Parts are as follows:

1" steer-tube threadless fork & headset
1&1/8" stem
Stem riser (to be determined)
1" to 1&1/8" adapter sleeve

Assuming I need the additional rise of a stem riser, what is my best option - to install a 1 to 1&1/8" adapter and then put on a 1&1/8" stem riser or to install a 1" stem riser and then install the 1 to 1&1/8 adapter? I'm kind of confused as to exactly how this contraption is to fit together...

Main concern is structural integrity.

Thanks!

I used the 1" to 1-1/8" adapter on my existing stem (1") and then a 1-1/8" stem riser. Seems to work fine. I think this method may be an advantage in that you have some tolerance for height adjustment on the stem riser, and you would not have to deal with moving the shim along with the stem if you choose to change height.

For myself I insist that ALL my bicycles have the "Kalloy" brand
1 1/8 adjustable stem installed. I've converted both bikes now
with a spare "kalloy" ready for another bike should I buy one.

While some here will pooh pooh this stem it's really great for
setting the bars "just right" where you want them.

Hi Old Grandad!

Thanks for the reply - my concern is that the "ears" of the stem (in this case, the riser), normally clamp directly to the fork's steer-tube. With the adapter in place, the stem-ears are clamping to a rotating sleeve, apparently, with no direct contact to the actual steer-tube. Doesn't this introduce the danger of turning the handlebars, having the adapter-shim rotate on the steer-tube, and leaving the fork and wheel to continue in their original direction of travel?