DubT

I posted an update on the front tubeless installation here: https://www.bikeforums.net/showthread...ess-update#top

This is an update on the new Schwalbe One tires.

We had a long discussion over lunch and then later in the car. Chris, my dear wife and stoker, wanted a detailed update on the wheels and tires that I have on the bike. We have now ridden outside 3 times on the new Schwalbe One tires. The front is the tubeless and the rear is a tube type. Both tires are new for this riding season. The reason that she wanted to know is that she has noticed that the ride at her end is SIGNIFICANTLY improved. It feels like the tires are not hitting the ground, almost like we are just floating along. Her quote not mine. I have also made the observation that the bike is amazingly smooth and quiet. This is a bike that we have ridden almost 15,000 miles. The new Schwalbe One tires have done something very nice to the ride. I did not realize that changing tires could make such a dramatic difference. 23 front 25 rear.

Your Results May Vary!

waynesulak

For comparison what was the old rear tire make/model, tire width and pressure?

DubT

Wayne, I have been running Schwalbe ZX's both front and rear. 23 in the front and 25 in the rear. 115 psi in the front and 120 in the rear, latex tubes in both. On our ride today I lowered the from to 90 and it felt great, 117 in the rear, stoker just said that the ride was great.

Wayne, from Illinois, right now in North Little Rock, our daughter raced a road race and we rode the course in reverse (open course, with permission)

Bad1

Been using the Schwable "1" 700x28 clincher 245 grams, 80 gram tube on Hed Beligum C2 the last 2 months for training purposes, 90 psi front & rear, these are by far some of the smoothest rolling tires I've used, 28's probably factor into that, but up at speeds descending they are so rock solid feeling and fast I'm having second thoughts on throwing the 23's away. I think the "1"s will live up to the hype!

Ritterview

23 front 25 rear?!

Geez, aren't these kind of narrow for a tandem? We switched from Conti GP4000S 25 mm to Schwalbe Ultremo 28 mm, and that was a SIGNFICANT difference. I attribute just about all this difference to increase in width. We have Schwalbe One 28's mounted now, but haven't had a chance to ride (changing the freewheel on our rear hub from Campy to Shimano so to be able to mount an 11-32 11-speed cassette, don't ask). I expect that the Schwalbe Ones will be nice, but not dramatically different than the width identical Ultremos.

Comparing the ride quality between two different 23 mm tire models on a tandem, that's sort of like....

• Discussing which of Winchester or Remington .22LR rounds have the greater stopping power.
• Debating whether a Blackberry or a Treo is a better smartphone.
• Contrasting the delicacy of the bouquet of Night Train Express and MD 20/20.
• Differentiating between the nutritional benefits of Twinkies and Ho Hos.

waynesulak

Amen. Lower pressure is key. I expect part of the advantage of tubeless is the ability to run lower pressures. Wider tires however allow lower pressures with less tire deformation than a narrower tire at the same pressure. Deforming the tire is a source of rolling resistance so less deformation means less rolling resistance. Especially true with a tandem load. Possibly wide tubeless is the ultimate tire.

waynesulak

Basic tubeless question. Why do bicycle tubeless tires need sealant when auto tires do not?
It seems like the same technology and even at some of the same pressures. Run 40 psi in my car tires and I hear of tubeless mountain bikes running the same.

Bad1

To Funny!

DubT

Will, the difference between 23mm and 25mm is ONLY 2mm, really insignificant. At my weight of 140 pounds I can safely run a 23 mm front tire, our combined weight is under 300 pounds hence 23 front and 25 rear. When running tube type tires on the front we never had any pinch flats. I use the same wheels on both bikes so that is one reason for the 23/25 mix. According to HED, the 23 is a better match for the HED3 wheel, we need every advantage that we can get. The aero advantage is more significant on the front wheel.

As they say here in OK, it is what it is, I am happy, happy, happy and so is my stoker, which as you know is the most critical component of the equation!

