Once inserted into the steer tube, the wedge won't be over-riding the stem like it does in your picture. That is, your red line shouldn't be aligned to the edge of the wedge, but rather to the top of the angle cut on the stem. You might have a couple threads overlap, but unless godzilla torques down the stem bolt it oughtn't be a problem.

Some good points. Thanks for all your responses. I'll cable the bike up and take it for a test ride when I get the chance. Unless I'll need to substantially raise the stem it should be ok as it is then. One of those things that you need to be sure of before putting some fresh bar tape on!

Happy cycling all!

I've just come across this now, quite by chance, on Rivendell's website:

https://www.rivbike.com/blogs/grant-...-thwack-update

(scroll down for the non-Brad Pitt relevant bit)

Interesting, eh?

also a wedge type stem is a little kinder to the steerer tube than a cone (Cinelli)

the setup you've described here looks fine.

/markp

watch it !!
 

keep a big amount clearance..
one would think that weakest link is the stem ...
but you should keep in mind that the bike frame was build for a system ...if you have the same hardware to replace the smaller stem ..ok. keep compatibility up...or loose safety...
if it's alluminium keep to alluminium or steel same thing ..even the weight difference can be effective and cause a deffect or crash...
they made alluminium parts for like forever so newer hardware could just right INSTANTLY KILL your old SYSTEM ALLUMINUM or other ...
be well !!!✌🤏