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Discussion Starter · #1 · (Edited)
Can't get beyond 100 psi with Topeak RaceRocket HP pump

Although the Topeak RaceRocket HP pump is rated for 160 psi, I haven't been able to use it to fill my 700x25 Continental Gatorskins (maximum pressure 120 psi) to more than 100 psi. As I continue to pump after I've reached 100 psi, I can tell that I'm moving air and there is normal resistance to the pumping, but the tire does not get any harder. I reported this to Topeak and was told that I needed to replace the pump, which was still under the 2-year warranty. The replacement RaceRocket arrived yesterday but I'm still unable to fill the tire beyond 100 psi. Do any of you have relevant experience with this pump?

Topeak® Cycling Accessories ? Products - RaceRocket HP, black

John Link
 

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I have one, but 90 psi is the max I run in my 25mm tires so don't know if it'll go higher. 100 is as high as I ever went with 23mm tires. I also have the normal non-HP version of the Racerocket. It may be better at achieving high pressure as it's a bit higher vollume, but the force required to pump is significantly higher as it's larger in diameter. I have no problem getting 90-100 psi with it either.
 

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If you actually need to pump 25mm tires above 100PSI, you're too heavy to be riding 25mm tires.
 

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How do you know you're at 100? Does that pump have a gauge on it? Without a gauge you may not be perceiving accurately what's happening. You say the tire "does not get any harder" as you pump more, but it's very difficult to tell the difference between 100 and say, 120 by squeezing the tire. It might actually be going up.
 

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Discussion Starter · #5 ·
If you actually need to pump 25mm tires above 100PSI, you're too heavy to be riding 25mm tires.
Your comment doesn't address the issue I raised about the pump, but I'm interested nevertheless. Would you explain your reasoning? How do you determine the pressure to which to pump your tires? By the way, I weigh 163 pounds
 

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Discussion Starter · #6 ·
How do you know you're at 100? Does that pump have a gauge on it? Without a gauge you may not be perceiving accurately what's happening. You say the tire "does not get any harder" as you pump more, but it's very difficult to tell the difference between 100 and say, 120 by squeezing the tire. It might actually be going up.
I carefully remove the pump and check the pressure with a Lezyne floor pump that has a gauge. I know that's not a perfect procedure but when I use the floor pump to reach 110 psi, after removing and reattaching the pump the gauge reads about 108.
 

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Your comment doesn't address the issue I raised about the pump, but I'm interested nevertheless. Would you explain your reasoning? How do you determine the pressure to which to pump your tires? By the way, I weigh 163 pounds
This calculator will tell you what pressures to run based on your weight:

Bicycle tire pressure calculator

Let's assume you plus your bike is 180 pounds and you have a more race-like geometry for a 45/55 weight distribution. You should be running 69PSI front and 87PSI rear. If you go by the 40/60 weight distribution, it should be 60PSI front and 95 PSI rear. You have no measurable advantage by trying to run 120PSI and in fact may be slowing yourself down due to suspension losses.

We also have a Wheels & Tires subforum that has covered this topic many times if you care to peruse it.
 

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Discussion Starter · #8 ·
This calculator will tell you what pressures to run based on your weight:

Bicycle tire pressure calculator

Let's assume you plus your bike is 180 pounds and you have a more race-like geometry for a 45/55 weight distribution. You should be running 69PSI front and 87PSI rear. If you go by the 40/60 weight distribution, it should be 60PSI front and 95 PSI rear. You have no measurable advantage by trying to run 120PSI and in fact may be slowing yourself down due to suspension losses.

We also have a Wheels & Tires subforum that has covered this topic many times if you care to peruse it.
This is very interesting and has me completely baffled, given that the recommendations of psi above seem very low, and I've always heard the advice to inflate the tires to nearly their maximum.

My bike and I weigh about 190 pounds. Using the 45/55 weight distribution the calculator yields the following results for various tires of 25 and 23 mm:

25 mm: 73/92
23 mm: 88/109

Are those pressures of 73, 88, and 92 above the minimum pressure for Gatorskins? Here's a picture taken of the box in which the folding 700x25 Gatorskins just arrived. What's the meaning of 95 psi for the 25 mm tires and 110 psi for the 23 mm tires?

Text Technology Font Black Circle
 

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This is very interesting and has me completely baffled, given that the recommendations of psi above seem very low, and I've always heard the advice to inflate the tires to nearly their maximum.

My bike and I weigh about 190 pounds. Using the 45/55 weight distribution the calculator yields the following results for various tires of 25 and 23 mm:

25 mm: 73/92
23 mm: 88/109

Are those pressures of 73, 88, and 92 above the minimum pressure for Gatorskins? Here's a picture taken of the box in which the folding 700x25 Gatorskins just arrived. What's the meaning of 95 psi for the 25 mm tires and 110 psi for the 23 mm tires?

View attachment 315382
Don't read the box, throw it away. Those pressures were probably decided upon by suit wearing lawyers not lycra wearing cyclists. The pressures you got from Sauron's link are the ones you should go with. In fact you could probably run the pressures for the 25c tires safely in the 23c tires. I weigh about 185lbs, sans bicycle, and run about 85 front\95rear in either 23 or 25c tires.

