Sliding Seat vs Sliding Crank

[Bodhi]

I've started building my streetfox and I was wondering the advantage/disadvantage of having a Sliding Seat or a sliding crank, or both. Do you have to do anything with the chain when you sliding the crank forward or back?

[trikeman]

I've started building my streetfox and I was wondering the advantage/disadvantage of having a Sliding Seat or a sliding crank, or both. Do you have to do anything with the chain when you sliding the crank forward or back?

I personally think its easier to build a bike with a sliding crank, than a sliding seat, but not really a whole lot. The main advantage I see to a fixed seat is that you can design the bike with the intended amount of front/back weight distribution and it will stay that way. Depending on how much you slide the crank forward/backward, you may have to adjust the number of links in the chain.

[Bodhi]

I'm 5 foot 10.5 inches tall. My wife is 5 foot 3 inches. will I have to remove links?

[greenevegiebeast]

there are two other ansers,

1. tandem trike/recombant

2. a second trike/recombant.

My wife still prefers an up wrong (she was sick enough to marry me)
im still trying to get her bent.:jester:

[trikeman]

I'm 5 foot 10.5 inches tall. My wife is 5 foot 3 inches. will I have to remove links?

Although you are over 7" taller than your wife, based on standardized body proportions I suspect your X-Seams differ only by about 4" (average women have longer legs in proportion to their torsos than average men). That said, it means you will probably be moving the crank up or back 4" when you change riders. If you watch the beginning of the video below for a properly adjusted rear derailer, you will see the chain tensioner spring on the derailer taking up the slack as the chain moves from low to high hear. It is probably moving about 4" normally to do the gear changes. Asking it to adjust for an additional 4" may be too much to ask.

http://bicycletutor.com/adjust-rear-derailleur/

If you watch this next video on adjusting chain length, it is easy to see that if the chain is properly ajusted for one length, it will not be for an additional 4" of forward or backward movement.

http://www.youtube.com/watch?v=lMMUEjc12QY&feature=related&pos=2

You might be able to add an additional chain tensioner mid-stream to handle the additional adjustment needed, but I have never tried it.

It really isn't that hard to make an adjustable seat. When I put the seat on my DW, I wanted it to move forward and backward so I used the seat rail method similar to the one illustrated on 25Hz's site shown below:

http://www.fleettrikes.com/trike%203%20seat%20rail%20sm.jpg



Others with more expertise, such as Brad, may have a better answer.

[TheKid]

If you use the rear derailler method for the return side chain idler, you can get a little more adjustment for the BB. To find your x-seam, sit against a wall and measure from the wall to the bottom of your foot. There may not be that big a difference between your x-seam and your wife's. Brad mentioned a while back that there wasn't much difference between his x-seam and a friend of his who is much taller.

[Bodhi]

I have one tadpole and my wife has a Sun USX HD delta style trike. I'm building the Streetfox cause I want to have suspension on the trike.

Here's the tadpole I built.

http://www.geocities.com/bodhibkb/the_black_pearl.jpg