Rene HERSE Cycles tech info.

In MTB circles 26" is generally considered obsolete and retro.
I started a thread at MTBR on this and 5k views in 3 days, and 10 pages long. Lots of 1990s MTB coming out of storage.
It seems that one thread there has more interest in old bikes than this whole forum

You should take up snoring.
If the other forum is so good, go there. I find this forum excellent for all aspects of cycling. There are some very nice and clever people here.
 
Could you be more specific please. Did you go wider than you had before, and went faster too? I think that's the big question here.
Also which casing did you use? The standard, or the reinforced version? I'm going straight to the lightest one to see what this is all about.
Ok. This might be long.

I run all of these with tubes, because it's easier and I'm allergic to latex. So I don't want to use latex sealant.

I've run RH Extralights on my gravel bike, 700cx35, and 650bx42 and 48. (in that order, obviously new wheels between the 700c and 650b). I also threw on a 48mm Gravelking TLC on the rear for a few hundred miles when I needed a local replacement between the 42s and 48s. It also had a couple of other pairs of tires on it for a ride or so before the RH ones came in.

The tandem has had (last 5 years anyway) some Schwable 26x40mm City Jet (kevlar) on both ends, then RH 26x44mm Natchez Pass EL (front) and 26x53 Rat Trap Pass Standard (rear), then a new set of Standard weight, same sizes, and now due to failure I'm running a Schwable 50mm Kojack on the rear. The 44 is as big as I can fit on the front with fenders, and the RTP is about the same on the rear.

Performance wise, the only apples to apples comparison I really have is the Schwable -> RH transition. The tandem went from ~15.75mph average to 17.25mph average over ~6 similar rides on either side of the change. The previous max average speed for a ride was in the 17.2 range, so there was a significant step jump there. The only other changes at the time were new fenders with better clearance and new bar tape, so I don't think that either of them were a significant contributor.

I don't think I've been able to tell the difference between the EL and Standard on the tandem, but I've never gone straight from one to the other.
I'm not sure about the Kojack though, because it went on at the end shoulder of the season and fitness changes make that difficult to tell. We're certainly not as fast this year as last year, but that's training as much as anything. Running the RH tires at 45psi is certainly more comfortable than the previous ones. 45 psi is basically high enough to avoid pinch flats on driveway curbs, and high enough that the stoker isn't bouncing. I have to go higher than that on the rear when I have a slightly heavier stoker (70 vs 60kg).

Some things to consider:

I've had 10 of their tires. 3 are still on, 2 were retired with some life left due to the wheel change. 1 was pulled off with minimal life left. That leaves 4 failures, 2 RTP, 1 Babyshoe 42mm EL, and 1 Nachez Pass. The Nachez pass died after a good life when there was a particularly bad puncture that cut the threads, and the carcass started to pull apart. Had to boot the tire for the rest of the ride, but the tire was done for after 3k miles.

The other ones though -- could have been doing it wrong, could have just been that they're delicate tires. The rear 42mm tire developed a sidewall failure where the carcass essentially started to split along the periodic cross threads that hold it together. This led to cm long frizzy bits in the threads, which ate into the tubes (due to flexing) and eventually split the threads, so the sidewalls were cut. This was probably me running a super low pressure for most of the life of the tire -- basically avoiding noticable squirm under cornering and pinch flats, but significantly below where their tire pressure calculator would say for the low end. But it was comfy. This was ~2700 miles into their life, so not significantly short, but they could have gone longer.

The RTPs both failed when the sidewall started pulling away from the bead and delaminated. One lasted 2500 miles, one only 1k. I'm pretty sure that what happened here is that the tire didn't fully seat, and there was about an inch where the bead was stuck inboard on the rim, so the tire was bent over the bead more sharply then it should, and that lead to the outside threads fraying and then failing. After the first one, the dealer recommended higher pressure -- but that didn't really go well. They also insist that the brakes damaged the tire, but I'm 100% positive that wasn't the case. I think it's just that the 25 yr old rim that I had (with Velox Fond de Jante tape) just wasn't letting the tire seat properly.
 
Don't know too much about the science, I bought some Rene Herse after having a go on a friends bike. That was all it took to convince me.

They've been on my main rider ever since. I miss the tyres more than the bike whenever I take another bike out, they are so comfy and fast.
 
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I ordered the Herse Rat Trap Pass tires today 26x2.3" . I'll post back when they're on the bike.
The tandem went from ~15.75mph average to 17.25mph average over
Thank you for the speed reference. Since wind resistance squares with speed I used 16mph, and 17.5 mph and got 17.5/16=1.094x1.094= 1.195
Almost a 20% gain in net output. TBH I ride the Ebike mostly. The XC bike just back and forth to the park for some weight machines, and some sandy trails there. So durability isn't much of an issue for me. I suspect the tandem might have been overloading some of those racing tires.
I'll probably be running these down around 32psi.
Better grip, smoother ride, less inertia, and more flotation in the sand. Plus 20% more power.....
AND they're called Rat Traps!

I didn't use the word Randonneur to describe HERSE bikes because I don't speak French and have no idea what that word means.

Rene HERSE Cycles is a continuation company in the US now. Whether that is good or bad IDK. They seem to be carrying on his example of quality lightweight racing parts. The tires are the only thing there that interests me personally.
I'll be running them with tubes, and Mariposa Caffelatex tubeless tire sealant. I've had 0 flats on the Ebike with this and non reinforced Schwalbe Big Ben tires. The weight saving will be from just the tires themselves.
 
