I am restoring two Miyata Team Titanium road bikes. One is a 1990 and the other is a 1991 based on the serial numbers.

The seatpost sizes are i think the same for the both years...

Would appreciate any Miyata Guru or someone with a sure answer to help out in this one.

Thank you very much.

based on my chromo team miyata, guessing 26.8, but not sure for the team titanium.

Thank you chi-james

Speaking of 26.8, it was a common size on some of their early nineties MTB lines and am sure the size doesn't fit the Team Titanium Road bikes.

Based on my rough estimate i would say it is sub 26mm.

I dont know what size it is but it's not that small. for some reason I want to say it's the same as their other alloy frames like the 'QuickCross'.

That is possible. Do you know the size for that ?

Thank You

Can you also confirm the quick cross was Miyata's hybrid line ? and the Alumicross was the Cyclocross variant ?

Would you trust random comments from others on the internet, or would you take your bike to a nearby LBS and get it measured?

Confirming other Miyata models? Check out the catalogs that are on line.

Trust random comments but use a hammer to verify (cuz it will go in),

I'm assuming the OP was hoping that someone on BF had one of these which could be used to verify. Otherwise, Thrifty Bill is right, measure it properly or deal with the consequences.

This is a tool that your should have with your bike tools. (I am not recommending this model or this vendor it was the first one I goggled)
4" Digital Caliper

The whole reason this thread is up is because where I live, bike shop mechanics look in a condescending way at vintage stuff. Call it a lack of experience or culture which is a common issue here in other aspects of life.

Looking at the miyata catalogs website hasn't revealed much since the spec sheets didn't specify seatpost sizes .

Ultimately, it will be on my shopping list if all else fails...

this is the right tool for the job but it's pricey, Stein Seatpost Sizing Rod Set - Outside Outfitters