Looking at gravel geometry. 7.8 cm bottom bracket drop?

[Kingson]

Originally Posted by sparky33

what wheel/tire size?

7.8 sounds fine for a large 700c tire. Too much drop for 650b imo.

700

[litcrazy]

If you intend to ride road and traditional gravel, it should be fine.
If you want a bike that you ride road, gravel and single track, it may have a lot of pedal strike. Especially if you need to pedal through rock gardens and the like. Also if you like longer cranks, it could be low.
Different folks have different vision of what a gravel bike should be able to do.

[Mark McM]

Originally Posted by prototoast

Many people find excessively tall headtubes aesthetically unappealing, and so for a rider looking for more stack with a shorter head tube, more bottom bracket drop is one way to achieve this.

Really? People are willing to risk pedal strikes for a shorter head tube?

There is generally just one consideration when a frame/bike designer selects the BB drop - the lowest drop that will provide the desired pedal clearance. If the BB drop is lowered further for aesthetic reasons, it means less pedal clearance than desired for that type of bike, making pedal strikes more likely.

[EB]

Consider two common "gravel" tire sizes, 38mm and 45mm. The beat seat diameter of a 700c tire is 622mm. The 38mm tire yields an approximate wheel diameter of 698mm, and the 45mm tire yields 712m. The radius is what matters for our purposes here, so the difference in radius between the two nets out to 7mm.

So all things being equal, if I have a "gravel" bike with a BB drop of 68mm, and another with a BB drop of 78mm, the difference in ground clearance is almost cancelled out by running larger tires.

And we all know what they say about running larger tires.

[DfCas]

If you have pedal strikes your bb is too low. If you dont have pedal strikes your bb is too high. 😀