Less pressure will roll faster, flat less and ride more comfortably.
 

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Discussion Starter · #10 ·
Don't read the box, throw it away. Those pressures were probably decided upon by suit wearing lawyers not lycra wearing cyclists. The pressures you got from Sauron's link are the ones you should go with. In fact you could probably run the pressures for the 25c tires safely in the 23c tires. I weigh about 185lbs, sans bicycle, and run about 85 front\95rear in either 23 or 25c tires.

Less pressure will roll faster, flat less and ride more comfortably.
I came looking for advice about a pump and it looks like my pumping practice is to be completely revised! I just received a pair of 700x25 folding Gatorskins that I will use to replace some 700x25 non-folding Gatorskins that are at the end of their life. Before I install the new Gatorskins I will ride with 73/92 and see how it feels.
 

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It's a sign. See! It led you here. Haha.

Still, isn't the answer to your original query simply to use the Lezyne floor pump?
 
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Discussion Starter · #12 ·
It's a sign. See! It led you here. Haha.

Still, isn't the answer to your original query simply to use the Lezyne floor pump?
The floor pumps weighs four and one half pounds and is large, whereas the RaceRocket HP pump weighs less than three ounces and is small, so the floor pump is useful at home but not on the road.
 

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The floor pumps weighs four and one half pounds and is large, whereas the RaceRocket HP pump weighs less than three ounces and is small, so the floor pump is useful at home but not on the road.
Ohhh!! Haha! Thanks! Why do you care if your road fix mini pump can't pass 100psi? You just need to finish a ride and go home. 100psi will well accomplish that goal! Are you flatting so often that it actually matters? That would be weird, and I'd say the tire or rim is the culprit. My Lezyne mini pumps up to exactly "OK that oughta work psi." It's the same PSI attained by CO2 carts.
 

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Discussion Starter · #15 ·
Ohhh!! Haha! Thanks! Why do you care if your road fix mini pump can't pass 100psi? You just need to finish a ride and go home. 100psi will well accomplish that goal! Are you flatting so often that it actually matters? That would be weird, and I'd say the tire or rim is the culprit. My Lezyne mini pumps up to exactly "OK that oughta work psi." It's the same PSI attained by CO2 carts.
I've learned today that I do not need to fill my tires even to 100 psi, and I don't flat very often, but when I'm on a multi-day ride I need to be able to continue with my ride whether or not I can find a bike shop with a floor pump.
 

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I've learned today that I do not need to fill my tires even to 100 psi, and I don't flat very often, but when I'm on a multi-day ride I need to be able to continue with my ride whether or not I can find a bike shop with a floor pump.
In this case you need to carry a gauge. CO2 carts will deflate quickly in this context... A gauge will be light and affordable. Also, if you are doing multi-day rides you should get a much larger frame mounted pump. Again, context matters. I wouldn't go multi-day riding with only a mini. In this kind of riding, load up the bike. Do you have packs? Tents? Or do you ride motel to motel? Still, you need STUFF for this kind of riding. Rain gear, tubes, tools, food... I'm not sure I get this whole line of thought...
 

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I would be happy with a small pump that could give you 100psi on the road. But I carry 1 CO2 cartridge and then have the pump for insurance. I just had my 2nd flat this year on today's ride. I just used the pump as it was the front tire and I do not need much pressure in it anyway.
 

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Discussion Starter · #18 ·
In this case you need to carry a gauge. CO2 carts will deflate quickly in this context... A gauge will be light and affordable. Also, if you are doing multi-day rides you should get a much larger frame mounted pump. Again, context matters. I wouldn't go multi-day riding with only a mini. In this kind of riding, load up the bike. Do you have packs? Tents? Or do you ride motel to motel? Still, you need STUFF for this kind of riding. Rain gear, tubes, tools, food... I'm not sure I get this whole line of thought...
The line of thought is to travel as lightly as possible. I stay in motels or airbnbs. The RaceRocket HP pump perfectly suits my needs, now that I know that 100 psi is more than enough pressure. I will buy the smallest and lightest gauge I can find.
 

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This calculator will tell you what pressures to run based on your weight:

Bicycle tire pressure calculator

Let's assume you plus your bike is 180 pounds and you have a more race-like geometry for a 45/55 weight distribution. You should be running 69PSI front and 87PSI rear. If you go by the 40/60 weight distribution, it should be 60PSI front and 95 PSI rear.
That's downright absurd. That's a pinch flat waiting to happen.

Absolutely no one I know even remotely close to that size runs anywhere near that low precisely because of the above.

Perfect example of a "calculator" failing to take into account the real world.
 

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The line of thought is to travel as lightly as possible. I stay in motels or airbnbs. The RaceRocket HP pump perfectly suits my needs, now that I know that 100 psi is more than enough pressure. I will buy the smallest and lightest gauge I can find.
I'm all for traveling as light as possible. But a frame pump is a place I'd splurge on. There are so many great designs, made exactly for the purpose you are angling. Light and out of the wind... you are taking the weight penalty on wider tires, and that's a good one in your context... Pump is a close second.

There are great, small, accurate and cheap gauges out there, I just know the super low psi ones and not the high psi ones or I'd recommend from my experience.

Good luck at random internet facsimiles of B and Bs. Stay safe!
 
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