Post your Small budget weight saves

Discuss light weight issues concerning road bikes & parts.
WILLIAMDENYS
Posts: 78
Joined: Fri Aug 24, 2018 5:06 pm

by WILLIAMDENYS

wheelsONfire wrote:Exactly!
Still strong enough?


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- ridley fenix sl 105 - not lightweight
- sworks tarmac sl 5 r8050 di2 - vision tc 24 wheels = 7,1kg

by Weenie


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themidge
Posts: 1176
Joined: Fri Jan 13, 2017 4:19 pm
Location: underneath sweet Scottish rain

by themidge

dmp wrote:
Wed Nov 21, 2018 7:58 pm
Changing to Ti cleat bolts and washers for Look saved (if I remember correctly) less than 10g. But weight savings wasn't the reason I did it- it was because the Ti fittings don't rust, and cleat bolts are highly subject to rust.
This is a great excuse for doing a little bit of bolt tuning, I like the idea of have a bike that is as non-corrosive as possible (so bolt-tune your winter bikes everyone! :D ).
Places I can think of where bolts are likely to corrode eventually:
- brake bolts/recessed nuts, these are the worst for rusting
- cleat bolts, as mentioned already
- limit screws
- bottle cage bolts if left unattended long enough
- not bolts, but the steel axle of quick release skewers can suffer

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Stendhal
Posts: 195
Joined: Sun Sep 25, 2016 1:43 am
Location: Silicon Valley

by Stendhal

maxxevv wrote:
Tue Nov 20, 2018 7:50 am
Stendhal wrote:
Tue Nov 20, 2018 3:49 am
My suggestion -- and I am surprised no one has mentioned it yet, to my knowledge -- is to fill your tires with helium instead of air. Helium is lighter than air so you'll save some grams. Plus, you may be able to float up the climbs, ahead of your club ride friends. (Why else do you think Ridley named its climbing bike the Helium)? Also, at coffee stops, you can delight your friends by taking a nip from the tire valve and speaking in a squeaky voice.
Except that you can't use helium on normal rubber tubes nor tyres ....
True, unless you line the tire and tubes with mylan. I'm surprised this hasn't happened yet

https://en.wikipedia.org/wiki/Lifting_gas

As the article states, it would not help as much, but you could use neon instead. As a side benefit, your tires will glow in the dark!

Thinking about this further, now we know why Miguel Angel Lopez was not able to keep up with Chris Froome on the mad climbs up the Sestriere on stage 19 of this year's Giro. Lopez rides for the Astana team, on Argon 18 bikes. Obviously they were filling their tires with argon, which is heavier than air.

All in good fun! Seriously, wouldn't it be the height of weight weenism \ First World optimization to develop lighter than air tire systems? Maybe this is occurring in secret, like the secret motors inside wheels "discovered" by the Italian press. Call the UCI -- there could be Air Doping going on!
Specialized S-Works Tarmac SL6 (6.39 kg), Cervelo Aspero (7.87)
Retired: LOW// mki, Pinarello Dogma F10 \ F8, Lapierre Pulsium, TIME Fluidity, Wilier Cento1 SR, Ridley Noah, Cyfac Cadence, Cervelo S2, R3, R5, Felt Z25, Klein Quantum, Cannondale 2.0

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C36
Posts: 644
Joined: Fri Mar 03, 2017 3:24 am

by C36

Helium is not new. If I recall properly Merckx did his hour record with helium in the tubulars.
The molecules are so small that they pass though the rubber and pressure drop is really quick.


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Stendhal
Posts: 195
Joined: Sun Sep 25, 2016 1:43 am
Location: Silicon Valley

by Stendhal

C36 wrote:
Thu Nov 22, 2018 1:02 am
Helium is not new. If I recall properly Merckx did his hour record with helium in the tubulars.
The molecules are so small that they pass though the rubber and pressure drop is really quick.


