Average speed and a few other thoughts

JRA

Well-Known Member
Average speed is a benchmark of sorts in the bicycle world and you see it bandied about often here and elsewhere. I know I always go for that figure at the end of a ride to see what it says, but I really am more interested in my wh/mi figure and keeping that in the mid teens as that relates to how far I can go on a charge and speed, terrain and the elements all play a part in it. As an example here are the stats from my ride today which was on fairly flat terrain, mostly pavement but about 8 miles of gravel and a nice breeze.
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Over time this has settled in to pretty much the norm for me and my style of riding which includes active pedaling at all times. I usually feel pretty good about a 20.7 average speed but after reading about the Dirty Kanza 200 mile gravel race that took place this weekend in Emporia, KS the ability of a fit rider really puts it in perspective

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The "Pace" is his average speed from start to finish including any comfort or food breaks. Very impressive considering the terrain being exclusively gravel. But another impressive figure to me was the psi he was running his tires at:

"Stephens is a member of the Panaracer Gravel Team, so naturally he was running Panaracer tires – opting for 700 x 40c GravelKing SKs. Set up tubeless on 28mm wide Stan’s NoTubes Avion wheels, apparently tires pressures were set at 26.5 psi for the front and 29.5 psi for the rear"

There has always been the belief that you must run high psi in your tires to decrease rolling resistance and get the best speed/mileage but with the advent of the use of wider rims along with wider tires it seems like that is being challenged. Tubeless also plays a big part in the equation also.

I have been using a similar setup since I built up my silver bike last year and find that due to the extra weight, at 41 lbs. probably close to twice the weight of a race bike, I can run in the low 30's dependably but usually at least 35 psi.. I still get decent speed/distance and the increase in absorption of road surfaces like gravel and crappy pavé and traction are what really make it work for me.

Also keep in mind that the above race was in the Flint Hills of KS notoriously known for flatting tires, flint was what the natives made arrows out of after all so flat protection is enhanced as well due to the sealant involved. I know that since using tubeless I have not experienced any flats whereas on my other bike with tubes it is kind of a crap shoot, especially trying to run low psi.

I think that tubeless technology has gotten to the point where there is no reason that e bikes should not benefit from it and I hope that soon the manufacturers will spec it on their bikes. Unfortunately it is kind of expensive to switch over as you need new rims and tires but if they came at the OEM level the cost would not be much if at all more. And you can still run tubes if you want and carry one in case of flats.
 

Over50

Well-Known Member
...Tubeless also plays a big part in the equation also...I think that tubeless technology has gotten to the point where there is no reason that e bikes should not benefit from it and I hope that soon the manufacturers will spec it on their bikes. Unfortunately it is kind of expensive to switch over as you need new rims and tires but if they came at the OEM level the cost would not be much if at all more. And you can still run tubes if you want and carry one in case of flats.

I've been wondering what it takes to go tubeless. I noticed some recent bikes like the Bulls Cross Lite E and perhaps the R&M Roadster (if I recall correctly) say they are tubeless ready. So I'll show my ignorance here quoting Court's recent review of the Cross Lite E and asking a followup question:

https://electricbikereview.com/bulls/cross-lite-e-step-thru/
"and the tubeless ready wheelset could help you shave off even more weight if you decide to convert from stock inner tubes."

So what exactly does that mean? What does one have to change on the bike, if spec'd for tubeless by the OEM, and what are the benefits/pitfalls of making the change?
 

JRA

Well-Known Member
Tubeless ready means that the rims are tubeless compatible. What makes a tubeless rim varies from company to company and some use a hooked bead and other do not. However the constant is that the rim tape, instead of just being a strip inserted in there is an actual tape that seals off the spoke holes and runs from bead to bead. It also comforms to the profile of the inner rim. There are tapes available by the different manufacturers but I have had the best luck personally using Gorilla Tape as the yellow tape is stiff and fragile and hard to get to conform easily without a lot of bubbles and it will tear quite easily. Some companies may have already done this step but that has not been my experience to date.

Next in the process is a specific valve stem that you insert into as small of a hole as possible, I usually just make an x slit over the valve hole large enough for the metal part of the valve to go through, and the rubber grommet on the inside end will pull down in there and seal after tightening the ring nut from the outside. Now you are ready to install a tubeless compatible tire.

Usually tubeless tires are a pretty tight fit on the rim as the standards set by the industry make them so. It is very important to get the first bead in to the center channel fully in order to best get the 2nd bead up and over the edge of the rim. Once you get the tire mounted you can work the tire up on to the bead shelf as much as possible and if you are lucky with a hand pump you can get it to blow up and seat the bead. If not then a compressor will do the trick. It is best to add air slowly and it will pop and make noise. If it doesn't seem to be seating you can add some soapy water to the trouble spots to help it out.

Oh, but what about the sealant as mentioned? Well some like to put the sealant in before the last of the 2nd bead goes on but I prefer to seat the bead if possible before adding the sealant, leftover fear from the first time I did it that way and the bead let go and sealant went all over the place I guess. The aforementioned valve stem has a removable core which you can insert the sealant in to easily and mess free after getting the bead sealed I find.

I have been using Stan's sealant because I have a jug of it but have heard good things about Orange Seal also. For my MTB 2.3 or so tires I use 3 oz. of fluid and for my 40c or so tires I use 2 oz. and that seems to work ok. After about 6 months or if you see that your tires aren't holding pressure well you can add more. Basically the sealant is a latex and will dry out after awhile and need some replenishment.

As far as saving weight goes a couple of oz's of sealant weighs less than a tube but I am more in to the flat protection and the fact that running low psi I won't get pinch flats.

Plenty of how to's online and this is just a quick summary of what has worked for me. I use the WTB system and it has been great. There is also what they call Ghetto Tubeless that you can use any rim for but I have never gone down that road. Plenty of how to's online for that method also.
 

Nutella

Active Member
There's really no need for ghetto tubeless anymore since there's so many better options out there. You can buy rubber rimstrips that work pretty well, tape is ok if you're careful. The obvious is that tubeless ready rims and tires make life so much easier, especially recent models. I prefer Orange Seal, mainly for the lack of Stanimals and you can get and they have an endurance formula that resists drying out.

My workflow these days is to mount the tire dry with the valve core removed and hang it in my work stand. Using a compressor, blast air into the valve stem which is usually enough to initially pop the beads in place, then with a finger over the hole, grab the stem and screw it in, keeping most of the pressure. Add sealant and soap up the beads and sidewalls. Air the tire up high so the beads pop in place with a scary "bang!". Perform the sealant shaking routine and leave it overnight. That's when all goes well. If you have a not tubeless ready tire, or rim, or they just don't want to play together, you can struggle to get the bead to seat. The tires just work better without tubes and will seal small holes on their own. Bigger holes need a casing plug or in the worst case, a tube.