tyres for south downs way?

chrisannear87

hi all,

i need help! me and some mates are doing the BHF 100 mile along the south downs way in one hit.

im on a ht and at the moment i run 2.35 Maxxis Minion up front and high roller on the back. im thinking i may want some thin a bit better rolling!

thanks chris

scottfitz

Stick the HR on the front and get some thing faster on the back, if your a Maxxis fan the Larsson TT is a good tyre.

andyg1966

Depends how fit you are, its a tough ride, having done SDW in a day recently. You need a fast XC tyre, Maxxis Crossmark, Conti X King.

Don't go too fast from the start the last 5 hills are long and 4 go from sea level. Don't bust a gut on the steep Amberley mount, walk!

Plenty of taps along the way so no need to carry too much water, 1.5 litres is enough between taps.

I did the route in 12h49, averaged 8mph at the start, dropping to 7.5mph at the end. Keep moving, take food / gels / bars you can eat on the move and don't waste time stopping apart from water and pee breaks. 3 x 20min breaks is an hour!

Good luck

njee20

It's quite flinty too, a lot of people have punctures.

I'd choose something like a Racing Ralph/Furious Fred Snakeskin or Double Defence.

Barteos

If you want to go fast - Racing Ralphs 2.25 or 2.40. Keep the pressure low for better rolling.
If you want a speed boost, trim the centre knobs of the rear tyre with side cutters 8)

njee20

Or just use a Furious Fred, which is far far lighter anyway!

Wouldn't use the 2.4s, they're huge, the 2.25" is a good size though.

BigJimmyB

And if it's wet, there are bits in Sussex (near Devils Dyke area) that will clag your bike with mud, so something that gives good clearance may help...

njee20

And if it's wet, don't bother

FTFY

scottfitz

Keep the pressure low for better rolling.

:? You mean high yeah :?

Barteos

scottfitz wrote:

Keep the pressure low for better rolling.

:? You mean high yeah :?

Lower is faster, unless you ride on smooth concrete

The Rookie

Err....no.

Barteos

Oh dear... :roll:
Do several timed runs on the same course at 60PSI and then repeat them at 30PSI and get back to me.
There's really no point of starting another "Rolling resistance for beginners" thread

njee20

He's right - Schwalbe did some testing which found that lower pressures (and indeed, all things being equal, wider tyres) were actually faster.

The trouble is all things aren't equal, but a good proportion of road teams are now running 25c tyres over 23s, and XC racing tyres are generally getting wider and softer!

But yes, because of the additional energy required to deflect a tyre at higher pressure you're better off softer.

IceDog77

Me and some mates are doing the SDW in August, but we are doing the westerly route from Eastbourne to Winchester.

Firstly, is there anything we should know about the route doing this way round, and secondly I am also trying to work out the best front rear tyre choice/ combo for my HT 29er. Any thoughts?

The Rookie

Barteos wrote:

Oh dear... :roll:
Do several timed runs on the same course at 60PSI and then repeat them at 30PSI and get back to me.
There's really no point of starting another "Rolling resistance for beginners" thread

OK, but since most MTB tyres are rated nowhere near 60psi, you need to compare circa 30-40 PSI with the lowest people will run (say 22psi) at which point you'll find the 30-40 faster.....there has to be a reversal in the trend otherwise flat tyres would be fastest of all.......

Barteos

The Beginner wrote:

Barteos wrote:

Oh dear... :roll:
Do several timed runs on the same course at 60PSI and then repeat them at 30PSI and get back to me.
There's really no point of starting another "Rolling resistance for beginners" thread

OK, but since most MTB tyres are rated nowhere near 60psi, you need to compare circa 30-40 PSI with the lowest people will run (say 22psi) at which point you'll find the 30-40 faster.....there has to be a reversal in the trend otherwise flat tyres would be fastest of all.......

