Originally Posted by
Chris_W
Just received two more forks back. This time both of them got the insert. One was from a bike ordered in November 2011, the other in August 2012. They may have abandoned the x-ray process and just started to put inserts into all forks, but we need more data before having any degree of certainty about it. We've been weighing forks with and without inserts, unfortunately some are different lengths, and we never weighed the same fork before and after the insert, but we estimate the extra weight of the insert to be about 10-15 grams, so no big deal. Forks that get the insert also come back with a new compression plug included since the internal diameter is greatly reduced.
That's interesting Chris. Thanks for the insight. Sounds as though this very light 'insert' is a 'sleeve'. Since you mention that it decreases the inside diameter of the steerer thereby requiring a new expansion plug.
Could you snap a couple of pics for the future? Have you removed the expansion plug to see how its changed? The stock expansion plug...I have included a pic below...is 48mm in height. Obviously placing a sleeve inside the steerer for its entire length will reinforce the steerer. Since the weight increase is so small, sounds as though the sleeve is very thin. What do you think its made out of? Maybe a glass reinforced nylon versus carbon fiber which would be more costly?
Thanks again.
PS: Another thought is...the thin plastic sleeve aka insert maybe just lightly pressed in place. It would therefore be locked into position once the expansion plug is expanded. Its thin wall would likely deform creating a tight fit to the ID of the steerer. This approach would be simple for Specialized. They would choose an insert aka sleeve length to match the steerer tube height and wouldn't require any messy epoxy to hold it in position. What do you think?