new Co MOtion racing frame

[ElRey]

over at cyclingnews.com there's a small article about a new Co Motion racing frame that builds up to a 24 lb. bike! Uses a 130mm rear so you can run any wheels you like. The design looks a lot like the Paketa Magnesium design. Easton aluminum tubing. 300lb team weight limit.

[mrfish]

Yep - it's shown under special custom frames in the Co Motion catalogue, which suggests 130mm hubs and no lateral tube might not be for everyone... yet...

[Ashen]

300 pounds for both riders? Yeah I'd say this is definitely still a specialty item. I'm pretty darn fit, and near 200 by myself..

[scrooge]

over at cyclingnews.com there's a small article about a new Co Motion racing frame that builds up to a 24 lb. bike! Uses a 130mm rear so you can run any wheels you like. The design looks a lot like the Paketa Magnesium design. Easton aluminum tubing. 300lb team weight limit.


Could you post a link? I can't find it...
THanks

[TandemGeek]

http://www.cyclingnews.com/tech.php?id=tech/2006/news/07-27

Scroll down to the 8th item... about 4/5th of the way down the page.

http://www.cyclingnews.com/photos/2006/tech/news/07-27/litebike.jpg

[zonatandem]

Not surprised that Co-Mo is introducing a light sub-25 lbs tandem. They had a time trial tandem at Interbike, same open frame design. They also have the 'no lateral' design on their very succesful Periscope.
They are joining ariZona Tandems, Calfee and Paketa with the open frame (no lateral) and sub 25-lbs design . . . made popular (but not 'invented') by the late custom frame builder Tom Bruni.
In mid-80s, we did 3-months test riding for Schwinn's DuoSport tandem, which was an open frame tandem; we were quite surprised at how well such a design, and at a then low price of $1400, performed!
Also had the opportunity to test ride one of the early Bruni open frame 2-seaters when we were at MTR in Indianapolis. We lacked some real hills, so Rudy stoked while friend Doug piloted the Bruni up, and down, a 4 story parking garage. We were both a-grinning! Tom really had a superior bike, even if it did not have an internal lateral.
Wonder what Santana has up its sleeve?

Pedal on TWogether!
Rudy and Kay/zonatandem

[Murrays]

300 pounds for both riders? Yeah I'd say this is definitely still a specialty item. I'm pretty darn fit, and near 200 by myself..

My wife and I top out at about 270lbs.

-murray

[lhbernhardt]

Hmm, looks like the stoker's bottles go underneath the top tube.

I think I read that the idea is based on compact frame design (note longer seatposts). But I find something about no laterals to be somehow unaesthetically pleasing. Besides, I've never liked the look of compact singles, but chacun a son gout.

- L.

[asu_gt]

Anyone concerned about using standard road wheels on a tandem? I don't know enough about the testing that goes into road vs. tandem wheels, presumably the tandems are a bit stronger.?.

Jay

over at cyclingnews.com there's a small article about a new Co Motion racing frame that builds up to a 24 lb. bike! Uses a 130mm rear so you can run any wheels you like. The design looks a lot like the Paketa Magnesium design. Easton aluminum tubing. 300lb team weight limit.

[TandemGeek]

Anyone concerned about using standard road wheels on a tandem? I don't know enough about the testing that goes into road vs. tandem wheels, presumably the tandems are a bit stronger.?.


Standard road wheel load ratings apply... so, yes, if a given wheel has a load limit that falls below the tandem's combined team weight then you're somewhat at risk or will at a minimum see a greatly reduced service life and reliability.

For example, when Shimano's Ksyrium wheels first came out there were a bunch of folks with go-fast tandems... Calfee Tetra Tetras come immediately to mind ... that started using them respaced to 145mm. The early users raved about their performance but then slowly began to report problems with the wheels going out of true, etc... Ultimately, they proved to be inadequate for routine tandems use.

The latter is the operative phrase: routine tandem use. For folks who race, they often times play in the margins with event specific wheels that they feel are "strong enough" for limited use. At the same time, a lightweight team can build up a pretty good set of lightweight conventional set of tandem wheels using Campy Record hubs with aero rims. There are also some Rolf Prima sew-up racing wheels that can be used on racing tandems that probably use 130mm hub/axles that are also part of the impetus for this specification....