Max. pressure rating on tyres is decided by lawyers not engineers. Most of tyres could be inflated to twice the rated pressure safely.
How low you can go is limited by handling and risk of pinch flats/rim strikes. No one is suggesting running your tyres flat. If you can run 20PSI without any ill effects instead of 30-40PSI you're going to roll faster on anything other than a perfectly smooth surfaces but even on some rough British "tarmac" lowering pressure can offer advantages.
I run 26x2.10 (shaven) Racing Ralphs on my commuter almost every day and at 165lb I run 20PSI front and 30PSI rear. Any higher than that and I'm not getting any faster (based on actual speeds not on feel). That's on the road!
http://bartthebikeman.wordpress.com/201 ... road-tyre/

Don't make assumptions or rely on how the bike feels or what other people run or are telling you.
Just time your runs or use your mates as a benchmark.

chrisannear87

cheers,
Ive just ordered some Racing Ralphs 2.25 from crc. we have a 41 mile audax this Sunday so im going to try and do two laps in prep for the 20th and see how the new tyres hold up! psi suggestions? im 73 kg wet.

thanks agen!

scottfitz

Don't make assumptions or rely on how the bike feels or what other people run or are telling you.
Just time your runs or use your mates as a benchmark.

Good point Don't make assumptions How can you tell some one to lower the pressure when you don't know how much the have in the first place.
I run 30ish PSI all the time in the South downs, drop it a bit if its muddy. I don't know anyone one that run 60 PSI for mountain biking (In my group of friends)

scottfitz

chrisannear87 wrote:

cheers,
Ive just ordered some Racing Ralphs 2.25 from crc. we have a 41 mile audax this Sunday so im going to try and do two laps in prep for the 20th and see how the new tyres hold up! psi suggestions? im 73 kg wet.

thanks agen!

are the RR Snakeskin or Double Defence?
You are the same weight as me.

njee20

I run mine about 25psi, very slightly lighter than you.

IceDog77

I am afraid to run my tyres at less than 60 Psi but maybe I should try it. Even at 60 Psi my rear tyre is compressed by half but that may be due to being 15 st.

Barteos

scottfitz wrote:

Don't make assumptions or rely on how the bike feels or what other people run or are telling you.
Just time your runs or use your mates as a benchmark.

Good point Don't make assumptions How can you tell some one to lower the pressure when you don't know how much the have in the first place.
I run 30ish PSI all the time in the South downs, drop it a bit if its muddy. I don't know anyone one that run 60 PSI for mountain biking (In my group of friends)

I'm not telling anyone what to do and I never question individual decisions. I only fight misconceptions and try to offer useful advice.
60PSI is nothing more than an extreme example, so the differences in speed are more obvious after a test ride or two.

scottfitz

Barteos wrote:

scottfitz wrote:

Don't make assumptions or rely on how the bike feels or what other people run or are telling you.
Just time your runs or use your mates as a benchmark.

Good point Don't make assumptions How can you tell some one to lower the pressure when you don't know how much the have in the first place.
I run 30ish PSI all the time in the South downs, drop it a bit if its muddy. I don't know anyone one that run 60 PSI for mountain biking (In my group of friends)

I'm not telling anyone what to do and I never question individual decisions. I only fight misconceptions and try to offer useful advice.
60PSI is nothing more than an extreme example, so the differences in speed are more obvious after a test ride or two.

Its always good to have a play with your set up to see if it help you inprove your riding.

OP anything around 27 to 30 psi shoud be fine.

diy

I'm assuming this is for the BHF ride on the 20th?

Personally I would run light XC tyres and run them a little harder than usual.

The first 20-30 miles is easy as the big hills don't start until you are about 15 miles out from Devils Dyke. The last 30 is the hardest. 4 drops to sea level in that section alone.

You want to travel as light as you can. Flapjacks/cereal bars, energy gels and hydration additives. A couple of spare tubes, repair kit (some chain lube and a small brush if its muddy) a rain jacket and a small first aid kit. There are plenty of taps and water stops so don't over fill your water bag. 1L-1.5l is plenty between water stops.

I will be running S-Works Fast Trak 2.0 at about 38-40psi (pretty much max). I'm 73kg

Lots of sun screen.

Good luck - I'm doing it again this year 4th time.