I am a frame builder AMA

It looks very much like a too short seat post was used

Apparently so. I pick it up already like this so unsure of the exact details.

tempting.
there will be a pretty sparse amount of material left once its been cut back.
do you know of any quil like alternatives that might be an option?

I made my own.

Have a look in my co thread. I'll dig it out later if you can't be bothered.

too short seat post was used

ahh yeah that'd make sense.

do you know of any quil like alternatives that might be an option?

https://www.youtube.com/watch?v=yB3k3vBkw_4

this is a guy making something similar, his is really short so not exactly the same

im not that sure if you can buy them that easily.

I remember seeing the one you made a while back. Is it practical? Does it ever slip?

Thats pretty sound. looks clean too

It does not slip. It does move a bit back and forth, but I am a heavy rider and the seat tube is a bit ovalised from heat distortion and having a too short seat post mounted.

I found it:

https://www.lfgss.com/comments/15330682/

https://www.lfgss.com/comments/15332273/

I want a little project, I own a mig welder and want a rack like this:

What steel would folks recommend? The easiest to mig weld is mild steel, but will 10mm tubes of this be strong enough? Will they bend too easy?

Most people seem to recommend stainless steel for racks, but I'd probably need to up my MIG game to get decent welds. Contamination being easier, and my welder living amongst spiders in a shed.

Any advice?

10mm x 1mm should be strong enough i'd have thought? the main advantage of stainless would be rust resistance over strength in this application (again, guessing)

Aha, that makes sense.

I'll probably plastikote it and it will only get occasional use as I tend to only manage one grammable adventure a year, so not massively worried about rust resistance.

i have a load of that tubing from when i wanted to build a rack. but then my son was born and i put it on hold. he turned four last week.

if you want it, it's in my garage in manchester :)

If I tell you the lengths I want, you could just chop it up, mitre the joints and post it all down here?

Most people seem to recommend stainless steel for racks, but I'd probably need to up my MIG game to get decent welds. Contamination being easier, and my welder living amongst spiders in a shed.

I've been MIGing a fair bit of stainless recently making trelliseseseses for the garden. I'm not enjoying it. I like TIGing stainless, but given that the last two trelliseseseses had over 30 joints to weld, I'd still be doing it if I'd used TIG.

Depends on the loads you want to carry on the rack, but I would've thought 10mm mild steel would be fine. Personally I'd use 4130 or T45, but that's because I'm daft.

Sounds like you are sorted but if not, b&q do 10mm mild steel tubing that I’ve used for racks.

Probably not the most economic way to buy it but it’s handy that you can just pop in and pick some up.

Ah grand, thanks for the feedback all. Yeah, may end up popping to B&Q - do you know if their 10mm tube is 1mm wall? The web doesnt want to tell me. Homebase looks like they also do the right stuff.

All looks pretty cheap. Just gotta work out how much I actually need. Drawings first.

I’ve also used the b&q steel for some racks and it’s been fine

Where would t45 sit on the Reynolds product scale..?

To put it another way, if you used heat treated 4130 would it be similar to t45 or is one superior? Or is it a little more complicated than that

T45 is stainless I thought.
Not sure the same kind of alloy as Reynolds 953/931

Definitely not stainless - it's similar to 4130 CroMo but doesn't require post-welding heat treatment which technically 4130 should have, albeit quite often doesn't get in bike frame construction. T45 is similar to non-heat-treated 4130, so equivalent broadly to 525/531 Reynolds stuff in terms of ultimate tensile strength. If you used 4130 and heat-treated it after construction it would be superior (slightly) to T45, but ain't no-one got time for that.

much as i'd love to slip you a length, i will leave you with this: for mitring the joints, i recommend getting a 10mm round file (surprisingly hard to find marked as such).

Not too sure but I have some in the garage so can check in a bit for you.

What does everyone think about drilling (and just drilling) holes in steel tubing for dynamo cable routing?

It's on my own bike, the one I've changed the back end on recently. Wish I'd thought about it before painting it so I could do some sort of reinforcement but alas I did not.

It's fixed with only a front brake so there's no other cabling to route the dynamo cable along to a rear light. I would go for di2 guides but I've read they are actually a bit shit at sticking to stuff and given my paintjob is splatters and all bumpy I think there's nae fucking way they'll stick to my frame so I'm thinking drilling either the top or downtube is the only way to keep it neat.

Could probably drill the DT near the headtube, run it down there, around the bb, along the chainstay and out the breather that's already in the hooded Surly style track end. Might need to enlarge the breather slightly but I don't think that's too dangerous.