timtak

I have a Topeak Joe Blow pump and a Bontrager pump both with scales that end at 160 psi. I want to pump up my tyres to 170psi. But I can't even get to 160 psi with out bouncing on the pump. Putting my weight on the pump does not budge it about 150psi. Are there special pumps that use some sort of gearing to reach the higher pressures?

The tyres are rated to 225psi. .

FBinNY 

As far as I know, there are no tires rated to 225psi, and if there were there wouldn't be any advantage to pumping then that high. Pumps tend to top out at 160 because tires generally pumped to a range from about 60psi to 120psi.

As far as why you can't pump beyond 150 on your pump, that's a matter of simple physics. When the pressure in the pump chamber times (expressed in pounds per square inch) multiplied by the area of the piston equals your body weight it'll support your weight and you won't be able to push it down. So if you still want to pump beyond 150psi, you'll either need to get a narrower pump or gain some weight.

I suggest you recheck the tire rating, and maybe read a this little article about tire pressure.

davidad

https://www.adventurecycling.org/res...SIRX_Heine.pdf

dahut

What kind of tires are rated that high? I feel like Im missing something...

timtak

Sorry, the tyres are rated to 220psi
https://www.tufo.com/s3-lite-215g/
They are 21mm. They came with the carbon wheels on ebay. The graph in that article is saying something up near the pressure I am talking about for the rear wheel if I were a few pounds heavier. But though I thank you for the responses, my question was about pumps. I have the tires at 160 now and they feel fine but it was a ***** to get the air in.

Does anyone know of a pump with which it is easy to pump to high pressures?

krome

The SKS Renncompressor has a gauge that goes to 240psi (16 bar). It has a smaller diameter barrel than the Joe Blow, so It should be easier to pump for a given pressure. I never go near those pressures, I just wanted a durable pump.

Edit: my old Silca pump goes that high as well. I'm not sure what model it is, but I've had it for years. The Renncompressor I just purchased.

HillRider

An industrial air compressor should meet your needs. I'll also ask, despite the fact the tires will withstand 220 psi, what do you hope to accomplish by running them that high?

Nerull

Aren't tire pressures above 120ish generally reserved for velodromes? When you're riding on a polished track, you don't need a tire that absorbs any shock, but I wouldn't want to ride pressure that high on the road.

CACycling

12V compressor will do it. Why you'd want to is another question.

dahut

Kinda what I was wondering...

timtak

Thank you very much for the pump recommendations, especially Krome. I plan to get a SKS Rennkompressor.

As to why, as at least one review reports, the tyre is less likely to get flats at higher pressures and I am not having any problem with the ride at 160. I like the ride. Maybe my posteriour has more padding that everyone else.

FBinNY 

The gauge's range is not a reliable indicator of how much pressure you can pump to with any given floor pump. The key factors are your weight and the pump cylinders inside diameter. The handle force needed is roughly equal to 3/4ths of the square of the diameter. Below is a small chart of the handle force needed per psi with various diameter pumps.

1".......... .78#
1-1/8" ... .99#
1-1/4".. 1.26#
1-1/2".. 1.76#

As you can see, with the typical 1-1/8" HP floor pump you'd need to weigh 218# to pump a tire to 220psi. This simple issue of pump physics explains why women especially find pumping tires so difficult.

kevin_stevens

Also note that the force needed will be lower with a smaller diameter pump, but so will the volume. It'll take more strokes, not sure if that translates to "easier" for you. TANSTAAFL.

KeS

woodway

You could always skip the pump and go with something like this:

https://www.airfreetires.com/shopping...trial-622.aspx

ultraman6970

This was discussed before, to the OP, that a tyre or a tubular is rated to whatever psi doesn't mean is the right thing to do. In a matter of fact 120 is kinda too much already for some brands even tho are rater way higher.

You can test go all the way to 180 if you want, but would love you to let us know how many miles you will get out of the tire before does bam!

timtak

I think that more strokes will be easier. I am pumping them up to 150 very quickly but the last 10psi require more than my weight in force hence the need to bounce. Here is hoping the SKS Rennkompressor has a narrow bore.

I am not sure if airless tyres are a joke or not, probably not, but the Tufos are half the weight of those on the page referenced. Thanks for the reference but I like these Tufos. I feel like I am on wings.

The tyres are said to last quite well but, in my experience and in those of other reviewers, the higher the pressure the longer the tyres last. Since they are about 50USD a go, I would like to pump them up hard and 160 is not hurting at all. I got a flat in one that was at about 110 psi.

If I were in the US I would buy that SKS Rennkompressor which is only 49USD from amazon.com but here in Japan it is 120USD. I will save up and bounce on my Joe Blow for the time being.

cobba

220psi + Cheap Unbranded Carbon Rims form ebay + Dollar store glue = ?

3alarmer

..............

mulveyr 

A helmet-cam is all that's needed to complete this story.

ultraman6970

That one I would love to see but you guys forgot something else, add some road conditions like for example, going downhill with switchbacks or in a sprint and over the pedals with 53x11 That I would love to see.

njkayaker

???

This thread begs all sorts of questions.

How much does he weigh?
Does he ride in a velodrome?

FastJake

Hahaha. I'm thinking this guy is a troll. 220psi? C'mon.

OP: how much do you weigh? Read some articles about tire pressure. You might wear out your tires if they're way underinflated, but 120-140psi is definitely not in that range.

FBinNY 

Come on guys, Lay off.

The OP asked how to pump that far, and didn't ask whether it was wise. At this point he's seen the posts, and made his decision.

I'm with you in thinking that his desire is off the charts, but this is America (or Japan) and it's his bike and he's free to ride at the pressure of his choice. Certainly snarky comments aren't going to convince him to ride at lower pressure so we shoiuld move on and help people who want it.

HillRider

Maybe it's more correct to say he's free to ride at any pressure he can obtain.

FBinNY 

That goes without saying. I'm free to live in the big house on the hill, hobnob with the elite, do the job of my choice, and have all the money I want.

But just because I'm free to, doesn't may it'll happen, it just means I may (if I can).