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Flex of Ti tandem frame?

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Flex of Ti tandem frame?

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Old 01-18-19, 09:55 AM
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Anavycrna
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Flex of Ti tandem frame?

Hello,
I"m in the market for a Ti tandem (Seven Evergreen). I contacted an online dealer that cautioned against flex and recommended steel or carbon. My team weight is 460#.
What does the group think?
yes, I know we need to lose weight hence the bike
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Old 01-18-19, 12:05 PM
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Have ridden a lot of tandems in the last 35 years and my thoughts are as follows.

You will be spending a premium amount on this bike so it would be good to make sure what you buy makes YOU happy.

One mans noodle can be another mans comfy ride.
What works for some would be unacceptable for others.
Every team has different needs and expectations.
Some folks stand and power a lot and others never stand.
Some folks decend hard and fast, others not so much.
Some folks are very performance minded, others not so much.

We all have different expectations from our machines and what will make each of us happy differs greatly.

I suggest you beg, borrow, rent, attend rallys, make friends who have tandem bikes of different materials and ask to ride them. The differences in ride can be huge. It is very eye opening for sure. Many of my preconceived thoughts on things have been right and others totally wrong.

You will find what YOU like and be able to make a better informed decision.

What makes this even more challenging is same material buit into a bike by different manufacturers can also ride very differently.

So, bottom line. Test ride all you can or buy an entry level bike in meantime while searching to build the dream bike.

I hope you end up with a bike that suits your needs and will be happy with it and ride it a lot.

Good luck
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Old 01-18-19, 12:51 PM
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I agree with your online dealer. Also, the more the frame builder and the dealer have dealt with tandems the better.
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Old 01-18-19, 02:54 PM
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This is a valid concern and one to sort out as you can. We are a heavier team and ride steel which has been fine for us. Titanium can be built to mimic steel with the diameters and wall thickness of the tubing used. Seven would be someone very well versed in building with titanium. Not sure where you live but a weekend trip to a dealer with a Seven might make sense. Where do you live you don't have that listed in your profile maybe someone on the forum could help.? Something else to consider if you are on Facebook the Tandem Bicycle group has over 2,000 people, someone near by you might have a Ti bike your could try. If you are anywhere drive-able to the East Coast the Tandems East Expo will have a couple of Sevens you could demo. That's scheduled for April 7 & 8, those are bikes are in their stock if I remember correctly so you could check them out at any time that at their shop.
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Old 01-18-19, 05:13 PM
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Thank you to all... Paul, I live in Sitka, Alaska
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Old 01-22-19, 02:21 PM
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Originally Posted by Anavycrna View Post
Hello,
I"m in the market for a Ti tandem (Seven Evergreen). I contacted an online dealer that cautioned against flex and recommended steel or carbon. My team weight is 460#.
What does the group think?
yes, I know we need to lose weight hence the bike

Are you looking at a custom bike or something stock? For your weight I'd consider going with a custom bike so the builder can tailor it to your team and intended use. It might not cost as much as you'd think as Ti tandems are a pretty small market and most (maybe all?) are built to order anyway. As others said it isn't the material, but the choice of tubes and the build that will determine if your bike is a noodle or a rail. The only possible limitation for Ti compared to the other materials would be if the builder can't source tubes in the needed diameters or doesn't have the ability to design around and work with those tubes.

A local couple has a Seven that they ride about 7,000 miles per year. Their team weight including the bike is < 300 lbs. The frame broke at the rear dropout a few months ago and had to back to Seven for repair. That was after about 2 years of riding, so probably somewhere between 10K and 15K miles.That's a lot of miles, and they are really strong riders, but I'm surprised a Ti frame broke under such a light team riding it unloaded and only on paved roads. Seven definitely knows their way around titanium, so if they're building the bike custom for your team it will probably be quite a bit different to the bike my ~270# friends ride.
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Old 01-22-19, 02:58 PM
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If you are planning on dropping $10K into a bike, why don't you and your partner plan a vacation to the factory showroom. See if they'll loan/rent you a bike for the weekend.

Talk to some sales reps in person. Special needs? Narrow tires? Wide tires? FAT tires?

