1.) CRG, Birel and OTK all make an extended porch. The CRG kit will fit on Parolin/Merlin, I know that for sure. Also remember CRG, Birel and OTK make a lot of different brands. I can send photos if need be.
2.) Yes, the overall length will increase roughly 4 inches.
3.) Height is one thing, but it’s really the inseam. If you are looking to purchase a chassis, try to seat in one first.
4.) Most chassis now some to be either 30mm or 30mm/32mm combination.
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