The title is rather lengthy but that is because Compass has re-branded itself in the time period in which I have been hoarding these tires. When I received the tires as a birthday gift from my siblings 3 years ago, Jan Heine’s company was called Compass and the line of tires made for them by Panaracer of Japan were branded Compass accordingly. The renaming of the company occurred in 2019 but these tires are essentially interchangeable with newer stock except for the sidewall labels.
The Chinook Pass tires I installed remain a listed item in the company’s catalogue and can be seen here: https://www.renehersecycles.com/shop/components/tires/700c/700cx28-chinook-pass/
The tires are available in two versions, the Standard which has a slightly more robust casing (248 gm) and the Extralight (229 gm) which is the subject of this article. At the time of writing, the Endurance casing is not offered in the Chinook Pass line. The difference in the two offerings is about 20 gms/.5 ounce. According to the on line catalogue specification, the inflated tire measures 28 mm on a 20 mm rim with the Extralight being slightly larger. More on this later.
What prompted the tire change was the not so gradual deterioration of my Avocet Fast Grip slicks on my black Bertin C 37 randonneuse. Originally purchased in 2006, the bike looked looked this on Maillard Helicomatic wheels.
The following year, having collected the requisite parts and cash, I spent C $1,100 restoring and modifying the bike. One of the changes was a new set of Avocet Fast Grip 700C x 32 wire bead tires since I intended to do randonnees with the Toronto Randonneurs/Randonneurs Ontario. At that point, the bike looked like this:
The Avocets were excellent tires for the period, 300 gm (actual) in wire bead with a nominal 700C x 32 mm sizing. I say nominal because no tire I have ever installed actually measured the rated size once seated and inflated to the manufacturers’ specs. The actual size of the Avocets when inflated to 90 psi/6 BAR (rear) and 75 psi/5 BAR (front) was 28 mm when on Rigida 1320 alloy rims and the measurement was the same when I had new HF Maillard 700 wheels built with Velo Orange PBP alloy rims and then installed the Avocets.
The current problem with the Avocets was age. Over time, ozone attacks the rubber as does the UV radiation in sunlight and the rubber compounds off gas the solvents that initially keep the tire flexible and grippy. I knew 3 years ago that the end was near but the passage of time had made an option into an imperative.
The Avocets looked like this at replacement time:
Between tread cracking and accelerating sidewall delamination, it was past time to replace the tires but I hate installing Kevlar beaded tires so I had procrastinated. Since I was installing new Michelin tires on another project, I decided I would simply do the Michleins one day and the Compass Chinook Pass the next.
The next day, the 300 gm Michelin Dynamic Sport wire bead slicks went onto Rigida 1320s in a straight forward manner. (Very nice, well made, reasonably priced tire.) The next day was the turn of the Compass tires. At the start, they looked like this in the bags with the Extralight clearly marked on the packaging. At the time this is written, a Chinook Pass EL tire is US $83/C $112 so I was appreciative of my family’s generosity.
Unpackaged, the clean molding and careful workmanship became quite obvious with the tire even having an easily pealed cover over the sidewall model label visible as a shiny surface over the label in the next photo.
At this point the difficulties began. These tires appear to be flat molded which means there are no stresses built into the casing as the curved tire is molded to the wire beads. Instead, the Kevlar cord beads flex and flop around since these tires have exceptionally fine fabric in the casing. The tire was a challenge to get onto the initial rim bead of the front PBP rim which I thought might be due to my retention of the original Velox fiberglass reinforced rim tape (outstanding product, by the way). Nonetheless, the tire succumbed, seated itself on the rim and I began the tube installation. The tubes were butyl Kendas with 35 mm Presta valves in 700C x 28 sizing. These had come out of the Avocets and I foresaw no problem with their reuse.
Problem. The tubes could not be made to fit within the Compass’ casing. No matter what, as the second bead began to seat, the tube would pop out somewhere due to the flex in the Kevlar. After an hour of trying, I determined that I would use a 700C x 25 tube since that was what I had on hand but I was quite concerned about durability since over speccing tubes into larger casings leads to the tire being flat prone since the inner tube is overstretched and more likely to puncture, tear or have valve stem separations.
