Scalpel 29er Project

Discuss light weight issues concerning mountain bikes & parts.

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ludovic
Posts: 20
Joined: Tue Aug 06, 2013 3:10 pm
Location: Canaan Valley, West Virginia (USA)

by ludovic

Bought the cheapest Cannondale Scalpel I could find (Scalpel 4) and transformed it; it's almost 22 pounds, including pedals, and racing ralph 2.25.
After 400 or so miles, I'd like to review it and share my project with other bikers who care about weight saving / trail-worthy bikes.
Disclaimer: pictured below is with the 27.5 wheels / only 15 miles of easy riding on that setup so far.

Frame:
The frame is alu, thus has one extra pivot in the back. It’s good because it’s stronger, it’s bad because it’s a little heavier (okay, a lot heavier than the carbon frame). It feels very sturdy, and that was the most important factor.

Frame size is a medium – while the med alu frame is smaller than the med carbon frame, I really wish I had gone with a small frame (better adjustments, since I am only 5’6” with a short torso).

Drive Train (XX1):
First, let me say that this drivetrain make the entire bike the quietest bike I have ever been on. Looking closer, I am now debating about using a 30-tooth chain ring coupled with an 11-32 instead. Using a rear XX cassette and XX derailleur will save weight where it matters most. I’ll probably spin-out quicker, but that would save (maybe) ¼ pound – especially after shortening the chain. Otherwise, I have yet to drop a chain, even in the most grueling descents.

Wheel Size:
I have two sets of wheels – 29er and 27.5” – both with xx1 cassettes. Most of the time, you’ll find the 29” wheels. The 27.5 change everything about the bike; it’s very fun, very lively, but does lower the bottom bracket. It climbs like a goat though (smaller circumference) but surprisingly enough, doesn’t shave that much weight at all. Rolling resistance is nearly identical, though the smaller wheels require more “body effort” – very negligible. Meanwhile, think of this setup as 2 different bikes: quite fun.

Tires:
On the east coast of the US, rocket ron tires are pretty much worthless. In the 27.5”, they are officially the worst feeling I ever had – on any bike. Instead, I found racing ralphs to be perfect in 29” and 27.5”. On the 29” wheels, I use a 2.1 in the rear and 2.25 in the front. I find this combo is light and super efficient. This option doesn’t yet exist on the 27.5 version.

Stem:
I am looking for options on my stem. Since I am running a lefty, this is tricky. Currently using a 90mm stem with a -5 degree. The ideal would probably be -15 degrees… but I am not even sure when to start looking.

Overall:
The bike is absolutely crazy fast (yeah, climbs like a goat even with the 29 wheels). The super technical descents are easily taken care of with the rig. Longer rides prove to be comfortable (though I could certainly tweak my front-end some to suit my short torso).

Compared to my 29er hard tail, this bike’s geometry is so much more precise and lively. The hard tail was like the first generation 29er from Cannondale (a boat), where the full suspension scalpel is so very nimble.

What I love:
Super Nimble 29er bike, super fun to ride - sort of "go anywhere / do anything bike".

What I question:
The bike's ability to carry water - certainly the worst I have seen.
Cable routing: ugly, requires tape to protect your frame.

Cost:
You could buy a scalpel ultimate (11k) or scalpel 1 (7k), but in the end, you’ll spend far less if you purchase a scalpel 4 AND modify it from the ground up. The result will be a lighter bike, totally customized (and money left in your pocket for races).

Other Option:
I have built a scalpel 26 bike (carbon frame) with 27.5 wheels - xx all over the place. The bike was almost 19 pounds with pedals. The geometry was very different; I love saving weight, but this 29er bike (weighing almost 3 more pounds) is really remarkable.

Hope this helps.

PHOTO: Image
SCALPEL 29er with 27.5" Wheels

by Weenie


justaute
Posts: 227
Joined: Fri Jan 04, 2013 7:17 pm
Location: UT/TX/PA, USA

by justaute

Interesting project. As far as stem goes, a good option would be the Syntace Flatforce, which I recently installed on my bike (see link). The longest available length is 77mm, but Syntace purportedly will produce 88mm and 99mm length later this year. My understanding is that the stem's zero-rise is equivalent to a -17 degree angle.

viewtopic.php?f=10&t=117435

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the_marsbar
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by the_marsbar

I've had a lot of trouble with the Rocket Rons as well (29x2.25, Evolution tubeless-ready). I've punctured a few times on gravel roads, where Stan's saved me. Last week the rear tire got cut by a flint stone (I know, because it was rattling around inside the tire, approx. 1x3 cm in size). They were also a pain to set up.

I had Racing Ralphs (2.1, Evolution tubeless-ready) before that, and they were fine. I think I'm going back to them.

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ludovic
Posts: 20
Joined: Tue Aug 06, 2013 3:10 pm
Location: Canaan Valley, West Virginia (USA)

by ludovic

Thanks for the link above... that is one really nice looking bike.
Regarding my stem / steerer tubes combo, I am running a Lefty - clearance is definitely an obstacle here.

STEERER TUBE
I thought about going this route: http://www.starbike.com/en/mcfk-lefty-steerer
Has anyone tried it on a Cannondale?

STEM
Based on what I am reading about the steer tube above, I will be able to use "just about any" 1 1/8" stem - which sounds almost too good to be true.
My only limitation will be with the new stem: it will need to push my bar away from the fork leg (at least 85mm) - so that will have to be the minimum distance (with or without a rise).
As anyone successfully tried putting a 90mm stem with a -15 degree on a Cannondale?
A dream come true would be 85mm stem with a -15 degree... but that might amount to me being in a dream/coma.

