not as puncture-resistant as stiff, belted tires like a Schwalbe Marathon. However, especially the wider Compass tires still have more than enough puncture resistance for most riders – but if you ride through glass or steel wires from exploded car tires a lot, then you might choose different tires!



Jan Heine
Founder
Compass Cycles
www.compasscycle.com

This jives with my experiences pretty much...most of my flats happen around my suburban/urban area regardless of tire choice and pressure, due mostly to the type of debris I encounter on those rides like Jan describes above. When I take my bikes to the 'country' or on rides like Ballers, D2R2 or other gravelly adventures I rarely if ever flat despite encountering more rocks etc. Most recently I've been on either stampede pass (32mm regular casing) or pacenti-branded 650B panaracer tires. A few times on various continental models as well, same experience.

[Mark McM]

Originally Posted by wallymann

what about the roller being made of smooth/polished metal? that tire-road interface is nothing like what you'd see with smooth asphalt, much less the coarse stuff we experience in the real world. asphalt interactions with rubber, thus rolling resistance, must be massively different! this drum testing seems wack across the board.

Roller testing for rolling resistance measurement is the standard used for all types of tires (automobile, truck, motorcycle and bicycles), and its validity has been confirmed many times over. (Also note that the BicycleRollingResistance test drum is not smooth, but has raised texturing).

As you are alluding to, rolling resistance can vary greatly depending on surface texture. Rolling resistance on rough surfaces can be much larger than rolling resistance on smooth surfaces. However, the relative difference in rolling resistance between tires does not vary much with surface texture. In other words, if tire A has less resistance than tire B on a smooth surface, then tire A will also have less resistance than tire B on a rough surface. So, even though BicycleRollingResistance uses a metal surface drum for their testing, the relative differences in resistance of the tires will correspond quite well with the relative differences in resistance of the tires when ridden on pavement. So if tire A tests better on the drum than tire B, tire A will very likely roll better on pavement than tire B.

The caveat here is that comparisons between tires can only be made if they are tested under the same conditions and protocols. The rolling resistance numbers from one test may not correspond to the rolling resistance numbers from a different, completely independent test. This is similar to aerodynamics testing, where drag comparisons can only be made if the same conditions and protocols are used between different tests.