Reducing weight of TT bike for London 2012

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Pokerface07
Posts: 213
Joined: Wed Jun 06, 2012 11:43 pm

by Pokerface07

Long time lurker, first time poster.

I have a 2012 Felt DA Di2 TT bike that I'm in the process of re-tooling to shed as much weight as realistic in preparation to ride the London 2012 Paralympics. I'm already a World Champ in the TT, but looking for the 'big one' now.

This year I upgraded my bike from the 2011 model with Sram Red to the 2012 model with Di2 - and there was a noticeable weight difference.

So looking for any ideas I might have missed to shed weight that I may have missed. Here's what I've got or have planned...

Spec:
2012 Felt DA Di2
3T LTD Brezza II bars
Dash Stage.9 saddle
Zipp Firecrest 808 tubular front
Lightweight Autobahn Disc rear
Look Keo Aero Blade pedals with upgraded titanium spindles
Rotor 3D SRM chainset with Aero Q-Rings
Vittoria Chrono tubular tyres
Recon 11-23 Alloy cassette (on order)
KMC X10SL DLC Chain

As many bolts as possible are being swapped out for titanium or alloy ones (on order).


I think I've covered off everything I can think of to get the weight down. Some things can't be changed (like the SRM) for performance reasons and some equipment chosen for sponsorship or aerodynamic reasons.

If anyone can think of anything I may have missed, would love your feedback!

Many thanks,
Colin
Twitter: @FormerTTchamp https://twitter.com/FormerTTchamp

by Weenie


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styrrell
Posts: 167
Joined: Mon Apr 19, 2010 10:33 pm

by styrrell

If its a low yaw day the 808 (non FC) tests faster and is lighter. If its a flat or slightly hiily course a single chainring front (carbon) with a fd and no shift lever or cable will be both lighter and more aero. Ti spokes in the front will be fine. Use JB weld to fair the cleat pedal interface.

Dalai
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Joined: Wed Dec 15, 2004 10:54 am
Location: Melbourne, Australia

by Dalai

styrrell wrote:Use JB weld to fair the cleat pedal interface.


Doubt the commissaires would allow this modification...

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Pokerface07
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Joined: Wed Jun 06, 2012 11:43 pm

by Pokerface07

The London course is mostly on Brand's Hatch - which is a lumpy race circuit (think they used to hold the F1 there, now used for motorbike racing). Wind conditions likely to be variable (but it's a twisty course so it's gonna hit from all angles).

The bike is Di2 - so removing shift cables is a problem!

I had considered rebuilding the 808 with lighter spokes and a lighter hub.
Twitter: @FormerTTchamp https://twitter.com/FormerTTchamp

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Pokerface07
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Joined: Wed Jun 06, 2012 11:43 pm

by Pokerface07

Dalai wrote:
styrrell wrote:Use JB weld to fair the cleat pedal interface.


Doubt the commissaires would allow this modification...


What exactly IS that modification?
Twitter: @FormerTTchamp https://twitter.com/FormerTTchamp

xnavalav8r
Posts: 2594
Joined: Mon Jan 21, 2008 12:09 pm

by xnavalav8r

Small but important gains can be made...

Brake calipers. Many aftermarket brands are lighter than Shimano.
Brake cables. Nokon, I-links, or similar housing paired with Power Cordz.
Bontrager cork brake pads. Super light and work really well with carbon rims.
Cut off as much seatpost as you can, leaving only what is necessary to safely clamp it in the frame.
Switch all bearings to full ceramic.
Alloy rear derailleur pulleys with ceramic bearings.
Once stem is properly positioned and tightened, remove expander plug and top cap.
Remove valve extenders from wheels prior to race.
Quick release skewers. Aftermarket ti skewers can be found sub-40-grams.
Use the shortest chain you can without fear of snapping it.
Run a single chainring up front if the course is a big-ring only profile. (With a chain catcher?)
Find lighter shoes what what you are wearing (rotating weight).

I don't know if you ride with a prosthetic limb, but I know a couple para-cyclists with some amazing custom made versions... lightweight carbon fiber and aero shapes. Pretty amazing stuff!

I can't think of anything else. Best of luck to you in London.

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Pokerface07
Posts: 213
Joined: Wed Jun 06, 2012 11:43 pm

by Pokerface07

Thanks for those suggestions. I forgot that I had done some of them (like cutting down seat post).

Brakes on this bike are more or less integrated (specially made TRP brakes for this bike). Brake cables are Power Cordz.

Stem on this bike is a proprietary system. No fork crown, expander bolts, etc. It's actually a very adjustable set-up, but also heavy. Trying to source a lighter stem from Felt but they don;t seem to know where to find one (and they make the damn thing!)

Already has ceramic BB - and will be adding special jockey wheels (titanium plus ceramic bearings).
KCNC Skewers.
Looking into Bont shoes (currently using a Sidi Ergo 3).
Front wheel will have Vittoria's 80mm valve directly attached to tubular. But could run short valve and remove extender instead.

Just as an FYI, yes I wear a custom carbon leg. It was actually the one thing that turned me into a champion as it reduced rotating dead weight at the pedal by about 6 pounds! A couple of pics:

Image
Image


Colin




xnavalav8r wrote:Small but important gains can be made...

