Rear wheel travel

[noob-saibot]

When 'rear wheel travel' figures are quoted for bikes does this indicate the total travel for the rear shock spring. If this is the case would in around 130mm be an decent average figure for a sportsbike?

[racerhead]

Originally Posted by noob-saibot

When 'rear wheel travel' figures are quoted for bikes does this indicate the total travel for the rear shock spring. If this is the case would in around 130mm be an decent average figure for a sportsbike?

The rear wheel travel is the amount of movement measured at the rear axle of the bike.

The rear shock would only have a small amount of movement depending on the linkage set up but for most sportsbike's about 45-60mm at the shock.

And yes 130mm is about average for most modern sportsbike's
To view pics on this biker's forum - your post count must be 2 or greater.

[noob-saibot]

So for figures sake, if a sports bike has a rear wheel travel of approx 130mm and riders sag is usually set to approx 35mm than that's 26.9%. So 26.9% of a bike with a quoted rear wheel travel of 170mm is 45.7mm, which would be the riders sag for this bike. Have i got that right?
To view pics on this biker's forum - your post count must be 2 or greater.

[racerhead]

45mm would be a pretty big sag number. 30-35mm is the ball park figure for the rear end on most road bikes but as said below its alot to do with what feels good to you
To view pics on this biker's forum - your post count must be 2 or greater.


Here's a small extract from a race tech book

t's important to stress that there is no magic number. If you like the feel of the bike with less or more sag than these guidelines, great. Your personal sag and front-to-rear sag bias will depend on chassis geometry, track or road conditions, tire selection and rider weight and riding preference.

Using different sag front and rear will have huge effect on steering characteristics. More sag on the front or less sag on the rear will make the bike turn more slowly. Increasing sag will also decrease bottoming resistance, though spring rate has a bigger effect than sag. Racers often use less sag to keep the bike clearance, and since roadraces work greater than we see on the street, they require a stiffer setup. Of course, setting spring sag is only first step of dialing in your suspension,

[noob-saibot]

Originally Posted by racerhead

45mm would be a pretty big sag number. 30-35mm is the ball park figure for the rear end on most road bikes but as said below its alot to do with what feels good to you
To view pics on this biker's forum - your post count must be 2 or greater.


Here's a small extract from a race tech book

What i'm getting at is a basic riders sag for the ktm duke 2 as there's no real figures specified.

It's got more 'road based' suspension than the motocross and sm ktms but its rear wheel travel is 170mm which would lead me to believe it should have a bit more riders sag than a 'normal' road bike but less than a dirt or sm ktm, hence the percentage based estimations.

[noob-saibot]

Can anyone advise any more or pick any holes in the logic?

[chopper]

Just ride the feckin thing

[noob-saibot]

Originally Posted by chopper

Just ride the feckin thing

standard response to every workshop thread
To view pics on this biker's forum - your post count must be 2 or greater.


more curious about the logic than anything else..

[2strokey]

Re: Rear wheel travel

heres mine on a recent trip to spain
To view pics on this biker's forum - your post count must be 2 or greater.

[hotboxzerox]

To view pics on this biker's forum - your post count must be 2 or greater.


this site throws around a figure of 3.75 inchs/95.25mm for sag for a 200lb rider.


To view pics on this biker's forum - your post count must be 2 or greater.


this one says 20mm static sag and 45mm with rider on it.


To view pics on this biker's forum - your post count must be 2 or greater.


has a little section on suspension set up for 80kg rider.

[noob-saibot]

Originally Posted by 2strokey

Re: Rear wheel travel

heres mine on a recent trip to spain
To view pics on this biker's forum - your post count must be 2 or greater.

why has he got a ball sack in his drink
To view pics on this biker's forum - your post count must be 2 or greater.



To view pics on this biker's forum - your post count must be 2 or greater.

Originally Posted by hotboxzerox

To view pics on this biker's forum - your post count must be 2 or greater.


this site throws around a figure of 3.75 inchs/95.25mm for sag for a 200lb rider.


To view pics on this biker's forum - your post count must be 2 or greater.


this one says 20mm static sag and 45mm with rider on it.


To view pics on this biker's forum - your post count must be 2 or greater.


has a little section on suspension set up for 80kg rider.

See, very different figures knocking about. The two bottom links are blocked in work so will have a looksee when i get home
To view pics on this biker's forum - your post count must be 2 or greater.

[racerhead]

Originally Posted by noob-saibot

So for figures sake, if a sports bike has a rear wheel travel of approx 130mm and riders sag is usually set to approx 35mm than that's 26.9%. So 26.9% of a bike with a quoted rear wheel travel of 170mm is 45.7mm, which would be the riders sag for this bike. Have i got that right?
To view pics on this biker's forum - your post count must be 2 or greater.

Yes that would seem about right as a percentage and as I had said in the last post its alot to do with personal feeling.

You can try it at 45mm and see how it feels but give it a try 35mm also and see if it feels any different/better.

Are you adjusting the front or what sag numbers are there?

[noob-saibot]

Originally Posted by racerhead

Yes that would seem about right as a percentage and as I had said in the last post its alot to do with personal feeling.

You can try it at 45mm and see how it feels but give it a try 35mm also and see if it feels any different/better.

Are you adjusting the front or what sag numbers are there?

Haven't thought of the front yet tbh. Pretty sure there's no external sag adjustment, only comp and rebound so don't know whats the story there. Just wanted to get the rear to around standard first.