So just how dangerous are rain grooves? They were certainly disconcerting when I was descending the Grapevine on I5 last night, but are they actually dangerous? Is there evidence that they have actually caused accidents? Intuitively, anything that causes you to be nervous would seem to be a bad thing, but I just don't recall reading an accident report where someone suggested that rain grooves were the cause. Also, noticed that the one lane of I5 southbound, somewhere between the Grapevine and Los Banos, had about a 6-inch-wide wavy mild depression that went on for quite a few miles. Since it was dark I could see it but couldn't tell what caused it, but it did cause some wobbling of my front end. By the way, rain grooves aren't any fun on road bicycles either. --Mike-- Chain Reaction Bicycles www.ChainReactionBicycles.com
Rain grooves are not a "problem" unless your tires are squared off, or you have too tight a grip on the bars. Try it one-handed next time. Make sure your tires are aired up and not worn flat in the middle. Check head bearing adjustment and swing arm bearing preload. RickB
I can't recall seeing those grooves on anything other than freeways. Check out Highway 92 between Skyline and Crystal Springs Reservoir. --Mike-- Chain Reaction Bicycles www.ChainReactionBicycles.com
it varies with the tires.. When I tried Dunlop D205's, my bike would wander all OVER on grooves, while Metz MeZ4's and Z6's just laugh them off.
I've never considered rain grooves anything more than a political pork barrel, myself. I drove CA highways, sometimes for a living, for 30 years before their appearance and only once in all that time did I see a vehicle skid out on rainy pavement. I think the whole thing is a scam. But, I'd be open to argument on their need/efficacy, information which seems to be suspiciously scarce. There's no doubt in my mind they accelerate the overall degredation of our roadways. nb
In Washington State you can drive for miles without touching your steering wheel as your car will follow the twin troughs worn into the pavement by studded tires. Can you imagine what Calif freeways would look like if we used studded tires? <shudder> RickB
Rain grove wiggles generate fear in the inexperienced rider... fear smells and it loves all your attention to the degree of failing... Larry L 94 RC45 #2 Have a wheelie NICE day... Lean & Mean it in every corner of your life... If it wasn't for us the fast lane would rust... V4'S are music to the seat of my pants... 1952 De Havilland Chipmunk... Yank and bank your brains loose... http://members.ebay.com/aboutme/-xlax-/ http://home.comcast.net/~netters2/ http://www.fox302.com/index.pl?s=vg&user=netters2
They're fine if your tires are decent. Otherwise.. umm. Now, on the VF500 of yours, do you still have the ol 16" front wheel? I recall that finding decent rubber for that was challenging.. cds PS - A 17"er from an F2 fits without too much heartache, btw
they are really really hard on smaller bikes, (250cc, etc) or older bikes with skinny tires (305 Superhawk) and old bikes with skinny ribbed tires (royal enfield bullet-350) makes rain grooves on hwy 280 absolutely terrifying at speed. -- Assuring you of my best intentions at all times, Charles Statman Rocket Scientist/Wonderboy/Women's Legs Shaven DoD the Un-Numbered One
On a bicycle, thanks to narrow tires, they're worse than on a motorcycle. On your motorcycle, just stay light on the bars, and pretty soon you'll hardly even notice them. I rode I-5 from Los Banos into LA just a few weeks ago, and can't recall them at all. Al Moore DoD 734
actually they're the solution to pavement with a low coefficient of friction. the cost is negligible for concrete pavement - they're created as the paving machine finishes the surface. For asphalt pavement they're more expensive, but cheaper than people getting injured/killed due to an unsafe roadway. you must not have been paying attention. Weather conditions are tracked for accidents on state highways. A higher prevalence of wet weather accidents will prompt an investigation and corrective action if required. pavement is grooved to increase the coefficient of friction of the concrete surface (similar to a broom finish on a sidewalk). Only very rarely are they cut into existing asphalt pavement - mostly where there is a demonstrated traction problem. Here in California the freeway surface is often tested for skid resistance* prior to opening to traffic. There's rarely a problem with new pavement not meeting the friction requirements. On the other hand I've seen cases (EB80 in Albany, WB80 in Crockett) where the pavement has been too rough (thus making it too loud for people living nearby) and was ground smooth. There's significant doubt in my mind that the surface texture has any more than negligible impact on pavement life. If you look at older pavement surfaces they are noticeably smoother than new pavement, from "erosion" of the surface layer. This has no impact on ride quality. Most "potholes" form from the pavement breaking apart into pieces not from the surface wearing away. *you can check out the test method at: http://www.dot.ca.gov/hq/esc/ctms/CT_342.pdf
The original justification was some people ran bald tires. An airport study on rain grooves showed some reduction in hydroplaning. Ergo, Caltrans (even dumber than the people with bald tires), decides to put them on the highway. Now since this is the same group of public dis-servents that put's sand down on fresh asphault, one might be tempted to think they don't mind causing a bit of upset for bikers but I've been told no, it's only for the benefit of the bald tire people. Problem is that the airport study tested groove that were 90deg to the direction of the road allowing the water to go sideway where as to be cost effective on the highway, the groves are in the direction of travel. Also airplane tires are of a very special broad rib design with no cross hatch. I have seen a tire test in one of the car magazines that shows rain groves extend braking distance on all but bald bias ply tires in both wet and dry tests and has almost no effect on the resistance to aquaplaning because the water tends to build up in front of the tire. Worse yet, after that study which Caltrans had to admit to, they continued groving the roads for several years. Brand new roads.... I recall one case, many years ago, an LA CHP on an early Z1 police bike, narrow front ribbed tires and high mounted in the rear heavy radio went down because of the rain grooves. The problem is a lot less likely now with block tread tires and much better suspensions and tighter frames. Now the steel grate bridges in Seattle, those will move you around a couple of feet, even in my politically incorrect SUV.
You ride your road bike bicycle on freeways? I should have previously mentioned that something like 20% of the freeways in California *are* legal to ride a bicycle on. Anyplace where there's no nearby alternative, it's legal... which means there are many, many miles of I5 and a good number on I80 (heading up towards Tahoe) where you can legally ride a bicycle. Would you want to? Not if you can possibly avoid it! In most areas it's reasonably safe to do so (pretty good visibility) but it's *incredibly* boring. If you think 244 miles of I5 don't go by fast enough on a motorcycle with the throttle open wider that it ought to be, just think what it's like on a bicycle. --Mike-- Chain Reaction Bicycles www.ChainReactionBicycles.com
You and Ray just confirmed my suspicions. The other great pork barrel/scam is the the miles of sound walls that make ba driving a flashback to Dawn of the Dead. Miles of beautiful sound absorbing flora and fauna uprooted to enclose us in a sterile concrete causeway. While some of it was justified, at $1M per mile, most of it is outright political scumbaggery. nb.
