Help me please with choosing geo (and to understand what it gives)

[TriаlsRider]

So, for example we are moving from fourplay 2011:

1020 WB

380 CS

+20 BB

Reach?

73 HA

So, what will give me:

1) Changing WB in both ways (cons and pros)

2) Changing CS in both ways (cons and pros)

3) Changing BB in both ways (cons and pros)

4) Changing Reach in both ways (cons and pros)

5) Changing HA in both ways (cons and pros)

Maybe it would be helpful for someone else who choosing custom geo.

**For example: Higher BB = comfy on back wheel, lower BB = comfy on two. But maybe there are something not so obvious and interesting?

[FamilyBiker]

didnt i pm you about that?

geo itself isnt an issue if you were to choose from off-the-shelf-frames,all good manufacturers made their homework and got riders feedback,so theres nothing to go really wrong with if you know you ride street,comp or else.

tell yourself a question,aimed on a geo youve ridden and know how it handles:

what kind of moves is it bad for,or good for?how would you change the BEHAVIOUR of the bike if you could just tell it to do so?

then changes to make get more obvious,dont fix yourself on the values so much

Edited November 27, 2013 by FamilyBiker

[isitafox]

One thing I'd say is don't worry about the wheelbase, the reach, BB height, head angle and chainstay length will determine the wheelbase. If once you've decided on these the wheelbase seems a bit short or long you need to tweak the other measurements to suit.

This is where extensive R+D of frames like the Arcade come in so that the frame manufacturer doesn't have to compromise and can get exactly what they want out of the way a bike rides and handles.

[TrialsMan Dan]

I dont really understand what it is you are exactly asking here, since you have gave an example at the bottom of your post. You either know what you're talking about or you dont. If you dont know what effect each change will make you are probably not experienced enough in the sense that you have maybe only ridden one bike. I think you need to try riding some fellow trials riders bikes to get a grasp of how geometry affects the bike's handling. I take it you are looking for a custom frame next?

[TriаlsRider]

BB height affects only on what I said in my example or on something else?

What HA affects on?

What chainstay affects on? Isn't shorter chainstay is always better in street-trials?

What reach affects on?

____

Maybe need to say something about my riding style, so:

My riding style is pretty streety with a bit of trials and FR (I ride with brakes and brakeless). Mostly urban (but I love natural too).

Usually I just ride through the city and have fun with everything I find on my way (in one flow on speed without braking and sometimes I stay at some spot for a while).

I really love bunnyhops (on obstacles, BH gaps, BH dropgaps, "bunnysidehops", lol, don't know how to call it, BH to 180 and other) and high speed (to control my bike and overcoming obstacles on speed is so adorably). Also I love to go big in drops/dropgaps/ride some high obstacles and other scary stuff. Stuff that makes your heart beat faster. And besides all this stuff I also like trials (pedal-ups (especially to 90), pedal-kicks, pedal-punches zap taps and other) , and also brakeless trials alot.

I don't like to spent too much time on one spot and at all I very love diversity in tricks and in spots/obstacles.

[isitafox]

So you like to ride street, tgs, natural, with and without brakes and also do a bit of freeriding, and you want one bike to do all this on?

Arcade, to a degree, sounds like your best bet to me but in reality your asking for something that can't exist.

[FamilyBiker]

woah,not on one bike,at least not over a certain extent in every genre.

in every discipline you mentioned there would have to be big restrictions in what you can do.

get a street trials bike that suits you well and build yourself a hardtail fr bike,i´d say...

[TriаlsRider]

I'll do it all pretty well on my fourplay 2011 now with 22-17/14(want to get 22-17/12). I don't like suspension, maybe fork only. But the problem is that this fourplay is just my old Element with shorter chainstay and I want to try something new and different. Also I want to fully understand how changes in geo will affect on how my bike would ride.

So what advantages and disadvantages of changing HA to 74-75 will give?

And same question about shortening chainstay (to 375 or even 364).

And also I don't know what BB rise to choose (I know only that I don't like +30 and feel a lot better on +20, but to go lower will be really-really bad for rear wheel moves, right?)

And the last one - reach? Don't know anything about it except if it's too small bike would feel like a tabouette on wheels.

