3rd Road Frame Build

[schollen]

Hi all. I am beginning to work on my third road bike frame. On my first two frames i didnt seek any advice from you guys and made some poor choices on tubing....so i figured i would seek some advice this time. The bike i am building will be used mostly for riding 10 miles to work plus maybe some light touring. I enjoy a road bike that has nimble handling, corners well, and is generally fun to ride. So i may have some conflicting interests, but i am leaning towards more fun to ride over a bike that is going to stable for touring. I got a bike fit last week so the geometry of the front triangle is pretty set in stone.

Frame Geometry:
drawing.jpg

Tubing selection:
I am mixed between reynolds 631 and reynolds 853....I had an 853 bike frame stolen several years back so i have always wanted to replace that. I realize 853 is has a higher yield strength, so i could potentially build with thinner tubing, however i am not confident in welding thinner than .8 mm on the main triangle tubes. Does anyone have any experience with ride quality between the two? handling? responsiveness? The first bike i built was with 631 and it was fairly easy to work with compared to the practice tubing i used. Is 853 much harder to work with? Below i listed out two potential tube sets for 853 and 631. I ended up choosing the same OD on both sets so the frame should be the same stiffness between the two but the 853 a little stronger....Let me know your thoughts and your experiences with the two tube sets, both building and ride quality. I realize there are many other tubing suppliers out there but i am familier with reynolds, have an account with them, and needed to just narrow things down.

Additional Note: I am relatively new to welding still and the st ss junction is really tough for me. on my first bike there was some space between the ss's at the st and i was able to weld them fine. on my last bike i used a 28.6 st with 16mm ss which was very difficult to weld given the ss's were touching at the junction...i ended up brazing the section where the inner section of the ss junction. I was thinking for this frame i would use a 31.75 st but i cant find any from reynolds in the right length. Because of this i decided to go with 14mm ss.

853 tube choice:

Head tube DX2340 36.4 1.2 200
Top tube BX2060 28.6 0.8/0.5/0.8 635 100.50.300.50.135
Down tube BX2110L 31.75 0.8/0.5/0.8 680 120.50.300.50.160
Seat tube CX2364 28.6 0.9/0.6/1.2 650 190.50.260.50.100 bulge 27.2
Chainstays FX2510 17.5 x 29 oval 0.9/0.6 410 oval (reynolds 725)
Seatstays GX2620 14 0.6 620 s/taper (reynolds 725)

631 tube choice

Head tube DX5340 36.4 1.2 200
Top tube BX5050 28.6 0.8/0.5/0.8 635 100.50.300.50.135
Down tube BX5125L 31.75 0.9/0.6/0.9 680 120.50.300.50.160
Seat tube CX5364 28.6 0.9/0.6/1.2 650 190.50.260.50.100 bulge 27.2
Chainstays FC1510 17 x 29 oval 0.8/0.6 410 oval
Seatstays GC1620 14 0.6 620 s/taper



Thanks so much for all your input,

Scott

[Andrew R Stewart]

Scott- i can't commet on the tube choices as i don't weld except to say that a stronger frame is not really needed most of the time. (A strong enough one is needed, and both of these tube sets will get you that).

As to the geometry- I like a tad more trail and more chain stay length. I'd consider a 72.5 head angle and a 42.5 CS. But that's me. Andy.

[Eric Estlund]

I got a bike fit last week so the geometry of the front triangle is pretty set in stone.

Hi Scott- I just wanted to chime in on this bit. Divorce frame geometry from fit data. Fit info locates your body parts relative to each other. Frame geometry locates the bits of the bike relative to each other. Bike design balances these for the given rider and use.

Assuming the fit you did last week is spot on, use it to inform your bike design and frame geometry for your uses.

Second piece of advice- don't try to built a swiss-army bike at this juncture. If your priority is a "fun" road bike, work towards that on this pass.

Best of luck!

[NBC]

scott,

i think your fork length may be a tad short ? what one are you using ?

if it were mine, maybe think about using DC156 36 x 1.5mm wall head tube, will give you more tolerance to warping and to ream back out properly

631 is non heat treated 853, so you really won't notice a whole heap of difference between the two, certainly not weight wise

if using 853 use BX2125L down tube just as extra insurance

also give GX2600 16mm seat stay double taper 570mm length .6mm wall (725 material), or GC1600 16mm double taper 560mm length .6mm wall (525 material) a look, will give you more room between the top of the stays

good luck

NBC

[schollen]

NBC,

Thanks for the advice. I was planning on using the ritchey comp fork. As for the ss, how does using a larger 16mm diameter stay give me more room for welding?

Scott

[veryredbike]

He's recommending a double taper, it gets thinner at both ends, giving you more room, but still enough contact in the middle for a good solid brake bridge.

[Curt Goodrich]

What ever you tubes you choose avoid an 853 head tube. An air hardened head tube can ruin a head tube reamer/facer. Good luck with number 3.

[waterman]

Additional Note: I am relatively new to welding still and the st ss junction is really tough for me. on my first bike there was some space between the ss's at the st and i was able to weld them fine. on my last bike i used a 28.6 st with 16mm ss which was very difficult to weld given the ss's were touching at the junction...i ended up brazing the section where the inner section of the ss junction. I was thinking for this frame i would use a 31.75 st but i cant find any from reynolds in the right length. Because of this i decided to go with 14mm ss.

I'm building my first frame on my own now and had similar difficulties in that area. I'm sure that's why wishbone stays became a thing, welding between stays that touch without distoring the seattube is hard. My teacher told me the biggest thing you can do is practice. When he showed me there was one section in the very middle that he basically welded blind because of the angles required for torch, filler, and tubes. Ugh.

