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Old 01-27-2018, 06:17 PM   #1
glooey
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Lowside uphill Mt. Ham 27 Jan

Event: Lowside entering semi-blind uphill right hander - front let go in gravel
Location: Mt. Hamilton Rd, ~1/4 mile from entrance to Lick Observatory
Me: 3.5 yrs "real" riding, 60k miles total (commute, recreational twisties, road trips, track), ~20x up & down Mt. Ham Rd
Bike: '14 Triumph Street Triple R

Details / Pics:
Conditions were mostly dry and good. Road was relatively clean most of the way up - to state the obvious I was surprised when I hit the gravel patch.

Given the semi-blind turn, I chose the inside tire track on entry. I was carrying moderate speed (not put-putting but not going for a personal best), had set my lean angle and was at part throttle to maintain speed and chassis balance.

Partway into entry, front let go and - wham - I was down. Bike slid ~18 yards, I slid about half that.

Lowside initiated at patch on right, line up the road shows where the brake lever, right bar end, exhaust can, and other softer bits ground into the road:





Pretty standard gravel-induced lowside, I figured. But the part that's interesting / potentially instructive is how LITTLE gravel there was where the front tire slide initiated (see witness mark):





What I KNOW I did wrong:
  • Drifted too far into center of lane, where the gravel was. Inches matter!

What else did I do wrong, what should I have done instead, any other tips?

Pile on!

PS - other pics for morbid fun:
Gear did its job - all I ended up with was some rash on my right forearm. Jacket seems OK to keep in service:




Pants are toast, though:


Brake lever is now more dirt bike-ey than streety:
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Old 01-27-2018, 07:29 PM   #2
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I noticed a bunch of gravel there on the way down this afternoon. It doesn't look like much, but it doesn't need much to be slippery and catch the unwary.
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Old 01-27-2018, 07:50 PM   #3
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Originally Posted by glooey View Post
What I KNOW I did wrong:
  • Drifted too far into center of lane, where the gravel was. Inches matter!

What else did I do wrong, what should I have done instead, any other tips?

Pile on!
I think your biggest mistake was setting up in the inside tire track. A better technique for street riding is to setup wide so you can late apex the corner. In this particular case, a wider line would have meant the bike was more upright. The more upright your bike is, the less likely you are to fall over if traction becomes compromised.
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Old 01-27-2018, 08:25 PM   #4
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Originally Posted by fubar929 View Post
I think your biggest mistake was setting up in the inside tire track. A better technique for street riding is to setup wide so you can late apex the corner. In this particular case, a wider line would have meant the bike was more upright. The more upright your bike is, the less likely you are to fall over if traction becomes compromised.
Noted, thanks.

I prefer to late apex on the street, and as a rule do it on left-handers and when there's decent sightlines around rights. However, I've had enough close calls with oncoming traffic in my lane that I now enter blind/semi-blind right handers on the inside.
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Old 01-27-2018, 09:20 PM   #5
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Just going over potential causes in my head. Sometimes things just happen that we can’t explain. Glad you are OK and the bike is rideable. You have a good attitude about it...

Were you on the front brake at all before it let go?

Applying throttle or neutral throttle?

Do you feel that speed played a factor at all?

Excessive lean angle or abrupt bar inputs/turn in?

Tire pressure good?

Last edited by J-Boat; 01-27-2018 at 09:21 PM..
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Old 01-27-2018, 11:18 PM   #6
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It looks like the turn tightens a little beyond where you lowsided. On an inside line, you almost certainly had some continued pressure on the bars; the lean angle really wasn’t fully set yet.

Another vote for a wide entry, get the lean angle set, begin rolling on the throttle and have no pressure on the bars.
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Old 01-28-2018, 07:10 AM   #7
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I can't see any indication of speed or lean angle.

I'm also one of those who ALWAYS enters a turn on the outside, being ready to tighten it up to the inside if I detect any oncoming threats, or tightening it up at the end of the turn. This has served me very well since 2003, the last time I crashed a bike on the street. There is less dirt coming down from the hillsides on the outside tire track than on the inside tire track on a right turn. It looks like that would have made a difference for you in this case.
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Old 01-28-2018, 08:24 AM   #8
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Noted, thanks.

I prefer to late apex on the street, and as a rule do it on left-handers and when there's decent sightlines around rights. However, I've had enough close calls with oncoming traffic in my lane that I now enter blind/semi-blind right handers on the inside.
A wide line and late apex allow you to see further into the corner before you turn-in. As long as you're paying attention and not traveling at ridiculous speeds, there should be plenty of time to tighten your line if you spot someone occupying your lane. On Mt. Hamilton, setting up wide for a right-hander also reduces the risk that you'll have an unexpected encounter with a bicyclist...

Last edited by fubar929; 01-28-2018 at 08:27 AM..
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Old 01-28-2018, 09:52 AM   #9
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Quote:
Originally Posted by J-Boat View Post
Were you on the front brake at all before it let go?

Applying throttle or neutral throttle?

Do you feel that speed played a factor at all?

Excessive lean angle or abrupt bar inputs/turn in?

Tire pressure good?
I was off the brake, in 2nd gear, on maintenance throttle. Given how far the bike slid, I can not rule out speed being a factor - I don't know what my speed was at the time; from the feel/sound I think I was sitting at ~5k rpm in 2nd. I had already set my lean for entry (but see @tzrider below) - it wasn't a sharp bend as you can see in the pics. I was at 36f/38r when I set out in the morning (lowside happened around 1pm).

