Details of the PIH Cyclo Sportif Waroona have now been released. This event is set to be the ride of the year with a great challenging course and spectacular scenery.
Date: Sunday 19th September 2010
Start Time: 9:30am
Location: Waroona Recreation & Aquatic Centre – Hill Street, Waroona
Distances: A – 79 km, B – 42km (approx distances)
Lunch: from 12:00 midday
Presentations: 1:15pm
Registrations are open now.
The Perth Integrated Health Cyclo Sportif – Waroona participation event will take place on Sunday morning 19th September 2010. Teams of 4–9 riders will set off, aiming to complete the 42kms and 79kms course to the best of their ability. The Event assembly area / Venue is located at the Waroona Recreation & Aquatic Centre on Hill St, Waroona.
Please note the later Start Time of 9:30am.
This is yet another new event on our calendar, and we have left the best to last. This brand new course is an absolute hidden gem. The scenery is fantastic, the roads are in good condition, there’s little or no traffic and the Venue is a new and very large Recreation & Aquatic Centre.
Be warned though – this course is far from flat and can best be described as hilly and challenging – so don’t let the shorter distances make you think it will be easy. In fact, the only flat section is the first (and last) 1km. After that, the climbing starts and continues, on and off, all the way to the turnaround points. But just think of the return downhills – what a great way to finish. This really is a fantastic course and one that no Cyclo rider should miss.
Entry Costs
Members – $50 (inc GST) includes lunch and entry to raffle
Non-Members – $65 (inc GST) includes lunch and entry to raffle
Juniors – $40 (inc GST) includes lunch and entry to raffle
Please note that if you are not a member you need to register as a “Friend of BWA” for free.
Online entries close Tuesday 14th September.
Leave a comment if you are interested and we will try and put some teams together if we get enough interest. Please DON’T register yet. I will sort out the Teams once we know how many are interested.
Leave in the comments, your name, Cyclo Sportif distance you want to do and usual ride group.
Oh btw I’ll need a XL jersey if anyone has a spare for this event. Haven’t got any SPR kit (apart from gloves) yet.
Apparently these two were arguing over the correct tyre pressure
How many of us have done the old thumb test on our tyres before a ride, or even better (or so we may think) have got the track pump out and pumped up those tyres to 110 – 120 Psi before venturing out for the morning ride. Have you ever found yourself looking for new tyres and getting the 700×22 because the thinner tyres will go faster?
That’s what I have been doing, and I found out that this may be the wrong thing to do. I was recently looking for wheels on an overseas site and a friend pointed me to some tyres. Someone had done a review of the tyres and pointed to an interesting article that suggested we should not be pumping our tyres up so much, well at least we should not be having the same pressure in the front as the back. There was also the suggestion that those bigger guys (yeah at 85kg I qualify) should be riding wider tyres.
The article suggests that we (road cyclists) should look at what weight is carried at each tyre and adjust our pressure and tyre size to suit. An 80kg rider might be better off riding on 700×25 rather than 700×23 as there is less pressure required in the larger tyre to prevent excess tyre drop. So rather than having to pump up the tyre to 130psi to avoid a greater than 15% tyre drop, you only need to pump it to 100psi.
This assumes that the manufactures of tyres have what is called a recommended tyre drop percentage of 15%. That is that when inflated and the weight of the rider on the bike is applied, the rims should only move towards the ground, due to compression of the tyre, by a margin of 15%. I have asked a few tyre companies (Vittoria and Continental) whether they actually have a recommended tyre drop percentage and Vittoria have suggested the following table from their most recent catalogue for pressure, but not tyre drop. (I am trying to clarify further with Vittoria and will update when I know.)
Source – Vittoria
This table suggests that for differing compounds (tpi) you have different pressures both front and back, supporting the premise made regarding tyre drop. TPI (Threads Per Inch) is described as
“Lower TPI tyres have thicker cloth and the gaps between the threads are bigger. These take on more rubber as the tyre is made, making a heavier tyre but with sturdy, abrasion resistant sidewalls. A low TPI count is good for a downhill tyre.
Higher TPI tyres take less rubber to fill the gaps so give a lighter tyre with lower rolling resistance as a result of having more flexible (thinner) sidewalls. Also the smaller gaps between the threads make it harder for a thorn to penetrate the casing. For racing, touring, or any performance oriented tyre, a high TPI count is good.”
Vittoria also go on to suggest the following when determining the correct tyre pressure to run. They suggest to use a small criterium style circuit with varying types of corners. Start with the above pressures and each lap lower the pressure by 5psi until you start to feel the tyre “wallow”. This presure will be your low pressure point. Start again from the recommended and raise your tyre pressure each lap by 5psi until you start to bounce or skip across the surface. This is your high pressure point.
There are some issues with this, as I would not want my front tyre wallowing while cornering at the wrong speed, neither would I want it to skip as I was mid corner. This method is up to you if you want to follow it, but I recon just sticking with the recommended pressures would be good enough.
I received an email back from Conti regarding the question of tyre drop. The sales rep indicated that he had been working in the industry for 25 years and had never heard the term. He further recommended that you inflate tyres to the maximum pressure indicated on the side wall of their tyres. I guess everyone has a different view of tyre pressure.
The tyre drop article outlines a different view. We should be sitting our bikes on a set of scales. Put all the gear that you ride with on (ie if you commute then strap on the backpack for this exercise), then place the front tyre on a set of scales and hop on the bike, make sure you put something under the rear tyre so that you make it level. Record the weight on the front wheel. Then do the same for the back. Once complete look at the weight on the graph (and note that the weight is for the individual tyre not the whole bike) find your tyre size and inflate according to the tyre size that you have.
Breaking this down also allows us to adjust the width of our tyres from front to back, so having a 700×22 on the front and a 700×25 on the back and running pressures of 90psi/100psi may be the optimal set up for our handsome steeds (Did you here that Shrek, she called me a handsome steed. – Donkey from Shrek).
Conversely you can use the 40/60 rule for your weigh distribution. 40% of your total weight will be on the front wheel and 60% will be on the back (This only really applies to racers however). I have tested this theory out and with a total weigh (bike and body) of around 95kg + the 5kg bag that I carry to work, I figure that I have 60kg on the back tyre and 40kg on the front. After using the scales this measures up about right. But what does this say about my 700×23 on the back wheel. Looks like my next back tyre will have to be a 700×25 and I’ll have to pump it up to about 120psi. I think I might run a 700×22 on the front and run it at about 100psi. Thankfully I have a good floor pump, but that’s for another post.
So what size tyres do you ride on and what pressure do you run. Tell us in the comments.
