Time Trial / Time Trialling / TT

Good fun at the MDCC Boxing Day 10 this morning. I think 18 riders in total in quite nice conditions considering recent weather. 2 of us on fixed, and coincidentally we both finished in exactly the same time. Top marks to Tester for turning up on a dirt jump bike.

Pics or it..

Calling it a dirt jump bike is a bit of misnomer, since the one thing which characterises my off road riding is that I always try to keep at least once wheel on the ground at all times. Also, the frame was designed for Dual Slalom.

I'm building some wheels that I intend for fixie skidding use and TTing. These aren't a TT only wheelset and I can't stretch to that. I originally planned to use H Plus Son Artchetype rims but am now considering something a bit deeper (SL42) to benefit my TTing.

Any opinions on whether the £23 increase in price and 290g increase in rotating mass are worth the aero advantage of increasing rim depth from 25mm to 42mm? Also of note, the archetype is a 23mm wide rim. The SL42 is 19.5mm wide.

I think we agreed on that spoke count is a bigger factor than rim depth, what is your situation in that manner?

Are you budgeting more than the cost of Shimano RS30?

Edit: came to my senses, you definitely want a fixed wheel, right?
http://www.planet-x-bikes.co.uk/i/q/WPPXPCT5050/planet_x_pro_carbon_50_50_track_wheelset

Guessing from his rim choices he doesn't want tubular either!

I'm building some wheels that I intend for fixie skidding use and TTing. These aren't a TT only wheelset and I can't stretch to that. I originally planned to use H Plus Son Artchetype rims but am now considering something a bit deeper (SL42) to benefit my TTing.

Any opinions on whether the £23 increase in price and 290g increase in rotating mass are worth the aero advantage of increasing rim depth from 25mm to 42mm? Also of note, the archetype is a 23mm wide rim. The SL42 is 19.5mm wide.

Higher rotating mass is better for a TT unless it has a lot of bends you have to slow down for.

I was a similar tting/skidding quandary. I was using a mavic ellipse and changing tyres for tting, but now I have a spare wheel for skidding, allowing me to keep fast tyres/cogs on my ellipse.

What I need is quite strange. I have a set of 28h Mack hubs on order and am using a Cervélo P2C frame with a broken hanger. The Mack hubs are coming with 120mm and 130mm end caps so they're usable on the frame.

I think we agreed on that spoke count is a bigger factor than rim depth, what is your situation in that manner?
I'm not 100% locked in to 28h front and rear but as I'm wanting the front and rear to match with 3 cross lacing, I don't really think there's much give here.

Are you budgeting more than the cost of Shimano RS30?

Edit: came to my senses, you definitely want a fixed wheel, right?
http://www.planet-x-bikes.co.uk/i/q/WPPXPCT5050/planet_x_pro_carbon_50_50_track_wheelset

A set of Planet X track wheels will definitely be a feature at some point. Just not right now. What I'm trying to do is build a street wheelset with a bit of an allowance for TTs.

Guessing from his rim choices he doesn't want tubular either!

As above, A 50mm carbon tubular wheelset will be something for another time. One problem about this is that I'd have to choose a tubular that works well on tarmac but can be cleaned up and be sticky on a wooden track (Glasgow velodrome). This is a problem for another time.

Higher rotating mass is better for a TT unless it has a lot of bends you have to slow down for.

I'll have to have a look at the local courses. I've only done the one course multiple times but this season will branch out.

Any opinions on whether the £23 increase in price and 290g increase in rotating mass are worth the aero advantage of increasing rim depth from 25mm to 42mm? Also of note, the archetype is a 23mm wide rim. The SL42 is 19.5mm wide.

If you're stuck with 28h, the lower rolling resistance with the wider rim will counter some of the improved aero of short spokes. Depending on the course and how fast you are,the net difference might be negligible, so you might as well optimise your skidding and leave deep rims for later when you can get some with an appropriate spoke count

Higher rotating mass is better for a TT unless it has a lot of bends you have to slow down for.

Is it? You still have to push that weight over any rises.

EPO, CERA and bloods.

No we had, Soup, Turkey & Christmas pudding ;)

"Higher rotating mass is better for a TT unless it has a lot of bends you have to slow down for."

"Is it?"

No it is not.

That's what I thunk.

I think what he meant to say was that a heavier, more aero wheel is better for timetrialling than a lighter, less aero wheel.

I think what he meant to say was that a heavier, more aero wheel is better for timetrialling than a lighter, less aero wheel.

Yes then. When you've gained momentum weight (up to a certain point) isn't much of an issue.

Also, a more rigid wheelset will provide greater power transfer. While typically slightly heavier than "traditional" wheels, a high end aero profile wheelset will kill two birds with one stone.

Hippy, put your 2012 times in your TTForum profile, you'll easily top the forum long distance table

What's a type A event?

Updated the values in that thing. Will see what happens. Does someone pick these up semi-automatically then?

Champions Night dinner tonight. They have no record of my email confirmation though so it could get interesting.. :)

What's a type A event?

An Open or Association event, i.e. not a Club or Inter-Club event. Rides in West London Combine events are type B, for example.

Updated the values in that thing. Will see what happens. Does someone pick these up semi-automatically then?

NikB does the tables, not sure how, it seems to be quite labour intensive.

CTT site needs an RSS or twitter feed or something.

It needs a lot more than that, it's nearly as shit as the TTForum

Yeah well, there is that but I can find the info I need so can't complain. It'd be good to see when any new stuff goes up that's all.