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Discussion Starter · #1 ·
I have a 2013 stumpjumper fsr comp carbon 29er. The specs say it has 69* head angle. With my phone it measured 68*. I wanted to slacken the head a bit more and increase travel so I changed my 130 fox float to a 150 pike. Now my head angle measures 69*. Somehow got steeper. Am I missing something?
 

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Those phone inclinometers aren't very accurate. I'd recommend using a plumb bob and a tape measure and break out your high school SOHCAHTOA. Tape a yard stick to your fork to get an exact measurement of where it intersects the ground. Then subtract your fork's offset. If you really want to get close, remove air till your fork rests at natural sag. This still won't be perfect but close(er).

I have typically seen around .7 degree slack for every +10mm a2c. Also remember +10mm travel does not always mean +10mm axle to crown. Different forks have different a2c's.
 

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Discussion Starter · #4 ·
I haven't tried it yet. I will see if I can get some trail time today. As far as the phone goes, I tested it on my sx trail and it is still giving me the same numbers as before. Before making the purchase I tested my brothers 140 pike from his stumpjumper evo and I got a 1* slacker change and I liked it. The 150 I put on now is reading 1* steeper. I know the phone is not the most accurate, but I wondering if there are other factors. Would fork offset play any role? Do different forks have a different angle that they enter into the crown? I am measuring off the sanctions.
 

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A smartphone is a pretty poor tool to use as an angle-finder. I'd bet it's not too consistent.

Go get an analog one for $10 if you're concerned, but it's really the ride that matters, not the angle of the dangle.
 

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As others have said, make sure you were on absolutely level ground, measure the angle off the centre of the HT top and bottom, not the fork. Basically I'd use some blue painters tape run right down the centre of the HT, level ground and have a go. Another thing to remember is that just because one brand fork has "X" travel, doesn't mean that another brands "X" travel fork will have the same A2C, so check the actual A2C of the old Fox and the new Pike, also measure exposed stanchion and make sure the fork is actually a 150mm and not shorter.
 

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Discussion Starter · #9 ·
Thanks. I have been making all measurements in the same place in my garage, so trying to keep all things equal. I did look at the A2C before purchasing and the pike is longer. It also appears to be 150mm. It has a label on the back. The sanctions have labels as well for setting sag and it says 160mm.
 
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