Fixed Time Trial Bikes

Current iteration of TT rig. Still fiddling with position, and excuse the slight scoblestack - the bike does a lot more than just time trials so can't justify cutting it down. It gets its first proper test at the Wednesday club TT week after next

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I've never ridden fixed really before, but I'm building a FGTTB for fun. When looking for a rear wheel is there anything in particular I should be looking for? I'm on a bit of a budget, and I'm a very, er, modest time triallist, so I suspect I should just get a cheap wheel and see how it goes.

Also, any tips on gearing? I ride 45/18 around town. No idea about tt. I see big scary numbers chucked about on here. Is there a rule of thumb?

Gear for your desired cadence at your estimated average speed.

Just get a cheap rear to start.

Ah cheers ;) seems obvious when you put it like that.

This is all gonna be guesswork because I've never measured cadence, but I can work out speed from my previous times.

85"-90" I reckon.

Gear for your desired cadence

Which will take a while to figure out :)

85"-90"

85-90rpm, since 66" around town is about what I'd use so @fizzy.bleach seems to be in my region on the mash-spin scale. 85" covers times from 26:18 to 27:51 for 10 miles.

I'm doing the sums now and I've just come a cropper with the term "desired cadence :)"

I used to do 80" around town way back, so I'm gonna go with something like @dbr suggests and see how shit I am.

85" covers times from 26:18 to 27:51 for 10 miles.

The good end of that is a decent PB for me, so probably a good start. Thanks for the advice :)

I had 19:13 with 46/14, 3.28 ratio but for 7,5 miles time trial. Also it was super windy, and competition took place in 2.5 mile long race track. On straight it was awful to pedal with super high cadence , but rest of the track was quite okay with that ratio.
Also, here's pic of my rig.

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19:13 with 46/14, 3.28 ratio but for 7,5 miles

90rpm average, that's about the point where I know I need to go up a gear.

That was the target, 90rpm average, and bigger gear would kill me when I was riding into the wind, and speed decreased from 41-43 to 33-34 :D

speed decreased from 41-43 to 33-34

You have to be flexible if you're going to TT on fixed. Last time out on 72" with a strong wind my speed ranged from 21 to 52 km.h^-1, or 60rpm to 150rpm.

Now I know, it was first time back then :)

+1

80" is a nice beginner gear. I got down from mid 29s to low 24s on 53x17 before feeling the need to go bigger.

http://www.ebay.co.uk/itm/252550692837?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

just saw this. v short headtube, 56x54

just saw this. v short headtube, 56x54

Picture is obviously of a different size, the description says 14cm head tube. Even the MAMIL-friendly new generation P3 is longer and lower than that.

Is it a genuine Cougar? Seller is listing another apparently 58cm version that looks exactly the same?!

edit: and 49 and 50cm versions listed too.

Most likely not a genuine pre-'Dolan'-brand Cougar, but the eBay account selling belongs to Julie Dolan, so it's as 'genuine' a modern Cougar as you're going to be able to find.
Maybe it's a batch of frames fabricated or bought-in, originally intended for use by a team or trade customer, and now being badged as 'Cougar' to avoid confusion with the current, much more well known range of Dolan track frames? Still, just speculation.

Good one

I was going to mention this in the 3mm thread on TTF but then decided I couldn't be bothered with the hassle.

Doesn't the 3cm rule unfairly penalise riders who want to ride fixed? I'd guess most fixed riders will be using bikes originally designed for track racing (as opposed to TT bikes stripped of their derailleurs or using a magic gear). Since such bikes have almost universally tall stack and short reach most riders will surely be 'making do' with a suboptimal set up that will very often involve buying a smaller frame but compensating with a longer stem?

I can't remember the exact details but when I was looking at Pre Cursa frames I seem to remember that the stack on the 54cm frame was about right but I'd need an enormous stem. On the 56cm frame the reach was ok but I'd need some kind of negative risers to get the stack right. I tried and gave up trying to use a Tokyo Dart for TTing when I still couldn't get the correct position with 130mm -30º stem. The T3 is about the only frame that would get me close to my current position, but is £££.

It's ok, when they change the rule to a roll up test it'll favour fixed.

Think I was always way more 3cm compliant on my Cinelli than I am on my T3 however...

Doesn't the 3cm rule unfairly penalise riders who want to ride fixed?

The acceptance of dérailleurs for racing unfairly penalises riders who want to ride fixed :)