Reducing weight of TT bike for London 2012

Discuss light weight issues concerning road bikes & parts.
thisisatest
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by thisisatest

im sure people have told you this, but dont trade lighter weight for something less aero or less efficient. shortening a chain a couple links saves a couple grams, but increases pulley cage tension, increasing friction any time youre pedaling. id doublecheck all bearings to make sure theyre perfect, then remove inward facing seals, clean out most or all of the grease and replace it with oil. run a light oil in your freehub for those moments you have to coast...
back to the weight thing, lose any and all bar tape. maybe a little hockey tape where you absolutely need a little grip. most aftermarket quick releases come extra-long-shorten them. lose the qr springs. the vittoria extensions are very light- youd be surprised how much of a non-issue that is. some aerobar pads are quite heavy. can probably homebrew some out of a thin piece of foam and felt, or something like that. it would also be cool if a felt bike had felt on it! are you allowed to shorten brake levers? on the front end-how much modification is allowed? ...and what if it's unseen? one could enlarge the bore inside the stem extension, machine "tune" most of the hardware up there in general...

by Weenie


alibongo
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by alibongo

Tub choice is important, I'd opt for a faster tubular. The evo is nice for road racing, however the rolling resistance is also important.
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kx_1
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by kx_1

Hello,
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My Builds so far... C50,EPS Erik Zabel, C59 Di2.

Phill P
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by Phill P

Tyre and rim selection is probably going to be your biggest selection.

Do some research into low rolling resistance tyres but also aero properties with your wheels.

I wouldn't want to go to a big race like that if you have a chance of the podium with just one set of wheels either. Surely you need a lower profile front and a non disc rear.

Why use QRs? Get some bolt ons. Lighter and more aero. In fact for your purpose why not even try and source a long enough Ti bolt with a domed hex head to go the entire way through, then a suitable size nyloc on the other end. I remember there was talk at the last Olympics about the track axle bolts the Brits were using as being boarder line illegal as they were aero designed (and nobody liked the fact they hadn't thought of it!)

Yaban do a lighter Ti roller chain. It is lighter than KMC, but a lot more expensive.

For a one day race, why not use ceramic bearings and take at least the inboard seal off. You could even wash out the grease and run oil. A lot of maintaince, but how much are you willing to spend/do to get an edge at the Olympics??

Machinenoise
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by Machinenoise

Have you looked at these brakes for the front brake?? http://www.tririg.com/articles.php?id=2 ... Production" onclick="window.open(this.href);return false;
They aren't released yet, but I have one on pre order due for shipping by the end of the month. I would be willing to ship it to you to use for the paralympics if you wanted? (PM me if interested)

The Felt looks like a fairly standard fork bolt set up on that frame from what I can see on internet images! Unless the bolt goes the opposite direction to normal??

If nothing else all the TRP brakes I've ever seen weigh massively more than competitors.

As said above world class tubs could buy you another 5+watts. I'm thinking Dugast silks. 99€ each is too much for me (a 20min 10TT man) but the olympics is everything.

Also carbon derailleur mods + pulley wheels from fibrelyte?

Have you considered contacting Simon Smart at http://www.smartaerotechnology.com/wp/" onclick="window.open(this.href);return false; they might be able to help or offer some sponsorship?? As having a world champ and potential paralympic gold medalist could only be good PR for them! (you don't ask, you don't get!) Possibly the same with USE as their Tula aerobars are considered to be the fastest UCI legal thing out there and I know they've been testing a new version with Hutch for the last 12 months.

And most of all GOOD LUCK!

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Pokerface07
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by Pokerface07

Thanks everyone for the great replies!!

Some really good ideas in there which I will definitely look into.

The bike can be modified a fair bit, however I have my limits as to how far I want to change it. But a lot of the 'one-day' type modifications make sense.

I got to the top, in part by spending a lot of time trying to get as aero and light as possible with my bikes. So far, so good. But you have to constantly stay on the cutting edge.

As for tyres - I agree it's possibly the biggest factor you can change on race day. I normally opt for the Vittoria Chrono as it's light and fast. Data I've seen indicate it's one of the fastest. (We're not talking the EVO CX which is the road tyre).

But fast comes with a trade-off. You have to finish the race also! I'm hesitant to go for a tyre that can puncture too easily. No good being fast if you don't finish.

I've been in touch with the good folks at SMART already. Getting some clothing from them actually. Had hoped for wind tunnel time but they said no.

Have seen the Tri-Rig brake and watched it evolve over time with interest. The front end on my Felt is 'problematic' so not sure if that brake would work, although they claim it will. Will check again. Means adding a center-pull hanger somehow.


Anyway - thanks again and if you think of other, practical things, I'll put them on my list!

And once i have everything - I'll post up some pics.