However, at the end of the day, remember that what Co-Motion displayed is a custom, one-off frame, the point of which was most likely to demonstrate that they too can produce a lightweight open framed racing tandem that is weight (and perhaps cost?) competitive with the Calfee open-framed Tetra Tandem and the magnesium Paketa tandems that have recently garnered a bit of market exposure. Clydesdales need not apply for the Co-Motion (300lb limit) or the Calfee (380lb team is at the high-end), but Dave Walker seems to be willing to take them on with his Paketas.

[asu_gt]

I have about 700 miles on a new Co-motion Robusta and am currently building up a lightweight Paketa. Once I have it built and have some miles on it I will post a comparison between the two.

I will say that so far I quite like the handling of the Robusta; it is almost like riding my single bike. We were riding a Trek T2000 (about 6000 miles); both the stoker and I agree the Robusta is a more comfortable ride and much better performer (not a real fair comparison, I know).

Also, I plan to post a summary of power distribution of the captain and stoker under laboratory and real world conditions...I just need to write it up.

Jay

Standard road wheel load ratings apply... so, yes, if a given wheel has a load limit that falls below the tandem's combined team weight then you're somewhat at risk or will at a minimum see a greatly reduced service life and reliability.

For example, when Shimano's Ksyrium wheels first came out there were a bunch of folks with go-fast tandems... Calfee Tetra Tetras come immediately to mind ... that started using them respaced to 145mm. The early users raved about their performance but then slowly began to report problems with the wheels going out of true, etc... Ultimately, they proved to be inadequate for routine tandems use.

The latter is the operative phrase: routine tandem use. For folks who race, they often times play in the margins with event specific wheels that they feel are "strong enough" for limited use. At the same time, a lightweight team can build up a pretty good set of lightweight conventional set of tandem wheels using Campy Record hubs with aero rims. There are also some Rolf Prima sew-up racing wheels that can be used on racing tandems that probably use 130mm hub/axles that are also part of the impetus for this specification....

However, at the end of the day, remember that what Co-Motion displayed is a custom, one-off frame, the point of which was most likely to demonstrate that they too can produce a lightweight open framed racing tandem that is weight (and perhaps cost?) competitive with the Calfee open-framed Tetra Tetra and the magnesium Paketa tandems that have recently garnered a bit of market exposure. Clydesdales need not apply for the Co-Motion (300lb limit) or the Calfee (380lb team is at the high-end), but Dave Walker seems to be willing to take them on with his Paketas.

[ElRey]

dude, how you gonna do it? The power dist. thing????? I wanna see that.

[zonatandem]

Will be interested in your test . . . want to throw a Beyond in the mix?

[mrfish]

This cyclingnews quote made me laugh. It's clearly been written by someone from marketing.

Accordin (sic) toCo-Motion's Clay Lundgren, "One of the biggest weight saving came from using a 28.6mm seat post which allowed the use of a regular FSA stem, rather than the typically very heavy stoker stems. We also saved significant weight by going to 130mm rear spacing instead of the traditional 145 tandem drop out spacing.

1) On my Trek T2000, the adjustable stem can be swapped for a standard A-headset stem - the size is exactly the same. Same shim works for both. You don't exactly have to be Sherlock Holmes to find this weight saving.

2) If the typical stoker stem is so heavy, one wonders why they don't just make it lighter?

3) How much weight exactly is saved by 130mm rear spacings compared with 145mm??? I would have thought 15mm of extra hub centre and axle and the equivalent of one extra spoke is not worth writing about, particularly as it's at the expense of durability. I would much rather hear about a pair of tandem spec Lightweight wheels. Now that would be exciting.

4) The light weight is achieved through careful component selection which could easily be applied by anyone to any tandem. Just by looking at the picture you can see that this is a pretty light selection, for example SRAM gear changers and derailleurs and what looks like Sub-Zero stainless brakes. If you want to see some special bikes, check out Weightweenies. I imagine another few pounds could easily be saved by going for some really light stuff.

[zonatandem]

If typical stoker stem is 'so heavy', one wonders why don't they make it lighter?
They have: checkout ariZonaTandems and see the answer to lighter stoker stems.
Stoker's been using one for the past 11,000 miles . . . and with c/f handrests.