This may well be a good time to get out of Alaska for a few days

Also, how much Tandem experience do you have? I might be more apt to hunt down a used tandem for < $1000 for your first "starter tandem". Figure out what works and what does't work for you and your team before dumping a fortune into a lifetime tandem.
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Old 01-23-19, 06:10 PM
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Originally Posted by Alan_F View Post
Are you looking at a custom bike or something stock? For your weight I'd consider going with a custom bike so the builder can tailor it to your team and intended use. It might not cost as much as you'd think as Ti tandems are a pretty small market and most (maybe all?) are built to order anyway. As others said it isn't the material, but the choice of tubes and the build that will determine if your bike is a noodle or a rail. The only possible limitation for Ti compared to the other materials would be if the builder can't source tubes in the needed diameters or doesn't have the ability to design around and work with those tubes.

A local couple has a Seven that they ride about 7,000 miles per year. Their team weight including the bike is < 300 lbs. The frame broke at the rear dropout a few months ago and had to back to Seven for repair. That was after about 2 years of riding, so probably somewhere between 10K and 15K miles.That's a lot of miles, and they are really strong riders, but I'm surprised a Ti frame broke under such a light team riding it unloaded and only on paved roads. Seven definitely knows their way around titanium, so if they're building the bike custom for your team it will probably be quite a bit different to the bike my ~270# friends ride.
Among my high mileage friends, there have been a couple of TI single bikes with broken welds, under riders who were not particularly heavy or exceptionally powerful. They went back to their custom steel bikes from before rather than have the TI repaired. I don't remember the builders. I also have a female friend who had a Seven single built which was for her unrideable it was such a noodle. She couldn't even sell it. Also went back to her custom steel. My guess was that Seven had no clue about how much power a small woman could put out. She pulled our paceline at 25+.

There can be issues with everything. If cost were not an issue, I'd say carbon because it can always be modified if the handling isn't appreciated. Steel would be my second choice. Custom for both of course. I doubt any stock tandem would be satisfactory.
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Old 01-27-19, 03:19 PM
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After talking with a local tandem dealer, I suspect that Seven could build an Evergreen (https://www.sevencycles.com/bikes/bi...ergreen-sl-007)
that would handle 460# without undue flex. The 650 wheels would be a better option than 700c at that weight and at least 36 spokes. With dual hydraulic discs and
couplers you would likely be north of $12k. Any one building Ti tandems is going to slot them into the custom bike build as the market for these jewels is limited. Your
problem absent experience is knowing what you want in a frame size and configuration. I would be more leery of carbon than Ti, as CF is very tough but when its limits
are exceeded, like glass it breaks. For travel purposes I think a single wheel trailer would be preferable to loading the bike up with front and rear panniers. Depends
on where you are going. Personally I have about 75k miles on 3 Ti frames, so far so good, only problem was with a '70s era Teledyne made from reactor tubing that lasted
30 yrs. Teledyne did NOT know what it was doing and ignored their own engineers advice to use 3.25Al-2.5V alloy, using CP Ti instead.

One other aspect of dual disc brakes is that the frame can be made for tire clearance of 50mm (or more) and for fenders. Gravel bikes have had the option with disk
brakes of either 700c or 650 wheels, with the smaller diameter of the 650 allowing larger tires for more unpaved options.

Last edited by sch; 01-27-19 at 03:24 PM.
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Old 02-04-19, 08:10 PM
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Originally Posted by Anavycrna View Post
Hello,
I"m in the market for a Ti tandem (Seven Evergreen). I contacted an online dealer that cautioned against flex and recommended steel or carbon. My team weight is 460#.
What does the group think?
yes, I know we need to lose weight hence the bike
I'm on my 5th tandem. I have not ridden Ti or Carbon for the tandem.
I like alloy. I like the feel of steel. Much of this depends on you style of riding. Touring, group rides, or kinda racing which was a thing. Any material, or every material has/have ways that they should be constructed for the application.

Seven builds nice stuff. I am not a fan of couplings, unless you need couplings. That is a bigger issue to me than material.
Stoker stems on seat tubes, small sync chainrings, cross over drive, seat post, disc brakes, are all more significant than material.
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Old 02-07-19, 08:52 PM
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To the OP:

My reading comprehension isn’t what it could be,so maybe I missed the part where you talked about your current fitness training/cycling experience. The reason I ask is that usually I suggest incremental steps before recommending spending north of $10k on a new tandem. It’s your money but....