Colin
Twitter: @FormerTTchamp https://twitter.com/FormerTTchamp

BobSantini
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by BobSantini

That's interesting. You don't seem to be using mid foot cleat position on your natural leg but your prosthesis doesn't have gastrocs so it behaves as if it's a leg with mid foot cleat. That would seem to imply that your seat position will be sub optimal for one side.
I suppose you've worked through all that so I'm just curious.
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edmundo
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by edmundo

I raced a motorbike around Brands (short circuit) eons ago. My guess, like others, is that you will need both chainrings, especially if you find yourself on the day going uphill into wind.
On the subject of brakes, I wouldn't be surprised if you find yourself not using them at all!
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Pokerface07
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by Pokerface07

BobSantini wrote:That's interesting. You don't seem to be using mid foot cleat position on your natural leg but your prosthesis doesn't have gastrocs so it behaves as if it's a leg with mid foot cleat. That would seem to imply that your seat position will be sub optimal for one side.
I suppose you've worked through all that so I'm just curious.



The artificial leg is built shorter than my 'real' leg. I also use a shorter crank arm on the artificial side.

This combination means the weaker leg turns in a smaller circle, and also prevents me from being 'pushed over' to one side every pedal stroke (as the artificial leg is fixed and can't change length at the top of the pedal stroke as a natural leg would through moving the foot/ankle).

The long and the short of it (pardon the pun) is that we spent a lot of time in a lab with prototypes to get something that worked for me. My other leg also has a disability (it's not obvious) that prevents me from pointing my foot downwards. I therefore always pedal 'heel down'.
Twitter: @FormerTTchamp https://twitter.com/FormerTTchamp

Machinenoise
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by Machinenoise

Chrono tubs are very good, I was just thinking that race circuits especially for a Olympic event should have beautiful tarmac with none of the normal crap dragged onto the roads that we usually ride on. So was guessing puncturing would be much less likely.

I appreciate the comments on the brake it does look a bit of an issue, but still willing to let you have it for a play to see if you can get it to work! I doubt you'll actually have to use it in the race any way! Just looking at the photos from the Dauphine prologue and its interesting that argos-shimano (felt riders) have ditched the stock front brake for 7900 front calipers.

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Pokerface07
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by Pokerface07

HA!! I wish the race circuit had perfect tarmac. I'm assuming that Brand's Hatch will be good, but when we leave the circuit and head out on the main roads it'll be a different story. However, once I ride it in a few weeks I'll be able to figure out what's what.

Argos use several bespoke parts (including the stem). I've tried to get ahold of one as I have contacts inside Felt, but no luck. I think the Argos set-up is more aero as they hide the cables very well.


Machinenoise wrote:Chrono tubs are very good, I was just thinking that race circuits especially for a Olympic event should have beautiful tarmac with none of the normal crap dragged onto the roads that we usually ride on. So was guessing puncturing would be much less likely.

I appreciate the comments on the brake it does look a bit of an issue, but still willing to let you have it for a play to see if you can get it to work! I doubt you'll actually have to use it in the race any way! Just looking at the photos from the Dauphine prologue and its interesting that argos-shimano (felt riders) have ditched the stock front brake for 7900 front calipers.
Twitter: @FormerTTchamp https://twitter.com/FormerTTchamp

lactatehate
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by lactatehate

From the photo you posted you could look to glean a few watts by running the USE base bar with the in line brake levers.....

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Pokerface07
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by Pokerface07

lactatehate wrote:From the photo you posted you could look to glean a few watts by running the USE base bar with the in line brake levers.....



Probably... but I'm not willing to change to USE bars. Sponsored by 3T, plus run Di2 so want the Di2 brake levers with the shifters on them.

There are some things I can't/won't change. Just trying to glean what I can from whatever else is left over!
Twitter: @FormerTTchamp https://twitter.com/FormerTTchamp

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Maximilian
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by Maximilian

Pokerface07 wrote:HA!! I wish the race circuit had perfect tarmac. I'm assuming that Brand's Hatch will be good, but when we leave the circuit and head out on the main roads it'll be a different story. However, once I ride it in a few weeks I'll be able to figure out what's what.

Argos use several bespoke parts (including the stem). I've tried to get ahold of one as I have contacts inside Felt, but no luck. I think the Argos set-up is more aero as they hide the cables very well.


Machinenoise wrote:Chrono tubs are very good, I was just thinking that race circuits especially for a Olympic event should have beautiful tarmac with none of the normal crap dragged onto the roads that we usually ride on. So was guessing puncturing would be much less likely.

I appreciate the comments on the brake it does look a bit of an issue, but still willing to let you have it for a play to see if you can get it to work! I doubt you'll actually have to use it in the race any way! Just looking at the photos from the Dauphine prologue and its interesting that argos-shimano (felt riders) have ditched the stock front brake for 7900 front calipers.


Have you tired contacting the Argos wrenches over twitter or the team's website? They might be willing to help out with the stem.
--Max.

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Maximilian
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by Maximilian

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