[TandemGeek]

This cyclingnews quote made me laugh. It's clearly been written by someone from marketing.

While I don't dispute that Clay Lundgren is essentially a marketing guy, his comments have probably been somewhat taken out of context... Remember, you're looking at a one-off custom frame and built kit that probably has more to do with Co-Motion demonstrating its capabilities (what's possible) vs. the introduction of a new production model (what's practical).

By context, a logical question from CN would have been... "So, exactly where does the 5lbs of weight savings come from when compared to its sibling, the 29.4lb Robusta"? Given that the author of the CN piece has already addressed the compact, lateral tube-less aluminum frame and the very lightweight Alpha Q fork, the quotes from Co-Motion’s new product manager, Clay, then fall into place. "One of the biggest weight saving came from using a 28.6mm seat post (not mentioned in the story, but those are very lightweight Alpha Q seatposts) which allowed the use of a regular FSA stem, rather than the typically very heavy stoker stems. We also saved significant weight by going to 130mm rear spacing instead of the traditional 145 tandem drop out spacing. This allows for conventional road wheels to be used."

Remember, as others have noted, open-framed lightweight racing tandems aren’t a new concept. I saw my first “contemporary” open frame racer at Elliott Bay Bicycle’s in Seattle, WA, back in 1989; a custom Davidson tandem with DuraAce components and a very cool custom paint job built for EBB icon Bob Freeman who, along with his stoker, made for a very clean riding, lightweight team that did not need the internal tube on their chromoly racing tandem. Again, as already mentioned, folks like the late Tom Bruni and Dave Bohm (Bohemiam Bikes) have been offering custom make, one-off big-tubed open tandem frames for a while as well.

However, it has been the highly visible combination of this inherently lightweight tandem frame design with the cutting edge frame materials and lightweight components that are finding their way into the marketplace from Dave Walker and his magnesium Paketa tandems and Craig Calfee with his Calfee carbon-framed tandems. Both of these tandems have grabbed a lot of attention in that they are full-size, long wheelbase tandems that come in at unseemly low weights in the mid-20 pound range. So, here you have another builder -- Co-Motion -- who is demonstrating that their material of choice, Easton's 7000 series aluminum, can also be combined with similarly svelte road bike components to create a 24lb lightweight racer using this same frame design. Yes, it seems as though the Co-Motion racer imposes a lower weight limit but I'm not sure if it's biased towards the 130mm single bike racing wheels or the frame's lack of the internal tube. In a recent "chat" with Craig Calfee he noted that they have built an open framed Tetra Tandem for a 380lb team and Dave Walker is confident that his magnesium frames can handle 400lb teams. I suspect that all of this is highly subjective in terms of just how much frame defelction would be considered acceptable on a lightweight racing tandem.

Anyway, I didn't intend to ramble... it just happens. However, in closing, your points regarding component selection and grams shaving are valid points. A quick side-by-side comparison of Co-Motion's Robusta and Roadster / Supremo and Speedster will quickly reveal just how many pounds you can reduce with high-end, lightweight components (and at what cost) while still producing a tandem that your average-sized tandem team won't over-tax. However, it's still impressive when a tandem frame builder can find ways to shave a couple more pounds off of that all-purpose frame that can still support 300lb teams.

Again, it's not about "what's practical" it's all about "what's possible". Just get out your checkbook.

[TandemGeek]

If typical stoker stem is 'so heavy', one wonders why don't they make it lighter?
They have: checkout ariZonaTandems and see the answer to lighter stoker stems.
Stoker's been using one for the past 11,000 miles . . . and with c/f handrests.

Speaking of ariZona tandems in the context of the very lightweight tandem market, how many tandems a year?

[ElRey]

Tandem spec Lightweight wheels? You're joking, right? You can buy Clydesdale Zipps off the shelf, I'm sure they can be got with the appropriate axle spacing. Half the price, all the performance. And actually available. Conti Comp GPs come in 25s as well!!!!!!

[TandemGeek]

You can buy Clydesdale Zipps off the shelf, I'm sure they can be got with the appropriate axle spacing. Half the price, all the performance. And actually available.

FWIW: Zipp 404 Clydesdales are around $1,800 pr., 808 Clydes closer to $2,000 pr. Awesome wheels, but certainly not for the faint of wallet. Clincher version is about 100 gr lighter than Rolf Prima Vigor tandem wheelset @ $900 pr.