My bride and I have two tandems. The aluminum one is stiff without being harsh, the steel one is comfortable but more “forgiving” (read not noodly but a bit flexible). I don’t know how they’d compare to Ti, but we love them both.

Have you spent time on a tandem? Are you and your stoker comfortable with the captain/stoker dynamic? Does the local weather allow a decent length riding season? Are there roads where you can ride without a lot of hills (especially in the beginning) with good road surfaces and light traffic? Have you considered spending 1/10 the price and getting a gently-used tandem to ride while you begin feeding the addiction?

Just some thoughts. Best of success in your adventure!
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Old 02-14-19, 09:56 AM
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Our team weight is less that 350# and half of us are not power riders.
Our first tandem was a steel Kent in red. which we picked up for about $300.00. I sold that one within a week and picked up a road Giordano Viaggio aluminum with the expectation of having to replace a lot of crappy components. It is a very harsh riding aluminum frame. With new quality drive train components, it didn't ride as easy as the Kent.

We are replacing the Giodanno frame and I would not even consider with a Ti frame. I've seen too many anecdotal stories of it developing stress cracks and on a tandem wear and strain is compounded. For your team weight, my complete non professional opinion, is to go with a steel frame. My road bike is carbon and rides well; however, it is quite chattery on rougher roads.

We have an eye possibly on a Ritchey or I will go back to Doug Curtiss at Curtlo cycles for a custom build. Doug built our mountain tandem for us and did a FANTASTIC job through the entire process.
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Old 02-18-19, 06:05 PM
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We have a Seven Ti Axiom 007. And it is a l o o o o ng one, for my stoker. In fact, it is the longest wheelbase I know of and as it now is, some years later in our late 60's , we could go shorter. And we might, if I buy that Hawthorne E-Tandem I've been drooling over. But the chatter about flex is, in my opinion, chatter. Other tandem riders (I know and have done tours with two Lynskey guys) I have spoken to allow that low spoke count wheels are the source of flex. And I have a set of Spinergy's too. Just tell the folks at Seven what you weigh, how you ride, and what you want. Compare the draft drawings to some other tandems in the shop, other tandems, specs of that guy in California who builds tandems and knows everything, and then buy a Seven. You won't regret it.

PS - get some 40 or 48 spoke wheels too. Just think about it.
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Old 02-19-19, 03:50 AM
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Not sure what the original poster has or is doing. Certainly some great advice. I though would lean a bit differently than some suggestions, considering the teams size and I believe being new to tandems, I suggest buying either a new or used Fandango 29 mountain tandem and running a reasonably sized tire with street performance. The frame will be adequately stiff under the teams weight. The tires and wheels will also hold up better. Overall, this will fill the initial gap and learning curve until the time may be better to get the titanium bike.

So much more difficult to enjoy a bike that is flexy and difficult to control, especially just getting into tandems.

Maybe give Alex Nutt a call, he owns MTBTandems.com and certainly has built bikes that are road versions of Fandangos.
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Old 02-19-19, 07:33 PM
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Originally Posted by sch View Post
After talking with a local tandem dealer, I suspect that Seven could build an Evergreen (https://www.sevencycles.com/bikes/bi...ergreen-sl-007)
that would handle 460# without undue flex. The 650 wheels would be a better option than 700c at that weight and at least 36 spokes. With dual hydraulic discs and
couplers you would likely be north of $12k. Any one building Ti tandems is going to slot them into the custom bike build as the market for these jewels is limited. Your
problem absent experience is knowing what you want in a frame size and configuration. I would be more leery of carbon than Ti, as CF is very tough but when its limits
are exceeded, like glass it breaks. For travel purposes I think a single wheel trailer would be preferable to loading the bike up with front and rear panniers. Depends
on where you are going. Personally I have about 75k miles on 3 Ti frames, so far so good, only problem was with a '70s era Teledyne made from reactor tubing that lasted
30 yrs. Teledyne did NOT know what it was doing and ignored their own engineers advice to use 3.25Al-2.5V alloy, using CP Ti instead.

