M20 AIRWAVE BOOSTER Thread

[Al Bundy]

Albundy, I had one of those fail on me. The rubber pulled out of the steel compression ring at the bottom. I had Fast send me another one I believe they are 114$ from them. I'm not sure if Fast has them made specifically for that application. Does the bottom of the air bag get bolted to an aluminum arm that also locates the inner idler wheels just behind the front w arm?

Yes, that is correct. When fast sent yours did the bottom cap have female (threads) or male (bolt) to mount on the aluminum arm?

 

[Elton Buss]

It had a bolt. I was just checking on Google all of the different types of Firestone air sleeves and what bases they had. With all of the measurements you might be able to find one. I was always more concerned about the air line then the sleeve. I have used it since 05 and have never had any other problems with the sleeve.

 

[Redbeard]

I believe the bottom cap just screws onto the aluminum shaft, but not sure if the stud is on the cap or shaft. Anyone that knows please chime in.

Yes, the bottom part threads on a metal stud coming out of the aluminum arm.

 

[Redbeard]

Ok, I removed the air spring from my Vector and started looking closely with a magnifying glass and discovered the Firestone part number is stamped on the upper band that secures the rubber sleeve to the top cap. It reads:

Part number - WO2-358-7199

There are cap and piston numbers as well:

Cap number - NBD 10183
Piston number (lower black plastic part) - NBD 10238

According to the online Firestone PDF catalog, the 7199 air spring part number does not exist. The cap and piston numbers are good, but they're not shown as being used together in an assembly. That must mean they are custom and only produced for Fast; explaining why they're more than twice as expensive as a comparable spring online.

A Firestone WO2-358-7073 is almost identical to the custom 7199, but the lower piston is aluminum. I'm not sure if trying this spring is worth the risk for saving $60?

Also, I discovered the color of the Firestone logo represents the composition of the rubber sleeve. I'm going to assume the orange logo on the M20 spring would be a much more tough rubber than average to withstand the abuse.

 

[Al Bundy]

Ok, I removed the air spring from my Vector and started looking closely with a magnifying glass and discovered the Firestone part number is stamped on the upper band that secures the rubber sleeve to the top cap. It reads:

Part number - WO2-358-7199

There are cap and piston numbers as well:

Cap number - NBD 10183
Piston number (lower black plastic part) - NBD 10238

According to the online Firestone PDF catalog, the 7199 air spring part number does not exist. The cap and piston numbers are good, but they're not shown as being used together in an assembly. That must mean they are custom and only produced for Fast; explaining why they're more than twice as expensive as a comparable spring online.

A Firestone WO2-358-7073 is almost identical to the custom 7199, but the lower piston is aluminum. I'm not sure if trying this spring is worth the risk for saving $60?

Also, I discovered the color of the Firestone logo represents the composition of the rubber sleeve. I'm going to assume the orange logo on the M20 spring would be a much more tough rubber than average to withstand the abuse.

View attachment 127891 View attachment 127892 View attachment 127893

Way to go on that! So there it is. I edited my post and removed that link so folks don't get frigged up!

 

[Al Bundy]

I bought a small bicycle tire pump yesterday and tried it on the front shock. It wouldn't fit; the pump head was too big, so I picked up schrader valve extention. M20 install is back on this evening, and I'm going to try my hardest to finish (maybe sneak out of work early). Pike fishing scheduled tomorrow and Snowmobile ride Sunday.

 

[Al Bundy]

Help! I've got the limiter strap where I think it goes but only one set of holes in the strap line up with the holes in the adjuster. And what the hell is the function of this crazy aluminum c clamp?

 

[Elton Buss]

Albundy, the bolt that you show doesn't get Used to fasten the limiter strap. It is only used to limit the travel of the steel u band. The aluminum collar goes between the u band and the grease zerk for protection. As for the limiter strap it only bolts to the hole at the end of the u band. The bolt that goes through the band gets tightened just enough to keep the band from loosing contact with the cross shaft under compression stroke.

 

[Redbeard]

Al, play around with the limiter strap setting once you get rolling. I rode my M20 for 2 years with the strap all the way out and ever touched it...didn't think I needed to until Soldiers Papa and Dusty Dan recommended I try.

I cinched up the strap one hole from all the way out and "WOW"...what a difference! I couldn't believe how much more difference it made. I then fine tuned even more with the bolt and I'm very satisfied! What an amazing suspension!

 

[Al Bundy]

Albundy, the bolt that you show doesn't get Used to fasten the limiter strap. It is only used to limit the travel of the steel u band. The aluminum collar goes between the u band and the grease zerk for protection. As for the limiter strap it only bolts to the hole at the end of the u band. The bolt that goes through the band gets tightened just enough to keep the band from loosing contact with the cross shaft under compression stroke.

Al, play around with the limiter strap setting once you get rolling. I rode my M20 for 2 years with the strap all the way out and ever touched it...didn't think I needed to until Soldiers Papa and Dusty Dan recommended I try.

I cinched up the strap one hole from all the way out and "WOW"...what a difference! I couldn't believe how much more difference it made. I then fine tuned even more with the bolt and I'm very satisfied! What an amazing suspension!

You guys rock!

 

[Al Bundy]

Thanks Elton and Northernsledder for setting me straight on limiter strap.

 

[Al Bundy]

I couldn't use the new protector because it was designed for a longer air line. I will be repositioning the schrader valve to a spot further back.

For now though I'll use what I've got

 

[Al Bundy]

I first put about 60psi in the rear shock; sat on the sled and it was squishy. I bumped it up to 75ish and what a difference. Fast sure is right when they say a couple pounds of air will make a big difference.

 

[Redbeard]

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Thanks Elton and Northernsledder for setting me straight on limiter strap.

Credit goes to Elton! I only offered my .02 on the limiter strap position. Play around with that. Heck you may find a different settings that works best for you.

I think you are going to love the upgrade, and I would recommend the M20 to anyone!

 

[Elton Buss]

Al, you are more than welcome. I wish I had half the talent Northersledder has. I am about 255 without gear and I run anywhere from 75 to 80 lbs in the rear air sleeve. Front about 40 psi. I ran the first year without the onboard compressor and it wasn't any fun. I don't care for the system they have now but as Northernsledder has done so beautifully you can get a compressor cheep on the web. If you ever have a question you can pm me and I'll give you my number. Enjoy