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Hello how come full suspension bikes have 10mm less travel in the rear usually? For example 140mm fork 130mm rear travel. It seems that way for every bike. There must be a reason, right?
Suspension numbers
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Because bikes tend to ride better that way, for a number of reasons.
Here's my attempt at explaining some of those reasons: most of your weight is on the rear suspension, and you have legs to help absorb much of the impact, so you don't need as much back there. A lot of suspension back there can also sap some of your pedal power, although that has become less of an issue with most modern bikes. Up front, if you're riding really rough stuff, a little more travel gets you a bit more forgiveness in the front end and a bit more capability. You lose less power with increased front suspension. Your front suspension has to work a little harder in big rough stuff because there's less weight on it, your arms aren't quite as good at absorbing bumps as your legs, and stuffing your wheel could mean OTB.
Bottom line - slightly less travel rear compared to front makes the bike feel a bit more balanced.
Here's my attempt at explaining some of those reasons: most of your weight is on the rear suspension, and you have legs to help absorb much of the impact, so you don't need as much back there. A lot of suspension back there can also sap some of your pedal power, although that has become less of an issue with most modern bikes. Up front, if you're riding really rough stuff, a little more travel gets you a bit more forgiveness in the front end and a bit more capability. You lose less power with increased front suspension. Your front suspension has to work a little harder in big rough stuff because there's less weight on it, your arms aren't quite as good at absorbing bumps as your legs, and stuffing your wheel could mean OTB.
Bottom line - slightly less travel rear compared to front makes the bike feel a bit more balanced.
That's true, bur the reason is different. The rear travel is vertical travel, that's how all the manufacterers measure it. On the front you would have 140mm of vertical travel if the steering axis was at 90° but it isn't. If you do the math 140mm fork on 65° HTA gives you roughly 128mm ot vertical travel. On a slacker bike I would go for +20mm in the fork to maintain the same balance.
Now THAT I understand!!
Well, you learn something every day.
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On some downhill bikes there is more travel rear than front. My 2017 Jedi has 230mm rear. I believe v10s were 240mm rear, both with 203mm in the front.
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305 Posts
Mine as designed has 160f and 163 rear...so yep.
-Paul
-Paul
My previous bike was 160f/165r with really high leverage ratio at the begining (3:1) . The recommended rear sag was 35% which is measured at the shock, once you multiply it by the leverage rate you get around 53mm of sag at the wheel. My current bike is 160f/140r with leverage ratio of 2.4:1 and recommended sag of just 18%. So my point is that travel alone doesn't give us the full picture.
ok so I don’t do maths so good.What ifyou were running 160mm front travel with a 65* HA. What’s the formula?
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For those of us that don’t like math, 90% of front travel is a good approximation for typical trail bike HA.
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