sub-5kg Guru Photon

Discuss light weight issues concerning road bikes & parts.
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Posts: 19
Joined: Fri Jul 04, 2008 1:45 am
Location: MA, USA

by carhillclimb

bike Guru Photon Photon
frame custom 789
fork scapula 226
wheels dash hubs, stans rims 1102
tires veloflex record 272
tubes vredestin latex 100
tire air 8
skewers tune 23
saddle ax phoenix 53
seatpost schmolke 83
headse kcnc 41
handlebars schmolke 168
stem extrallite 110 86
aero bar w brake hed 277
rea shifter camoy 165
front shifters campy 165
rear der camp super rcrd 156
fr der campy mod 56
brakes ax 3000/fibula 130
cranks clavicula 406
sprockets custom triple 133
pedals speedplay zero nano 125
cluster Recon 116
chain Ymc ti 209
handlebar tape cinelli 36
handlebar plugs cinelli 3
seatclamp b-t-p 3
rr brake cable powercordz 4
rr brake housng powercordz 19.2
fr brk cable KCNC Ti rear 3
fr brk housing bungarus 24
der cable powercordz 6
rr der housing alligator mini 19.2
ft der housing alligator mini 12.8
der cable adjusterrs 8
error -32

The error is to get the spreadsheet number to match the total bike scale weight.

kg 4995.2
pounds 11.01234568

The bottle cage is chinese e-bay. The JANDD saddlebag weighs about 750gm with spare tire, tube, minipump and a few allen wrenches. Total as it resides in the rack is under 13 lbs.

I do not race. I have entered maybe 9 races in my life. I am 59. I have been more-or-less daily commuting on a bicycle since 1970. Right now about 24.8Km each way, 6 weeks ago I did the round trip on this bike in 1:29:50 (over 20 mph average). This is my second stupid-light. I have not been strong since I was 30 and not fast since I was 54 (cancer, pulmonary embolisms, ECMO etc.) I am off the bike for a bit because I crashed (steel frame Amieya, undamaged except 2 flat tires) and broke my left clavicle and had a concussion - 0.5 hour unconscious. What is hard to explain is why the aero bikes are not faster on my relatively level commutes, but much of it is that I will put out more power for the 45 minutes on a light bike than I will on an aero bike. Not sure why that is or if I could be trained differently.

I do not glue tires on my bikes. I tried that in the 70s and I am not going back.

I really like the aero bar, and also the brake lever on the aero bar which of course is for the front brake because that is the only brake that really does anything for rapid speed reduction.

I really like the shifters on the handlebars; I am not going back to down-tube shifters either.

The cluster is:
Cycle Dynamics Ti 11 t cog with other 10 sprockets
custom recon 13-27 for Shimano 10 speed freehub,
machined a bit more because the Dash hub left it too far right

This is the first triple I built that worked OK; I did this because the 26-46 double on my Ritchey Breakaway was a bit annoying to downshift. The front shifter is a Campagnolo Veloce Escape QS triple with a Record brake lever, the rear is a Super Record 11 shifter. I do not notice the mismatch when riding. The shifters have B-T-P hoods and clamps. The front sprockets are:
24 t ? was SR thin aluminum but that broke when I was missing a bolt
36 t IRD triplizer lightened
48 t eggring lightened by Hipath

I normally use 46 or 47 tooth big rings (except my P4 time trial bike which has 34-53 and an 11-25 12 cog cassette - yes 12 cogs).

24-27 is enough gear for the 2008 version of Michael Wilson to ride up Mt Washington Newton's Revenge in 1:19:13 (a different bike, the previous stupid-light Trek Madone SSL OCLV55, actually with 30-34 gears on a clavicula compact with custom chainring bolts, bike stolen in June 2014, I have another bike with a similar 30t 110bcd setup, see pictures on my folder in geared hub bikes).

46-11 (actually 54-13) is enough gear for the 1998 version of Michael Wilson to ride a 180 mm crank 1978 Bob Jackson bike at 82 km/hr down a hill that was about 80 meters elevation drop on my way home from work - West Bare Hill Rd Harvard MA.

The 15-19 corncob section is a great level road set of gears on the 46 or 47 or 48 big ring.

I cannot imagine why anyone who is not riding in a pack or a time trial wants an 11 and a 12 and a 13 tooth cog on their cassette. They are all downhill gears. Most of my bikes do not even have a 14.

The 48-27 and yes I use that still gets me up most hills in Eastern Massachusetts on main roads. Not usually up the hill to my house though. (I mis-spent my youth commuting spring summer and fall on a fixed gear 49-18 (actually an ASC that I never shifted) and I used to be able to ride that down without braking or up any paved road in Eastern Massachusetts, but that will never return.)

I am having trouble embedding the pictures, and the main picture needs to be redone anyway. Any hints on how to add pictures accepted.

Michael Wilson
Michael Wilson

Posts: 382
Joined: Wed Apr 08, 2009 8:01 pm

by Denavelo

Hints on how to post pictures?

You should get a Flickr account, and the site has web options for posting.

Most cycling companies use Flickr as a source of storing and uploading images...

Here's Speedvagen / Vanilla's flickr:
Speedvagen Road Machine "2011 Surprise me | Cannondale SuperSix Evo | Rob English "Mudfoot" 29er | Firefly Ti #419 | Kogswell 650b Rando | Crema Cycles "Duo"

by Weenie

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Posts: 1570
Joined: Tue Aug 28, 2012 2:45 pm
Location: Stockholm, The Arctic...

by PSM

:beerchug: Nerd.

Posts: 1145
Joined: Sat May 26, 2012 11:26 pm

by NiFTY

Very nice build, and i am very keen to see your photos. Not sure i understand your gearing logic though. 48x14 @ 116rpm is 50kph. Hell 53 x 14 @ 120 rpm is only 57kph. I understand that you have had some very serious health issues but your disbelief at anyone needing fewer than 14 teeth (and presumably anyone using a 53T chainring) seems nuts. I would hazard that over 50% of the people on here race at least a few times a year. I would say 99% if not more rode in bunches regularly.

In a bunch sprint over a 1km straight, which averages -1% I have spun out a 53x11 at 65kph at 105rpm and was reaching for the next gear (which wasn't there). I am not saying this to flaunt my sprinting credentials, i am not a sprinter, i am a climber, i am just illustrating that in real world circumstances most half decent cyclists still require more than a 46x14.

I lastly find it strange that you think 54x13 is enough to power you to 82kph, which would be a cadence over 160 just to engage the freehub, let around generate significant watts to actively accelerate you. You were at the will of gravity my friend.
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