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meow meow
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Discussion Starter · #1 ·
so heres the deal: i have an 08 jamis xam and love everything about it but the 68.5 ha. i find it to be just a bit too steep for what i ride (and honestly i think its fairly silly a 150mm bike was designed with a steeper ha but hey, im no engineer). anyways i would love to slack it out some so im thinking of two options: 1, get a x fusion vengence, the a2c is about 10mm more than my 55 and 20mm would slack it out a degree right so i would get half a degree right?. and 2, wait for the 44mm angleset. im kinda hesitant on that cuz ive only heard rumbles on the internet and really have no clue how viable an option that would be. if you read that whole thing thanks, any insights as to what to do?

*spark notes: want to slack my 08 jamis xam out a bit. how should i do it? :thumbsup:
 

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meow meow
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Discussion Starter · #6 ·
mullen119 said:
From what I can tell, half a degree will be pretty accurate, The only downfall will be the seat angle changing as well. I would lean towards the new fork rather then the angleset if it was me.
thats what im thinking too. either a vengeance or a 170 lyrik. any input on either?
 

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I've had better luck choosing a shorter rear shock than a longer fork, unless the bike is too low in the BB height anyway. The advantages of lowering your BB as well as slacking out your head angle make a much faster bike and outweighs the slight loss in rear travel. I've done it by buying a shorter shock and by buying a shorter shaft and modding the shock - pretty easy with a dhx or manitou where the rebuild guides are online - this way also gets you used to stripping and rebuilding the shock so you are more likely to start playing with the shim stack to perfect your damping.
All that being said - the angleset is going to be a great tool on many bikes. In fact I'm planning a bike with a shorter shock AND an angleset!
 

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meow meow
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Discussion Starter · #8 ·
weedkilla1 said:
I've had better luck choosing a shorter rear shock than a longer fork, unless the bike is too low in the BB height anyway. The advantages of lowering your BB as well as slacking out your head angle make a much faster bike and outweighs the slight loss in rear travel. I've done it by buying a shorter shock and by buying a shorter shaft and modding the shock - pretty easy with a dhx or manitou where the rebuild guides are online - this way also gets you used to stripping and rebuilding the shock so you are more likely to start playing with the shim stack to perfect your damping.
All that being said - the angleset is going to be a great tool on many bikes. In fact I'm planning a bike with a shorter shock AND an angleset!
but what size would i go with? i have a 7.825x2.25 now. if i put on a 7.5x2 what kind of numbers am i looking at? also there is a ton of used totems for cheap, im thinking of grabbing one of those and lowering it.
 

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b-kul said:
but what size would i go with? i have a 7.825x2.25 now. if i put on a 7.5x2 what kind of numbers am i looking at? also there is a ton of used totems for cheap, im thinking of grabbing one of those and lowering it.
You would be looking at a loss of 18.5mm of rear wheel travel assuming you have a straight rate suspension design. The good part about trying this method is you don't need to buy a new shock. Take the air can off and add 1/4 in to the top out bumper and you essentially have a 7.5x2 shock. Doing this would still change the seat tube angle by about a half degree, but like said by weedkilla1, It would lower the BB by about 4mm rather then raise it the same amount. Buying the vengence, lyric, or totem would offer a performance upgrade in the front over a 55 tst2 and help with your H/A problem as well. Its a tough call.
 

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meow meow
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Discussion Starter · #10 ·
ould it change the ha by .5 of a degree too? what im thinking no iw get a ventana +7 crown race and latter on down the road get a vengeance or lyrik. that should bring me to around 67.5 and like you said it would be an upgrade over the tst2. am i missing anything? the crown race would work with an inset fsa headset right?
 

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If the travel changes by 18.5mm (there is a bit of guess work here) you should lose 1degree on the head angle. What shock are you running? The topout bumper mod is great for trying it - costs nothing and takes very little time. Buy yourself an angle finder at the hardware store, measure everything, write it down and compare after the mod. Some shocks dont play that well with a longer topout bumper as it doesn't let the damper use the topout circuit in the rebound. (Poor description - but I know what I mean). If its an air shock you wont be able to see if it will affect your rebound - but you wont hurt anything by trying and if it feels normal when you ride it then your gold.
A 7.5x2 is slightly shorter when compressed than a 7.875x2.25, take your shock out and cycle the suspension until you have an eye-eye distance of 5.5" and make sure nothing hits before you buy a new shock.
Obviously no issue if you just shorten the shock you have - as it will bottom out at the same point.
 

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Not a damper I have opened sorry. Looking at the link here - http://forums.mtbr.com/showthread.php?t=491668 - I reckon it wont be too hard to pull the air can and add something to the top out bumper by making a sleeve to fit over the main shaft and sit against the big siler flange, compressing the shock slightly when its put back together. Looking at the damper rod you can see the ported hole for the top out cicuit, which wont get uncovered with the shock being restricted from extending completely. It may top out with a bit of a clunk, so it may just be a mod to see if you like the angles. May be fine - just warning you :)
The links to "shimming" usually are just to reduce the air volume - this is not what you want to do, dont know what you are looking at so just a guessing a bit.
 

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The 18.5mm travel loss is found like this: 150mm travel divided by 57mm(2 1/4''shock stroke) = 2.63(leverage ratio)....... 2.63 x 50 (new 2'' shock stroke) =131.5mm which would be your new total travel.... which would be a loss of 18.5mm of travel. Its not a guess, Its simple math with the only variable being if there is a raising or falling rate design which could make it a little more or less then the math shows. But not enough to be note worthy. All that being said, changing the shock is a good free/cheap way of trying to get the slackened HA you are looking for, But if you ride aggressive enough to want the slack HA, You probably want the travel in the back. I dont know much about the angle sets, but If budget is the issue, I would go that way. Other wise I would buy the longer fork, maybe both over time.
 

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meow meow
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Discussion Starter · #15 ·
ok, thanks for all the help guys. but im still confused. where exactly is the top out bumper located? and im okay with losing some travel but not crazy about it. i would rather shorten it by 1/8'' and get the ventanana +7 crown race. but will the crown race match up to my current headset (fsa z inset)?
 

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b-kul said:
ok, thanks for all the help guys. but im still confused. where exactly is the top out bumper located? and im okay with losing some travel but not crazy about it. i would rather shorten it by 1/8'' and get the ventanana +7 crown race. but will the crown race match up to my current headset (fsa z inset)?
the top out bumper is located in the bottom of the air can on top of the stanchion seal. im not sure if the crown race will work or not.
 

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meow meow
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Discussion Starter · #17 ·
mullen119 said:
the top out bumper is located in the bottom of the air can on top of the stanchion seal. im not sure if the crown race will work or not.
alright thaks. i think i'll reduce it by 1/8'' so i only lose about 9mm of travel and reduce the ha to 68 and look around for a good deal on a 170 lyrik or vengeance to slack it out to 67.5. does this sound like a good plan to everyone?
 

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meow meow
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Discussion Starter · #18 ·
ok, sorry for the noobish questions, i think this is the last one. but all i have to do to shorten the shock is unscrew the air can and put a 1/8'' spacer between the bumper and seal similar to limiting the travel on a fork?
 
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