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Moving the BB forward in geometry terms is just lengthening the chainstay and shortening the reach. This does not require any eccentric BB options. Mechanically there might be reasons for tube butts you might want but the geo can be independent of this. Within the range of adjustment possible you are better off with an axle flip chip and a reach adjust headset to play around with Front/Rear centre proportion (which is what sliding the BB forward or aft would do). From an opinionated perspective I probably would not even bother with a reach adjust headset. People spend a lot...

Most DH bikes I’ve tested are 110-120mm head tube length. If you can fit a straight tube 56mm head tube, you have tons of room for reach and angle adjust headsets.

That sounds sick! If you can get the stack dimension close to where you want it, going slightly shorter on the headtube can be pretty helpful for a dual crown fork by allowing a wider range of adjustment. My size R3 (XL) Trek Session has a 117mm headtube length, the same 9mm upper / 1mm of lower headset stack, and 634mm on the geometry chart which is shared acoss all sizes. While the stock configuration felt super low to me, that could be somewhere around what you're looking for. I played with bar height a lot to get things dialed...

Came here to say the same thing about 130mm+ being a great number to see when looking at a size XL geo chart. Also seems to eliminate a bit of flex from the steertube with less spacers under the stem.

As a tall person, the one headtube standard is for them to be too short. I've never needed less than a 135mm headtube, and even with that I'm often running a healthy dose of spacers under my stem. And if I haven't convinced you yet, taller headtubes tend to be safer because there's more distance between the top and bottom welds on the headtube, meaning less leverage acting on them. You're more likely to see a short headtube ripped off.

Maybe take a look at what PMW makes? They're a pretty popular supplier... https://www.paragonmachineworks.com/headtubes/steel.html

There is no standard but for trail/enduro bikes head tubes in the 100-130mm range in 10mm to increments are the most common. For metal bikes head tubes under 100mm can start to be harder to pass testing with. It's typical to increase ~10mm/size so something like 100/110/120/130mm for a S/M/L/Xl is a starting point. If you are building a standard large frame for yourself I probably wouldn't go under 110mm. You can correct with bars and stems spacers a bit but it's nice to not have too much under there.

This site has a lot of bikes but I don't know if you can get it to list just head tubes; you can however, compare a bunch of bikes like this: https://www.bike-stats.de/en/geometrie_vergleich?Bike1=Canyon_Torque%20… Edit: what @pinkrobe said

There is no standard length, per se. Head tube lengths often vary by frame size. For example, on the Forbidden Dreadnought V2, head tube length is 90mm on a small and 135mm on an XL frame. The Commencal Supreme V5 has a HT length of 112mm across all sizes of frame. This info is listed in the geometry chart for each bike model. To make it more entertaining, the stack height [distance from crown race to the headset top cover varies with the type of headset. Pressed-in bearing cups with the bearings outside the frame create the tallest stack, and...

To me, scrubbing is about shortening the height of a lip and therefore staying much lower while at a higher rate of speed. You’ll see top mx guys tires taking off several feet before the end of the lip and then dragging their footpeg, rear axle, and sometimes handlebars over the peak. RV2 recently said in a podcast that when following people into new jumps, there could be a 10+MPH difference in speed coming in depending on how they hit the jump. That speed is higher before, during, and hopefully after the jump.

NW Cup is not over, in fact registration opened last night for the final race at Dry hill in September: https://www.bikereg.com/nw-cup-finals-dry-hill