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Old 07-14-2012, 01:38 AM
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Ibedayank Ibedayank is offline
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Join Date: Oct 2011
Location: Columbia Tennessee
Posts: 1,171
Default Re: Bottom crank jack shaft.

Originally Posted by young grease monkey View Post
Unless you have a pull start, you will need to lock up the freewheel. This can be done by taking off the seal/shield and filling it with solder. If you need a freewheel, I think a bmx one would hold up ok. Try to find a good one, look up the models you have and find out which is strongest. They can handle quite a bit of torque. Oh, and hankman, HP is torque times rpm. Torque is converted to rpm and vice versa. HP is what really matters, torque means nothing without rpm.
I think you need to do your research on how a SBP shift kit works.
If what you say was true you could not pedal start a shiftkit bicycle at all anymore but yet everyone that has one that has unmodified freewheels can.
The ONLY freewheel that is suggested to make Fixed is the one that comes in a 4G belt trans as it is crap and blows up.

Oh and torque means EVERYTHING big rigs have a rpm redline of 2200 rpm

Mechanical horsepower

Assuming the third CGPM (1901, CR 70) definition of standard gravity, gn=9.80665 m/s2, is used to define the pound-force as well as the kilogram force, and the international avoirdupois pound (1959), one mechanical horsepower is:

1 hp ≡ 33,000 ftlbf/min by definition
= 550 ftlbf/s since 1 min = 60 s
= 5500.30480.45359237 mkgf/s since 1 ft = 0.3048 m and
= 76.0402249068 kgfm/s 1 lb = 0.45359237 kg
= 76.04022490689.80665 kgm2/s3 g = 9.80665 m/s2
= 745.69987158227022 W since 1 W ≡ 1 J/s = 1 Nm/s = 1 (kgm/s2)(m/s)

Or given that 1 hp = 550 ftlbf/s, 1 ft = 0.3048 m, 1 lbf ≈ 4.448 N, 1 J = 1 Nm, 1 W = 1 J/s: 1 hp = 746 W


A force applied at a right angle to a lever multiplied by its distance from the lever's fulcrum (the length of the lever arm) is its torque. A force of three newtons applied two metres from the fulcrum, for example, exerts the same torque as a force of one newton applied six metres from the fulcrum. The direction of the torque can be determined by using the right hand grip rule: if the fingers of the right hand curl in the direction of rotation and the thumb points along the axis of rotation, then the thumb also points in the direction of the torque.[6]
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