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Easy question..... what's the proper pressure for the tires in a Sonex/Waiex? Also.... I got my Airworthy cert today !!!!!!!!

Congratulations!

Tyre pressures - check with your tyre manufacture for pressure range.

My Legacy has Goodyear, Flight Custom III, 5.00 – 5, 6 ply, which I inflate to 40 psi

Congrats! 45-55 psi. I usually fill to 55 and am happy with anything 45+. If you do 30 psi like on the casting, the tire & tube will spin and tear the valve stem.

Hi Bryan,

Do you think it would help if you mentioned the tyre brand, model & ply rating?

Thanks for the info so far. Right now... they are just the factory tires. Over the years, I remember people saying to run more pressure than the wheel casting said. And.... the inspector yesterday was telling me of a pits that went over on it's lid because a tire was very low. (Bad ground loop on landing) Eventually, I will put on some 5.00x5 tires.... but for now... it's just the little stock ones.

Have about 500 hours on my Sonex, all with the 5.00 x 5 tires. The 50 PSI Sonex calls for may be right for the standard small tires, but with the 5.00 x 5 tires, I find 25 PSI quite adequate. As I recall. the aluminum wheels are marked 35 PSI max, and while they seem to be perfectly okay with the small tires, the increased sidewall area of the larger tires puts additional stress on the wheels so staying closer top the wheels maximum rating seems prudent with the larger tires. I know some will immediately think that air pressure is the same everywhere, why should tire diameter matter, but the added side wall area means more total force applied trying to spread the two halves of the wheel and bolt failures in those wheels has been known to happen. (I replaced my bolts with aircraft grade ones.)

David A.

I always used the factory Chen Shin (sp?) 11-4X5 tires and inflated them to 45 psi and never had any issues. They do a remarkably good job holding air! I normally checked them every 2-3 months and they never lost more than a few psi.

Thanks guys

When I was working at Sonex, I always ran the tire pressure on the factory airplanes at 45 psi. Seemed to work great.

Sonerai13 wrote:When I was working at Sonex, I always ran the tire pressure on the factory airplanes at 45 psi. Seemed to work great.

The assumption that ALL Sonex are using the mythical Sonex standard tyre(???) is plain weird.

How about respondents quote the tyre make, size, ply rating and might also be helpful to disclose, mostly sealed/grass runways.

AND
If there is a particular rationale for their preferred pressure eg Manufactures Recommendation, etc