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!

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

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.

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BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5890g/12.98 lbs

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 ...

HEAVY SUGGESTION!

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BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5890g/12.98 lbs

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!

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.

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BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5890g/12.98 lbs

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

Word:

(image is link to VeloNews article)

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Exp001

Yes, indeedy. viewtopic.php?f=3&t=76357#p673292

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?

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Trek 5500 - 13.75lbs on a $1400 Budget
20 gram 1x10 chain guide

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.

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.

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BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5890g/12.98 lbs