|The start of T.I.V7|
There are two things, in my mind, that are paramount regarding lighting for Trans Iowa, or similar rides where fast descents may be occurring on gravel. First is getting light up the road.
You can easily reach speeds of 35mph and probably up over 40mph on some of the descents on gravel for Trans Iowa. Your lighting may be adequate for pavement, but how do you "read the road" on gravel? You only have a precious few split seconds to make decisions at these speeds, and on gravel- any sudden maneuvers will result in going out of control, or crashing, which are both bad things and usually go hand in hand. Knowing what is coming as soon as possible is very important then. And if you didn't know- the darkness in Iowa is........really dark!
So here is the other important thing- the beam pattern and quality of that pattern. Having a high powered light with crappy optics isn't going to do you any good at night on gravel roads. Dark rings, spots, or weird shading may not be an issue while you are going down a paved road, because the differences between those oddities in optics are nothing like the surface you are riding. But out on gravel, these things can become trouble since the gravel can mimic shading, weird patterns, and yes- even circular shading, so it becomes difficult to know if you are looking at weird optics or six inches of gravel piled up in your path. You also need a broad swath of useable light. Spot beam patterns are not ideal. What if you want to switch your line to the right? If you are not sure if the gravel is deep, rutted, muddy, or dry outside your spot beam pattern, you have no idea what you are steering into until it is too late at higher speeds.
|T.I.V7: Image by W. Kilburg|
My set up uses a cheapo Eveready camp light I hacked to a Cat Eye computer mount. The beam pattern goes from ditch to ditch and up the road far enough to comfortably ride the flats. My helmet mounted torch is going to be a Lezyne Super Drive, which will get my beam way up the road for the descents and will work for sign identification for navigation needs. My handle bar mount is going to be a Lezyne Mega Drive set on a lower setting for down the road lighting.
I set my Eveready light on a mount off my front rack, lower than the handle bars, and it shows up washboarding, pot holes, and dips quite nicely down there. On my Fargo, that light will mount off my low rider mount which will do the same thing.
There is my set up for night time gravel grinding and it will be an improvement over my old set up, which wasn't quite adequate enough, (for me), on fast descents. Again- it's my opinion, and based off my experiences and perceived need. You should take this only as a guideline and do due diligence by testing your own lighting set up well before Trans Iowa.