# Rear Wheel Travel - Definition



## ROB_V2009.1 (Jan 22, 2009)

Can someone explain rear wheel travel?


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## SurfSailRide (Dec 18, 2008)

"Travel" refers to the actual distance the rear wheel can move when the rear suspension is compressed. This is different than "stroke." Stroke refers to the distance that the shock's shaft compresses. Rear suspensions on different bikes use different ratios of leverage, which equate to different lengths of travel. For example, the stroke of the rear shock on my Specialized Enduro is only about 2 inches. But the 3:1 leverage of the linkage means that the rear suspension can compress a full 6 inches (of travel) when the rear wheel hits a bump. "More travel" (6"-10") means a plusher, more comfortable ride, with more control over big bumps and drops. Less travel usually results in more pedaling efficiency, since less of each pedal stroke's energy is lost to "suspension pedal bob." That's why a lot of XC racers ride "hardtails" with no rear suspension. On these bikes, nearly 100% of pedaling power goes directly to the back wheel.


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## ROB_V2009.1 (Jan 22, 2009)

*Rear Wheel Travel and Sag*

so regarding sag in the rear shock, essentially the less sag I have the stiffer my tail, the more force is transmitted from the pedal to the wheel?

I ask because I'm setting the sag of my rear suspension (GT iDrive 5) and the suggested tolerance for my shock is 15 - 30% of wheel travel (5.5"). Right now I have it set to 22%, which is just about middle. So, I basically have from 15 - 30% that I can play with to stiffen or soften my rear which in turn will determine how comfortable or how much power I'd like to have transferred to the rear wheel, correct? Forgive me if this seems like common sense - I'm very new to this.


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## PsyCro (Jun 8, 2007)

22% sounds like a good starting point for that bike. Although its not a problem to play around with it to see what works best for you. Try upping the sag to 25-27%. Itll give you a plusher ride, you might like it. If you have propedal or something similar you could try up to 30% for an even softer feel.. just turn propedal on if youre crankin the pedals. Just make sure its not so soft that you bottom-out the shock.. bottom-out is when the shock comes to the end of its travel aggressively, which is not good. 
Any firmer than 22% and your probably losing suspension performance.


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## SurfSailRide (Dec 18, 2008)

You're basically spot on.

Sag is (as you seem to understand) the amount of "stroke" that occurs due to the riders weight alone (not due to any other forces). So "15-30%" refers to 15-30% of the shock's stroke, with 15% being on the much stiffer side. If you're looking for a more efficient ride, I'd say stiffen up the shock by reducing sag. Just be sure not to go over the PSI limits for the shock, you you may inadvertently cause damage.

What kind of shock is it?


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## ROB_V2009.1 (Jan 22, 2009)

My rear is a Rock Shox Bar. IT came with the bike. Thanks for the info - makes sense.


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## SurfSailRide (Dec 18, 2008)

Well, you don't have "ProPedal" then (a feature on many fox shocks that reduces low speed compression rates to eliminate "pedal bob"), but play with the rebound as well. A slower rebound will give a stiffer feel.

I suggest getting out on the trails with your shock pump, and just playing around with different settings to determine the shock's range of tunability. After a few rides, you'll be able to tune it for your riding style.


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