Step-Thru seat/steering tube dimensions


Active Member
The Step Thru seat tube is marked J31.8 *400.
( Presumably the 31.8 is the diameter in mm. The 400 indicates mm, it rounds to 15.75 inches. minimum insertion mark is approx. 3.75 inches.)

The Step Thru steering tube is marked 28.6 MM. (minimum insertion mark at approx 3.5 inches, ...not marked as to length.
I measured it at 9" insertable)

I do not have an XP, so don't know how/if its dimensions differ.
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