Brake calipers. Many aftermarket brands are lighter than Shimano.
Brake cables. Nokon, I-links, or similar housing paired with Power Cordz.
Bontrager cork brake pads. Super light and work really well with carbon rims.
Cut off as much seatpost as you can, leaving only what is necessary to safely clamp it in the frame.
Switch all bearings to full ceramic.
Alloy rear derailleur pulleys with ceramic bearings.
Once stem is properly positioned and tightened, remove expander plug and top cap.
Remove valve extenders from wheels prior to race.
Quick release skewers. Aftermarket ti skewers can be found sub-40-grams.
Use the shortest chain you can without fear of snapping it.
Run a single chainring up front if the course is a big-ring only profile. (With a chain catcher?)
Find lighter shoes what what you are wearing (rotating weight).

I don't know if you ride with a prosthetic limb, but I know a couple para-cyclists with some amazing custom made versions... lightweight carbon fiber and aero shapes. Pretty amazing stuff!

I can't think of anything else. Best of luck to you in London.
Twitter: @FormerTTchamp https://twitter.com/FormerTTchamp

drewb
Posts: 96
Joined: Tue Aug 24, 2010 11:53 pm

by drewb

Pokerface07 wrote:The London course is mostly on Brand's Hatch - which is a lumpy race circuit (think they used to hold the F1 there, now used for motorbike racing). Wind conditions likely to be variable (but it's a twisty course so it's gonna hit from all angles).


Brands Hatch - I used to race motorbikes there. It was a couple of years ago so sorry for the hazy response - it is a bit hard to picture it now as a cyclist - but from memory you may well need both big and small rings. It has 1 rise that can be quite steep (possibly 2), then 2 downhills that will require a lot of gear changing. I am not sure of the tightness of the corners in relation to having to brake - possibly only 1 corner at the base of a hill. I guess you will be up and down from the drops to the bull horns a bit.

All in all, well worth saving weight, but not at the expense of gear changing (reliability and speed) and usability. The surrounds are very very pretty with a lovely surface, but a bit of a sh1t of a TT course for the pure TT guys. Also - terrible food - typical english diet of chips and gravy and red bull.

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Pokerface07
Posts: 213
Joined: Wed Jun 06, 2012 11:43 pm

by Pokerface07

I actually live in the UK, so am used to the food! (Grew up in Canada, and race for Ireland through my father).

Yes - the course is lumpy (and even leaves the grounds and circles around and back in). I won't know for certain what it's like until later this month when we actually go and ride the course. I've watch videos of it though and I suspect that I won't have to brake often but will have to climb (steeply) a few times. Not out of saddle stuff, but may need small ring as I've opted for a 11-23 cassette to save weight.




drewb wrote:
Pokerface07 wrote:The London course is mostly on Brand's Hatch - which is a lumpy race circuit (think they used to hold the F1 there, now used for motorbike racing). Wind conditions likely to be variable (but it's a twisty course so it's gonna hit from all angles).


Brands Hatch - I used to race motorbikes there. It was a couple of years ago so sorry for the hazy response - it is a bit hard to picture it now as a cyclist - but from memory you may well need both big and small rings. It has 1 rise that can be quite steep (possibly 2), then 2 downhills that will require a lot of gear changing. I am not sure of the tightness of the corners in relation to having to brake - possibly only 1 corner at the base of a hill. I guess you will be up and down from the drops to the bull horns a bit.

All in all, well worth saving weight, but not at the expense of gear changing (reliability and speed) and usability. The surrounds are very very pretty with a lovely surface, but a bit of a sh1t of a TT course for the pure TT guys. Also - terrible food - typical english diet of chips and gravy and red bull.
Twitter: @FormerTTchamp https://twitter.com/FormerTTchamp

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mlchang
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Joined: Tue Dec 15, 2009 3:09 pm

by mlchang

Custom lightweight Di2 battery?

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Pokerface07
Posts: 213
Joined: Wed Jun 06, 2012 11:43 pm

by Pokerface07

mlchang wrote:Custom lightweight Di2 battery?



Yes - possibly. Especially if it can be hidden inside the frame somewhere. And if it doesn't require significant re-wiring. Right now it's down near the BB, but with an aero cover over top.
Twitter: @FormerTTchamp https://twitter.com/FormerTTchamp

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mlchang
Posts: 118
Joined: Tue Dec 15, 2009 3:09 pm

by mlchang

Somebody used to post on here about his/her internal battery kits....
Could save like 40 grams off the battery at least and the weight of the aero cover as well.
Let me do a search and see who that was

cyclenutnz
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Location: Cambridge, New Zealand
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by cyclenutnz

Isn't the battery cover illegal anyway (assuming you're talking about Felts DT one) - which is why Felt have the special seatpost for it?

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Pokerface07
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Joined: Wed Jun 06, 2012 11:43 pm

by Pokerface07

cyclenutnz wrote:Isn't the battery cover illegal anyway (assuming you're talking about Felts DT one) - which is why Felt have the special seatpost for it?


Well, if you call it a weather seal or waterproof protection for the battery, then you can get away with it. Comms looked it over last race and didn't make me take it off. Might be different in London though.

I would have preferred to mount it behind the seat post, but it came mounted down low. Didn't want to rewire the bike to move it!
Twitter: @FormerTTchamp https://twitter.com/FormerTTchamp

by Weenie


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styrrell
Posts: 167
Joined: Mon Apr 19, 2010 10:33 pm

by styrrell

Pokerface07 wrote:
Dalai wrote:
styrrell wrote:Use JB weld to fair the cleat pedal interface.


Doubt the commissaires would allow this modification...


What exactly IS that modification?


JB weld is an epoxy compound. You can use it to to smooth the step out on the front and back of the speedplay cleat so their isn't the right angle bend catching the wind.

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