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Geo Help


Miss-Higgy

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After snapping two second hand onza frames in less than two months, and not being that bothered about weight, I've decided to get a steel frame.

I'm used to riding my t-pro and i like the geo. I can't find the exact geo in the quick scan of the internet I've done. The chain stays are 355mm that's as far as i've got.

Does anyone know the geo off hand? Or how do i measure the other bit's without rebuilding the frame? Not to mention i wouldn't know how to measure BB rise even if it was built.

Next question is would anyone recommend different geo? I'm not TGS style and have no intesion of ever wanting to be so i don't think i require the 200,000 BB rise. What does the BB rise change on a bikes reactions anyway?

Been looking at different frames and they are all slightly different, so what would people say is the most street trials orientated 20" frame?

The ECHO lite 09(short) geo looks roughly what i'm thinking how simmilar is it to the t pro geo i'm looking for i know the chainstays are longer by 12mm?? Will that make it harder to lift up with the shorter mod stem i'm plan on running?

101 questions because i think a custom frame is like a tattoo, put no thought in, rush it and regret it...?

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the geo of my t pro was

+30BB rise

1000WB

and I think the chainstays were a bit longer than 355, maybe 360.

Anyway they're great frames but I think something a little bit higher BB will be nicer, something around +50 isn't too high that you can only do rear wheel stuff, but not too low you can't even stay on rear.

If you're looking for something streety you could consider something like flipp's bike, which is really short and flicky (he'll have to state the geo as I can't remember) but I rode his bike at radfest and it was really easy to spin and bunnyhop from what I gathered, easy enough I looped out trying to 180 :P

Sorry I was a bit wavery on the answers there, but trying to answer everything at once :P either way, short and flicky sounds good for you, makes everything easier so all you have to do is worry about your technique :)

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Nick Cooke's Triton is a Monty geometry.

He's just a f**king beast and can ride any bike however he likes :P

My frame is:

Reach: 595

WB: 980

HA: 73*

CS: 350

BB: 70

If you want something T-Proish: WB 1010, HA 72*, CS 360, BB 55/60 is a reasonable approximation.

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Do not think that nick cooke's triton rides nice, you will be as disappointed as I was :P He just rides everything insane.

I had never really considered headtube angle until flipp talked about it, but it seems to make a big difference to him so I guess there is a lot of change by such a small adjustment.

And the above posted geo sounds perfect

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Well you say you want to ride streety stuff so you'll be spending a lot of time on both wheels as opposed to those who just back hop everywhere. If you're doing rolling moves and so on then stability and quickness of turning will have a lot to do with head angle. The steeper it is the quicker it'll feel - too steep and it might feel overly jerky, even wobbly as it might be too responsive. A slacker angle will feel slower to turn as it's a more layed back position.

For example most trail bikes now are around 66-67 degrees which sometimes when rolling along on the flat feels a bit bloated and wallowy to turn, but as soon as you point it down it makes sense and gives you a good feel, puts you in a good position on the bike and is more than responsive enough.

Despite all these comments just go 73 degrees as it's just tops.

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That won't work.

The reach is a result of the front end being combined with the HA. You can't specify lengths that won't fit together.

Ie. A 1000mm WB frame with a 72HA will have a certain length reach (according to BB rise and CS length), but you can't specify you want that same length reach on a bike with the same geometry except for a 73HA. It physically can't happen.

My reach is 595. Your CS is 5mm longer than mine, and wheelbase 15mm longer (making front end 10mm ((or very very nearly, anyway)) longer). With that wheelbase and head angle, the reach would be more than 600mm. It'd be more like 610.

Seeing as the wheelbase doesn't effect the ride as much as the reach - if you're settled on a 600mm reach, just tell whoever builds the frame you want a 600mm reach with a 73 HA, and let the WB be whatever it works out at.

It's easy enough to work out, if you wanted to know, but just thought I'd mention it.

Edit: Pro diagram:

Untitled-14.jpg

This is what'd happen if you adjusted the reach around the WB.

If you adjusted with WB around the reach, the reach'd stay the same, and the wheelbase would shorten.

Second way is better, in my opinion.

Getting the reach you want will make more difference than a specific wheelbase with a slightly too long reach.

You should take in to consideration the stem, too.

If you want the same bar position but quicker steering, you can run a shorter and steeper (or shorter with more stackers) stem and steepen the head angle.

You need to know what you want, really. Else just go with a geo of a frame you know you like.

Edited by aener
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I have measured the reach off my t-pro frame, so i definitely think that reach is what i want.

I've put a quote in with Jaf Bikes and thinking thats who I'm going with, he has done me a drawing of the geo i stated earlier.

264766_4371212367884_1972284436_n.jpg

do you mean where the HA angle line comes out, it don't meet the 1000WB line? so it would be better with a 990ish wb?

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Shhhhh!!! You have to spoil everything!

lol no i wasn't thinking that but i could just glue it on! Besides we have two other bikes that require pivitols, and i seem to collect bike seats i have like 10 plus ones on bikes lol!

But on the other hand it could be a good thing as i do like a seat, it helps my manual balance :) Damn you another thing to think about!

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If that's a drawing from Josh, then I stand corrected.

I was only running the numbers through my head, and they didn't seem to add up.

The geo in that diagram should ride pretty nice, but I'm a fan of short stays. 350 all the way, for me ;)

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do you mean where the HA angle line comes out, it don't meet the 1000WB line? so it would be better with a 990ish wb?

The centre of the front axle won't be in line with a straight line right down the centre line of the head tube due to the rake of the forks.

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Last night me and my boyfriend both sat down and sketched this with Geo that should be good although i disagree with his 40+ bb rise i think 50+ would be nicer

422317_4372766446735_2081032763_n.jpg

Just a vague sketch for now.

Reach: 610mm

CS: 340mm

HA:73

BB: 50+

And yes it has a seat post.. Will be running the shortest mod stem TrialTech make and TrialTech disc only forks with an uncut steerer tube. And high rise bars ^_^

Waits for hater's....

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