The best way to make getting a flat worse is not being prepared to fix it. There are a number of mini pumps ans inflators out there designed to make the process as easy as possible, but a new company thinks they have a better idea. Named CrankPump, the company’s name is a bit misleading since instead of hiding a pump inside your bike’s bottom bracket, the gadget allows you to stash a co2 inflator.

CrankPump seems like a sure fire way to have access to inflation when you need it… Updated

crankpump leavers off work bench great focus yellow_2996 crank pump

Included in the CrankPump assembly is the co2 inflator itself, a threaded co2 cartridge, and two specially designed tire levers that are designed to “unzip” your tires from the rim with a patent pending method. More details on the levers should be available when the CrankPump goes live with a Kickstarter on the 16th.

Designed to only work with Shimano Hollowtech II cranksets, CrankPump actually replaces the plastic preload bolt that is included with the cranks. Ideally, you would adjust the bottom bracket as normal, tighten down the crank arm pinch bolts, then remove the preload bolt and replace with the CrankPump. Though in our experience you would at least need to loosen the outside pinch bolt to remove the preload bolt. The CrankPump also looks like it will require a special tool for installation and removal, so we’ve reached out to the company for more details.

CrankPump will ensure that you have at least a single co2 cartridge, inflator, and tire levers when you get a flat, but we can’t help but note that due to the design the CrankPump’s mass will be added to the rotational weight of the crankset. If you’re into the convenience of always having it on hand, and don’t mind having to unthread it from the bottom bracket to use or the extra weight, CrankPump could be very useful the next time you get a flat.



Damon from CrankPump got back to us with a few more details. The packaging of the CrankPump will double as a removal tool for the Hollowtech II preload bolt. You will have to loosen the pinch bolts to remove the Shimano bolt, but the CrankPump is designed with a smaller flange so you will be able to install and remove the inflator without tools. The cap is designed to use your fingers to turn in either direction, but it was designed to be easier to turn counter clockwise so it won’t get stuck.

Due to the design constraints of the axle, the CrankPump is limited to 12g co2 cartridges which typically inflate a standard road tire to 90 psi.


  1. wheel-addict on

    “we can’t help but note that due to the design the CrankPump’s mass will be added to the rotational weight of the crankset.”

    Umm, by putting it in the crank spindle, rather than near the pedals, the amount of additional rotational weights is negligible, and certainly could not be detected by a human.

    Looks like a great idea. I like it.

  2. Guy on

    Pretty neat little idea there. On a side note, does everything in the world now have to be funded by a kickstarter campaign?

  3. Nate on

    With the presumption that most people do not toque their crank bolts properly, I foresee a lot of lost crank arms. I’ve seen a decent number of people ruin their Shimano cranksets by having that preload cap loose or missing altogether. Now you take away someone’s ability to properly tighten it? Disaster.

  4. dead on

    Have you guys taken a shimano hollowtech fixing bolt off before? you need to loosen the pinch bolts before taking this pump off and should be reinstalled with a torque wrench. Better luck next time.

  5. Topmounter on

    “…but we can’t help but note that due to the design the CrankPump’s mass will be added to the rotational weight of the crankset.”

    LOL, seriously? Please, do some extensive power meter comparison testing w/ and w/o and let us know what you find.

    @Guy – Kickstarter is the new preorder. Besides, this is PRE-Kickstarter. T minus 5 days and counting.

  6. CrankPump on

    @Nate and @dead – thanks for the comments. CrankPump can be used to preload the crank axle. Shimano recommends the preload bolt is tightened to between 0.7 to 1 NM. Once the pinch bolts have been tightened, the axle tension is firmly clamped, and you can remove CrankPump (by hand) when you need to fix a flat tyre.
    To ensure CrankPump can be removed without loosening the pinch bolts, its flange is a slightly smaller diameter than the original preload bolt, so CrankPump doesn’t get clamped in place.