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I ordered the Herse Rat Trap Pass tires today 26x2.3" . I'll post back when they're on the bike.

Thank you for the speed reference. Since wind resistance squares with speed I used 16mph, and 17.5 mph and got 17.5/16=1.094x1.094= 1.195
Almost a 20% gain in net output. TBH I ride the Ebike mostly. The XC bike just back and forth to the park for some weight machines, and some sandy trails there. So durability isn't much of an issue for me. I suspect the tandem might have been overloading some of those racing tires.
I'll probably be running these down around 32psi.
Better grip, smoother ride, and more flotation in the sand. Plus 20% more power.....
AND they're called Rat Traps!

I didn't use the word Randonneur to describe HERSE bikes because I don't speak French and have no idea what that word means.

Rene HERSE Cycles is a continuation company in the US now. Whether that is good or bad IDK. They seem to be carrying on his example of quality lightweight racing parts. The tires are the only thing there that interests me personally.
Randonneur translates roughly to hiker. There is a thread dedicated to this sort of bicycle.
 
So that would be a Touring bike? It's not what I do. The bikes may be similar in many ways, but being in or around cities I don't need to pack any baggage. I do see an occasional loaded touring bikes around here. The Ebike is probably as heavy. But the XC bike is more like a gravel bike than a normal MTB. In fact I got the Softtail version to keep my feet from vibrating off the pedals on gravel roads. I tried Eggbeaters too. But not suitable for road use around here at all.
I've been running these shock absorbing pedals for a while now. IDK how much shock they actually absorb, but my feet stay put.
https://lunacycle.com/cnc-luna-pedals/ 1717802623445.png
 
I ordered the Herse Rat Trap Pass tires today 26x2.3" . I'll post back when they're on the bike.

Thank you for the speed reference. Since wind resistance squares with speed I used 16mph, and 17.5 mph and got 17.5/16=1.094x1.094= 1.195
Almost a 20% gain in net output. TBH I ride the Ebike mostly. The XC bike just back and forth to the park for some weight machines, and some sandy trails there. So durability isn't much of an issue for me. I suspect the tandem might have been overloading some of those racing tires.
I'll probably be running these down around 32psi.

So some of the caveats that didn't make it into the previous novel:

Since wind resistance is basically proportional to cross sectional area * v^2, a tandem has ~ the same wind resistance as a single, with twice the power. It's really more like 40% more wind resistance, and probably not quite twice the power.

Rolling resistance is proportional to m*v, so it's likely that rolling resistance is proportionally more important for a tandem than for a single. This is even more important/pronounced on hills, where the limiting speed is really power vs mgh, and there's basically no wind resistance. Climbing speed dominates the overall average if you're doing anything remotely lumpy.

Looking at Bicycle Rolling Resistance, I'm seeing the Kojack at 25w, and the Snoqualmie Pass EL at ~15w. (I don't see a RTP, but basically, all of the RH tires with the same casing should be approx similar. Also, The BRR caveat is that their rolling resistance shows a clear inverse relationship with pressure, so they're only measuring 1 portion of the rolling resistance, excluding suspension losses. See: https://www.renehersecycles.com/the-science-behind-the-tire-pressure-calculator/ . ) So, if we do some math, running 2x Kojacks with 2x the mass should be looking at ~ 25w * 2m * 2 tires == 100w. If I drop in a pair of ELs, I get to 60W. (@ 18mph). I feel like the kojack is better than the cityjet, but who knows, as that one doesn't show in the database.

The gain you see will definitely depend on the previous tires. My gravel bike came with the worst tires I have ever used. (Vittoria Randonneur 700cx38?. They weighed 800g each, and it felt like riding through sludge). I probably put less than 30 miles on them, and they weren't even pleasant pumped up on the city bike. The gravel bike with RH tires, even at 12kg, is as fast as my 8kg carbon bike with okish 25mm tires. (literally, 6 second difference over a 2.5 hr hill workout a couple years back)

Bottom line -- I like the tires, I'll keep using them on any bike I have that they fit on.

I didn't use the word Randonneur to describe HERSE bikes because I don't speak French and have no idea what that word means.

Rene HERSE Cycles is a continuation company in the US now. Whether that is good or bad IDK. They seem to be carrying on his example of quality lightweight racing parts. The tires are the only thing there that interests me personally.
I'll be running them with tubes, and Mariposa Caffelatex tubeless tire sealant. I've had 0 flats on the Ebike with this and non reinforced Schwalbe Big Ben tires. The weight saving will be from just the tires themselves.
Randonneur would be not-racing, but long unsupported rides. The classic brevets are 200,300,400,600, and 1200 km rides. The general idea is a bike that can go the distance, in comfort, at speed.

Some disclosure -- I know/knew Jan back in grad school. We rode together for the UW Husky team when I was there for a Civil Engineering masters and he was there for his PHd (Geology IIRC). I trust his experimentation, knowing some of the people that he's collaborated with on it. I'm not sure I buy the details of all of his physical explanations, but some of that may be lost in translation for a non-engineering audience. There have only been a couple of times where I think what he's saying isn't really correct, but it's mostly details and not the big picture.
 

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