Crank height relative to axles? [Frame Design]

[Ch00paKabrA]

Like the Marzocchi 888? I've seen a couple of sets of those for sale.

Do the regular suspension forks I've seen with adjustable travel achieve a variable crown-to-axle length?

I'll bear the spacers in mind. You've also reminded me of the Crane Creek offset headsets, but they ain't cheap.

I don't know what type of bike you have but I don't think that the Angleset headsets from canecreek will fit in a regular 1 1/8 head tube. I have one on my Gary fisher Kingfisher but that has a 1.5" head tube and I have to use a 1 1/8 steerer tube fork on it. Also the angle change is relative to the length of the head tube so even if you get the 1.5 degree angle set, if you have a really long head tube, it may only slacken (or steepen) the head tube angle one degree.

also the 888s use a 20mm through axle. Do you have a 20mm front hub? If not, then you have to buy a new (or used) front wheel which will set you back dinero.

 

[Punx0r]

I'm going for a straight 1.5" head tube so I can fit pretty much any fork out there with the appropriate headset. The forks I have are 1 1/8 straight steerer with 20mm through axle - a new wheel was on the shopping list anyway since I bent the old one.

Speedmd, thanks for the insight - I did quite a few miles on a friend's Marin with a 68.5° head angle and got on fine with it. If the 70° head angle turns out to be a screw up I'll just have to admit my mistake and reweld the headtube

I was having some trouble finding space for an 18S 10Ah battery in the frame. The Multistar packs seemed an easy solution, but testing by Icecube57 revealed they are too low powered (3-4C). 6S 5Ah Turnigy bricks seemed hopelessly bulky until I realised I was being foolish. 3S (and 6S "long" packs) packs are 1" wide by 2" tall and in a ~3" box like my proposed frame I can lump four packs together.

That's what the drawing below shows. Each of those purple blocks is 4 off 6S 5Ah "long" packs. There's room for the 12 FET controller inside and I could probably fit another 4 off 3S 5Ah packs around the controller if I wanted to. Switches and wattmeter, I'll just find space for. In the future it will probably be an 18650 pack that makes efficient use of the odd spaces. Time for a cardboard mock-up

 

[speedmd]

Angles should be fine for your motor bike. With the added speed, it is always better to err on slackening the head a bit as it adds straight line steering stability as well as wheel base. No issues for a general purpose bike. Like the battery setup. I found some stock 3 inch by 8 inch aluminum box extrusion that built up well as a battery box for the 8mah zippy bricks that I am using. It does seem like the right width for riding. Lots of frame options are easy with it also and it is hard and protects the packs well. Look forward to seeing the finished bike.