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That's so cool! Proof again that Eddy Merckx > us mere mortals.
Specialized S-Works Tarmac SL6 (6.39 kg), Cervelo Aspero (7.87)
Retired: LOW// mki, Pinarello Dogma F10 \ F8, Lapierre Pulsium, TIME Fluidity, Wilier Cento1 SR, Ridley Noah, Cyfac Cadence, Cervelo S2, R3, R5, Felt Z25, Klein Quantum, Cannondale 2.0

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Lewn777
Posts: 833
Joined: Thu Mar 09, 2017 5:35 am

by Lewn777

I would be very careful about cutting seat posts and using small and light expanders. Likely you'll save 50g-100g between them but it could cost you your frameset.

The stem bolts need to be supported and some manufacturers recommend their OEM expanders only. Using a small lightweight expander could void your warranty and cause undue unintended stress on your steerer. Some manufacturers are okay with small and light expanders but most are not.

Some manufacturers demand that you use at least 10cm or even no more than 10cm inside the frame. Therefore if you cut a shorter seatpost than the OEM one even if you are longer than the marked minimum insert you can void your warranty. Some bikes are well reinforced around the seat post and top of the seat stays and brake bridge but some aren't. If your frameset or bike comes with a stock seat post than isn't a boat anchor I'd just leave it. If it came without one or was heavy find a nice one but measure 10cm inside the frame and ignore the minimum insert mark, any weight saved is a bonus.
Last edited by Lewn777 on Thu Nov 22, 2018 1:28 am, edited 1 time in total.

mag
Posts: 405
Joined: Thu Mar 16, 2017 12:23 pm

by mag

You may seal the frame and fill it with Helium as well ;-)

Anyway, drillium!

WILLIAMDENYS
Posts: 78
Joined: Fri Aug 24, 2018 5:06 pm

by WILLIAMDENYS

Lewn777 wrote:I would be very careful about cutting seat posts and using small and light expanders. Likely you'll save 50g-100g between them but it could cost you your frameset.

The stem bolts need to be supported and some manufacturers recommend their OEM expanders only. Using a small lightweight expander could void your warranty and cause undue unintended stress on your steerer. Some manufacturers are okay with small and light expanders but most are not.

Some manufacturers demand that you use at least 10cm or even no more than 10cm inside the frame. Therefore if you cut a shorter seatpost than the OEM one even if you are longer than the marked minimum insert you can void your warranty. Some bikes are well reinforced around the seat post and top of the seat stays and brake bridge but some aren't. If your frameset or bike comes with a stock seat post than isn't a boat anchor I'd just leave it. If it came without one or was heavy find a nice one but measure 10cm inside the frame and ignore the minimum insert mark, any weight saved is a bonus.
Does the smaller expander destroy your tube because you tighten your handlebar where there is no pug inside?


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- ridley fenix sl 105 - not lightweight
- sworks tarmac sl 5 r8050 di2 - vision tc 24 wheels = 7,1kg

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pdlpsher1
Posts: 2424
Joined: Thu Jul 19, 2012 6:09 pm
Location: CO

by pdlpsher1

dmp wrote: Changing to Ti cleat bolts and washers for Look saved (if I remember correctly) less than 10g. But weight savings wasn't the reason I did it- it was because the Ti fittings don't rust, and cleat bolts are highly subject to rust.
+1. I got my Shimano cleat bolts and plates on eBay and shipped from China. Very high quality and they won’t rust.



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pdlpsher1
Posts: 2424
Joined: Thu Jul 19, 2012 6:09 pm
Location: CO

by pdlpsher1

WILLIAMDENYS wrote: Does the smaller expander destroy your tube because you tighten your handlebar where there is no pug inside?


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Yes. Most stem clamps are 40mm tall. You need an expanded that’s at least 45mm tall.