I am beginning to believe that tubeless truly has advantages for tandem use. If I can ride tubeless and not have a blowout and if tubeless will withstand more heat than a tube type tire when braking then it is a win, win!

Wayne

DubT

Some people run tubeless with out the sealant, I have chosen to run the sealant as a preventative measure, it is SUPPOSED to seal punctures up to 1/4", if you have a flat with a tubeless tire you have to drain the sealant and install a tube, something that I do not want to do on the road unless absolutely necessary. I am also using rims that are not tubeless specific so the sealant is a step to help make sure the tire seals on the rim. So far so good, no discernable leakage.

wayne

Team Fab

I raced tubeless for years offroad and have yet to see sealant work on 1/4 inch hole. That being said sealant seems to help with smaller holes. However actual UST tires come with the inside of the tire coated with a rubber that seals the holes(maxxis anyway). UST tires are heavier than tubeless ready etc... so people convert regular tires to tubless using sealent(regular tires are not air tight) to save weight.

a trick to help seal the tires without sealant is to uses liquid soap on the bead.

tubeless tires blow off the rim much easier than using a tube if you over pressurize.

and roll off the rim easily at low pressures. i would not risk running ultra low pressures on road tubless ever. the cost of rolling a bead on a high speed corner is to great.

DubT

The tire that I am using is a tubeless tire! I used the Schwalbe installation fluid on the beads to help with the seating/sealing.

I am running 90psi, what do you consider to be ultra low pressure for a road application?

Carbonfiberboy 

On group rides, so far my impression of tubeless is negative. Of course we only get to see the sealant failures. But what a mess to fix! Doesn't seem to take much of a hole for the sealant not to work. I just look on in horror. I can see it for MTB.

diabloridr

If that's the case, why not simply run 23mm front and rear?

BTW, that 2mm change increases the tire volume by ~ 18% - not insignificant in my book.

DubT

But insignificant in mine! Your book, my book.

Ritterview

Our 295 lb team never suffered a pinch flat blow out with our Continental GP4000S 25 mm tires inflated at 120 psi until we did. Riding over a joint on a freeway overpass at 18 mph. Before I knew it, we went down, albeit quite slowly with just scrapes. Now while descending at 35 mph and hitting a road irregularity I think (and my stoker asks) ---was that a pinch flat? Should I stop to check? I'm more confident that it is not with 28 mm tires.





If 140 lb. UCI cyclists are on 25 mm tires, then a 300 lb. tandem team has no business being on a 23 mm tire. The risk of pinch flat by itself is enough to go wider. If they'll fit, I don't see any drawbacks to 28 mm tires. Doff those 23/25 mm's and don 28 mm's. Once riding these, even if you wanted to return to what you had, your stoker would forbade.

waynesulak

I have come to believe that tires and wheels are the first decision in a bike purchase. Tires and wheels have a big impact on how you can use a bike and how it will ride. Because of this the best upgrade is often tires and or wheels.

From what type of bike, mountain, cyclocross, rough road, smooth road or track. Tires and wheel size will determine a lot of the fork and fame design. It should be the first decision made when deciding on a custom bike and one that cannot be easily upgraded later.

Team Fab

I think that at 90 you are already getting there. I would not go below the recommended minimum.

Does your set up lose air over a 24 hour period. If so take that into consideration on long ride days.

Carbonfiberboy 

We used to run 23mm on our tandem because they were fast. It was noticeable, coming from 28mm Gatorskins. Very light tires, very high pressure: 140 front and rear. Also a 300 lb. team.

Not all 23mm tires will take that pressure, so yes, 23mm tire model does make a difference. TG used to run 23mm. A local long distance racing team, heavier than we are, ran the identical tires with great success. I'd call a record a great success.

However, a thin casing, high pressure, and a lot of weight per tire made for a delicate tire. Too many flats, too many sudden deflations from cuts. We went to 25mm at 115 lbs. Much better and still fast. Now we are running PRO4 Endurance 25mm, which measure 29mm on our new 23mm rim. We run the PRO4 tires at 110 on 19mm rims and 100 on 23mm. Bike still feels fast, and way fewer flats, which increases our real-time speed. 2 minutes is forever on a group ride, and 10 minutes is never see them again.

