Custom Cranks

[Too Tall]

Orange you glad I didn't say potato?

OK all you sleuths supreme. Tired of the drug wars? Fire up your blogs and tell me what you can find on Tom Slocum's Custom Alum billet 7075 cranks. What I do know is that Tom has been making cranks for customers and at least one private brand supplier for yrs. Tom can produce cranks in any length with a spider of my choosing. They look good however I've never EVER heard of them or seen a set and can not find and references.

My goal is to fit the new track tandem with a set of real 144 bcd track cranks that are not re-tapped or otherwise modified.

Plan "B" is to modify a set of Sugino 75's. Not a bad choice. I don't WANT to be bad I just am.


http://www.hscycle.com/Pages/slocumcrankset.html

[zap]

You need to confirm the quality of the billet is before you go further.

[Richard]

I have no knowledge of these. What I can offer is that CNC'd cranks are the last option I would chose. Cold forging is by far the strongest, hot forging second, CNC a distant third. I've seen CNC'd cranks snap during mtb races and the spear that remained on the bike looked scary. There were a lot of CNC aftermarket cranks sold to the mtb market and they seem to have all gone away. This was in the days of all things blue, green, red, etc. on cool mtbs.

[Too Tall]

Agreed, that was my worry too. Tom has overbuilt these and the customs he supplies incl. many in the 200mm+ range and claims no returns. You have a good issue to note. Thanks.
Zap, how do I do that?

[zap]

True, cnc cranks failed, but they failed for 2 reasons. One, some manufacturers used inferior billets and/or alloy. Two, far more common, manufacturers went over the top to reduce weight, ie Topline. These cranks had so little mass left that riders with even average strength could break them over time. It's all in the design and unfortunately, machine shops decided to beat Shimano by going after low weight. I think some of these aero engineers under estimated the stresses cycling can put on components.

For identical parts, compared to "quality" 7075 alloy cnc'ing, cold forging under the highest pressures will lead to a slightly stronger part.

Billet aluminum is also forged and then sawed into sections. But the amount of pressure varies. More expensive billets will be forged under higher pressure, say over 70,000psi. I don't have the figures in front of me, so if someone here knows for sure, please correct me.

Also, 7075 T6 aluminum is stronger than 6061 T6 alloy.