Hallihallo my dearies,
since my Koncept broke a few months ago and I don’t think the replacement will hold up much longer I want to build my own frame this summer/autumn. I want to do it myself so I’m thinking of doing a framebuilding course (any experiences?) and I want to have my geometry mostly set when I go there so this will be where I post my first-timer questions in hopes for input from the more experienced here :))
Whats set so far:
-160 cranks (or shorter)
-short and agile: steep head angle, super short wheelbase
-mostly based around Koncept geometry because I’m happy with that
-26", maybe 27.5"
And here’s my first questions:
-welding/fillet brazing - any objective advantages/disadvantages? Everything I heard so far is that it doesn’t matter much for the end product just welding is a little harder
-Head tube length: I had the idea of maybe using a Max Power Fork so I have one less thing to worry about. However with their low axle to crown height and the handlebar height I am shooting for I will need something like a 25cm head tube on the frame. Are there any practical limitations to that other than the fork steerer needs to be long enough?
if you want to spend a few days in vienna this summer, i built mine together with a friend (IG: @morassiframes, but i can also give you another contact or ask them first). they have a super nice workshop and i could imagine they would be up for doing that together! also maybe another gay or (A) disc guard?
Just my 2 cents advice : since you are planning to spend money on a brand new custom frame, you should maybe consider to make the fork with it and to go with 44mm head tube, tapered steerer and trhu axle.
The combination of these 3 “details” will completely change the bike.
I think I have at home a 26" fork that was used twice in pick-ups, feel free to contact me if you need details.
What exactly is the advantage of tapered steerer? I was told by other people that it doesn’t make sense for steel… Would be good news for me tho because I would be able to keep using my fork :D
yeah, a tapered headtube on a steel frame is unnecessary and has no benefits beyond reusing the fork you already have, which could be a good thing if you want to save the money!
if you do make a fork as well, i agree with using through axle dropouts, much nicer and stronger than qr.
welding would be easier, faster, and cheaper to do vs brazing, but brazing is prettier imo. it would come down to which skills you or whoever’s gonna build the bike has/wants to learn.
if you’re happy with koncept’s geo, i’d just use that if i were you! i’ve done a couple frames now and have been using enforcer’s 13 geo since that’s what i’ve got and am used to. it’s nice using numbers that you already know work well.
Tapered steerers make your bike stiffer, especially with the thru axle.
It’s true in theory.
It’s true in reality for me since I’ve had exactly the same bike with and without the 3 things and it feels very different.
At least, you could use a 44mm head tube and start with the MP fork and an adapter on the crown.
welding/fillet brazing - as far as I know there are many differences between both in durability, “fixability” etc - but at the end probably you should just consult a frame builder about preferred technique for each “joint”. I’ve got a frame that is 100% fillet-brazen and have no single issue - 5 years of bike polo and another 5 years of commuting on it. My current frame is partially welded, partially fillet brazen - no issues yet
Head tube - I was told by every framebuilder I had a pleasure to work with that the longer the better if you want stiffness and durability, Ive also heard the same about tapered headtube
Thru axle ftw !!!
Geo and Fork - if you have geo that works for you - stick with it (there is no worse thing than new frame that you’ve just spend money on and it doesn’t work for you - been there, done that). Fork and frame are a “unit” - without fork frame has no real geometry in terms of steering, so if you already have a fork or you want a “stock” fork - that’s the thing to start with
framebuilding course is an awesome idea - most courses I’ve seen so far are build around building your own frame, if you then have any access to welding machine that sounds like a dream
Sooo we’re making some progress!
I’ve decided to to keep using my existing Fork, less work and less cost. this means:
-tapered steerer, EC44/40 - ZS44/28,6
-headtube length comes at a more moderate 192ish mm(to be adjusted based on availability)
I have also been looking at the rear end of the bike. Seat Tube will probably be 550, maybe a bit less, have to check standover height. I really want to keep my ultra short chain stays (355). I also like my effective seat angle of 73°, however without the bend in the seat tube that results in a gap between tire and seat tube of 2,92mm (calculated using outer diameter measured on my current wheels and seat tube). That would mean I can only ever run skinny 26" tires and I would love to hear some experience whether a gap that small is feasible or to sketchy due to tolerances in manufacturing and my measurements. A seat angle of 73,5° would have a gap of 4,04mm.
Another factorat play here is the outer diameter of the seat tube, I assumed the 31,8 I have on my current frame but don’t know if that is even available in steel. maybe just a thinner tube will do the trick? XD
i’m sure any frame building school will have the stuff to dimple a tube, usually you gotta dimple the chain stays for tire clearance anyway. i mean i just dimpled this frame last night in my shed before brazing in a new cross brace and i don’t even have appropriate tools haha