  7. Rico on

    Not bad idea to utilize that space. I still like using my jersey pockets to carry stuff. On any standard jersey i can carry – iphone, 2x power bars, tube or tub, co2 and chuck, car key, money, cotton rag, and at least one full bottle. I just put the loose stuff in a zip lock. Honestly though I flat like once every two years because I use stans in all wheels incl. tubs. And this is on sh*tty roads.

  8. buriedundersnow on

    I like it! I’m a fan of projects like this versus another brand of carbon wheels…..If it works as intended, I’m in.

  9. Ventruck on

    Nice to know the potential issue with the pinch bolts was addressed. Kinda curious about those tire levers too.
    LOL @ the question of the effects of the rotating mass, though.

  10. Frippolini on

    @ Greg… that’s hilarious, LOL. 🙂

    Otherwise… if the readers on this forum (the correct customer segment) finds the product questionable… hmmm… unless these guys manage to squeeze in additional features and benefits, I have a hard time believing this will take off.
    Let me phrase it this way… I still have to use my pockets/bag for some other tools, food, phone, rain jacket, etc.; so why should I bother getting one of these???

    Nice try guys, but please try again when you have figured out how to put more functionality into the product (and I don’t mean squeezing a banana into the BB).

  11. Rob on

    This is a great idea. I dislike saddle bags for a number of reasons, just never liked them. I also ride a lot, sometimes somewhat spontaneously. I have been on the road only to later realize I forgot to toss the CO2 in my pocket. This completely removes that risk, so I’m all for it. I also prefer relatively less stuff in my pockets if I can avoid it.

  12. Henry on

    (deleted) No offence, but what’s the bloody point? Instead of reaching for your back pocket or saddlebag, now you want us to unscrew this from within the bottombracket???? Takes more time, costs more money. ON the other hand… no wait, there’s no plus side to this…

  13. Slow Joe Crow on

    This would be even more clever if they made a version for SRAM/Truvativ and FSA cranks that inserts on the drive side like the ballast weights some pro road race teams use. This also eliminates the need to futz with preload bolts. I’m still not sure about those tire “levers” especially with some of the bead/rim combos I have done battle with.

  14. CrankPump on

    Thanks for all your comments. It’s great that the people here on BikeRumour have different and well-informed opinions.

    @Frippolini, CrankPump doesn’t try to do everything, it’s just a convenient way to store a pump. If you’re going to carry a CO2 pump, it’s pretty cool to not have to remember it. It’s also nice not to have it in your back pocket beating up your kidneys when you go over a bump.

    @Henry, CrankPump doesn’t take much time or cost more. Unscrewing it takes about 10 seconds, and you’ll get to see that in the Kickstarter video. It’s priced about the same as most other CO2 pumps.

    @Kevinfromva CrankPump is capable of preloading your bearings. It’s made of the same glass fibre reinforced Nylon66 material as your existing preload bolt.

    @Haggis – we will talk with Shimano at Eurobike in two weeks about this

    @il Bruce, thanks for appreciating the Softride Rocket we used as a bike model!

    @Slow Joe Crow, I would love to make an SRAM and FSA version, and it is planned for the future.

  15. Gabe on

    And I can keep my spare tube in my steer tube 🙂

    I like the idea for the minimalist look and would buy it if I weren’t a hippie who carries and actual pump.

  16. Jupes on

    I get it – but it just doesn’t warrant the extra expense or time to me in my opinion. I’ll continue to carry the CO2 cartridge in the saddle bag.

  17. Tim on

    I think it is a great idea. Otherwise unused space. My only concern would be rattling, metal canister in a metal tube, gotta be loose or it won’t go in,(that’s not what she said). A foam sleeve or an end cap that centers it perhaps. Maybe we can use it to turn our cranks into a paintball gun, oh wait, I think I have gone too far, have a great night.

  18. CrankPump on

    @Tim, glad to hear you like it. CrankPump includes a small cylinder of closed-cell foam that you pop into the axle the first time you install CrankPump, and stays at the end of the axle, preventing the cylinder rattling.


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