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trail bike shock tune....

saruti

Turbo Monkey
Oct 29, 2006
1,145
67
Israel
Sorry for this unrelated question
But in other forums people don’t really know about these things.
I ride an iron horse MKIII for the last 6 years for AM rides
I want to buy a new trail frame/bike. And was thinking about the giant trance x .
The maestro link is a lot like the DW link so I figured it will need a low compression tune.
Am I right?
I rode a friend trance x bike yesterday. He swapped the original rear shock to a kashima shock with M tune. And doesn’t remember what tune the original shock had…
It felt good. But I think it will feel even better with a low tune.
What do you think?
The leverage ratio of the trance x is progressive.

thanks guystrancex.jpg20121031_150050.jpg
 

6thElement

Schrodinger's Immigrant
Jul 29, 2008
4,997
2,579
I thought the Trance was 5" with a 1.75" stroke, so how can it have > 2.86 leverage ratio?
 

-BB-

I broke all the rules, but somehow still became mo
Sep 6, 2001
4,256
28
Livin it up in the O.C.
what do you mean?
why cant it be?

thanks.

He is saying that bc 5/1.75 is 2.857.... So if it were linear it would have a 2.857 LR. It isn't linear so the ratio curve can be above and below 2.857, but it has to average out to that number. From the graph you posted it appears that the curve is way over 2.857 for the majority of the travel and then just a tiny bit below for the end stroke. So the average is probably well above 2.857 across the curve. I thik that is what is causing him to question. I'm no shock expert, but it makes me question as well.
 

Steve M

Turbo Monkey
Mar 3, 2007
1,995
23
Whistler
He is saying that bc 5/1.75 is 2.857.... So if it were linear it would have a 2.857 LR. It isn't linear so the ratio curve can be above and below 2.857, but it has to average out to that number. From the graph you posted it appears that the curve is way over 2.857 for the majority of the travel and then just a tiny bit below for the end stroke. So the average is probably well above 2.857 across the curve. I thik that is what is causing him to question. I'm no shock expert, but it makes me question as well.
The Linkage files for a lot of short link bikes like that are not that accurate (and in some cases, neither are manufacturer stated numbers for travel), so don't rely too much on the numbers you find in there unless you've measured stuff up for yourself. The files you find in there are usually handy for getting a vague idea of what a bike's characteristics are like, but trying to actually numerically derive useful information from them is no use whatsoever unless the input geometry is accurate. The shorter the links, the less accurate the Linkage files usually are (for example, the Sunday ones are way out of whack with reality). Measure the bike up yourself, put the points into the Linkage file and then have another look. A good indicator of accuracy is usually whether the shock length comes out close to its stated size (or approx 2mm shorter if it's a Fox air shock).
 

Udi

RM Chief Ornithologist: “I Brake for Birds”
Mar 14, 2005
4,776
929
-BB- is correct, however the discrepancy lies in one of two factors:

1) Manufacturer has declared the actual travel value falsely. Probably not the case here, but it has happened in the past.

2) Linkage graph is inaccurate. Most bikes are generated by mapping points on a photograph of a frame, which is particularly inaccurate for bikes with short links, like the Trance. You can increase accuracy greatly by measuring a frame in some sort of jig, but that doesn't apply to the majority of bikes in the Linkage library. It's worth noting that this isn't a fault of the program, rather "garbage in, garbage out".