Author Topic: Long, steep descents -- questions about safety  (Read 2135 times)

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Offline New Jawn

Long, steep descents -- questions about safety
« on: July 02, 2022, 04:05:51 pm »
Not long ago I finished a section from Oxford, OH to Newton, KS -- yes, some hills but nothing that I would call mountainous.  Now I'm looking at some long rides that will definitely have steep descents, some perhaps long, continuous descents (think western CO) or long descents with lot of curves (Appalachian Mts). 

So, just let it roll unchecked?  I would guess that speeds  could easily go over 40 mph and perhaps higher?   Just thinking about it makes me a bit nervous.  Assuming the road isn't too curvy, just not worry about how fast I'm going?   I've seen Tour de France footage of those guys going downhill like rockets and there's no way ever that I would have the guts to do it. 

If I try to keep the speed down, I'd think that my brakes could overheat (Surely Disc Trucker), so alternate front and back brake?

Any advice on how to address long, steep descents in a safe manner?

Thanks in advance.

Offline jamawani

Re: Long, steep descents -- questions about safety
« Reply #1 on: July 02, 2022, 04:56:39 pm »
I think I got up to 53 mph loaded down with gear on a long, straight descent in Nevada.
I actually passed a dump truck that had down-shifted.
The driver saw me coming up behind him and had a shocked expression.

But really - airport runway straight and almost zero traffic - plus I had 1.95 tires.

Descents depend upon a number of things:
1. % Grade - The steeper it is the more likely you may get into trouble.
2. Road Width - 12-foot lanes or less? Shoulders? Mountain roads are often narrow.
3. Traffic Volume - The more traffic there is the more the challenge. Drivers are grumpy if you are just doing 30 mph.
4. Road Surface Condition - Mountain roads often have more wear & tear. A sudden pothole and you are done in.
Also 5. Brakes - Disc brakes or rim? Disc brakes are more powerful and rim brakes can really heat up your rims.

In contrast to Nevada, I've ridden Going to the Sun in Glacier N.P. more than a dozen times.
The west side has a longer descent at a constant 8%, but the road is narrow and packed with cars.
What I do there is stop frequently at overlooks to let traffic go by and then start again in the gaps.

Obviously, if you have a lot of switchbacks, you can't let it rip.
(If you are not sure, you should expect a switchback or two just to be prudent.)
Also, be careful for the oncoming, uphill traffic.
Impatient folks behind a slow truck can and do pull out into your lane to pass.

Hope this helps. - J
« Last Edit: July 02, 2022, 04:59:30 pm by jamawani »

Offline Pat Lamb

Re: Long, steep descents -- questions about safety
« Reply #2 on: July 02, 2022, 05:32:29 pm »
In addition to John's road condition consideration, I'd add whether or not there's gravel (or rocks) on the road, and whether the road and/or your brakes are wet.  There was one lovely pass where the road was a consistent 6%, but there were occasional 3-6" rocks on the road -- you want to make sure you can safely steer around those!

Also, brake early and often if it's raining so you can clear your brakes.  Rim or disc, if the braking surface gets wet you don't have brake power.  And yes, it can happen with a good rain rate on discs!

Other than that, brake as you need to maintain your speed so you can steer the bike.  Riding the brakes is bad, you're better off either alternating wheels (front for 10 seconds, rear for 10 seconds), or pulsing the brakes (brake hard for 5 seconds, let it roll for 5).  If you think the brake surface is getting too hot, stop and let it cool.  Take a few pictures, have a drink and a snack, squirt some water on the rims and see if they've stopped hissing when you do that.  It's possible to blow even a mountain bike tire off the rim if you overheat it too badly; skinnier tires at higher pressure are closer to blowoff if you ride the brakes.

Offline Westinghouse

Re: Long, steep descents -- questions about safety
« Reply #3 on: July 02, 2022, 06:50:49 pm »
I have done some very long steep descents. One was so long and steep and at such an angle that by the time I got down to level ground again both hands felt as though they had been beaten with a hammer. All I can tell you is this. Work the brakes alternately and sometimes front and rear at the same time, off and on off and on off and on. I have heard of rims Heating and popping the tube. Never had that problem. Just break to keep the speed down and let off. Break to keep the speed down and let off, and just keep doing that.