Quote:
Originally Posted by tzrider View Post
It looks like the turn tightens a little beyond where you lowsided. On an inside line, you almost certainly had some continued pressure on the bars; the lean angle really wasn’t fully set yet.

Another vote for a wide entry, get the lean angle set, begin rolling on the throttle and have no pressure on the bars.
It wasn't a sharp turn overall - it was more like a bend. The sharp right turn was ahead of it. That said, you're right in that it was a decreasing radius bend. Therefore, if I was paying attention (I want to believe I was), then that spot may have been where I added bar input to get through the next radius.

If I was adding bar pressure at that spot, it would better explain how the front let go with apparently very little gravel at that spot (see pics). Also reinforces the point about the outside tire track being preferred, with associated lower bar pressure (and probably less gravel).

Thanks for pointing that out.

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Originally Posted by ScottRNelson View Post
I can't see any indication of speed or lean angle.

I'm also one of those who ALWAYS enters a turn on the outside, being ready to tighten it up to the inside if I detect any oncoming threats, or tightening it up at the end of the turn. This has served me very well since 2003, the last time I crashed a bike on the street. There is less dirt coming down from the hillsides on the outside tire track than on the inside tire track on a right turn. It looks like that would have made a difference for you in this case.
Quote:
Originally Posted by fubar929 View Post
A wide line and late apex allow you to see further into the corner before you turn-in. As long as you're paying attention and not traveling at ridiculous speeds, there should be plenty of time to tighten your line if you spot someone occupying your lane. On Mt. Hamilton, setting up wide for a right-hander also reduces the risk that you'll have an unexpected encounter with a bicyclist...
I can definitely see why this could have been a better turn to take wide+late apex. In perfect hindsight, I would have been on the cleaner track with less lean angle. I can of course rationalize my line choice (wasn't going super fast, corner wasn't completely blind, not a tight turn, yadda yadda). But I think you all are right.

On a more general topic about street lines, I pretty recently changed my approach on right turns (see earlier post). I used to be very deliberate about entering street turns with the intent of maximizing my sight line, which meant entering wide and turning in when I could see around the corner (late apexing). I switched to entering on the inside on right turns after enough close calls with opposing vehicles in my lane (especially on Mt. Ham Rd.). I need to re-think this approach.

As long as this isn't a dead horse (I would think this is highly relevant), I'd learn a lot from a continued debate on this. . .

Last edited by glooey; 01-28-2018 at 10:07 AM..
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Old 01-28-2018, 10:48 AM   #10
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I bet you unconsciously weight the bars more than you realize and this is just the first time you’ve been caught out. You should be able to take both hands off the bars atter lean angle is set.
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Old 01-28-2018, 10:49 AM   #11
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Nice write up and evaluation of your crash. I'm not going to add to what's been said, and I think you've learned what you'll do next time.

Crashing is a probability every time you throw a leg over, but learning from a such an event is not so certain. IMHO, you've made the best out this situation to become a rider that has lowered your crash probability going forward.
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Old 01-28-2018, 11:21 AM   #12
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I bet you unconsciously weight the bars more than you realize and this is just the first time youíve been caught out. You should be able to take both hands off the bars atter lean angle is set.
I wouldn't rule that out. I used to do drills for this: chicken wings first, then letting go of the inside grip mid-turn. Haven't done it in a while - I should go back to it and check my assumptions/practices.
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Old 01-28-2018, 02:13 PM   #13
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If I was adding bar pressure at that spot, it would better explain how the front let go with apparently very little gravel at that spot (see pics).
FWIW, I wouldn't be so quick to blame gravel...

The last time I was sliding around on Mines Rd. I didn't see anything on the surface of the road. Finally stopped to check the surface and it looked perfect! Since it was a cool Fall day I took off a glove to check tire temp, which was fine, then put my hand on the road to check pavement temp... and my palm came away covered in sand! Turns out there was a thin layer of those little microscopic ball bearings were everywhere...
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Old 01-28-2018, 06:25 PM   #14
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Originally Posted by fubar929 View Post
FWIW, I wouldn't be so quick to blame gravel...

The last time I was sliding around on Mines Rd. I didn't see anything on the surface of the road. Finally stopped to check the surface and it looked perfect! Since it was a cool Fall day I took off a glove to check tire temp, which was fine, then put my hand on the road to check pavement temp... and my palm came away covered in sand! Turns out there was a thin layer of those little microscopic ball bearings were everywhere...
This-on mines and del puerto after a rain there can be silty,sandy runoff that is almost impossible to see.I never,ever ride inside lines where i can see there could be some run off the side of a hill.
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Old 01-28-2018, 06:57 PM   #15
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Originally Posted by fubar929 View Post
FWIW, I wouldn't be so quick to blame gravel...

The last time I was sliding around on Mines Rd. I didn't see anything on the surface of the road. Finally stopped to check the surface and it looked perfect! Since it was a cool Fall day I took off a glove to check tire temp, which was fine, then put my hand on the road to check pavement temp... and my palm came away covered in sand! Turns out there was a thin layer of those little microscopic ball bearings were everywhere...
I bet this wasn't in one of the tire tracks. The places where the car tires go clear off rather quickly. So when the surface is questionable, it's best to slow down a bit and stay in just one of the tire tracks through all of the turns. Personally, I prefer the one closest to the center line, but I'm always ready to move to the other side of the road if the need arises. I slow down even more for the blind turns.
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