MDI - Meidai Bicycle Pumps: Do you have one and do you love it?

  I've stumbled on a topic which no one has posted and for which there is very little information elsewhere. There is no question people love their Silca, SKS, Topeak, Park Tool, Lezyne, or other favorite brand pumps but let's lend a little focus to a defunct brand which sold many bike pumps to American consumers and which have served us well for years and years.  I'm doing some maintenance on mine, such as adjusting, cleaning, and installing replacement parts, so I felt inspired enough to document the process.

  MDI sold pumps under the Cyclepro name and that is what I have had since about 1994, and it's otherwise known as the Meidai Top Super.  Please note:  This also applies to MDI manufactured Schwinn and Rampar branded pumps!  The maximum pressure (on the gauge dial) for these pumps is 140 PSI, which is enough for everyone who has "clincher" tires, but I've pumped up tubeless Tufo tires to 180 PSI with it.  It has survived weekly or biweekly sessions of pumping up tires through thousands of miles on my various bikes.  I have never changed the pump washer or tube washer until now.  I haven't needed anything to maintain it, except a little lube, until now.  The cylinder walls are still thick and intact despite all of the fillings and refillings of my tires through the years.  It has put up with neglect in various basements, survived crashing to the floor countless times, and it has put up with my overwhelming zeal for cycling.

  Simply stated, my MDI/Meidai Top Super bicycle pump is a rock solid tank which just needs a little TLC to keep going.  Here are the components I'm considering this week to keep my pump in shape for the next 20 years:

• Three feet of 1/4" ID (Inside Diameter) oil and grease resistant Air Hose (250 PSI) from MSC Industrial Direct.  Silca sells a 3/16" ID replacement hose and includes slightly smaller pinch clamps than those mentioned in the next bullet item.
• Pinch clamps and pinch clamp crimp tool (to secure the air hose to the pump and pump head)....I refuse to use hose clamps since I don't see them lasting another fifth of a century.
• Milton Easy-On Style Air Chuck with 1/4" hose barb (max pressure is 150 PSI...ahem...so it's not as good as MDI or its Silca counterpart...and I'm not completely sure it's appropriate for a bicycle pump but I might eventually use it anyway)....there are better options than Milton which I may discuss at a later date.  
• 30mm Silca 74.1 pump washer (The ID of the MDI pump cylinder or compression chamber is 29.8mm).  My pump has a 3/8" shaft so I gently ran two standard drill bits through the center of the leather washer, 11/32" and then stepping up to 3/8" to avoid cracking the leather and for more precise results.  The dimensions of the original MDI pump washer are found here.
• Silca N.F.S. conditioner or "Pump Blood" for the pump washer and pump lubrication.
• The hose barb which connects the hose to the pump can be replaced.  This hose barb which connects to 6.4 mm or 1/4" ID hoses is suitable for the new Continental tubing I linked to above.  Interestingly enough, a JMF 1/4in x 1/8in Hose Barb Lead fits right into the pump base without the need for washers.  Note that these brass hose barbs are only rated up to 150 PSI and higher pressures will require a stainless steel hose barb.  I was careful not to over tighten it and to grease the threads to prevent seizing should the hose barb need to be removed at some later date.  This component is available from MSC Direct.

  I am still hanging on to my old MDI thumb lock air chuck as it still works just fine.  Also, after rebuilding the head with a new valve washer and housing it works like it did when it was new, losing at the most 5 PSI when compared to a hand held gauge.  I've had an original brass SILCA Italian made classic style presta head in my tool box for many years and when attached to the MDI air chuck it works effortlessly.

  Bypassing a full overhaul, the easiest thing to do is simply replace the hose and hose barb and to maintain the original internal hose diameter - (as of 8/6/2017 I concede I've found the right tubing on McMaster Carr for $0.60 per foot) 3/16" ID 250 PSI tubing by the foot, 7/16" OD, Thermoid VALUFLEX/GS McMaster SKU 5304K42 with Oetiker hose clamps McMaster SKU 5435K12- makes the Silca 3/16" tube kit with clamps look like a bargain for one pump but expensive for two.  See the link below for the hose barb to make 3/16" hose work on your MDI - the original hose barb just isn't long enough for hose clamps to really keep the hose from falling off the pump. The original MDI hose only worked because a fitting was crimped to the end of the hose by a specially built machine at the factory in Japan.  Since this fitting is brass, be sure to use a little grease on the threads before screwing it into the pump base and be certain to keep the pump away from water or damp areas - if kept wet the brass fitting will seize and rust into the base and you won't be able to get it out or replace it. You may also be able to find this at your local hardware store, Menards, etc. Dynaflo 3/16" Hose x 1/8" Male NPT Brass Hose Barb, for up to 150 PSI applications, Fastenal SKU 69918, UNSPSC 40141734, comes in pack of 5, $3.80 per pack, $9.61 shipping.  Personally I moved to having both 3/16" and 1/4" hose and accessories on hand...but (as of 8/6/2017) I've also employed a method of attaching and detaching these with reliable, relative ease.

  MDI was forward thinking enough to allow their customers to easily access the pressure gauge dial face for adjustments.  Two screws are taken out and you are there.  With a small screwdriver (1/8" wide slotted head) and a Post-It note protecting the dial face one can gently pop off the needle and readjust it to zero.  There is no threading or retaining nut keeping the needle on, it's just a very solid friction fit like the minute hand on a clock.  I adjusted mine and it is reading PSI and Bars accurately as compared to my two tire gauges which I recently had calibrated by G.H. Meiser (under their amazing and wonderful lifetime warranty!).

  Thankfully Silca has the pump washer and lubricant that appears most appropriate for this maintenance project.  I'm quite certain it will work, but I'll repost when everything is installed.  I could keep going with the original MDI pump washer but I'd rather replace it now before it falls apart.

  As I said at the beginning of this article, my caveat about these pumps is of course that the company no longer exists.  However I am bolstered by my research.  G.H. Meiser in Posen, IL said they would take a look at it if I sent it in for service as well, but fortunately this is not necessary.  

Please let me know if you have any information or critique about this project.

Regards,

Matt M

"I'm sure there's a crying need for that."

- Mrs. Hudson, Sherlock, The Empty Hearse, 2014

(P.S. Several Ebay auctions are active for MDI/Meidai pumps. If you would like to investigate further also look for Rampar and Schwinn 1500.)

Please note that  I am not liable or responsible for any repair to any pump you may attempt as a result of the recommendations of this article.  You will be relying on your skills and expertise for your various projects.  Please be safe and take the necessary precautions that all of your pneumatic connections are secure for high pressure applications.