I am currently contemplating construction of a tadpole (for practice before building a Locost sports car from plans) and would like to clarify one item I found on your construction site. I worked for 22 years at a steel fabricating firm founded by a former sports car racer, and am very familiar with the subject of high strength fasteners. What you say is correct but incomplete. There are three grades of steel fasteners in common use in the US, 3, 5, and 8. Standard stainless fasteners will not be much stronger than grade 2s, but will be tougher, and of course rust-resistant. The grade 9 and 10 and high strength stainless fasteners are normally available more from industrial fastener houses than from hardware stores. An excellent reference on industrial hardware is http://www.mcmastercarr.com. They are rarely the least expensive source for anything, but they have an extensive stock and informative catalog on line. You are exactly right in recommending Grade 5 fasteners for load-bearing. We used them in overhead lifting for the exact reason that altho they are not ultimately as strong as Grade 8s, thhey would bend rather than break.
Which type of front brake (manufacturer and model) do homebuilders recommend for the front brakes for a homebuilt trike? My WizWheez has Sturmey Archers but I am not sure about availability for a homebuilt project. Would Sachs VT5000 be the best solution for front brakes. Thanks for any tips.
Sachs VT5000 are just fine. The only "thing" remaining is the modification to stronger axles.
Very simple (if a lathe is somewhere near). 1) remove the original axle 2) remove the cups 3) the remaining holes are aproximately 27.7mm (or something like that) machine them to 28.00mm (so that "6001" sealed bearing fit inside snuggly) 4) drill a 16mm hole through the hub 5) after measuring the distance between the bearings, prepare a 12/15mm dia (hole/out) distancer that will keep the bearings in the middle and one 12mm long piece that will fit between the inner bearing and the brake holding plate 6) Drill a 12mm hole in the brake plate 7) put the pieces together and pull through a 12mm axle 8) done...
The "6001" bearings should have exactly a 12mm hole and 28mm outer diameter. Some mopeds use 12mm axles (cheaper than custom made)
Also see what's on the IHPVA text page.
Thursday, 29 January 2009