BikePower

because the thread is about ride comfort on a mountain bike with a dropper post, not a road bike. Tire pressure is related to suspension and ride comfort. Now we are talking about my percieved trade off with comfortable tire pressure being increased pedal effort and increased friction.

cyclezen

Quote:
Originally Posted by Darth Lefty View Post
I don't know why you guys are arguing in a dropper post thread in the MTB sub about road bike tire pressure. A retread, if you will, of a familiar topic. Perhaps you are lost and need directions?
Quote:
Originally Posted by BikePower View Post
Maybe dumb question but can you have both a dropper post and a suspension seat on a mountain bike? Thanks.

not to be contentious, but Darth Lefty was bringing up the pertinent point. OP was about dropper post with possible 'suspension' - no mention of intended use...
then you added more ...
again the pertinent point seems to be the bike is used on-road mostly.
commonly a dropper is used for 'off-road' riding - not saying you can;t use it however, but that - your intent wasn;t stated...
... I, as prolly many others, made a wrong assumption - that you had a HT and riding 'offroad', wanted both a 'dropper' feature as well as some suspension to take the edge off 'hits' and smooth the ride a bit.
nor was there a mention of 'gravel riding' - which might be another area where a dropper/suspension post might be desirable... then the 120 tire pressure thing out of left field.
... there's a huge amount of data out there for tire rolling resistance/tire pressure/profile... most of it for 'road' tires, now showing further expansion into 'gravel' widths and treads.
... not much on knobby mtb tires - as expected...
best way to clarify 'preconceptions' and misconceptions is to search and read what's on the internet.
Ride On
Yuri

BikePower

Heres where I clearly stated my intended use.
The 120psi mention was only to illustrate that tire pressure matters to minimize rolling resistance. It is clear by the context. It is understood that I am not suggesting that I will use 120psi in a mountain bike tire.

You are forcing a misunderstanding where there is none to prove what point Im not sure? This is a nice thread, we are talking about dropper posts with suspension seats which has led us to talk about bike suspension and tire pressure being one of the variables of same.

I am here in the forum talking to like minded people about mutually interesting topics. I do this in lieu of googling 1 gazillion results. A forum is infinitely superior to googling. Moreover, often times any googling of bike topics results in links to this very forum! If I should dare click on said link and reply to it, then the same folks will complain of ressurrecting a "zombie" thread.. Oh nooooOO!!!

Again there is no problem here but the one you are creating. I invite you to join the coversation and talk about the subject or kindly peruse other threads of interest to you. Please do not come in here and denigrate others. Thanks.

cyclezen

so, yes, always better to 'pass' and go to other interesting things; so moving on is always a better tack - and will be taken.
Otherwise, I don;t believe I've denigrated (you?).
you're recent posts can be interpreted as condescendingly confusion, quote " why do racers you high pressure tires 120ps? Why does it feel harder to pedal when I have low air pressure? Why do I get much less mpg fuel economy on my truck when I dont keep the tires inflated to the correct pressure? Im very interested if you can bust this misconception that I have. Thanks."
I mean, not cute, not thought provoking, not.
There are a lot of posters in this forum with good/great experience and info - with good info up front, they come thru with good ideas to consider.
treat them cheap, and that's what comes in return.
me, I have a lot to learn, so always gleaning whatever good I can find.
Ride On
Yuri

BikePower

Thats your interpretation and you are entitled to it. Those questions I posted are legitimate and sincere questions that I asked myself when informed that low tire pressure does not use up the pedaling power. I'm interested to know how low tire pressure does not increase frictional losses and at the same time make it harder to pedal. It's not meant to be condescending but if it is interpreted that way it may say something about the reader and not the author. In addition to that, text is not a great way to communicate and is rife with misunderstandings without intonation, body language and facial expression. When using text to communicate it is good practice to believe the best and leave latitude and err on the side of optimism. Ask for clarification if necessary instead of just starting swinging at folks.

katsup

Lower tire pressure is more comfortable for the rider since the tires are soaking up some of the bumps. Because the rider is more comfortable, they are able to go faster.

Type "bike tire pressure" in YouTube and watch some of the many videos explaining this.

prj71

A.) Tires don't replace suspension. Get that out of your head.

B.) Lower tire pressures increase rolling resistance due to a larger tire contact patch which increases the power required pedal.

BikePower

Thats what i thought too. but some are adamant saying that is not so.

Kapusta

Yeah, really

Happy Feet

What was the question?

Bikepower, you are trying to argue road application in a mountain bike forum. Someone pointed out a dropper that has suspension but, other than that, suspension in mtb is gained by "suspension" so not a lot of thought is put into adding it to the dropper. While you may nominally have a mountain bike, what you are really doing is city riding.

Equally, arguing road tire pressures in this forum is also a mis-application. The theories about high/low rolling resistance coupled with supple/hard tires belongs there, not here. Most mtb pressures are below road standards and rolling resistance is not factored the same way. All you are going to get is mtb opinions about your road riding observations.

Miraculously, you got your specific answer in post 2, that's a record. To continue a debate about tire pressure from one genre to the next now will only result in confusion. Don't feel "put upon" if that happens.

unterhausen

As a practical matter, some mtb rims aren't rated to road bike pressures, although some of them allow you to use higher pressures with smaller than mtb tire sizes. That always seemed questionable to me. Some stan's rims are max 37psi.

Of course, some manufacturers never bothered to spec max pressure, which makes me think that sticking with mtb pressures is a good idea.

I like low pressure on rough surfaces. I often go a little too low and notice my steering is scary taking a hard corner on the road. Off-road, the same pressure feels fine during cornering. The rolling resistance sites will let you do a comparison. They often play with the y axis to make the rolling resistance as a function of pressure look more pronounced. It's generally not that much. Nobody I know of has figured out how to do a comfort comparison

2old

BP, thanks for initiating this thread since I may be a customer for the PNW. FYI, there was a comprehensive, objective study in a German magazine about 15 years ago that showed the relationship between tire pressure and rolling resistance on a variety of off road surfaces. Higher tire pressure didn't prevail. Also, as you probably know, your extremities provide a fair amount of suspension.

cyclezen

FYI - I just received an email from PerformanceBike.com - they have PNW stuff on sale for 20% off.
so, for anyone considering the dropper posts, especially the Dropper + Suspension Post - Coast
it's now $143 for the external routed and $159 for the internal...
seems like a good deal, and I'm thinking about it for my HT.
Ride On
Yuri

Polaris OBark

There might be a reason for the adamant insistence.