[afwalker]

On your first few bike welding jobs, why not try just a bit thicker tubing sections? Maybe the 0.9mm ones like BX2063 and BX 2125L. That extra .1mm cannot weigh that much, and if you're not burning through the tubing as much, and can still lay down enough heat that the weld is solid, maybe move to thinner later. I have two sets of XCR that I refuse to touch until I've done at least 20 frames, and I may not do it until I do 100. That seatstay area and the toptube seattube joint will be the hardest as you've seen with your other bikes I imagine. Nothing frustrates me more than kind of being on a good rhythm and then blowing a big hole to spend lots of time repairing. I'm getting better (I hope) and after 17 bikes kind of can say it's getting easier:) I would think the 631 and 853 would weld the same, but actually I've only tried the 853, even the headtube was fine (I didn't do the reaming so I can't comment on if it was a bear, I'll ask the guys who did however)
So you're looking for the goldilocks weld, not to hot not too cool. If's its just a little easier with slightly thicker tubes, give yourself the advantage and thin it out on later bikes.
12161943134_91236c98c2_m.jpg
cheers
andy walker
Walker Bicycle Company | | Walker Bicycle Company
Flickr: afwalker's Photostream

[waterman]

Are you using anything as a heatsink in the seattube? A piece of brass aluminum bar turned down to size, or even just a thick aluminum seatpost will help some.

[NBC]

if your planning on using the bike as more of an adventure / commute / fun bike, maybe think about using a fork for long (47-57mm brakes)
typically these forks are 378mm, 45mm rake, but give you 28mm + mudguard room
with tig, there's no restriction on what angles you can make everything, so it would seem slightly foolish to limit yourself on tyre size too much !

NBC

[schollen]

No im not using any heat sinks currently. That is something that i should probably consider though, i imagine that would help reduce distortion on all of my welds.

[schollen]

Thanks NBC,

honestly i just chose that fork somewhat randomly and didnt really consider tire size being a function of fork length. The number of subtleties that go into tube and component selection is way more than i ever imagined. do you have any specific carbon forks that you recommend. i have owned and liked ritchey components in the past but i doesnt seem that they offer anything longer.

Scott

[NBC]

deda black rain, or the columbus hiver fork, depending on what your budget is,
i'd probably use the deda as it's an alloy steerer, and going to be generally more robust for a commuter type bike (and a fair bit cheaper)

where abouts are you ? i'm presuming england somewhere, given that you want to use reynolds ?

NBC

[schollen]

im from colorado. my first road bike was a lemond zurich which used 853 reynolds steel for the frame, the brand just stuck with me when i went to build my first frame.

[schollen]

Waterman,

do you use a heat sink for all of your welds? also do you usually wait to cut the ht and st until all the welding is finished?

Are you using anything as a heatsink in the seattube? A piece of brass aluminum bar turned down to size, or even just a thick aluminum seatpost will help some.

[Gallus]

another problem with using 853 is that it will be harder to cold set, and with welding distortion is inevitable. I am a brazer, so don't have any direct experience with TIG, but a lot of the welders I know have said that you have to learn the right welding sequence so you can somewhat control the distortion and end up with a straight frame, especially with heat treated tubing. If you are still learning your welding techniques I would stick to thicker less expensive tubing, you could probably get 2 sets for the price of one and get to frame #4 quicker.

where in Colorado are you? I recently (April) moved to Denver.

[waterman]

Waterman,

do you use a heat sink for all of your welds? also do you usually wait to cut the ht and st until all the welding is finished?

I'm just an amateur, but what I've learned from my teacher and reading is that the pros generally don't need heatsinks, but they help reduce distortion and burn through for those of us still figuring it out, and they can raise the level of QC for the pros who have reached a level where they'll make a measurable difference.

Cutting the HT and ST is part of the process you have to decide, if you're making 100's of frames you should know where to cut them before you start and then you can face the HT before you start welding. If you're making one bike and you're going to to be finishing with a hacksaw and handfile and the taking it to the LBS for facing & reaming, it doesn't really matter. I am leaving my HT a little long in case I screw something up in the process.

From what I've read, the guys who make a lot of frames all have their own process for cutting, setup, alignment, facing & finishing, etc. that they have determined over time works best for them and the frames they make with the tools they have. My process is determined by the fact that for the most part the only tools I'm using are a hacksaw, some files, a bench grinder, and my welder, so I try to leave room for error and don't worry about how much time the process takes.

[schollen]

cold setting is a good point as on my first two bikes there was some required. after reading everyones comments and looking at cost i cant really justify going with 853. it seems that the only advantage really comes when you are in a high stress situation, say mtb, or you want to use thinner tubes to save weight and acheive the same strength...neither of which i am doing. so i will probably go with 631. I am in Boulder, CO. If you want, id like to meet and talk frame building over a beer or something. I havnt actually spoken with any other frame builders before so my only info has been through these forums and making lots of mistakes

[afwalker]

I wouldn't imagine not using heat sinks and back purging with argon. If you can control and improve any aspect of your build process, why not do it?
If you know better, do better. Make yourself some aluminium or brass sinks or buy the real deal Heat Sinks
And don't forget to back purge. RE: [Frame] re: Do I really need to internal purge?
I converted my sputnik non-purged heat sinks to purged ones, and here's a mod to reach deeper
10218128253_cce61b9d2e_m.jpg12144472184_9f014287d7_m.jpg
cheers
andy walker
Walker Bicycle Company | | Walker Bicycle Company
Flickr: afwalker's Photostream