Vitess D5: swapped out handle bar post but I'm worried about the spacers I used.
I'm not sure all of my terminology in the description below is correct, please bear with me.
I swapped out the original Vitesse D5 handlebar post to a quick release two-section variety. Unfortunately the new post has a shorter base (the section of the handlebar from the head tube to the hinge). Because the base is short the fork sticks out by 8mm. This means I cannot unfold the handle bar post because the sticking out fork interferes with the top section of the post. To fix this I bought 8mm worth of AHead spacers and put them around the fork under the handlebar post base (please see attached photo). I wonder if that's OK. My concern is that the post's base and the head tube have a significantly wider diameter than the spacers.
I don't want to cut the fork by 8mm, but should I? I originally thought putting the spacers in was OK because these are the spacers used on many AHead sets. But I worry that Dahon's long lever handlebar post may require the wide diameter base to sit right on the head tube.
I'd say the spacer will be ok for short term but that area gets a strong load and you might want to consider getting a custom one machined that matches the diameter of the parts above and below it. If you do a bit of research it shouldn't be too hard to find somebody that has a computer controlled CNC machine that will run off a nice new spacer to the exact dimensions you need (measure them with a vernier caliper!) and not cost the earth. I just did this to get a custom lugged spacer I needed to help hold the tensioner on to the frame with non-standard Phil Wood axle nuts on my Brompton/Merc hybrid lightweight and don't regret it at all.
As for just banishing the gap - I'm not quite sure how there is excess of length if you say the new tube's stem is too short, so cannot comment on that puzzle. It LOOKS like it's too long and you need to shave off the excess so that the quill type (it is quill type right?) can descend further into the head tube but with that photo this is only a guess.
No the head set is AHead type, not quill. Originally I put the spacers right against the tightening nut (inside of the handlebar post base), but the fork protruded too far out to swing the handlebar post to the closed position.
Thanks for the hint w.r.t. finding someone to machine a more substantial spacer. I will look into that.