mavic517

I am not new to changing tires. But, MA-40 rims & Continental Tires are a Nighmare when paired together. Has any one else had this problem?
Questions:
1) Are the MA-40's slightly larger than other 700 CC Rim?
2) Are the Continental GP-4000's slightly smaller than other 700 CC Tires?
I mean, its a nightmare to dismount & remount this pair.
3) Do you have suggestions?

Thanks for your time,
Steve (email: hohobike1@aol.com)

fietsbob

the double wall double eyelet extrusion design, does not have much of a drop center
between the bead seats.. . so the tire bead within
the rim has no slack to pull into, on the opposite sides..
so much different than rims with a drop center portion
Like the Wolber Super champion model 58 .. similar era..

Do you want to look at different rims or tires?

Jeff Wills

Yes, it's more difficult to change tires on MA-40's. They aren't "larger", it's just that the shape of the rim doesn't have the extra wiggle room that makes it easy to remove or install a tire. Continental tires tend to be a little stiffer (especially when new), and that can make them tough to install, also.

Here's what you can do:
Install a thinner rim strip. This will give you more room to maneuver the tire bead on to the rim. Velox rim strips (as much as I love them) are quite thick. If you use a thin reinforced nylon rim strip (such as Rox) your tires will be easier to mount. I still think they're susceptible to heat, but I don't think there's any huge downhills near Tampa.
When changing the tire, pinch the beads together all the way around to put them at the center of the rim. This will give you more wiggle room to remove the tire.
Use a Crank Brother Speed Lever. This braces itself against the axle to ease installation/removal.

BTW: it's "700C", not "700 CC" . 700C is just a designation of the rim size, not a measurement. Read on: https://sheldonbrown.com/tire-sizing.html

Asi

I have mavic ma-40 with continental gp3000 and it is a bit harder than usual but manageable. I have to use the levers* for the last bits when I put it back.
(i know that it may be hard with levers too, but it depends on the lever advantage. short plastic levers may give a hard time.. i use some flathead screwdrivers, but i cannot advise to do so - it can be dangerous for the innertube, but at least I have lots of leverage action).

By the way, the wheel is nice, good rim, good tyre, and they fit well (with a small effort)

dsbrantjr

+1 on the thinner rim strip. I like the Continental Easy Tape myself; I've never had any heat-related problems with them. A little soapy water may help ease the last bit of bead over the edge of the rim.

Some tire/rim combinations are just rough to mount. If you need to use extreme measures to get them installed in the workshop, you might want to ponder whether you are going to be able to make repairs on the road as you decide if you are going to stick with this particular combo.

mavic517

Thank you for the info. It will really help !!