And the wretched tube slipped into place without pop outs or unseating as though it had been made for that size of tire. The final seating of the tire onto the rim was brutal. The Kevlar seems to not stretch or accommodate and it required three tire irons and brute force to get the tire seated. (As an aside, I talcum powder all my inner tubes and the interior of any tire to prevent the tire/tube combination sticking together. This is not done universally anymore but I have seen adhered tube/tire combos and this is an easy precaution.) Full marks to Compass/Rene Herse as a full colour, highly detailed, multi page photograhic installation guide was included with the tires that looked like the the illustration on the left. The newest version is linked here.
Once on the rim, lightly inflated and carefully seated in the rim beads (as per the illustrated instructions) the tire was gradually brought up to pressure while repeatedly being checked for bead seating and potential rim blow off. The front tire’s initial pressure was 80 psi/5.5 bar and the width was 25.5 mm measured with digital calipers.
The rear tire and tube installation went much smoother without the long and frustrating attempts to stuff an overly large tube into a too small tire casing. Nonetheless, the final several inches of the the Kevlar bead were a real struggle and a tire jack would have been quite useful. Again, the tire was inflated in easy stages, the tire bead to rim seating repeatedly checked and then the tire brought up to full pressure. For the back tire this was 100 psi/7 bar. At that pressure the tire’s width was 25.7 mm. It is clearly evident that tires are over measured for width calculations and therefore, it easily explains why the wretched 28 mm Kenda tube would not ever have fit into the Compass/Herse tire casing.
I installed the newly shod wheels into the Bertin’s frameset and allowed them to sit for a week, intending to check air pressure leak down with the new butyl tubes. After the full week, the front Chinook Pass was at 60 psi /4.1 bar and were 25.4 mm on the Velo Orange PBP alloy rim. The rear tire was at 75 psi/5.2 bar and measured 25.7 mm.
As a rider, with specific ideas of tire size and pressure related to your personal use of your tires, you should be aware that tire sizes seem to constantly end up undersized when installed. The original Avocet Fast Grip slicks were labelled as 700C x 32 but measured 28 mm when installed and at pressure. The Michelin Dynamic Sports I mentioned earlier sized 700C x 23 measured 22 mm at pressure. And finally, the Compass Chinook Pass tires, installed on the PBP alloy rims, measured 25.5 – 26 mm when at the final pressures I settled on for my immediate riding use. When selecting tires, it may be prudent to actually up size your tire selection when intending a direct like for like replacement. If you want 28s get 32s, if you want to up size then go to 35s, but whatever you select, be aware that you will not fully know your tire size until the product is installed, set at your selected tire pressure and stretched out.
The Bertin now looks like this with the Compass/Rene Herse Chinook Pass tires installed: (click to enlarge for details)
As you can see from the profile photo above, the tires have very accurate molding and follow the fender contours at least as well as the Avocets. What worried me, initially, when I saw the effectively smaller tire sizing was that there would be visual gaps between the tires and the fenders. Thankfully, the tires sit within the fenders and fill them sufficiently full enough that you cannot see through the fenders which also means reduced splash from spray because the fender edge drop will be sufficiently to hold water within the fender.
Having done the installation and then the one week long pressure retention check, I was rather in a hurry to get out on the bike. I set the front tire pressure to 75 psi/5.1 bar and the rear tire pressure to 90 psi/6.2 bar. On the day of the ride I weighed 185 lbs (84 kg). The ride was on a previously ridden, fairly flat course and the wind was the same velocity and direction as the ride the previous week before the tire change. A disclaimer, if I may. I was sceptical of the enthusiastic and effusive comments I had read of the Compass/Herse brand tires performances. My experience with the Chinook Pass ELs is that this tire line is worthy of every ecstatic comment made about them. They are absolutely amazing. They roll with incredible ease, they swallow pavement buzz equally amazingly and they attenuate impacts very well indeed. There is a clear differentiation coming up through the seat and bars as you roll over different paving textures but it is muted. One odd difference where these tires under performed compared to the Avocets was on freshly rolled black asphalt. On the course I rode, fresh black top had been laid down on two side streets. I rode up one and down the other to even out wind effect and the Chinook Pass tires rolled slower than the Avocets. I put it down to the fresh, sticky rubber in the Compass tires compared to the older, dried out Avocets adhering easily to the oil and tar in the fresh paving. In every respect and by substantial margins, the narrower Compass ELs out performed the old, wider wire beaded Avocets. If you are considering randonneuring, if you just love the ride of a quick supple bike, if you wish to improve performance for the cost of a pair of tires buy these things, they are absolutely excellent!