32mm front tyre for mountain descending

casperradil wrote:

Thanks for all the answers. When I crashed, I had pretty much confidence, and I was very low in the corner, so it was probably the result of my unjustified confidence in my skills or position (I even managed to get a few meters on the front group on another descent). But if I understand you all correctly, it wont help my grip to go 32mm, I just need to regain confidence somehow.

In a nutshell yes. As one of the others said they had a massive tank slapper, well so did I. This was at about 42 mph on Ventoux, I was white with fear when I finally stopped, so I've had to regain my confidence over time, and I still have days when I'm not at my best, so build it up bit by bit.
I disagree with the above about not going with a good descender, as following someone who knows where to brake and take the right lines is a good way to improve your skills. It's something we do on motorcycle track days, and doesn't mean you take extra risks. I've never taken any notice of my speed, I'm too preoccupied with my line through the corner or looking down the descent which is far more important. I know to judge my own speed without looking at my computer.
I got rid of the bike that had that tankslapper, it'd done it once too often!

maviczap wrote:

casperradil wrote:

Thanks for all the answers. When I crashed, I had pretty much confidence, and I was very low in the corner, so it was probably the result of my unjustified confidence in my skills or position (I even managed to get a few meters on the front group on another descent). But if I understand you all correctly, it wont help my grip to go 32mm, I just need to regain confidence somehow.

In a nutshell yes. As one of the others said they had a massive tank slapper, well so did I. This was at about 42 mph on Ventoux, I was white with fear when I finally stopped, so I've had to regain my confidence over time, and I still have days when I'm not at my best, so build it up bit by bit. I disagree with the above about not going with a good descender, as following someone who knows where to brake and take the right lines is a good way to improve your skills. It's something we do on motorcycle track days, and doesn't mean you take extra risks. I got rid of the bike that had that tankslapper, it'd done it once too often!

Following someone else and THEIR line is not going to do you any good, their bike is different, their handling skills are different, their weight distribution body shape and ability to shift their body is different, their assessment of risk is different, their speed will be different. What someone else does is not what you should do for so many reasons particularly since you're not racing!

You have no idea why they are taking that line and if it's safe, you are taking it on faith but it's their line for them and their ability not yours, frankly it's not just dumb it's reckless to attempt to follow someone elses line and if they are a better descender they are going to lose you on the descent anyway and you'll end up guessing and going too fast and huge increase of crashing. We see this happen in the pro ranks every single year!

Also you have no idea how many times that person has crashed descending (that they'll admit to) basically it's everything you shouldn't do. People like Richie Porte try to follow other better descenders and the likes of himself and others end up coming up a cropper too often.

If the OP thinks this is a better method (to follow someone else) to improve their descending, that's up to them to decide however I would seriously advise to really give that option some thought as this is not how people learn how to descend for themselves and do it SAFELY, that is as I said the be all and end all, nothing else matters over this!

Pub bike wrote:

Was it grip that was the problem that is prompting your thoughts, or was it just carrying too much speed into a bend for the conditions?  If you can't crank the bike over because you're going too fast, having more grip might actually be worse for you.

In the French Alps, for example, a lot of hairpins are similar.  If you can keep one eye on your speedo, you can quickly get to know the maximum speed you can safely carry into a dry hairpin on different lines e.g. inside line, outside line, racing line, which will be three different speeds .e.g 14mph, 18mph and 21mph.   Also, if you have very good visibility down the next straight after a right hand hairpin as you're approaching it then you can take a faster line and achieve a higher speed before the next one.

Once you've worked this out, you just have to make sure you hit those target speeds before you enter the bend.  Sitting upright in good time to maximise drag, and pulling very hard on the ends of the levers from the drops may be necessary if you are carrying a lot of speed e.g. > 40 mph.   Also, if you have panniers on the front, then you have to pull the bars round harder but the bike will still turn in as long as you're not going too fast for the bend.  In the wet the speeds are going to be different of course, but you'll be likely riding much more gingerly in such conditions.  It can be possible to descend safely at around 30mph when it is raining.

 

Got to disagree with a lot of that. You can’t use exact speeds for every bend as every bend is different! And how did you come up with the 30mph figure for safety descending in the wet? I’ve descended at much greater speeds in a straight line in the wet safely, however I’ve gone around bends at significantly slower than 30mph in the wet too. As I said, you can’t give blanket figures for any scenario as they are meaningless.

PP

Pilot Pete wrote:

 

Got to disagree with a lot of that. You can’t use exact speeds for every bend as every bend is different! And how did you come up with the 30mph figure for safety descending in the wet? I’ve descended at much greater speeds in a straight line in the wet safely, however I’ve gone around bends at significantly slower than 30mph in the wet too. As I said, you can’t give blanket figures for any scenario as they are meaningless.

PP

I know.  Each to his own.  That 30 mph is in a straight line. There aren't many hairpins I've done at 30mph!!  Maybe on the Simplon pass going West but can't think of any others.     The wet weather experience was really tested riding down the Tiefenbach Gletcherstraße where it is 13% most of the way.  It was raining when I came out of the tunnel.  The target speeds for hairpins were examples (e.g.) by the way.  I have to disagree with you about every bend being different.  The scenery certainly is, but the radii don't vary massively unless the ground is very steep.  Some of the more obscure Italian passes like Colle dei Morte and others in that area are very variable, but heavily engineered descents like Galibier, Telegraph, Izoard, Turini, Bonnette, Stelvio etc tend to  dish up a lot of the same. 

On another note, I like looking down the mountain for very long straight sections where I can try and get a speed record.  My PB was coming down from Kuhtai in Austria where there is a 16% straight section coming in Greisen.  I expect a better known section for very high speeds is towards the bottom of Izoard riding South where there are three villages separated by long 10% straight sections.

Pub bike wrote:

On another note, I like looking down the mountain for very long straight sections where I can try and get a speed record.  My PB was coming down from Kuhtai in Austria where there is a 16% straight section coming in Greisen.  I expect a better known section for very high speeds is towards the bottom of Izoard riding South where there are three villages separated by long 10% straight sections.

I descended that side once, admittedly a long time ago, and the road surface on the whole of the Izoard descent was rough as hell and not at all confidence inspiring. My personal speed record was also in Austria descending the upper part of Timmelsjoch heading North. Thinner air at altitude and a long gently curving section with a good surface allowed a crazy high speed.

Coming back on topic, good brakes and a larger volume tyre are certainly no bad things when it comes to managing a descent. 

Miller wrote:

My personal speed record was also in Austria descending the upper part of Timmelsjoch heading North. Thinner air at altitude and a long gently curving section with a good surface allowed a crazy high speed.

I did that climb the day before I had my PB.   On Timmelsjoch my max top speed was about 4 mph slower than I achieved the following day coming into Greis im Sellrain, which gives an idea of how steep it is.  This is the start of the hill.    There is a sign indicating that the next section going East is 16%.  The road then just falls away.    There's a Swedish cycle tourist who freewheeled down it at 91 km/h according to his website!

Pub bike wrote:

There's a Swedish cycle tourist who freewheeled down it at 91 km/h according to his website!

Interesting read but that seemed like quite a major traffic accident he had at the end, poor bloke.