Recent content by cllsjd

I hate to admit it, but I did something wrong. The measured displacements are just not matching up with the analysis. The analysis is actually saying that the displacement of the stock setup and a slivio type set up have roughly the same displacement. The measured displacement indicate the...

I made a foolish error. I assumed the steering tube was aluminum. I had it off this morning and it seemed heavy. A magnet verified it is steel. Time redo my numbers.

I used the loads from Super Slim on my Quest beam model. The deflection at the bottom bracket was 3/16". To satisfy my own curiosity, I added a couple of beam elements to the top of the steering tube to sort of simulate handlebars. The deflection of the bottom bracket increase by 1/16"...

Super Slim; I agree with you about my load. I went out in my driveway and had my wife helping me with measuring deflections. It was only after we were done did I realize what a huge gear (53-16 and 155 mm crankarms) that I was in. It was okay for what I was doing, but you're 100% right about...

"Aluminun is hugely variable in strength and stiffness." You've hit on my pet peeve. Yes, aluminum does vary in strength. For a given cross section it absolutely, positively doesn't vary in stiffness. You can argue with me until the day you die and you'll never be right. Never!!! For a...

I realized I had made in error on saying it was 15% and I removed it. The G is for aluminum in general. Depending on your source and type of aluminum it may vary some. All joints in this beam model are perfectly rigid. I've made a course model. The clamping of one tube in another tube...

Yes, I removed the steering tube from the model. I did nothing to the extension tube / boom. Billy, it is good that you're a bit skeptical. However, sometimes the engineering is right even when we don't like the answer. The equation for twisting in a tube is θdegrees ≈ 584 L T / (G (D4-...

New disclaimer! :) I don't own a Silvio, I've never ridden a Silvio, nor do I have access to a Silvio. I made my finite element model for my Quest a bit more Silvio like by moving node 1 to x =-3 y=0 and z=2.270. This puts node 1 inline with node 2 and node 6 about 3 inches behind node 2. In...

Per my analysis I was wrong to think changing the fork material would imporve things. The one best thing you could do, based on the analysis, is to make the "steering tube" stiffer. The "steering tube" is my name for the vertical tube that runs from the headset up to the handlebar stem. I...

I created a finite element model and ran some initial calculations. Let me make some disclaimers and realize I probably should have about twice the number I have. This is an approximation. I measure my Quest to get the node location. Your bike would have different node locations; therefore...

Billy, thank you for your help. My finite element model seems to be producing reasonable result. In addition to the numbers you gave me, I did some of my own measurements. While my driveway isn't very long it is a 7.3% grade. Just holding the bike stationary produced about 3/4" of...

Sorry, my fault I didn't consider the internally geared hub. I really want to know the gear ratio. Shift the bike into the gear you would use to climb the hill. Then turn the crank arms / chain ring one complete turn and tell me how many revolutions the wheel made. You can put the bike on a...

I'm only a year behind, but I thought I'd ask a few question and see where I go. I'm not criticizing what was done. I've created a finite element model using beam element to model the front end of my Quest. That wasn't too hard. Then I needed to come up with some reasonable loads to apply...

Down Hill I'm 6' 2" and weigh 190 lbs. I find the Quest quite stable. With a 6% grade and a tail wind, I have hit speeds in excess of 45 mph. I try to relax as much as possible. If I'm not pedaling I tend to drop my right hand into my lap and clamp the head set between my knees. Don't ever...

Handlebar Stem Flex I'm not sure my arms are strong enough on a long climb, more than a few minute, to really make much difference to my climbing speed. However, a cheap fix might be to run a piece of stainless steel wire from the bottom bracket or the extension clamp up to the handlebars /...