Offline aggie

Re: Long, steep descents -- questions about safety
« Reply #4 on: July 03, 2022, 10:25:47 am »
In addition to everything mentioned above - be wary of loose gravel.  I was coming down Mt Graham in AZ, wasn’t loaded with gear, had to be doing at least 30 mph just before a hairpin curve.  As I was breaking I hit a patch of gravel.  Not sure of the exact chain of events but front tire went flat - bike and I did a complete flip.  Broke my collarbone and a couple of ribs and my helmet was cracked in 5 places.  Needless to say I am very cautious before entering any hairpin curves.  I slow down well before the curve.

Online staehpj1

Re: Long, steep descents -- questions about safety
« Reply #5 on: July 03, 2022, 10:41:41 am »
I have known of a few tour ending or tour interupting crashes on long fast downhill runs, but I love bombing downhills and tend to let it all hang out.  That said if you want to be sensible, alternating front and rear braking, keeping speed down, stopping for breaks on the way down all help.  Also your disc brakes are better for avoiding melting a pad or blowing an overheated tire.

Offline ray b

Re: Long, steep descents -- questions about safety
« Reply #6 on: July 03, 2022, 01:00:59 pm »
    Everyone has a different terminal speed at which they are comfortable.

    Those speeds depend on talent, hard earned skill, and experience.

    • Confidence in mechanical skills and equipment.
    • Confidence in bike handling skills.
« Last Edit: July 03, 2022, 01:07:25 pm by ray b »
“A good man always knows his limitations.”

Offline John Nelson

Re: Long, steep descents -- questions about safety
« Reply #7 on: July 03, 2022, 07:44:20 pm »
I live in Colorado. Long, high-speed descents are part of my ride almost every day. It does take some getting used to. The more you do it, the more comfortable you get with it.

Speeds in the low 40s MPH are no big deal. As the speed gets into the upper 40s and low 50s, hyper vigilance is required. How smooth is the road? How straight is it? How clean is it? What’s the likelihood of side traffic? Can you see around the next curve? Is there traffic behind you? Coming up? Don’t let your speed get above 50 unless you get the right answer to all these questions.

Don’t brake excessively. It can cause lots of problems. Overheating your rims (if you have rim brakes), wearing out your brake pads, surprising the cars and bikes behind you, stressing your spokes.

When you get close to a curve, brake hard enough for the entire curve. Be more cautious if you can’t yet see where the curve ends, or if the grade is steep throughout the curve. Don’t brake in the curve itself, or do so very lightly. Lean your bike. As you come out of the curve, release the brakes and don’t reapply them until you get close to the next curve.

I don’t place much stock in the alternating front and back brakes idea. When you need to brake, use both brakes and brake hard. Keep your arms stiff and your butt back. Then let you brakes go completely. Do not lightly apply the brakes continuously for a long time.

Keep your bike in good repair. Check and adjust your brakes frequently. Do not ride on worn-out tires. Keep your tires inflated to the correct pressure. Make sure your wheels are true. If you are predisposed to high-speed wobble, lean your knee against the top tube (and get a different bike as soon as you can).

Offline ray b

Re: Long, steep descents -- questions about safety
« Reply #8 on: July 03, 2022, 09:53:58 pm »
John always manages to pack the critical info into a readable post.

In thinking further about what makes me comfortable at over 60 mph, I'd have to add the motorcycle.

John mentions hypervigilance and where your eyes need to be. Riding a motorcycle at speed certainly helps get the brain reved up for speed.

Sent from my SM-N950U using Tapatalk

“A good man always knows his limitations.”

Offline OHRider

Re: Long, steep descents -- questions about safety
« Reply #9 on: July 04, 2022, 09:34:46 am »
We had a very long descent in high winds and warm temperatures in last fall's Southern Tier ride- The descent was on an interstate highway with fairly heavy traffic.  Due to the winds both my friend and I were braking heavily to keep the speed down. Trucks would buffet us which required hypervigilance as described earlier in one reply.

My bike had hydraulic discs and 700x32C's and my friend's bike had rim brakes and 700x25C's.  The highway shoulder had a lot of debris, much of which you couldn't see until you were right on top of it.  I'd say we kept at 20-30 mph most of the way and made a couple of stops to let brakes and rims cool off (our host had recommended catching a ride down the hill which likely would have been the wise choice).

