Looking at the POH for C172P model - can see a fair parallel between TOSS and Vx.
Cessna quote 60KIAS in section 4.3 - but in section 4.8 they use 56KIAS. Probably easier to eyeball the 60 mark on an analog ASI though.
There are some discrepancies in TOSS in the POH though:
* in the general notes, (4.8), Cessna quote 56KIAS as TOSS
* by calculation, using 49 as the 10 degree Vs - you get 49 x 1.2 = 59KIAS
Probably not even noticeable in practice though?
One interesting note is that they state you gain 10% by using 10 deg flap for t/o - which is why I've only used that stall speed for calcs.
Of interest to this thread is that the 'lift nosewheel' recommendation is actually in the C172 POH. ie, there is a Vr implied.....or are we being too strict in our read of the POH?
In section 4.8, it's stated to lift nosewheel at 55KIAS. But, elsewhere they use 56KIAS as their general TOSS number. Using the 10 deg flap stall speed of 49K - you can calculate a Vr of 54K, (x 1.1).
Using zero flap, you can calculate a Vr of 57, and will quickly reach a calc TOSS of 62 before reaching the 50ft barrier, and from there you may as well accelerate thru to Vy (76).
Conclusion - provided your runway is smooth, then Vr might be acceptable - but in real life strips, forget the Vr calculation and get your nosewheel lifted early. Doesn't prevent you complying with other speeds such as TOSS, Vx, and Vy though.
happy days,