Big Ass Build
 

Since most of the world is in quarantine, I thought I'd use the time to put together a build for a customer who is 6' 8". He's a tall dude for sure. I wanted to put up a list of tubing that I've chosen for the build to see what y'all think. For what it's worth, he's 210lbs and he's pretty powerful as well. Will this tubing selection be adequate for someone of his stature?

TT: Deda Zero 31.7mm 6x4x6
DT: Zona 35mm 8x5x8
HT: Paragon 230mm
ST: 31.7 Columbus Life 8x5
SS: Deda Zero 16mm
CS: Deda Zero 24mm Oval/Round

Thanks in advance.

Brandon

I'm 6'4" and plus 230#. My concerns would be the top tube only because of ease of denting? and the head tube/steerer length. Unless he wants to have a large seat top to handle bar height distance he will probably need a fork with a 350mm stem and longer head tube to limit the steerer spacers. At 6'4" my handle bars are 3-4 inches below the top of my seat with an uncut 300mm steerer tube. There are carbon forks with a 350mm steerer out there.

You can buy 44mm head tube material in 2 foot lengths from Nove, Bike Fab etc.

Thanks for the reply. Good thought about the TT. I think I'll change it up. This bike isn't going to be a Sunday special, so he's looking for a fairly aggressive design. I was going to use an Enve fork since they have steerer tubes of 350mm so I'm good there. Regarding the HT, I really like the look of the Paragon. They are nice and clean.

I agree with ws's suggestion of a thicker walled TT. Not just for dent resistance. I've long time felt that a frame feels best with somewhat balanced tube walls. A single step different (as is common with a TT being .1mm thinner walls often) sure. But two or three steps thinner seems out of step to me.

Consider allowing for more then typical (for intended use) tire clearances as a really tall or big rider needs more air between the rim and road.

Back in my Cyclery North time I built one of the 72 and 74cm frames we did that year. I wish I had the knowledge then that I have now. The frames would have been quite different. Here's a shot of the one I made. Andy
https://cimg7.ibsrv.net/gimg/bikefor...78368fa26c.jpg

Now that is a big frame. Thanks Andy, what you guys mention totally makes sense. I switched it out with a 7x5x7.

Your tube selection is on the thin side of average. Should be okay unless your friend is a masher. If that's the case moving to thicker CS's would be my first move.

Thanks Nessism.

He does have some big power. Should I go 969 on the DT? The CS I chose are 1.0 and .7 and 30.5 x 15.7mm; not thick enough?

That sounds pretty beefy. Zero tubing tends to be pretty thin thus my assumption that they were thinner/lighter.

Roger that. Yes I've noticed that as well lately the more I've been using it.

So I made a rookie mistake. I ended up ordering this ST, http://www.henryjames.com/columbus-3...t-tubes-3.html and I don't want to use it because I am going to make a custom seat sleeve for it and can't if there is a reducer glued into the end of the tube.

My question on this issue is if I can use a 28.6 ST in it's place and still be okay? My gut says yes, but thought I'd check with the masters.

Thank you in advance.

Brandon

I would hope that by looking down the length of the tube one could see any sleeve that's been inserted...

Moving to a 28.6 OD tube will need some small TT miter length increase (as well as SS length growth). While on paper there will be greater ST flex in real life the spoke tensions ot tire pressures will be greater an influence to ride feel.

Generally the tubing manufacturer isn't the one to install sleeves, that's the builder's work. I can't ever remembering seeing an un cut tube that had a pressed in (bonded?) sleeve direct from a supplier or manufacturer.

At about 1mm of sleeve wall thickness it wouldn't be too hard to turn one out and bond it in after the joint was completed. This sleeve could be steel (mild, for reaming/machining ease) or Al, I've even seen composite/plastic sleeves used. Andy

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I don't see anything about a reducer sleeve in that listing. I see a seat tube that is meant to take a 30.6 seat post. In any event, there is no way a seat tube would come with a sleeve pre-glued into it, because the glue would not survive the joining process(brazing, welding).

I'm confused by this post. There is no reducer, unless you add one. Please explain.

My thoughts on the seat tube, If you are going to buy a new tube get a double butted tube for strength around the seatpost or use the tube you have and add an external tube a few inches long at the tube junction. If the customer is a heavy and powerful rider it would give me peace of mind that the frame would not come back in year or two of hard use for a crack in the tubing. I would also go with a larger internal diameter and use a shim to make the post fit as it avoids the need to ream the seattube after building the frame, at least for me when I braze the frame I always get a rough surface inside the tube, maybe welding is different.

The tube I purchased has on ID of 30.7 on the post side. There isn't a seat post that I know of that will fit in that as they are either 30.9 or 27.2. So I'd have to purchase and glue in a reducing sleeve, which I don't want to do since I'll be adding a custom seat sleeve.

There are 30.6 posts on the market, although they tend to be nice and expensive, or lower end. Do an ebay search on "30.6 seat post" and you can see some options. There aren't any high end jobbies there at the moment (other than Thomson's) though. Regarding your "custom seat sleeve" is concern, please explain further. Is this something that goes inside the seat tube? If so, can't you design it for the ID you want to match the seat post of choice?

Thanks for this. Wouldn't a single butted tube be stronger and it doesn't thin in the center like a double butted does? My customer isn't heavy but is pretty powerful.

I'll be adding a custom external seat sleeve so I don't want to use any kind of internal reducing sleeve. The external sleeve will add strength to the seat tube as well.

Thanks for this. I haven't seen or used a 30.6. They must not used used often. We are going with a full ENVE finishing kit and I need a 400mm seat post. ENVE doesn't make a 30.6 post.

My seat sleeve is an external sleeve that will incorporate my logo on the back side of it. I take a piece of .058 and turn it down to .035 before cutting out my logo and design, and braze it on the seat tube. I would think it would add strength in the process.

There is nothing evil about an internal sleeve. After you get your external sleeve added ream the ID to make it round again and slide in a nice anodized aluminum adapter trimmed to fit. My first super oversize frame uses such a shim and that bike has a lot of miles on it without issues.

This the type of seat tube I am talking about, externally butted. https://www.bikefabsupply.com/seat-t...be-969-rid-272

As you are adding an external sleeve single butting will work.

Thanks, I thought you meant external butt, but wasn't totally sure.

Reaming a seat tube is more about correcting heat induced distortions then that of smoothing the ID surface. Honing does that. Andy

Thompson offers a 30.6 post in a few styles QBP part #ST7430 is one. Andy

I cleaned up the thread. If you wish to start a new one that continues the discussion that was OT in this one, feel free.