Rear Shocks, I2I, Stroke, Springs And All Of That Stuff.

[Radfax]

All of the bikes i have previously owned i have not had to fettle with the shock much, i have only ever removed them to have them serviced, refitted them and had some fun riding times. Any how I now need to replace a shock on one of my bikes and i need to know a bit more about them before i go out and buy something.

Now I understand the meaning of i2i but i am unsure on what stroke means?

When a spring is replaced does the stroke have to be taken into account or is it just a case of buying the suitable rating spring?

Now I have read up a little on this subject and come across a thread on another forum where people were using shocks which had a larger or smaller i2i and stroke sizes and it seemed to be a normal thing to do to slacken or lower the bike or the other way around.

Is it a common thin to use a different size shock in your frame?

Is any damage going to be caused if i use a shock which smaller or larger than advised?

I think that just about covered all of my questions for the minute.

Thanks

[haydon_peter]

TF Tuning - All you need to know about stroke, eye to eye and spring length is on this page.

Regarding shortening the eye to eye, what people are now doing is using offset shock bushings to reduce the effective eye to eye which in turn is dropping the BB and slackening the head angle, at the same time the stroke of the shock remains the same. You can also make this change using an angle reducing headset however using offset bushes is the cheaper option. You could read into this as much as you like but at the end of the day if you are happy with your bike there is no point in changing it really.

What bike is it for?

[Tomm]

Some frames will allow you to use longer or shorter i2i lengths, but you have to be careful. It's not difficult to mess up the geometry but worse case scenario (if you use a shock that's too small) is that the frame will bottom out on itself. Don't let that happen!

The i2i (or eye-to-eye) is the length of the shock from (the middle of) one mounting eye to the other. The stroke length is how much it moves. A common combination would be 200mm eye-to-eye and 50mm stroke (200x50).

If it's a coil shock you don't have to be that precise with the length of the coil shock since all shocks have a preload adjuster at the top end, so the coil can be +/- 10mm or so.

[Radfax]

Thanks for the replies! I have been doing a little more reading and think i may have come up with my answer.

I have spotted them off set bushings but ill explain the reason for this thread.

The Fox shock i have at the moment is a very basic shock that came on my IronHorse and it is like i say pretty basic with only 3 rebound settings and that is it. My last shock was a 5th Element and it was a lot more adjustable than what i currently have.

I was chatting with a friend who had a potential shock i could use and i wanted to know if it would fit.

My current eye-2-eye length from what i have measured is between 222/225mm (i cant seem to find my digital vernier so i am going from eye with this) which equates to around 8.5" I think. Unfortunately the shock i was looking at was around 241mm which we was working out at 9.5" which would raise the BB and head angle too much.

I have learnt a lot more now though so thanks for all of the help!