CaptainHaddock

So I'm looking to start bringing down the curb weight of our RT2. What I'm looking for are suggestions on how to go about doing so, while at the same time trying to keep this on something of a budget. So O wise internets, where are the first & affordable big weigh savings to be gained? Aside from captain & stoker weight that is, we're about 290 - 300 and trying to bring it down...

twocicle

Well, lacking a list of your current parts to judge weight/cost ratios, what kind of budget and intended usage?

- The number one big ticket item is wheels. One can easily save 1-2lbs depending on your current wheels of course.
- Cranksets, you might save 200-400gms.
- The smaller items add up surprisingly quickly. Seatposts (save 100gms/ea and dont forget that suspension posts usually weight near a full pound), stems especially long adjustable stoker stems can weigh a full pound, handlebars usually can only save 50gms each, pedals, seats... basically walk through the entire parts list...

Ritterview

Well, there is what I suggested on another thread a few hours ago:


The Fatty R weighs 935 grams.............................Enve 2.0. 350 grams
Avid BB7 300 grams, Rotor 200 grams.................Caliper, 100 grams.
1435 grams....................................................450 grams........................685 grams = 2.17 lbs

Yes, the fork is expensive ($400) , and lightweight calipers aren't cheap, but a 935 gram fork and a 500 gram brake have got to be the first to go. The fork alone saves 585 grams, or only $0.68/gram. Not too many WW moves are cheaper than 68 cents per gram. Even if you got a $300, 95 gram front eebrake, the cost would be only 74 cents/gram in comparison to the Avid.

If your lightening includes wheels (as it inevitably will), further savings are possible with dispensing with the disc brake hub.

Ritterview

If only the year was known, and that it was stock, the current parts would be known quite well. Like this.

Dean V

If you change forks check that it won't drop the front too much and give you insufficient BB height. The C'dales have fairly low BBs to start with.
The cheapest things that I would do to that stock bike would be to change tyres and tubes to something like 25mm Michelin Pro Race 3s and latex tubes. Then swap the stokers handlebars for something narrower if there is clearance for it. After that I would get some better wheels.
The tyres and bars will not really make the bike much lighter, but they will make it faster which I presume is the object of the exercise.

mwandaw

Practical & affordable ≠ weight savings

(Unfortunately!)

Onegun

Exactly. "Strong; light; cheap. Pick two."

TandemGeek

What he said: Practical & affordable ≠ weight savings

Questions:

• What's your budget?
• How much does it currently weigh?
• How much of that weight are you trying to reduce?
• Are you willing to accept a change in how your tandem handles?
• What are you hoping to achieve, i.e., easier to lift onto the car, less weight to haul up steep climbs, or just shaving grams off because that's what cyclists seem to do?

From CaptHdks introductory post, a photo of their machine for reference below.


FWIW, the "first" cheap and easy thing to do was already suggested: Try a set of 700x25 kevlar beaded, lighter weight tires and some lighter weight inner tubes inflated to something like 125 psi and see what they do for you in terms of making your C'dale feel more peppy. Of course, this will also make the bike ride a bit more harsh. This is under $100.

I don't think you'll get more than a 1/2 lb out of your wheelset unless you go with something like a set of Spinergy wheels and, frankly, I'd go that route vs. changing your fork, etc, as you'll get more bang for your buck without changing your brakes, altering the geometry of your tandem and you'll have a spare set of wheels to boot. The wheels will obviously be transferrable to any future tandem that shares the same rear wheel spacing. Of course, you're looking at $900-$1000 to get those to your front door.

The fork & front brake change is a wild card since you'll need to decide how much of a handling and geometry change you're willing to accept. It'll shave off anywhere from 1 - 1.5 lbs depending on which fork and brake combo you use. Again, not exactly cheap at $500 - $700 if you stick to mainstream brake options.

After that you can nickel and dime your way to another 1/2 lb of weight savings by going to lightweight seat posts like the Thomson Masterpiece and lighter weight handlebars, but that's going to cost another $500 retail, maybe $400 if you find some on ebay.

If it was me, I'd probably go the Spinergy route just because it would give me a second set of tandem wheels that I'd always have on hand, add some bling, remove some weight, trade off some of the loss in ride comfort that comes with the smaller, higher pressure tires with added compliance, and doesn't sink a bunch of money into a tandem that I may outgrow in a year or tw

waynesulak

I agree all of the above and add that is you are not in love with disk brakes and can mount calipers then that might save some weight.

DCwom

I find that "non-transport" gear offers the most weight savings, as others have posted you can nickel & dime a pound or two with expensive parts, but the extra "non-transport" gear adds up. For example, do you always come home with water left in your bottles, most tandems have at least 4. Do you have panniers to carry extra layers for convenience? Do you carry a lot of tools to be self-sufficient, or just a cell phone? Do you have lights but are riding in daylight, fenders in case it rains? How about a rack, GPS, or flight deck?

