Idiot Question Abou...
 

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[Closed] Idiot Question About Reach & Anglesets

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Quick query, will adding a 2 degree angleset to a rigid 29 HT increase reach to any noticeable extent?

Or will it decrease it? 😥


 
Posted : 18/11/2017 10:28 pm
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Decrease it - the bars come closer to you. Not by a lot, but 2 degrees will bring it back a bit.


 
Posted : 18/11/2017 10:32 pm
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Reach is horizontal distance between B.B. and centre of head tube at top, so it won’t change


 
Posted : 18/11/2017 10:37 pm
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The angleset will drop the front by raking the fork out, thus increasing the reach. But then the offset upper cup will cancel out almost all of that. Negligible difference.


 
Posted : 18/11/2017 10:39 pm
 gt56
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Haha 3 answers, all of them different. Great! 😀


 
Posted : 18/11/2017 10:44 pm
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It'll increase it a little bit by raking out the fork. And it'll decrease it a little bit by rolling the steerer back. And you won't notice either.


 
Posted : 18/11/2017 10:51 pm
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4 answers - only one correct

Iainc has it. You can’t change the reach on a frame. It’s got nothing to do with where the bars are


 
Posted : 19/11/2017 7:07 am
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Do you get points for the right answer if your working out is wrong?
You can alter the reach of a frame, by putting longer forks on for example.
In this situation though, I’m with northwind and CCG. You won’t notice any difference.


 
Posted : 19/11/2017 7:26 am
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Maybe it would be more useful if Reach and its brother Stack were seen as "bicycle" measurements, rather than "frame" measurements. Would clear up a couple of correct answers.


 
Posted : 19/11/2017 7:31 am
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By that logic you can alter the reach of the bike by having a flat tyre...though it can be confusing when you consider frame reach (an attribute of the bike) and rider reach (an attribute of where the bars are - which is dependent on the forks, stem, angleset, tyre pressure etc

Stack / Reach is really about what size a frame is in comparison to other frames


 
Posted : 19/11/2017 7:39 am
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Although I think the outcome is the same - either the reach doesn’t change (cos it’s fixes) or it changes so little that you won’t notice it


 
Posted : 19/11/2017 7:46 am
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As reach and stack are related to horizontal/vertical distances, not actual tube measurements, they are not fixed. If you play with the head angle, fork length, have a flat tyre or compress your suspension, then yes they will change. But you're right, it's not by much so I wouldn't worry about it.


 
Posted : 19/11/2017 7:53 am
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4 answers - only one correct

Iainc has it. You can’t change the reach on a frame. It’s got nothing to do with where the bars are

Where is the face palm emoji when you need it? 😉

The replies from Northwind and me did not mention the handlebars and we were correct because you absolutely CAN change reach (and stack and effective top tube) on a frame by changing the vertical height of the fork. This can be done by changing the fork length (or the lower headset cup height) or by changing the head tube angle (with an angleset).

The lower the vertical fork height, the more the frame rotates forwards, decreasing stack and increasing reach. However if you purely use an angleset to do this the upper cup rearward offset cancels out your increased reach.

It's all right angle triangles. Think.


 
Posted : 19/11/2017 8:05 am
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Thread of the year


 
Posted : 19/11/2017 8:07 am
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My answer was perhaps overly simplified, but as per mine, and some subsequent replies, it won’t change, well maybe a little bit, based on geometry, in fact about 3mm horizontal for every 100mm vertical 😀


 
Posted : 19/11/2017 8:45 am
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I’m with reach and stack as bike measurement rather than frame.


 
Posted : 19/11/2017 8:47 am
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in fact about 3mm horizontal for every 100mm vertical

Computer says no.


 
Posted : 19/11/2017 8:50 am
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Oh well, socahtoa, where tan = opp/adj, and if the angle is 2 degrees.....tan 2 x100 = 3.49.

Though that is just the horizontal effect...


 
Posted : 19/11/2017 8:57 am
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We had this question last week and we discovered lots of people really don't understand what they are on about.

It will increase reach but you'll probably not notice as top headset will counteract most of it when it comes to bar placement.

I think when I put a -2 on mine my bars moved 3mm.


 
Posted : 19/11/2017 8:58 am
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Oh well, socahtoa, where tan = opp/adj, and if the angle is 2 degrees.....tan 2 x100 = 3.49.

Though that is just the horizontal effect...

So will the front wheel mysteriously levitate to keep the frame at the same angle as before?


 
Posted : 19/11/2017 9:01 am
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And this is why the reach and stack are only really for comparing frames

So actually the OP is the one who’s asked the wrong question


 
Posted : 19/11/2017 9:18 am
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Chief, no, you are correct, though it is only a matter of millimetres 😀


 
Posted : 19/11/2017 9:41 am
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Maybe it would be more useful if Reach and its brother Stack were seen as "bicycle" measurements, rather than "frame" measurements. Would clear up a couple of correct answers.

^^This^^

In fact I believe we should use more full bicycle measurements when comparing bikes rather than the tube lengths and angles that were probably more use to someone setting up a jig...

So actually the OP is the one who’s asked the wrong question

As I'm fond of telling my kids there are no "wrong" questions...

it is only a matter of millimetres

It always is with these things, apparently the devil is in the details though...

Thinking about it OP, would rotating your bars forward in the clamp by a degree or two not counteract the effects on 'reach' to some extent? Or is that a bit simplistic...


 
Posted : 19/11/2017 9:57 am
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There is often only millimetres in reach difference between a small and xl frame. Eg for my 26 Bandit the reach varies by about 20mm between sizes.
379, 400, 423, 444.
It seems like nothing when you look on a ruler but you do feel the difference going from one size to another. I notice stem length changes of 10mm, perhaps 3mm will be more subtle.


 
Posted : 19/11/2017 10:24 am
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Chief and NW are correct.


 
Posted : 19/11/2017 12:51 pm
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cookeaa>>>

In fact I believe we should use more full bicycle measurements when comparing bikes rather than the tube lengths and angles that were probably more use to someone setting up a jig...

Effective top tube, bb drop, reach, stack, wheelbase, head tube angle and seat tube angle are full bike measurements. The only tube length measurements used much in published data these days are seat tube and head tube lengths (which are both useful in their own right) and chainstay length, which is generally so near to rear wheelbase as not to matter, and is also a useful dimension in its own right. No tube-to-tube angles are commonly quoted. Actual top tube is used by some, but most manufacturers don't give it these days.


 
Posted : 19/11/2017 1:08 pm
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tmb467 - Member

By that logic you can alter the reach of the bike by having a flat tyre...

Correct. Or more realistically, by changing fork pressures


 
Posted : 19/11/2017 2:07 pm

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