Tire pressure discussion.

[Denis Shelston]

Now that riding my Téo is getting closer and closer.

I have question on tire pressure with the Kenda Juggernaut tires on our bikes.

I guess I'm looking to know what is the optimal tire pressure for city strolling on pavement? One that would allow for the easiest pedaling... You see I promised my wife I would pedal more often than not, I need to get in better shape and lose a few pounds

I understand that very low pressure is ideal for sand and beach, as low as 8 psi I have read. Does that make sense?

Finally one could easily imagine inflating and deflating regularly on varied rides.

I bought myself a powered air pump, from Luna Cycle, but will also use a manual one when battery reserve is low..

 

[Denis Shelston]

I'll try that then.

25 psi

 

[tarhead]

Hi folks. I'm new to the discussion but couldn't help but notice the issue with high price for the pressure gauge. Check out your local Home Hardware (for us Canucks). $8.49 for 1-20 psi: https://www.homehardware.ca/en/rec/...Ntk-All_EN/R-I1638446?Ntt=tire+pressure+gauge.

 

[Falken]

Also you can go into any ATV bike shop and they will have low pressure gauges for sale I'm sure. That's where all the ones I have came from.

 

[mrgold35]

I have a similar ebike (Radrover) with the same Kenda 30 tpi tires. I'm at 270lbs plus another 25-35lbs for gear, rack bag, commuter bag pack, and water usually. I found 20 PSI was a good compromise for road and trail riding if your do both equally and don't have time to up/down the pressure. I can still power through deep sand in a mid-PAS setting, hard pedaling in 1st or 2nd gear, and a couple of twists of throttle when needed at 20 PSI with the Kenda. If I'm doing 100% trail with a mix of sandy, 13-15 PSI does a good job from hard-packed to sandy. If I'm doing 100% paved roads 22-25 PSI for efficiency. My rear tires only lasted about 800 miles with about 30%-35% tread left because of paved road work commuting 3-4 times a week at +60 miles a week.

Recently switched to Vee8 120 tpi and those are a real upgrade compared to the Kenda. Less rolling resistance for faster acceleration, less road noise, and 1-2 higher cruising speeds compared to the Kenda. They don't appear to be wearing as fast as the Kenda after +500 miles. I also think I'm getting a little better battery range since the tires have a much lower rolling resistance. The tires still have an aggressive tread to handle trail duties like the Kenda. I keep 19-20 psi in the fronts and 23-25 PSI in the rear and the Vee8 handle road and trail duties just like the Kenda.

I have the Topeak D2 Smart digital Gauge for both schrader and presta valves for about $25-$28 on eBay or Amazon (covers all 4 of my bikes and my cars). The only pain in the butt is this takes a CR2032 battery every few months.

Pics of Vee8 and Kenda tires:

 

[Falken]

Thanks @mrgold35 for that information. I am wondering with all of those miles you have put on, how many flat tires have you had? There has been a lot of discussion about having pumps, flat kits, tools etc. and it seems like a lot of gear to carry around for a "just in case" situation. I realize of course its always good to be prepared, but I rode bikes when I was a kid and teenager non stop in all types of terrain, jumping them off stairs, riding on gravel roads, you name it.... and I never got a flat. Not once. I would have thought that tire manufacturing would have gotten even better since that was a long time ago. Are flats a common thing with fat bikes?

 

[mrgold35]

I also grew up riding bikes as a kid in the 70s (I had a chopper bike with the banana seat once) and don't remember ever getting a flat with a lot dirt riding and ramp jumping in Colorado Springs.

I did the Mr. Tuffy tire liners for 4" fat tires and two 2-oz bottles per tire of Stans sealant (put into inner tube). In ABQ, we have a lot of cactus thorns, goathead stickers, and a lot of road debris in the share the road bike lanes sometimes (rocks, plastic/metal car parts, broken glass, etc...). I was seeing a few wet spots on my tires several times a week from Stans sealing leaks that made it all the way into the tube with the Kenda. Every flat from on my Kenda were in between the knobs. I only got one flat that stopped me with this setup on the Kenda when I ran over some glass or sharp metal that put a 1/8" slit in the rear tire at 5:30am. The hole was too big for Stans and I was out of air in less than 100 feet. I now carry an extra tube along with flat kit if it happens again.

Same setup and same routes with the Vee8 and haven't seen a wet spot from the sealant yet. I think the extra knobs on the Vee8 are providing extra protection compared to the really spaced out Kenda knobs.

 

[Falken]

Thanks for sharing that. So we should be adding sealant even when we run tubes? I thought sealant was for running tubeless? New to the fat bike scene, sry. I did some reading on the vee 8's. Not only did they score well in the rolling resistance, they posted the highest numbers for puncture resistance. They look like a real winner.

 

[mrgold35]

Running Mr. Tuffy, tube, and sealant seems to work for me for my riding conditions. You might only need Mr. Tuffy if you don't have to worry about goathead stickers or cactus thorns. I don't think my rims are tubeless ready? Not sure how a tubeless 4" fat tire would have don't against the 1/8" slit from road debris like I mentioned above compared to patching or replacing an inner tube in a few minutes?

 

[Falken]

I wouldn't know. I would think the tubeless would be dead in the water in 100 feet just like yours was. Like I said I'm new to fat bike tires. I've been watching vids and doing some reading to try educate myself and only saw the sealant being added to the tubeless. Lots to learn.

 

[YYZ2017]

don't know if this belongs in here but I installed hookworms and found even at 30psi it felt like high resistance (paved roads)
up the pressure to 55 and it made a world of difference. did some gravel roads too and it handled fine.

can't really tell about battery life since I have never drained it.

 

[mrgold35]

I installed new 700 x 38 Specialized Hemisphere Armadillos on my gravel grinder and noted that the recommended pressures on the sidewall are 75 psi min / 100 psi max. That seemed like a lot of pressure for a 38mm tire so I pulled up the BQ recommended pressure chart from Sheldon Brown's site. Assuming a 45F:55R (touring) weight distribution the BQ chart recommends a starting point of 55 psi F: 65 psi R for a 260lb rider/bike/gear combination (which is what I figured my max would be for gravel weekend touring). So, what say ye? Is it safe to run the lower pressures recommended by BQ or should I stay above the mfg recommended minimum of 75 psi?

I always adjust tire PSI factoring in riding conditions, best combo of ebike braking/handling, weight of the ebike, type of tires, and weight of the rider. My 75lbs rear hub Radrover fat tire rode best at 20F:22R with 4" tires and my full suspension mid-drive Himiway Cobra Pro rides best at 30F:30R with 4.8" tires. I don't know what is printed on the side of the tires for recommended PSI.

 

[fooferdoggie]

I installed new 700 x 38 Specialized Hemisphere Armadillos on my gravel grinder and noted that the recommended pressures on the sidewall are 75 psi min / 100 psi max. That seemed like a lot of pressure for a 38mm tire so I pulled up the BQ recommended pressure chart from Sheldon Brown's site. Assuming a 45F:55R (touring) weight distribution the BQ chart recommends a starting point of 55 psi F: 65 psi R for a 260lb rider/bike/gear combination (which is what I figured my max would be for gravel weekend touring). So, what say ye? Is it safe to run the lower pressures recommended by BQ or should I stay above the mfg recommended minimum of 75 psi?

usually you dont want to go below especially if it is not tubeless. bt it seeps pretty high. I would try 75 and see how the bike feels.