I’m thinking of getting / building a dirt jump / street / park / general tooling around hoping to develop some skill bike but i’m a bit stuck on sizing…

Accepted the seat tube length doesn’t mean a lot (as long as i can roll down to the local dirt jumps at 5 in the morning before the real riders and local kids arrive to mock me), whats a good place to start for top tube length.

I’m approx 6ft and ride medium XC frames with 100mm ish stem.

Any help greatly appretiated

Dj/4x frames usually come in short/long (<22″ or >22″ ish).Just get a long.

Have had a few DJ bikes and tried a Nukeproof Snap they were all long-ish and low. Top tubes probably in the region of 550-570 mm which was fine for me at 6’2″.

I am 6’7″ and have a 22″ top tube and 50 mm stem on my my Curtis SuperX

Thanks guys, looks like 22in is the best place to start… best give the DJ/4X frame with a 24in top tube i’ve been offered a miss then!

I was looking at MTB (26in wheels) how to BMX frames compare length wise, looking for the same kind of thing?

I don’t know if you would be interested but i have just stripped down my Identiti Mr. Hyde frame and will be listing it for sale when i can get a box for it.

Would probably be looking for £80 posted for the frame, seat post, seat camp and FSA Pig Pro sealed bearing headset.

also look at the seattube angle. Mine is about 21 inches, and is a short equivalent I guess, however if used for any other type of riding with the seat higher it soon becomes quite a bit longer. Mine is fine with the seat slammed or slightly higher for me, as it was for the my friend who’s 1 foot taller than me, for xc rides, with the seat raised some.

So i’ve been offer a 2004 Cannondale Chase (before the Cracknfail jokes begin i’m a big dale fan and have never had any problems with the 7 bikes i’ve owned) which the seller says is a large, however he has measured the top tube at 22.5 when the geo charts say it should be 24….

Why do geometry charts never match up with the real world!

Anyone have any experience with Cannondale Chase’s? Seems to get good reviews.

How has the seller measure it? Actual or effective? Cannondale may quote the effective like most do and he may have just measured along the top tube.

I’ve not had one but have come close to buying one on a few occasions.

I’ve built up an XS BFe as my play / jump / much about bike and it’s good fun and seems to be good for my shonky brand if jumping.