One other aspect of dual disc brakes is that the frame can be made for tire clearance of 50mm (or more) and for fenders. Gravel bikes have had the option with disk
brakes of either 700c or 650 wheels, with the smaller diameter of the 650 allowing larger tires for more unpaved options.
You rode a Teledyne for 30 years???? As in the frame with the crimped down tube (for DT shifters)??? That's truly unbelievable. And don't tell me you ALSO rode the OEM fork the whole time too! (If so, it is April 1???)

Still have it? That's a very cool collector's item.

Good luck with your tandem search. You definitely need to get out and rent some various tandems to see how it goes. Plus, do you and your partner have time tandemming together? (Or motorcycling together; it's a good alternate test.) It's very important you confirm you're compatible on the old "relationship accelerator!"
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Old 02-20-19, 12:10 PM
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The larger the diameter of the tube , the stiffer it is.. hence fat tube frames..
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Old 02-20-19, 02:17 PM
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LV2TNDM: The Teledyne was bought as a frame in 1975 IIRC ($365!! with Ti BB axle), built up as a race bike and ridden for 3 yrs sporadically, then hung up til 1998
when I removed the '70s era DT shifters/5spd freewheel/tubular wheels and rebuilt it as a 9spd brifter/clincher wheels set up. It was ridden from 1998 to late 2015, about 23000 miles overall.
I discovered a longitudinal crack about 4" long on the underside of the R side chain tube and
felt it best to retire the frame. The fork was OK til I had the bike tip over in the back of the van while in a fork tip gripper on a board
and the fork tip broke off. Replaced the fork with a CF. Still have the tip and Ti fork. Probably the frame could be welded and repaired (fork and chain tube)
but finding a Ti welder is not straight forward, so the frame is hanging in the basement stripped. All the '70s era
parts are long gone. A friend bought a Teledyne at the same time I did in 1975 and his frame cracked at the seat tube/BB junction within months.
Mine is relatively unusual in its longevity, still has the original decals.
So actually, I had the bike rideable for 40 yrs but rode it regularly about 20 of those. FWIW frame weight of the Teledyne was the same as the frame weight of my
Lightspeed which is now at ~26000 miles.

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Old 02-20-19, 09:13 PM
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Originally Posted by sch View Post
LV2TNDM: The Teledyne was bought as a frame in 1975 IIRC ($365!! with Ti BB axle), built up as a race bike and ridden for 3 yrs sporadically, then hung up til 1998
when I removed the '70s era DT shifters/5spd freewheel/tubular wheels and rebuilt it as a 9spd brifter/clincher wheels set up. It was ridden from 1998 to late 2015, about 23000 miles overall.
I discovered a longitudinal crack about 4" long on the underside of the R side chain tube and
felt it best to retire the frame. The fork was OK til I had the bike tip over in the back of the van while in a fork tip gripper on a board
and the fork tip broke off. Replaced the fork with a CF. Still have the tip and Ti fork. Probably the frame could be welded and repaired (fork and chain tube)
but finding a Ti welder is not straight forward, so the frame is hanging in the basement stripped. All the '70s era
parts are long gone. A friend bought a Teledyne at the same time I did in 1975 and his frame cracked at the seat tube/BB junction within months.
Mine is relatively unusual in its longevity, still has the original decals.
So actually, I had the bike rideable for 40 yrs but rode it regularly about 20 of those. FWIW frame weight of the Teledyne was the same as the frame weight of my
Lightspeed which is now at ~26000 miles.
Well, that's amazing. Somehow you dodged a major bullet with the fork, from what I understand. Were you aware of the recall?

And that the downtube survived for as long as it did is also amazing. Pretty cool story and thanks so much for sharing.

I'd hang onto the fork, regardless of the broken fork tip. Having the original frame & fork makes it a collector's item in my book. If you do part with it, be sure it goes to the right home.

Thanks again for the great additional information.

PS I'm still enjoying my 1998 Mongoose Ti hardtail. Still rides great, no creaks, no issues. This nice frame has outlasted at least ten iterations of full suspension model designs in its lifetime and is still going strong. Sure, it's old, but still fully functional and still a blast to ride. I'll eventually pick up some carbon full suspension whiz-bang machine, but until then, I'm perfectly happy on the ti.
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