AlexRIMs MD21 What width tires will it accommodate?

Johnitahoe

New Member
I have Alexrims MD21 on my cross style E-Bike.

I've been taking it down mountain bike trails and would like to install wider tires.

Can anyone tell me how wide I can go with these rims?

The current tires on the bike are 42-622.

Thanks,
John
 

E-Wheels

Active Member

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FlatSix911

Well-Known Member
I have Alexrims MD21 on my cross style E-Bike.

I've been taking it down mountain bike trails and would like to install wider tires.

Can anyone tell me how wide I can go with these rims?

The current tires on the bike are 42-622.

Thanks,
John

Your MD21 Alex rim specs are shown below along with the Schwalbe tire guide.

With a 21mm internal width, you should be fine running 35 - 62mm wide tires.

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1567440946418.png
 

Johnitahoe

New Member
Help!! I put Schwalbe Marathon Pro 29 x 2.10 on my AlexRIMS MD21. It appears as though the tube push out the tire and then the tube exploded. These tires are 54mm wide and according to the tables should be fine on my MD21s. Any thoughts on what might have happened and how to correct the problem? I was using MAXXIS welter weight tubes 29x1.9-2.35. I think someone measured the tires and said they were only 1.8. Could the tubes be too big for the tires? Thanks, John
 
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FlatSix911

Well-Known Member
Help!! I put Schwalbe Marathon Pro 29 x 2.10 on my AlexRIMS MD21. It appears as though the tube push out the tire and then the tube exploded. These tires are 54mm wide and according to the tables should be fine on my MD21s. Any thoughts on what might have happened and how to correct the problem? I was using MAXXIS welter weight tubes 29x1.9-2.35. I think someone measured the tires and said they were only 1.8. Could the tubes be too big for the tires? Thanks, John
It sounds like you have the correct size tubes for your tires... my guess is the tube got pinched during the tire installation and blew out.
Here is a pro-tip... try a bit talcum powder inside the tire before you inflate the tube. It helps to seat the tube and works like a charm. ;)
 

Nova Haibike

Well-Known Member
Help!! I put Schwalbe Marathon Pro 29 x 2.10 on my AlexRIMS MD21. It appears as though the tube push out the tire and then the tube exploded. These tires are 54mm wide and according to the tables should be fine on my MD21s. Any thoughts on what might have happened and how to correct the problem?
You did not mount the tire properly. The tube was caught under the bead when you installed it, and when you inflated it, the tube pushed the bead out and it exploded.

When mounting a new tire (or installing a new tube), dust it with talc/cornstarch/baby powder; this will make it easier to install. Give the tube some air too, just enough to give it a tubular shape. After mounting the tire, inflate it partially and look at the raised ridge just above the bead on both sides. It should be just visible over the top of the rim. If it bulges upwards, the bead is not seated. Deflate the tube and pinch that area; you will likely see the tube sneaking out under the bead. Massage the tube into the tire until it is no longer visible and partially re-inflate again. If the ridges look good on both sides, inflate it to your desired pressure.

How to Remove and Install a Bicycle Tire & Tube
 

Asher

Well-Known Member
I've done what Nova said without the powder, always worked - give the tube a little air, put it in the tire, mount the tire, deflate the tube and then pump the tube full. The tube often sits incorrectly if it's not pumped from empty to full while in the tire. Pumping from empty to full helps it take the proper shape and position.