Luckily we both made it to the bottom safely. When Brian pulled off at the last ramp and came to a stop his tire blew. Sigh of relief that it was there and not higher on the mountain.

We both had issues with rim tape moving during the trip- which once it opens up a sufficient gap to the spoke hole you will pop the tire.  I think this has been due to heat so beware of steep fast descents if it's hot.

Nothing I love better than flying down a hill but it's best to err on the side of caution- a loaded bike stresses brakes and wheels much more than an unloaded road bike.  At least panniers do a pretty good job acting as air brakes and keeping top speed down.

Offline BikePacker

Re: Long, steep descents -- questions about safety
« Reply #10 on: July 04, 2022, 10:56:08 am »
The original post prompts 2 thoughts:
1. As I was in a bike shop somewhere just east of the North Cascades and heading east, I heard sirens. 
Upon doing so the shop owner said it was for a cyclist who was coming down the same road I was just on and
the cyclist had an animal wander out into his path (he heard the report on his radio scanner tuned to a local EMT frequency).
Shop owned added (paraphrased) 'Happens about once a month - critters can not hear the cyclist coming down the mountain ...
if the cyclist is going too fast to control his rig, the outcome can be not good for the cyclist.
'
2.  Was surprised at how much the wind resistance (think front panniers : ) had on slowing my speed.

Online staehpj1

Re: Long, steep descents -- questions about safety
« Reply #11 on: July 04, 2022, 11:16:47 am »
1. As I was in a bike shop somewhere just east of the North Cascades and heading east, I heard sirens. 
Upon doing so the shop owner said it was for a cyclist who was coming down the same road I was just on and
the cyclist had an animal wander out into his path (he heard the report on his radio scanner tuned to a local EMT frequency).
Shop owned added (paraphrased) 'Happens about once a month - critters can not hear the cyclist coming down the mountain ...
if the cyclist is going too fast to control his rig, the outcome can be not good for the cyclist.
'
Yeah, one in my group had a semi close call with a cow moose or an elk (I forget which) on a downhill in Yellowstone. I and others I have been with have had similar with whitelail deer and once with a pronghorn antelope.  Only close calls though.  A few were real close while mountain biking.  When I was racing hare scrambles (motorcycle) a guy preriding the course hit a bear and separated his shoulder.  The bear ran off with no obvious injury.

Probably the one that came the closest to crashing me was when a squirrel ran into my spokes.  Fortunately for both of us he bounced off rather than tangling.

My dad had a poodle take his front wheel out and he suffered a broken collar bone.  It was on flat ground though.

So animals taking out or at least almost taking out bikes is a more common occurance than one might think, I guess.

Offline HobbesOnTour

Re: Long, steep descents -- questions about safety
« Reply #12 on: July 04, 2022, 11:26:12 am »
I'm glad someone mentioned wind!! That can be tricky.
I've nothing to add to the excellent advice offered above (maybe not a good idea to scare the poor OP with stories  :) )

However, I really hope that they'll come back to their threads when they've completed their tour and update them with the benefit of experience.

There's a world of difference between sitting at home and thinking about a big tour and actually getting out there and doing it.
In my experience the things that seem so scary sitting at home turn out to be interesting parts of an adventure, sometimes among the highlights!
I hope the OP finds similar.


Offline BikePacker

Re: Long, steep descents -- questions about safety
« Reply #13 on: July 04, 2022, 11:57:59 am »
... maybe not a good idea to scare the poor OP with stories  ...
For me,
I'd rather read the news reports and learn / benefit from same,
so that I am more able to tour with greater awareness of possibilities.

Online staehpj1

Re: Long, steep descents -- questions about safety
« Reply #14 on: July 05, 2022, 06:45:13 am »
(maybe not a good idea to scare the poor OP with stories  :) )
I should add that the stories I mentioned were spread over my experiences and people around me over the last 50+ years.  Also consider that I rode trails that were over run with deer and rode at racing speeds.  Also the actual crashes were really rare, most were just close calls.  The few interupted tours were strangers that I met or heard of when on the trans america or other long tours and one co worker whose incident I learned about years later when he was telling me about his 1976 bikecentennial ride (downhill crash in the rain, broken collar bone, Appalachians, went back and finished the route after healing).

So those events were widely spread and pretty rare events.
« Last Edit: July 05, 2022, 06:49:48 am by staehpj1 »