How much does rider weight affect travel/taper benefits?

jehosophat

It seems pretty clear that tapered head tubes and bolt-through axles are stiffer, and also that logically one ought to be faster downhill or across the gnarly stuff with more travel.

One thing I rarely see mentioned in mags is the effect of rider weight on this. If I am 70kg and my riding buddies 90kg, am I effectively getting the same suspension benefits on my 130mm F/115mm R trail bike as they are on their bikes with 140 or 150mm at both ends?

Having a pair of DT Swiss 130 1 1/8th QR forks I like, I also wonder how many benefits I will honestly see from tapered and newer axles too...

Interested to know from 70kg ish riders who have gone from good quality older spec kit to tapered/12mm axles and longer travel...

cooldad

Depends, depends, depends.

chez_m356

thats why you can change the air pressure in air forks and why you can get different strength springs for coil forks

Giraffoto

Well. . . . your suspension's job is (partly) to dissipate the energy of you and your bike hitting bumps/roots/the ground. At the same speed, a lighter rider will have less energy. The 15mm through-axle and tapered steerer are (partly) to resist bending forces. A lighter rider will, at the same speed and while putting in the same effort, apply less force.
However, there is a factor that cancels this out: you're likely to try rougher and bumpier trails and higher speeds until you're getting the full travel out of your suspension. It's human (or at least, cyclist) nature.

Long story short: don't downgrade

jehosophat

It seems logical to me that a heavier rider would benefit more from more travel, and possibly suffer less from the resultant greater "bob" as they generate more power and will be less affected by losing a few %.

One guy I sometimes ride with must be getting on for twice my weight - let's guess 120kg to be kind. Yes we could both ride 100mm bikes and set them up right so we had the right sag and were using the full range of travel, but his is having to do a very different job and I can't believe the bikes would feel the same to us.

I ask as I always assumed I would go to a 120-140mm trail bike next but if I set up the (115mm) Blur with the recommended sag, so that I am (just!) using all the travel on really rough terrain, it feels a bit soft to me on the climbs. Not terrible but enough to annoy me. And the 130mm forks are definitely borderline on smoother sections and climbs (though a lot better overall than the 100mm before them). Now seriously considering a well sorted 100mm with 120mm forks (Anthem, Blur XC, etc)

The other possibility is a 29er with 100mm - again I would think heavier people would benefit more from big wheels, the extra weight and rolling resistance would be more of a hassle for a lighter rider, potentially slowing each acceleration.

miss notax

I don't have the answer to this but I have pondered the same things about rider weights.... I weigh about 56 Kg and struggle to get the right set up with some forks, namely because I literally can't take any more air out!!

29ers are not an option for me as i'm only about 5ft 4" - regardless of what they say about them fitting all sizes I am not convinced

nicklouse

jehosophat wrote:

It seems logical to me that a heavier rider would benefit more from more travel, and possibly suffer less from the resultant greater "bob" as they generate more power and will be less affected by losing a few %.

why? set the bike up correctly.

One guy I sometimes ride with must be getting on for twice my weight - let's guess 120kg to be kind. Yes we could both ride 100mm bikes and set them up right so we had the right sag and were using the full range of travel, but his is having to do a very different job and I can't believe the bikes would feel the same to us.

sounds like it was not set correctly. they should do the same and feel the same.

I ask as I always assumed I would go to a 120-140mm trail bike next but if I set up the (115mm) Blur with the recommended sag, so that I am (just!) using all the travel on really rough terrain, it feels a bit soft to me on the climbs. Not terrible but enough to annoy me. And the 130mm forks are definitely borderline on smoother sections and climbs (though a lot better overall than the 100mm before them). Now seriously considering a well sorted 100mm with 120mm forks (Anthem, Blur XC, etc)

so reduce the sag. How much have you now?

The other possibility is a 29er with 100mm - again I would think heavier people would benefit more from big wheels, the extra weight and rolling resistance would be more of a hassle for a lighter rider, potentially slowing each acceleration.

Why? the changes are the same for any size rider.

jehosophat

It is hugely simplistic to say these factors affect all riders the same.

Two obvious ones:

1) Bike weight. If rider A weighs 120kg and buys a bike 2kg heavier than the last one, he will feel that a lot less than rider B who weighs 60kg and buys a bike 2kg heavier. The extra weight is a much smaller % of rider A's combined body and bike weight.

2) Rider power. If rider A generates twice the power of rider B, but the extra power needed to accelerate a heavier bike (say a 29'er with heavier wheels) is a constant, then rider A will feel it a lot less than rider B.

If your start point in terms of weight and power is much higher, the gains of lighter weight are much less - but it seems logical the gains of tapered head tubes, through axles, and so on are higher.

Whether the suspension action feels different for a given travel is much more subjective but with vastly more energy to dissipate I would expect short travel to struggle a bit with heavier riders and potentially more travel to be wasted on lighter ones.

Yes I have reduced the sag on the Blur - which makes me wonder, if I am not wanting to use the whole of 115mm, why buy a bike with more? Especially when VPP is a pretty good (if very "active" setup) - if I run the single-pivot Superlight anywhere near the sag levels of the Blur it suffers much more from bob, and over reacts to medium and bigger bumps, wallowing through it's suspension in a way the VPP does not (and yes I have run the exact same shocks on both bikes in the interest of science - handy when they are the same size!).

chez_m356

jehosophat wrote:

Whether the suspension action feels different for a given travel is much more subjective but with vastly more energy to dissipate I would expect short travel to struggle a bit with heavier riders and potentially more travel to be wasted on lighter ones.

air pressure and spring rates mate, you seem to be overlooking quite an important factor, suspension travel and action tends to be designed to cope with the various kinds of terrain, not how fat the bloke on top of them is

supersonic

I agree, travel is not a function of weight, but spring rates and dampers are.

craigw99

for cars unsprung mass also has an effect on things so the heavier rider may get better action out of the suspension as they have increased the sprung mass.
as for me i still dont know why you should run 30% sag seems like wasting good travel that could be used for bigger drops or am i missing something :?:

supersonic

Sag allows the suspension to drop into dips and hollows, increasing traction. Also some full sussers have a sweet spot where the bike pedals better.

With longer travel, running too little sag often results in the fork never achieveing full travel. Longer forks tend to have better high speed valving too.

toasty

supersonic wrote:

I agree, travel is not a function of weight, but spring rates and dampers are.

Exactly this, damping especially. I'm 6'6" and about 14 stone and ride the biggest bikes I can find, the missus is the other end of the spectrum and rides the smallest generally.

I find that smaller shocks, with big leverage ratios, I can't set the rebound up properly for myself. My old Enduro used to have a silly 165mm shock and slightly too much travel, even on max the damping was rubbish. On the flip side, due to being on the other side of the spectrum, I found it awkward getting the missus rear shock smooth, without having far too much rebound damping.

That said, that was from new, the shock seems to have loosened up a bit now.

I don't think it's really something that would make much difference unless you were at either extreme to be honest. They cover a healthy range.