Looking to create super light, 1x/year, climbing machine

Discuss light weight issues concerning road bikes & parts.
HarryS
Posts: 39
Joined: Sun Feb 05, 2012 12:16 pm

by HarryS

If brakes are no concern, Id use some kind of MTB trigger shifter and some narrow track drop bars. I like strange project bikes like this, looking forward to seeing what you come up with!

tonytourist
Posts: 1214
Joined: Sat Oct 10, 2009 7:13 am
Location: 93306

by tonytourist

User cmh has a pretty cool hill climb bike:
viewtopic.php?f=10&t=97416&start=0
8)

by Weenie


BmanX
Posts: 3844
Joined: Thu Nov 10, 2005 5:31 pm

by BmanX

There are lots of cool things that you could do if you have some time. The older FSA carbon cranks have a removable spider which would allow you to run a spiderless chainring in what ever size you want. You could have a pretty cool crank set. You could also do what others have said and set up your rear derailleur to run a few cogs on the back. You could use carbon spacers to space it out to the right chain line. I have done all of these things in the past and Fibre-Lyte were great to work with in sorting out the details. They even made me some 16t cogs for some single speed projects.

Looking at the link to the Scott build, you could lighten that up a fair bit. Also running a Berk saddle/post combo could keep the weight down. Do you have to run drop bars on the bike. The only reason I ask is that you could run a bullhorn set up with the shifter in the end of the right side for shifting and if you need 1 brake could have a vison lever in the other side at 35g.

So there is potential to do up a stupid light build. For hill climb bikes that do not have to follow any set rules, I honestly do not know why people run drop bars with heavy shifter/brake levers.

I have a lot of ideas for a killer hill climb bike but no funds to make one.

I do a lot of climbing where I live on the west coast and one a single speed builds I have used in the past a 32t upfront and a 16 on the back has allowed me to climb some big hills. If I was to gear it I would run individual cogs something like this. 15,17,19,21,23,25 and just have them spaced out on the wheels for a good chainline.

Maybe run Sram and tune the RD to around 110g easy, shifter are only 69g, KCNC brake is 68g front and i could go on.
BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5960g/13.13 lbs

KLabs
Posts: 380
Joined: Wed Dec 01, 2010 4:29 am

by KLabs

dparker wrote:I participate in the Mt. Washington Auto Road Hill Climb each year - 7.6 miles at an average gradient of 12% (22% for the last 100 feet, which is mean). At 12%, a 1% drop in total weight (bike plus rider plus stuff) translates to a 1% increase in speed - in other words, gravity provides 100% of the resistance.

So, given that I'm already so skinny my wife would kill me if I lost any weight, and that this race is really my only one each year - I train for it exclusively through the spring and summer, and finally that I'm turning 50 with in a year, and want to treat myself to something really silly - I thought of putting together a crazy light bike just for this race. And I don't want to buy anything new for it - just very light used stuff, so it shouldn't cost too much.

So here's what I'm thinking: I buy a used super light frame (maybe a Scott CR1 Limited?) and then turn it into a minimalist single speed, with no derailleurs, no brakes, tubular tires on super light rims, and shortened handlebars.

What do you think? Could I get down to 8 or 9 pounds total? Is it hard to use a standard carbon frame as a single speed - should I replace the dropouts so they're more horizontal?

Thanks
David


Hi dparker, sounds like fun. I am a little older than you, but much heavier, and there is a ride I like doing from Samford to Mt Glorious in Brisbane. It's about 6kms of climbing of which the last 2kms average 15% (the motorbikes like coming down this road). I have set my bike up just for this ride still using a standard crankset but with an 11-36T cassette and XTR RD. This gives me 39/36 if required and it always is towards the top.

So, what am I suggesting ... that you use a double or triple crankset (probably what you have already), with a single ??T sprocket (to give the equivalent of 34/34 gearing or lower 22(F)/24(R)) and a nexus or alfine chain tensioner (or simply use your current RD set to the single sprocket but I think it will be heavier). This will allow you to use the front chainrings as your gear change mechanism.