The only times we've had a pinch flat with any of these tires was when Captain screwed up and rode over a large rock with one side of a tire. Since one runs a smaller tire at an appropriately higher pressure, pinch flat likelihood remains the same. I do call "up" if I see it coming. I use tire size * pressure = 3000 for a tandem approximation. So we've had a couple pinch flats on the tandem as well as on my single bikes. Never an blow-off sort of pinch flat. I can't imagine how that could happen. If a tire can hold air pressure inside a tube, the tire should be able to hold pressure outside a tube. I don't see the difference. We had 3 heat blow-offs before we went to Deep-Vs, all with 25mm 4000s, but never had a tire come off the rim. Always got it stopped.

We still carry a 23mm light tire for a spare. Works fine. Gotta have a good pump, though.

Ritterview

If your asking about my photo, it appears more dramatic than it was. It was a fairly rapid deflation, but not a blow off. I didn't slow down quickly enough and the tire casing rolled off the rim, and I guess got caught in the caliper. After untwisting the tire we replaced the tube and rode home on it, and IIRC, continued using the tire until it wore out.

merlinextraligh

We've been riding Schwalbe One's (25mm) for about a month now, and they've been great. Noticeably better ride than Continental GP4000s.

The reason for narrow tires is aerodynamic. We usually TT on Zipp808 wheels with 23mm rims. According to the Zipp rep, the difference between 23mm and 25mm tires on our wheels (pre Firecrest) is about 8 watts per wheel, not insignifcant.

The aerodynamics of newer, wider rims, changes the issue a bit, in that some are optimized to work with 25mm tires. Zipp still recommends 23mm for their firecrest rims, but the difference between 23 and 25 on them is much smaller, than on the older Zipps. This is one of the main reasons you're seeing some pros go to wider tires, and they're still not doing it for TT's.

At a 350lb team weight, we don't have trouble with pinch flats on 23mm at 120psi, or 25mm at 110psi.

I do, however, like the 25mm for sharp cornering, just to have a bigger contact patch.

To put this in perspective, back in the day, we use to TT on 18mm tires on single bikes, and 20mm was not unusual for road races.

waynesulak

I like wide tires but must agree that aerodynamics is the one great reason to go as narrow as possible. If aero is a big concern then go as narrow as you can keeping in mind that one pinch flat and gets you dropped, kills the TT time or (for us) reduces the enjoyment of the ride.

I guess I am not sure of the 8 watts per wheel for us. Usually when I read the protocol for that kind of measurement, it is a 30 mph and often without a real rider. This applies to us only when we are in an aero tuck on a down hill or going into a 15+ mph headwind. No doubt wide tires cost us an aero penalty but with high drag riding positions I wonder how small a percentage.

diabloridr

Bingo.

I'd bet the wattage difference at the speeds most teams ride fades to noise.

rahill

This is really amazing - I pinch flatted a front tire on my single bike a couple of weeks ago (on a descent, in the dark, with cars following) -- 23mm Gatorskin, 110 psi. Not the first time I've pinch flatted on 23mm tires at 110 psi and my "team" in this case weighs 150 lbs. Before you ask, yes I try to avoid rocks, potholes, etc., generally ride on pretty nice roads, and keep my tires in good shape.

merlinextraligh

^ it's not like we've never had a pinch flat, but it's pretty rare. (last one I remember was hitting a major pothole while motor pacing behind a truck, not my brightest moment)

Some people just seem to ride "heavier" than others. We rode with a couple in Hawaii that couldn't have weighed more than 240lbs combined, and they pinched flatted 3 times in one ride.


In spite of being big, I tend to be light on wheels, avoiding crap, standing with loose knees and elbows when you do have to hit something.

Now if I could just convince my stoker to bunny hop the tandem.