[mrfish]

I was joking a little about the Lightweight wheels, but why not? The lightweight website says that there's no weight limit and that the standard wheel is pretty much unbreakable.

On the why not side, unfortunately I have other ways to spend £1800. Plus they weigh 1000g, which isn't hugely lighter compared with other carbon-rimmed wheels such as the Zipps mentioned. It would be cool though if they were tandemproof!

Lots of people want the lightest single bike, and every year someone shows a moderately rideable show bike at round about 10lbs, so why don't the tandem builders get to work and build a really light tandem? 20lbs should be quite achievable I think.

PS, take your point tandemgeek about the quotes being taken out of context. If I were Co-Motion I wouldn't be happy.

[zonatandem]

How many ariZona tandems a year?
You'd have to ask Bob Davis. However, he is a one-man operation, so don't expect huge numbers. To build quality, and mostly custom tandems and singles, takes a bit more time than doing production runs.
He also designs/builds his own fixtures, c/f fixed (or adjustable) stoker stems and c/f handrests, among other items.
Have been more than pleased with so-called one-man shops custom building our tandems through the years, including Matt Assenmacher and Colin Laing. When we had our Co-Mo built back in the 80s, they were a 3-man operation out of a garage. David Bohm of Bohemian Bikes and Andy Gilmour, both in Tucson, are other fine examples of meticulous tandem/single bike builders with low production numbers. The late Tom Bruni also falls in the above category, as do many other 'one man' shops.
Big box stores sell big numbers . . . big numbers to not equate quality, by any means!

[ElRey]

TGeek: "Lightweight" wheels are a brand name. They're about $4000 a set for the single bike wheels. I've owned 4 pairs of Zipp... know what they cost. Lightweights are double, for little if any advantage.

[TandemGeek]

TGeek: "Lightweight" wheels are a brand name.

Yes, I know...

But, for anyone who wasn't familiar with either of the wheel brands, I figured I provide a baseline for comparison since "half of" was not quantified in the thread and then take it to its logical next step by contrasting the clincher version of the Zipp with the Rolf tandem-rated clincher.

Last time I checked, the Lightweight were only offered in tubular models that started off around 1,100 grams and got more exotic from there. Like Zipps, not necessarily a good investment for a rider who hadn't already achieved maximum levels of personal performance and fitness... which, at least for me, is also true of the other racing wheelsets that are showing up on sport/recreational bikes.

[TandemGeek]

How many ariZona tandems a year? [snip] Big box stores sell big numbers . . . big numbers to not equate quality, by any means!

So I take that as "you're not at liberty to discuss"... fair enough. I can appreciate that many builders like to keep their production numbers close to the chest...

I've only seen two in the wild -- the one Bob had on display in in ariZona booth at the Midwest Tandem Rally in Dayton back in '03 (which, coincidentally, was right next to Tom Bruni's booth) and Marv & Miryam Rubenstein's "Aqua-Zone" (my pet name for their turquoise green ariZona). Of course, many of the smaller custom builders tend to have a better regional following. The cluster of Erickson tandems here in Atlanta is truly an oddity compared to what you'll see at a tandem event in the Northwest.

[dfcas]

"For example, when Shimano's Ksyrium wheels first came out"



I assume you meant Mavic....I much prefer the look of the no lateral/open style frame.but I expect i'll admire them from a distance since we've had our tandem out -once- this year.

dan

[zonatandem]

How many ariZona tandems a year?
Really don't know. Am a friend of Bob Davis' and never have asked him outright. Do know that his bikes are scattered all over; several in AZ, CA, GA, KS, WI among other places.
Bohemian has only built a couple tandems. Andy Gilmour, whom we've known for 28 years, about 50+.
Davis is a retired aerospace engineer, and like he says when you have to send something up in space, grams rather ounces quickly come into play.
He has built several 23 lbs tandems. Ours was the second tandem he built and weighs in at 26 1/2 lbs. Could we have gone lighter? Sure, but at a greater $$$.
Was impressed enough that I got rid of my Ti Merlin and had him build me a custom c/f single

Pedal on TWOgether!
Rudy and Kay/zonatandem

[ElRey]

gotcha