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WILLIAMDENYS
Posts: 78
Joined: Fri Aug 24, 2018 5:06 pm

by WILLIAMDENYS

pdlpsher1 wrote:
WILLIAMDENYS wrote: Does the smaller expander destroy your tube because you tighten your handlebar where there is no pug inside?


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Yes. Most stem clamps are 40mm tall. You need an expanded that’s at least 45mm tall.


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Oh okay so those tiny ones are bad


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- ridley fenix sl 105 - not lightweight
- sworks tarmac sl 5 r8050 di2 - vision tc 24 wheels = 7,1kg

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Lewn777
Posts: 833
Joined: Thu Mar 09, 2017 5:35 am

by Lewn777

WILLIAMDENYS wrote:
Thu Nov 22, 2018 5:37 pm
pdlpsher1 wrote:
WILLIAMDENYS wrote: Does the smaller expander destroy your tube because you tighten your handlebar where there is no pug inside?


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Yes. Most stem clamps are 40mm tall. You need an expanded that’s at least 45mm tall.


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Oh okay so those tiny ones are bad


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Not always. It depends on the manufacturer, but as a general rule, yes. There are some good threads about this, I should dig them out.

dereksmalls
Posts: 2225
Joined: Tue Aug 02, 2011 9:20 pm
Location: New Zealand

by dereksmalls

Tune cable housing

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C36
Posts: 644
Joined: Fri Mar 03, 2017 3:24 am

by C36

dereksmalls wrote:Tune cable housing
Read a bit about them but never seen them. What makes them light and anything special using them?


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by Weenie


2lo8
Posts: 539
Joined: Thu Mar 31, 2016 10:32 am

by 2lo8

Stendhal wrote:
Thu Nov 22, 2018 12:52 am
maxxevv wrote:
Tue Nov 20, 2018 7:50 am
Stendhal wrote:
Tue Nov 20, 2018 3:49 am
My suggestion -- and I am surprised no one has mentioned it yet, to my knowledge -- is to fill your tires with helium instead of air. Helium is lighter than air so you'll save some grams. Plus, you may be able to float up the climbs, ahead of your club ride friends. (Why else do you think Ridley named its climbing bike the Helium)? Also, at coffee stops, you can delight your friends by taking a nip from the tire valve and speaking in a squeaky voice.
Except that you can't use helium on normal rubber tubes nor tyres ....
True, unless you line the tire and tubes with mylan. I'm surprised this hasn't happened yet

https://en.wikipedia.org/wiki/Lifting_gas

As the article states, it would not help as much, but you could use neon instead. As a side benefit, your tires will glow in the dark!

Thinking about this further, now we know why Miguel Angel Lopez was not able to keep up with Chris Froome on the mad climbs up the Sestriere on stage 19 of this year's Giro. Lopez rides for the Astana team, on Argon 18 bikes. Obviously they were filling their tires with argon, which is heavier than air.

All in good fun! Seriously, wouldn't it be the height of weight weenism \ First World optimization to develop lighter than air tire systems? Maybe this is occurring in secret, like the secret motors inside wheels "discovered" by the Italian press. Call the UCI -- there could be Air Doping going on!
Realistically (as realistic as helium in tires go) you're not trying to get lift force though. Tires are under pressure. Assuming you have a constant pressure, according to the ideal gas law, (assuming ideal) PV=nRT. Assuming V is constant because of tire size, T is constant because it's not going to change based on gas, and R is a constant, that means P is proportional to n. The molar mass of helium is 4g/mol. The molar mass of air is 29g/mol.

For a 700x23 tire, experimentally, each bar/atm of air adds about 1g ( https://2lo8.wordpress.com/2016/06/24/j ... -than-air/ ), which should be directly proportional to the moles of air in the tire, and the mass directly proportional to the moles of air. So assuming that I didn't forget how to do stoichiometry, if you would normally have ~14g of air in your tires, that would be ~2g with helium. That would be about equivalent to 1 bar/atm of air pressure at sea level since that was experimentally determined to be ~1g/bar per tire.
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