I have a question about some geometry thingies... I'm planning to buy an Intense SlopeStyle 6.6 in Small. According to the site this frame has a toptube of 21,5".

My question now is;
- Is this the horizontal or actual toptube size?


I now have a Cdale Perp Medium. Sizes:
- Horizontal Top Tube: 23,4"
- Actual Top Tube: 21,5"

Any help or advise is also welcome!