Edited November 27, 2013 by TriаlsRider

[FamilyBiker]

as every value effects the other and vice versa its not that easy.

the easiest way is to figure out what you´d like a certain geo, you´ve been riding with, to ride like in the future.

go on from things you know.

if you have a certain geo and just change one value because the overall feeling is good and you´d just like a certain behaviour of your bike to be changed,you´ll be closer to a sweet spot than if you throw geo values together that give this or that in properties for theirselves,but not in relation to the rest of the geo.

know what i mean?

Edited November 27, 2013 by FamilyBiker

[Blake]

Don't shit yourself over geo. You shouldn't be thinking that hard about geo unless you've had lots of different experiences with it and know a fair bit about it. Just get what you like the look of and what sounds okay ish.

[HippY]

as far as I see, the geo does not make that huge difference

Martyn Ashton road rage

the Hungarian guy with the Echo 24 and sick street moves

Flipp with mod doing street

its more about the rider, and if you are very good, then maybe you can feel/need that 5mm+- geo, although I am quite sure most of the people here would not feel if the bike would have 5mm more bb height or wheelbase ( I am not talking about the ultra professionals here)

[FamilyBiker]

5mm+- geo,

thats not reserved for ultra pros i think.i once adjusted my rear wheel to around 6-7mm longer chainstays,and it was noticeable right away.and the difference was big,as in"learn how to pop the bike up"again

[HippY]

thats not reserved for ultra pros i think.i once adjusted my rear wheel to around 6-7mm longer chainstays,and it was noticeable right away.and the difference was big,as in"learn how to pop the bike up"again

how long are you riding a bike?

I meant ultra pros for everyone who can ride awesome compared to me. that is like loads of people.

[FamilyBiker]

since i was 3 normal bikes,since 2003 dirt,then street,next year is my 4th in street trials.

but i think it doesnt matter how long you ride,its like truing wheels,some see a buckle in the wheel if its just a 10th of a mm,some hear it when hitting the spokes

nah,i am not a prodigy or something,but i noticed the bike being less bunnyhoppable really

[isitafox]

Yeah the "it's not the bike, it's the rider" argument only works to a degree, Flipps mod is custom geo to suit how he rides so that is instantly a poor argument to use.

[HippY]

ohh okay, fair enough, thanks for the new info!

[sharn]

Bar and stem play as much in the geometry of a bike as the frame and fork. A bike should be considered in totality really. And it's not the same for everyone. when you mount a bike it's the geometry of you and the bike as an entire unit that matters. Example; the same bike with a tall and a short person aboard it will be two very different 'entities' moving through space (and time - which i suppose is (acutely) relevant to the discussion - with relevance to force and motion we are trying to create through the machine, with optimum efficiency. In the sense that your actual muscles operate better or worse at different 'angles' also).

Imagine the bike has fixed points of interest relative to itself (the geometry youre asking about), then your 'fixed points of interest' i.e your elbows,knees, shoulders, length of spine, legs, arms (etc) also create a relationship to the fixed points of the bike and create relationships all over this (now) singular unit of interest (i.e you and the bike together) So you might understand it's a very complex and wonderful thing that occurs and is (imo) one of the beauties of the man/bicycle relationship. Alhamdulilah! I love bikes (and biscuits. Ahem. *crunch*) It's all very acute, but collectively this all makes one person 'fit' a bike better than another.

Think about how you want the bike to feel and see what people can suggest. Give us your geometry (i.e your height and body type, i.e gangly arms or short arms etc) Example; imagine if you have short arms, that means no matter what bike your on your weight is further forward than someone with longer arms, which might make one bike feel better than another (to you) Same goes for every othe measurement of your body. Wheel-size is another thing, i.e you have 'wheelbase' and 'bike length' which are naturally different depending on the wheel size and this effects things like turning and spinning because of gravitational forces.

It takes a long time to 'understand' bikes and the way they ride. I read a thread mentioning being able to look at a bike and know how it'll ride. i feel that to an extent i can do this. But only for myself obviously.

Hope this helps you to understand it's simply not that simple. Bike fitting is a wonderful science And when it comes to trials it's even more complicated because we're moving around the thing in all directions.

Edited November 28, 2013 by sharn

[FamilyBiker]

man ,this post was pure art!

exactly how it is imo

edit:and that thread was actually his,too

Edited November 28, 2013 by FamilyBiker

[TriаlsRider]

as far as I see, the geo does not make that huge difference

Martyn Ashton road rage

the Hungarian guy with the Echo 24 and sick street moves

Flipp with mod doing street

its more about the rider, and if you are very good, then maybe you can feel/need that 5mm+- geo, although I am quite sure most of the people here would not feel if the bike would have 5mm more bb height or wheelbase ( I am not talking about the ultra professionals here)

Remember that video?