What do you think ...
Last edited by KLabs on Sun Mar 11, 2012 10:40 am, edited 1 time in total.

BmanX
Posts: 3844
Joined: Thu Nov 10, 2005 5:31 pm

by BmanX

HEAVY SUGGESTION!
BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5960g/13.13 lbs

Edster
Posts: 12
Joined: Thu Dec 22, 2011 11:03 pm

by Edster

Carbon EVERTHING! You can use vertical dropouts with a White ENO hub to make a single speed, but I think it would be better to go with Harrys's comment of a 1x something. Depending on direction the wind is blowing you could need a couple of teeth up or down. I would go with an aluminum 10 speed cassette and a downtube shifter. The Bullhorn bar setup sounds good as well. I did some quick math and came up with about 3630 grams / 8.00 lbs as a realistic target. This sounds like a fun project!

BmanX
Posts: 3844
Joined: Thu Nov 10, 2005 5:31 pm

by BmanX

Well for sh1ts and giggles I thought I would put together my Giant TCR Zero aluminum frame with Easton EC90SL forks on a hill climbing diet since it is in pieces already and built it up with Syntace basebar and stem, FSA carbon crank with 32t Spiderless chainring, EDGE 45 clinchers, Thomson Masterpiece, Fizik Arione Carbon, Sram TT500 rear shifter, KCNC 11/23 rear cassette and KMC X10sl chain with stock X2's and it came in at 11 lbs.

I think it would climb amazingly well and I like the hand position which reminds me of climbing on my MTB with the bar ends.

The frame is 1080g and the forks are about 324g, wheels are 1282g, tires are 164g each, tubes are latex, cassette is 110g, Sram Force RD tuned with carbon cages and pulleys, skewers were Omni racer as well as seat clamp. Masterpiece 31.6 post with carbon cradle, Fizik Arione carbon. Syntace stem is about 94g and the basebar has upturn cut so about 224g. Chain was full length for my standard set up so I could remove some links for sure.

This is going to be my trainer bike for now but with different wheels and I will add a front brake for those times I need to ride a 12.5lbs bike to the store. The lock will weigh more.
BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5960g/13.13 lbs

justkeepedaling
Posts: 1340
Joined: Thu Jan 03, 2008 6:14 am
Location: by Crystal Springs (Sawyer Creek Trail)

by justkeepedaling

styrrell wrote:Not sure if this is Kosher, but i have an old set of sub 1200 gm wheels (actaul weight, no tires cassette, qr, just under 1200 gms by a few gm, tubular /shimano compatible) that I will let go cheap.

smtyrrell99 at yahoo.com


5 dollars, that's my final offer. If I'm not mistaking, a year or two ago, the Mt Washington hill climb was won by a weightweenie with a R3SL

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prendrefeu
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Joined: Wed Oct 31, 2007 10:32 pm
Location: Los Feliz, Los Angeles, California
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by prendrefeu

Word:
Image
(image is link to VeloNews article)
Exp001 || Other projects in the works.

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HammerTime2
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Location: Wherever there's a mountain beckoning to be climbed

by HammerTime2


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2002maniac
Posts: 205
Joined: Wed Mar 28, 2012 3:16 pm
Location: Utah, USA
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by 2002maniac

Sounds like a fun build! I'd like to do something similar but not quite as extreme (would keep brakes for descending). I think 10-speed spaced rear cassete using every other gear (something like 11,13,15,19,25,28) with a single front ring would be pretty versatile. So what's a good cheap crankset that would be light and easy to convert to 1x?

socratease
Posts: 169
Joined: Thu Oct 13, 2011 5:25 pm

by socratease

Have you considered using flat bars w/ bar ends? Very easy to get a ~100g flat bar, but if you're running brakeless, the position would work better. You wouldn't need to put dummy hoods on it.

BmanX
Posts: 3844
Joined: Thu Nov 10, 2005 5:31 pm

by BmanX

If you are creative there are lots of light weight options. Like mentioned you could use a flat bar sub 100g, barends 50g, grip shift for the rear, tuned RD and if you do want to use a brake just use something like a cross lever for the front brake.
BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5960g/13.13 lbs

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