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Fun Bike Geometry Q...
 

[Closed] Fun Bike Geometry Question.

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[#5444333]

Pretend I am an idiot, shouldn't be too hard, and please tell me how the different angles between Bike A, and Bike B, will affect they way they ride.

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*click pic to make larger if needed*


 
Posted : 21/08/2013 11:33 am
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are we talking road bikes here?


 
Posted : 21/08/2013 11:35 am
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One will be better than the other one.


 
Posted : 21/08/2013 11:37 am
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Bike A will have a more lively ride whilst bike B will be a laid back cruiser.


 
Posted : 21/08/2013 11:38 am
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are we talking road bikes here?

Whoops.

CX bikes.

A = Merida Cyclo Cross 4
B = Boardman CX Team.


 
Posted : 21/08/2013 11:39 am
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A has a slacker head angle so steering should be less twitchy and better descender. Also has steeper seat angle, better climbing position? I don't really know ๐Ÿ™‚

Cross bikes?


 
Posted : 21/08/2013 11:40 am
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Bike A, head tube of 70.5 is quite laid back for a roadie. Bike B will steer a bit easier/quicker.

Is bike A a CX?

edit: I see they both be that. the boardman frame looks more like a traditional twitchy mofo road bike adapted for off road, the merida looks more like its designed ground up for rougher stuff.


 
Posted : 21/08/2013 11:42 am
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Whoops.

CX bikes.


Then neither will be fun ๐Ÿ˜‰

Pretend I am an idiot

Do you want some magic beans, PP Gift.


 
Posted : 21/08/2013 11:45 am
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In the old days, traditional cross geometry had a slacker seat tube and a steeper head tube to give a more forgiving back end with sharp handling.
Tri bikes where the opposite; steep at the back and slower handling at the front to allow a more open torso-leg angle and make them less twitchy to ride with tri bars.

The Boardman is closer to a road bike geometry, as are most cross bikes these days, and has a taller head tube so raising the bars.

There won't be a lot in it, tbh.


 
Posted : 21/08/2013 11:46 am
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I'm sure this was discussed a while back.

Personally I think unless you are very experienced in frame design its hard to tell exactly how a frame will feel from the just the numbers.

You can take one variable eg the head angle and say a slacker head angle will make the bike stable but will be a dog to climb.

Then change another variable eg the stack and keep this low so now your weight is over the front of the bike making it nicer to climb.

etc etc...

its a balancing act and changing one variable usually has an effect on another variable too.

I only have experience with MTB but I've ridden long travel bikes that were supposed to be great descenders but I felt more comfortable on shorter travel less "rad to the max" bikes.

Use the charts as rough guide to whether it will fit and try to get a demo to really see how it feels.


 
Posted : 21/08/2013 11:46 am
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I should explain, that the reason I am asking is because I recently got the Boardman, but despite it being a Small frame, it feels a bit too long for me as it has a 540mm TT.

The 48cm Merida has a shorter 520mm TT, but diff angles and a shorter headtube, so just wondering how much of a different beast it was.

Unfortunately, I do not have one locally to try out.

...or I could just lob a shorter stem on the Boardman 8)


 
Posted : 21/08/2013 11:50 am
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2 options; get a 10mm shorter stem, or get as short a reach compact handlebars as you can find, or do both. Er, that's 3 options..


 
Posted : 21/08/2013 11:53 am
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Well, the Merida has a steeper seatube, if you like your saddle in the same place behind the bb on all bikes, then you'll have to slide it right back on the rails. You'll end up the same length as on the boardman. Although the slacker head tube angle will bring the bars a bit closer, although the shorter headtube will move them further away....


 
Posted : 21/08/2013 11:55 am
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ride them; whilst we could all sit here telling you one will be twitcy/ responsive or the other is stable/ dead feeling. it's really down to perception/ preference.

I've got two 'cross' bikes with quite different angles. I don't prefer one over the other - but they are certainly not alike at all.


 
Posted : 21/08/2013 11:56 am
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Yeh, do what Crieky says. I have some Pro bars (cant remember which model) which have a 70mm reach (about the shortest I've seen).

This means I can run a 130mm stem to maintain a "pro" look, but also have an acceptable reach to keep my bike comfortable on rides of upto 35miles.


 
Posted : 21/08/2013 11:57 am
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Just took a punt on a 80mm stem as don't care about looking pro. As I am patently not ๐Ÿ˜€

...also, rightly or wrongly, figured it's easier to change one component, rather than 2.


 
Posted : 21/08/2013 12:00 pm
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๐Ÿ˜€

Just be careful, a 20mm shorter stem may do your neck some real damage.

I'd recommend going to your nearest Specialized store and getting fitted.


 
Posted : 21/08/2013 12:04 pm
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Just be careful, a 20mm shorter stem may do your neck some real damage.

Hmmm. Better order a neck brace as well. Cheers.


 
Posted : 21/08/2013 12:22 pm
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dt, have you been on holiday ? You appear to have been refreshed ๐Ÿ˜€


 
Posted : 21/08/2013 12:23 pm
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Jamie - Member

Just be careful, a 20mm shorter stem may do your neck some real damage.

Hmmm. Better order a neck brace as well. Cheers.

Be careful, you can only wear them with a full face. Otherwise, they can snap your head off.


 
Posted : 21/08/2013 12:26 pm
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scaredypants - Member

dt, have you been on holiday ? You appear to have been refreshed

๐Ÿ˜€

I went on holiday amongst other things, then I got bored of leading a normal life, so thought I come back on here to type.


 
Posted : 21/08/2013 12:27 pm
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Be careful, you can only wear them with a full face. Otherwise, they can snap your head off.

Hmm. That sounds a bit serious. Probably just sell the bike.


 
Posted : 21/08/2013 12:40 pm