Oct 5

Oct 5, 2004

This is cool - I was playing around with adding a permanent safety wheel and wanted to see what a faired version would look like. I'm not really sure how much safety adding a permanent outrigger wheel would add, but I am concerned about safety - especially after todays ride.

I added about 40 km yesterday and 60 today and I'm becoming a little concerned about stability at high speed - especially since I know that adding the fairing will increase the average speed by quite a bit - possibly 30% or so.

The TCR1 is so efficient and fast it's a bit scary at times. Today, I glide down minor hills without brakes and it's up to 60 kph in seconds, then I have to apply brakes because I don't feel that comfortable yet doing over 60. Today I was up to 60 going down a slight down-grade with a bit of a tail wind and hit a small pot hole - nothing major, more of a large crack in the road than anything. Scary - the trike sort of twitched, threw me sideways in my seat then the other side. Didn't like it at all. Maybe it's normal and maybe I have to get used to it, but it really feels like things could get out of control - but then again, I am still getting used riding it at faster speeds.

I have run over that exact same crack many times in the past, but never doing 60 - that was the problem. I think what happens is at those kinds of speeds, slight adjustments to the steering produce large turning movements. When you bump one of the rears, there is a resulting minor, but sudden movement of the pivot which produces an exaggerated jerk in turning.

Also I was cruising along a flat stretch today doing about 45 kph when this lady decides she needs to talk on her cell phone in the middle of my shoulder. I had to suddenly veer left to go around her and as I did so, crossed over the grooves cut into the side of the shoulder. I don't really know what the point to these bone shaking grooves are... quite possibly just to annoy the hell out of cyclists. Anyhow - the bumps produced the same kind of sudden swervy feeling. I didn't like it at all.

Here is a diagram that shows what I think is happening:

When riding straight on smooth road, the riders weight is keeping the trike pointed in a straight line.

When the left rear wheel hits a bump, it causes the pivot to swing right which results in a sudden left turn.

To confirm this, I placed a block of wood under the left rear wheel and sat in the seat. The pivot swung to the right and the front wheel turned to the left. When traveling at a moderate speed, this amount of bump steer is minor and isn't even noticeable. However, even with the steering cables really tight, when moving at a high rate of speed, a minor sharp bump is enough to cause a quite dramatic twitch in forward motion. I wasn't using the steering brake when this happened and I'm not sure how much it would have helped because there is still enough play or flex in the pivot brake to allow bump steer at high speeds.

The ideal steering system would be something that prevents ALL feedback from the road back to the steering - like a worm gear. With a worm gear, if there are no steering control inputs, then the trike is locked into delta mode - regardless of external forces like road bumps and wind. Once the fairing is on, I may have to look more seriously at trying out a worm gear system.

I also added another watts test - and I'm not sure about the result. I think something might be up with the watts meter because the 150 watt out and back course produced an average of 37 kph!! That's a good 6 kph faster than any of the previous tests. What leads me to think that the SRM meter was not calibrating properly was my average heart rate corresponded with about 200 watts - as did the resulting speed. The crank bolts weren't as tight as they normally are - possibly that's why.

Tew Dew LIST:

1. Buy and install right brake (FINALLY ordered it!)
2. Invent new cable tensioner to allow more steering bar turn radius
3. Add front derailleur
4. Order 20mm axle bolts for the rear wheels (I'm using 1/2 inch now which isn't right)
5. Design and machine 2 seat mounts out of aluminum to replace current steel ones (e-machineshop.com) LATER.
6. Design and machine 2 steering tensioners out of alum to replace LATER
7. Order a new front wheel! (Helen is kind of upset that I am user her Zipp race wheel!)
8. Start work on the first fairing (starting now)
9. Invent steering stiffener
10. Add larger chain ring and modify chain stays
11. Make clamp-on out riggers and try to flip it (changed to#25)
12. Fabricate new steering bar (aluminum or composite?) or rework existing
13. Lathe an aluminum collar for .5" hub axles (Ben E. said he'd do it for me) (That didn't work - I'll get someone else to machine it).
14. Design and build a trainer to fit mag trainer (donated by Michael Hoenig).
15. Replace steel cables with Kevlar (maybe not - I think the flex of steel is good....)
16. Crotch guard / fender
17. Narrow chain stays to allow foot to clear
18. fix derailleur
19. crank hitting chain stay
20. chain stay frame flex?
21. Narrow, high density foam for seat
22. Make front quick release safety
23. Change steer cable sheaves to Pete Heals idea
24. Add missing and new webs
25. Add a g-meter and quantify turning g's at flippage threshold. (add outriggers)
26. Firm up relationship with a charity (Helen???)
27. Find a PR person

TOTAL distance on TCR1
495.3 km

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