Custom Frame Geometry

since when did i say that???

I mentioned the old school bmx because i know how much less twitchy my track geometry will be.

This sounds like a train wreck waiting to happen. It doesn’t sound like you really know why you have made the geo choices you have.

Have you ever ridden a a frame with more neutral angles? There’s no real reason to have angles this steep.

I dunno, maybe I’m just out of touch with what the kids are doing nowadays, but it sounds awful.

I told you I wanted something crazy!!! Since you guys did even bother to answer my question, let me ask it again. Can high trail balance out twitchiness of the steep angles ??? And since you guys hate the angles so much, is 76/74 st/ht okay? (similar to argon 18 electron)

Your question doesn't make any sense that's why no one answered. Trail is a result of head tube angle fork rake wheel diameter.. whit a 75°ht and and a 30mm rake fork you have a trail of around 60 that is quite neutral but that alone doesn't mean nothing if the bike is impossible to ride because you have 80% of your weight on the handlebar due to the too step seat tube. You want something crazy go for 90°/90° sure it will be impossible to ride that will be CRAZY. There is a reason why bike in general have all similar Geo's, ask your self why you don't see any bike with the geo that you designed beside this guy https://www.fixedforum.it/forum/topic/78759-maza-max-workhorse/

I see. Well I won’t learn anything if no one answered. I thought it would make sense. About the guy, how does he ride his bike? I can’t speak Italian and google translate doesnt do much. I guess most of his weight would be on the handlebars? What I saw is 81/76 ht/st and that is extreme for me.

The more trial the less twitchy, like typical track bike.

Funnily enough the trail on your bicycle is very similar to a typical road bike (typically between 50-60mm), which is regarded as a good balance between twitchness and stability.

I dunno, maybe I’m just out of touch with what the kids are doing nowadays, but it sounds awful.

To be fair, you had ridden bicycles similar to the 75HT/77ST; that’s your Leader 725.

2 Attachments

thats the thing :/ well if i dont like the 77 degree seat tube ill just throw on a set back seatpost. What trail does track bikes usually have?

I found an article I think you’ll find useful;

https://urbanvelo.org/issue3/urbanvelo3_p46-47.html

Seat tube angle; by putting a setback seat post, you’re making the bike longer and possibly make it too long for you, and even a setback seatpost isn’t really enough to push your saddle back enough to be able to actually put weight on your saddle to reduce the sheer amount of vibration coming up from the front end of the fork with its steep head angle and small rake.

Apart from all that, I’d ride this for shit and giggle.

I see. The geo I designed has actually a shorter effective top tube than the one I have now. I actually feel a bit stretched out and way too far back. It has a more relaxed geometry 71.5ht/72.22st. I think I would really have fun on the compact and aggressive geometry I made. I think I would benefit from it a bit too. I wonder how the guy Matita24 mentioned uses his extreme geometry as a workhorse.

Have any of you guys heard of the Velove Torro? Apparantly it is a 77ht/77st frame.
https://en.velove.pl/our-bikes-1/torro

1 Attachment

With the saddle slammed back on a setback post because it’s too steep

I think the guy used it for a year or two and then the novelty of the freak bike faded and he bought a "normal" road bike. Anyway in the thread he said he was found to go on tour to Paris on that bike .

oh when i took the pic the saddle rail was sliding around lol

Yeah, 74 and 75.5 is relatively steep, but I had a set back post to counter the steep STA. Look at the front centre. 600! That’s more than on my road bike which has a 70.8° HTA with a 50mm rake fork... The leader was a relatively well behaved bike if memory serves me correctly. Was almost a decade ago, though.

The geo I designed has actually a shorter effective top tube than the one I have now.

By steepen the seat tube angle which actually mean the length will remain the same, some cases even longer.

I wrote a bit about it here;

https://www.lfgss.com/conversations/248406/

Just to clarify; I’m (and others, I think) are not lambasting you on your choices of geometry, just genuine curiosity that spark up interesting debates on it.

I remember never seeing anyone whose arm is as straight as your when you were on the bullhorn bar.

This is the thing; he put the saddle so far back, that the “advantage” of a steep seat tube is invalidated* when it’s set where a nominal seat angle with a straight inline pier will work just as well.

*some advantage is having the wheels very far forward keeping the wheelbase as short as possible**, which IMHO, a well designed front end geometry provide a bigger advantage than a slammed rear wheel.

**despite the picture showing a big gap!

Every time I hear ‘slammed back wheel’ I think of old claud butler polo frames. I recall someone came to the first few Tweed Runs on one.
I had an uswb tandem of a similar era with the curved seat tube. So sick.

1 Attachment

This is the thing; he put the saddle so far back, that the “advantage” of a steep seat tube is invalidated* when it’s set where a nominal seat angle with a straight inline pier will work just as well.

wait i dont understand this. can you explain it a bit more? my seat tube currently is only 72 degrees and who is he lol

and why are 30mm raked forks are so hard to find :C even the ones I have locally seems kinda sketch. retailer says its 30mm but the manufacturer says its 43mm :/ edit: nvm found one on aliexpress lol

Just to clarify; I’m (and others, I think) are not lambasting you on your choices of geometry, just genuine curiosity that spark up interesting debates on it.

I genuinely feel like I'm the dumbest guy in this forum.

Because it's gone out of fashion, whether a nominal fork will suffice for track racing as long the head angle adjusted accordingly, Cinelli Vigorelli for instance.

wait i dont understand this. can you explain it a bit more? my seat tube currently is only 72 degrees and who is he lol

Generally a steep seat tube mean the wheel can be move closer to the seat tube.

A slack seat tube mean the wheel cannot be as close as possible as the seat tube is in the way.

The conventional wisdom suggest it help with frames stiffness, drivetrain effectively (shorter chain), etc. which is not the case nowaday.

Ahhh I get it. Thank you very much!