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ludovic
Posts: 20
Joined: Tue Aug 06, 2013 3:10 pm
Location: Canaan Valley, West Virginia (USA)

by ludovic

Here are the actual specs for my new 29er Scapel (21.7 pounds - with 29" wheels / full suspension)

Frame: Scapel 4 29er - MED Aluminium Frame
Forks: Lefty (2011 fork, modified to 100mm of travel)
Bars: Schmolke carbon (81 grams - 620mm)
Stem / Steerer: Cannondale SI (pre 2012 version)
Headset: Pressed Cannondale
Grips: KCNC Foam
Bar Ends: None

Front Brake Lever assy: XX world cup
Front Caliper: XX world cup
Front disc: XX
Rear Brake Lever assy: XX world cup
Rear Caliper: XX world cup
Rear Disc: XX
Hoses: the ugly ones (standard xx)

Shifter: XX1
Front Derailleur: none
Rear Derailleur: XX1 (big, practical)
Chain Tensioner: Incorporated with the XX1 derailleur (pulley)

Seat: Selle Italia SLR (carbon, 135g) - actually very comfortable for 40+ miles)
Seat Post: MCFK carbon
Seat Post Clamp: Cannondale (do not over-tighten bolt - use carbon grease)

Cranks: XX1
Chainring(s): XX1 30 teeth
Chain: XX1
Cassette: XX1 (10-42)
Pedals: French Look (S-Trac Ti)
Bottom Bracket: BB30 pressed

Front Wheel:
Rim: NoTubes ZTR Racing (removed stickers, save 125 grams for both wheels)
Spokes: Racing 1.5
Hub: Cannondale lefty
Tube: none / stan's sealant
Tire: Racing Ralph 29x2.25

Rear Wheel:
Rim: NoTubes ZTR Racing (removed stickers, save 125 grams for both wheels)
Spokes: Racing 1.5
Hub: Stan's Ti
Freehub: XX1 adapter (heavy)
Tube: none / stan's sealant
Tire: Racing Ralph 29x2.1

Other:
GPS: Garmin Edge 500
GPS Adapter: Heavier metal (color matching, improved viewing angle)
Misc: Ti bolts for brakes and rotors

Image
CRANKS with new 30T chain ring

Image
TRANSMISSION with 10-42 cassette

Image
FRONT END with funky GPS adapter

Image
Almost complete - currently showing with 27.5 wheels

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dwaharvey
Posts: 493
Joined: Thu Oct 26, 2006 8:54 pm
Location: USA

by dwaharvey

As I said in Maxle's thread recently: an 85mm stem isn't going to work unless its either a 90 degree stem (and due to measuring / manufacturing differences is a mm or two longer from the 85x-5 I tried), or you team it with a bar that has some forward curvature to it near to the stem clamp, like one of the Ritcheys, or an MCFK 9 degree like the one I have on my Funk:
Image

Given the fact that a 90 degree x -15 stem projects away from the steerer/fork at more of an angle, it'll make clearance tighter than the 90x-5 setup that works for me, theoretically by: 90 * (cos(15) - cos(5)) = -3mm. I _think_ that'll still give you clearance, but it'll only be by a mm or so!

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the_marsbar
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by the_marsbar

I guess it should work since Cannondale sell 90 mm -15 degree OPI stems.

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dwaharvey
Posts: 493
Joined: Thu Oct 26, 2006 8:54 pm
Location: USA

by dwaharvey

I'm confused as to why you'd want to run 650b wheels on a 29er frame (as I learned yesterday, 650b is actually somewhat less than 27.5", about 40% of the way between a 26" and 29"). I can understand the motivation to run 650b on a 26er... bigger wheels get over obstacles better...same motivation for going to 29" in the first place. But the most common drawback to a 29er that people typically quote is them being less good in tight trails, and that's a product of the wheelbase... the chainstay length and front fork length... both of which are limited by needing to clear the big wheels. Why you'd want to take those "sacrifices" and then put a smaller wheel on it I just don't get.

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ludovic
Posts: 20
Joined: Tue Aug 06, 2013 3:10 pm
Location: Canaan Valley, West Virginia (USA)

by ludovic

@DWA
My 29er will have the same wheel base using 29" wheels or 27.5" - however, and for reasons I cannot explain: the bike is far more agile with the 27.5 wheels. It turns it into a "ferrari on steroids".
Having said this, the minor other advantages that I find using 27.5" wheels:
- Faster cornering
- More "pump" effect
- Stiffer Wheels
- Slight increase in acceleration
- Faster sprints
- Super fast change of gearing (all of the sudden, I can climb walls using the same gearing - perfect if I know I will ascend 5000+ feet a day)

Disadvantages:
- not much weight saving: (only 57 grams using identical setups)
- slightly less traction
- slight loss of rolling speed
- slight loss of comfort

I happened to have a set of 27.5" wheels - but knowing what I know today, I would most likely NOT purchase or use smaller wheels. The original idea was a lighter wheel set - but 57 grams is not exactly what I had in mind. Hardly worth the huge expense if you ask me.

ReLe
Posts: 2
Joined: Sun Jun 14, 2015 4:47 pm

by ReLe

Sorry to wake up old thread, but I'm looking at buying the same 2013 version and doing some weight reducements. What was the original weight of this bike? I can't find this info from around the net.

by Weenie


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