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Road Grooves

U

USADoug

Well travelled
Location
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Check out what happened to her. At second 0:08 of the video, where the wobble started, look closely at the road surface. I think she was on a Halcyon motorcycle.

The reason I mention this in this forum is because I experienced a nasty wobble on my Interceptor on the same kind of road grooves with the OEM Ceat Cruz front tire. I didn't crash but the bike was thrown all over the lane laterally. I was doing about 70mph, the posted speed limit. The Ceat Cruz front tire has a perfectly circular groove that would "trammel" on the road grooves. I replaced the tires with Michelin Road Classics and the problem was 95% cured.

There is an 'official' cause of accident report starting at 07:40 in the video.

 
There is a thread here where a few of us commented on the CEAT experience with concrete grooves. I found the CEAT tyres on the Interceptor interesting to frightening the first 1000 miles. No longer run them on the twin. Still have CEATs on The Bullet but they are acceptable for now.
 
There are a few threads I see over time. Here is one.

JK202

Thread 'CEAT Tires'

Hey guys,

I'm coming off sportier machines and I've always ridden my rear tire right to the edges. Does anyone try to exploit these stock tires similarly? I mean, are they that bad?

Next winter I'll do a tubeless tire conversion w/ Michelins, but I'd be interested to learn of others' experiences w/ the Ceats as our weather is warming up and the Shenandoahs beckon :)

Cheers!

JK
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Thanks to @USADoug for mentioning it again.
 
USADoug said:
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There is an 'official' cause of accident report starting at 07:40 in the video.
Click to expand...
Personally, I don't accept the expert's cause of the crash. The expert identifies some aggravating conditions but the cause was her trying to clamp the handlebars to stop what she perceived as a wobble. Those handlebars are big enough to give the rider a lot leverage. Sure the grooves were wagging the front wheel left and right. But when she locked down the steering that moment (inertia) shifted to the main section of the frame. The frame is a bigger lever than the bars so it instantly overpowered her arms and the wheel goes to full lock. Bam. Done. Down.
_ A light touch and steady throttle is always the call. Everyone should learn to ride dirt bikes.
 
The CEAT Cruz tires were fine for my riding style, until I hit the road grooves. The grooves are only on freeways where I ride so if I stayed off the freeways, which I don't/won't, I would still be happily using the CEATs.
 
I still use the CEAT Zoom Cruz tyres on my Royal Enfield Continental GT650.

When the bike hits longitudinal cracks in the bitumen, the front wheel follows the crack.

I will keep the CEAT Zoom Cruz tyres, until they wear out. Then I will buy a set of Metzler Sportec tyres.
 
Look at the tread design in the following photo. Combine this with the diamond cut grooves in highway concrete and the Interceptor's tendency to be a bit unstable at the front at speed (small rake angle?). In addition to a tire tread design change I dropped my Interceptor's fork tubes down by 6mm and stability on road grooves markedly improved. I plan to drop them another 6mm which is as far as they can go.

Screen Shot 2025-08-02 at 7.53.13 AM.png
 
The Ceat tyres on the 350 Classic are okay as the speeds on that style of bike is rather slow so they can handle it okay.
Tar snakes and road groves can be 'interesting' at times though.
 
The stock HD Dunlop's are awful for the diamond cuts/grooves.

As I instructed Mrs. 2LZ at the time (her Sportster, stock Dunlops), "Loosen your grip on the bars and let the bike wiggle it out the rear end like a dog shaking off rain water. When you Death Grip the bars to try to stop it, it gets worse."
 
For my ride out to the dealership open house in Albany, NY last Saturday I swapped out my 18/21 combo of Shinko 244s for the 6,000 mile Ceats on black rims I received from @oldbuck.

I put 404miles (650km) on that 60-85°F dry day and apart from grooves, ratings, cracks & tar snakes I found them to actually be good tires when riding on good pavement. I set pressures at 31F and 33R and found them very easy to trust, very easy to push hard. They never washed out, never lost traction or tracked sideways while accelerating, and always had plenty of braking grip especially during one memorable panic stop where I thought I'd have a problem (maybe the Abs helped).

The only other worn tires I can remember spending much time on were Dunlop D404s that were squared off, they passed an inspection in the spring but I'd thrown them away by August that year. They tracked like these Ceats do on cracks.
 
2LZ said:
The stock HD Dunlop's are awful for the diamond cuts/grooves.

As I instructed Mrs. 2LZ at the time (her Sportster, stock Dunlops), "Loosen your grip on the bars and let the bike wiggle it out the rear end like a dog shaking off rain water. When you Death Grip the bars to try to stop it, it gets worse."
Click to expand...
That's good advice in any road/tire situation and on any bike.
 
I've got 1500 miles now on the stock CEATs and I'm done with them.
Here in Texas the roads are as unpredictable as the weather - particularly the FM roads and smaller state highways that I ride the most.
I was able to grab a pair of the remaining Metzeler Roadtec 01s and I'm having them put on the bike Monday.
very nice.jpg
 
Probably instinctually gripped the bars harder when she felt the wobble start which caused her throttle to rev a bit.
Great teaching moment for all of us about the inherent danger of tensing up when the "oh sh*ts" happen.
Easy to say and harder to do.
 
Kenbone said:
Probably instinctually gripped the bars harder when she felt the wobble start which caused her throttle to rev a bit.
Great teaching moment for all of us about the inherent danger of tensing up when the "oh sh*ts" happen.
Easy to say and harder to do.
Click to expand...
I had a buddy who nutted up so badly on the grooves on the highway, he slowed way down in a heavy traffic area right in downtown Sacramento. The cars flying around him trying to miss him were far worse than anything he would have experienced on the rain grooves. He's lucky he made it out of there in one piece.
 
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