So what? Everyone should get something like this and ride it?

Good geo (at all and matched to you personally) makes bike more enjoyable and easy to ride. And it really matters, because shitty bike will take any joy from your riding and your riding will turn into suffering.

Edited November 29, 2013 by TriаlsRider

[Luke Rainbird]

Geo is only one part of the story though. Weight distribution, flexing of parts etc comes into it all too.

One sub-par component on a bike can totally kill the way it feels to ride, so having 99% shite only exacerbates that.

[HippY]

no I just said, that personally I would not really worried about 5mm difference in geo, ( not like 5 "ohmygodwhatisthat" like on the 2nd picture. god, that's ugly), although as some people told that it can be important

[TriаlsRider]

At all yeah, 5mm not so big deal, but I can notice 5mm difference in chainstay and in bars height.

If we moving from 1020 665(reach) 380 +20 I definitely want:

Easier front wheel stuff (nose manuals, etc.), easier manuals, bunnyhops, easier rear wheel stuff and not to loose comfort on two wheels. Reach is pretty good, maybe a little higher will be ok.

[FamilyBiker]

i think your already talking about either an arcade or an archive then

[sharn]

I'd say; Steeper head angle. +10/12ish on w.b (axle to axle) Of that 10/11/12mm - +4mm on chainstays/+6/7/8mm on b.b - fr.axle. Run a shorter stem 60/70/80mm (presumin youv'e got something longer) with a nice lofty riser set at 0. Stackers to taste. Start low(ish) - lower the front end the 'better' once it's on the back wheel (imo) But you need to find a balance between this so that you can still get the right timing for pulling up into (and finding the sweet spot for) a manual or leveling out a bunnyhop.

Nice wide rim to keep back wheel stability. +20Psi for bunnyhops .

It's hard to find a 'trials' set-up good for nose manuals. You'll probably need a front disc cos you'll still really have to throw it in.

That's my initial thinking for moving from the geo' youv'e got.

With any set up you should find you can get a quick, on the go tweek by tilting the bars forward or back. A big riser adds a nice amount of adjustability in this way because when u tilt them fowrard you add alot more to the reach So if the short stem set up is buggin you just tilt em forward (a touch). No bar should really be going too far back (from 0*) though :'( .

Hope some of that helps! Thats roughly how i would start myself but i'm a big lanky beanpole and don't actually ride anymore . All the best.

[TriаlsRider]

Well I almost decided what do I want.

At first - I very much like these three framesets:

1) André's Marino

Frame geo:
995mm - WB
25mm - BB+
375mm - CS
75º - Hta
72º - Sta
270mm - Seat tube lenght
130mm - Head tube lenght
135mm/10mm - Hub spacing
Reach???
Forks geo:
410mm lenght 25mm rake

2) Archive

74 980 +20 360 reach???

Forks: 410 30

3) Arcade

Frame: 74.5 1000 +25 364 reach 675

Forks: 410 30

So it's pretty difficult to choose betwheen that three, or maybe to get something a little different from one of these.

And I have few more questions that will help me to finally make a choice:

1) The reach. I'm afraid to get some too short reach (I'm 6' tall and one day I tried some "pure" street 26 bike and it felt so shitty I hated it, like a tabourette on wheels, extremely short and so low you will get a kyphosis and become humpbacked in first week of riding that bike) but.. maybe this is stupid because I have no experience riding other frames than element and fourplay. Now I feell myself pretty comfy on fourplay 2011 (73 1020 +20 380 reach 665) with 90x35 stem, 45mm of stackers and TT High Rise bars. And also I felt good on my Element (1025 385 +20 660) with 70x35 stem and 45mm of stackers on two wheels (but with that stem bike was absolutely uncomfortable on back wheel).

2) CS must be as short as possible (360)? Because it's just good and there are nothing bad in very short CS?

3) 74-75 HA. How it feels compared to fourplays HA.

4) +25mm BB seems to be ideal for 24 street-trials?

And if someone have an expirience in riding fourplay 2011 (73 1020 +20 380 reach 665) and some of that frames or just know difference between them - can you please describe it?

I'll appreciate any help, this is my last questions about geo.

Edited December 3, 2013 by TriаlsRider