Originally Posted by
gleearch
That said, I can't tell if a BD_1 or Bianchi is a Mark 1, 2 or 3. If they don't list the year of manufacture in the ads, it's hard to correlate. Plus I noticed that in some of the latest postings, they are selling Birdys in Japan, so not sure if BD-1s are no longer being sold.
How do I tell if a BD-1 or Bianchi is a particular make? Is it when the handle bar stem and seat post are black? I'm looking at the monocoques. Is there a way to visually tell the difference. Since I'm new to Birdy's, when I look at the frames, I can't see much difference other than colors of the seat post and stems. Well the look of the stems seems different from the Mark 1 and newer models. Are there other things I can look for?
A mk1 isn't monocoque. The easiest way to tell a mk2 from an mk3 from a pic on the internet is that the mk3 has the chain tensioner near the chainring while the mk2 has it on the derailleur. Pacific does sell the mk3 tensioner as an after market item so if you're in person, the mk3 has hydroformed rear arms and a non-welded leading link on the front. The front stem comes in two main variants: an upright one and a forward tilting "sport" version that R&M/Pacific spec on the bikes as they feel like it. My understanding is that some (the base model?) stems don't allow adjustment but mine does.
At the risk of being wrong on the internet, I suspect any new BD-1s you buy in Japan are going to be the new classic Birdy that got designed as part of the 20th anniversary. They look like the mk1 but I believe have refinements to the geometry and forks. Check posts/articles from the anniversary announcement time period for more details but I don't think I've seen a detailed breakdown of the differences. I don't know anything about the random asian Birdy models.
Originally Posted by
gleearch
Was there a significant difference in performance to justify changing out the wheel size? Did it cause issues with the fold and or with anything else like the derailleurs, parts rubbing against each other, etc?
I'm debating doing this on my mk3 with disc brakes. I believe the main reason to switch wheel size is for a wider tire selection. I believe the options in 355 are Marathons, Marathon Racers, Kojaks, and (if you import them) Panaracer Minits Lite for BD-1. Dropping to 349 should be fairly straightforward and is something I've considered depending on the availability of 355 tires going forward, it's only a 6mm difference in rim diameter but it doesn't open up tire selection that much. Going up to 406 is much more desirable for tire selection but from my reading, (probably same as yours) means dropping to a 28mm tire. The outer diameter between 38-355 and 28-406 isn't that large and the only thing I could see needing adjusting is tightening the screw on the rear triangle that locks it closed when the seat post is down plus maybe the brakes (but I haven't thought much about that due to discs).