I think you've already identified the first & affordable big weight savings in the last line of your post, captain/stoker weight (no judgement, I'm in the same boat). If you look at percentages, a 1% reduction in a 50 lb bike would be 8 oz, while a 1% reduction in team weight would be 5.8 lbs (<3 lbs/rider).

Looking at it another way an 8 oz reduction in bike weight is only a .08% reduction of total weight.

merlinextraligh

Going to a fixed length stoker stem will save a lot of weight, and can be relatively cheap, if the stoker fits with an available size.

We found a 140mm Easton stem for $7 awhile back. It saved around 200 grams compared to the adjustable stem which is a boat anchor.

Belt system is another fairly significant weight savings, although that gets more expensive, and personally I'd wait until the new center drive system is available for tandems. (Also I'm not sure whether the belt length will work with a Cdale.)

TandemGeek

I don't think so.

It's close but not close enough at 28.6" for the Small stoker compartments and 29" for the Medium stoker compartments.

twocicle

^^^ Based on the photo above, take a serious look at the Spinergy wheels. Not only will you save a lot of weight, but the ride quality will improve drastically. These wheels are also available as disc compatible front/rear, but you can still use rim brakes regardless - if you decide to go that route at any point. Nice thing about upgrading the wheels is that they can be used on a new/future tandem (given the same rear spacing spec - 145mm?).

The second most noticable upgrade would be the fork. If you don't anticipate selling this C'Dale, then look for a compatible spec carbon fork (likely not transferable to another tandem). As mentioned above, fork crown height and trail are the key factors to maintaining the correct geometry of your tandem. Depending on whether or not you intend to keep the front disc, will determine selection of available carbon forks - not that many are disc compatible.

Both the above changes alone would likely save 3.5-4lbs and improve this tandem ride quality by a huge factor.

Eliminating the front disc in favor of a rim/caliper brake is a slimmer saving in the order of 150-200gms depending on what model you select. Unless you intend to ride +6% grades frequently, probably a front disc is overkill. The rear disc can probably stay... it performs better than a caliper and adds a little cool-factor.

Note, the Spinery front hub flange is very widely spaced which maximizes strength of the wheel. However, my skinny Alpha-Q fork blade clearance to the hub is very scant... just a few mm. So if you decide to keep your beefy C'Dale fork, you may need to investigate the Spinergy hub clearance requirements and options - inquire at House of Tandems or Tandems East.

jnbrown

As others have noted, wheels, stems, seatpost.
Crankset is another one but can be really expensive (i.e. Lightning crankset)
I don't know the weight of the new Ultegra crankset but it might be worth looking into.

I have been considering a Ritchey C260 stem at 100g, but waiting for a good deal on Ebay.

Tiny amounts of weight savings on a single component seem foolish but it does add up.
Is it practical? Not really its more like a disease.

Dean V

As the C'dale has an oversize seat post you can't use an ordinary handlebar stem for a stoker stem. I used a Specialized stem on ours as they are over 1.25" in diameter so can be shimmed to fit. BTW our medium/small RT2 weighed about 32lb.

merlinextraligh

Couldn't you shim the seatpost to the frame? Of course, that means buying a new seatpost as well.

Wulf

You can save 2 kg by drilling out your water bottles.

waynesulak

I use a shim for a 27mm seat post into the frame and then a shim on the standard 1.125 stem used by the stoker.

twocicle

rothfl

Ritterview

I had the Avid BB7 weighing 300 grams on my spreadsheet, but I checked, and it actually weighs 240 grams. Also, 12 grams for the rotor, and 18 grams for the mounting bolts. A total of 460 grams.



This compares with a caliper, 95 to 160 grams, depending.


ee brake


Campagnolo Super Record 11 Front Brake Lever


Dura Ace 7900


So, the savings for doffing BB7 and donning caliper are from 290 to 360 grams (460 - 95/160). Campagnolo Chorus brakes are $225 for a pair, and the front weighs about 160 grams. Figure one caliper costs $150, and saves 290 grams. That is about 50 cents per gram, which is hard to beat.

If the Capt H's riding terrain is not vertiginous, ditching both discs for calipers would double the weight savings.

CaptainHaddock

Wow, thanks for all the ideas! Clearly I should have been clearer with what my tandem is. As noted, it is a 2012 Cannondale RT2. Stock all the way through.

DKMcK 

Here is a thread by WheresWaldo where he brought the weight of a 2005 Cannondale down to sub 34 lbs. What he did is quite consistent with what has been recommended in this post. This bike is our ride now as we purchased it from him when he got his Ruegamer.
https://www.bikeforums.net/showthread...-some-upgrades

Homeyba

You could just unbolt the seats and roll a new carbon fiber frame under the seats...oh you said affordable...

Dean V

Does anyone know how much the Cannondale frames weigh?

DubT

TandemGeek and Ritteriew have made available their build information with recorded weights, that might be a good place to start. I used their experience/expertise to help us build our tandem which is right at 27 pounds with pedals and 4 bottle cages.