Back2Kill

Was riding yesterday and the temperture was mid 30's. I found the suspension on my FSR Stumpy very low on performance. Could it be the cold???

*The rear shock was barely able to hold my weight as if I let some air out. But, I didn't???? It was also very slow on compression and rebound.

*The front Manitou Black was also much slower in it's compression & rebound as if I had changed all settings. But, I hadn't???

The temperature must change the consistency of the oil. It must also lower the air pressure causing it to not hold my weight. So, do I need to carry my shock pump and adjust according to temperature? Any experience or ideas********** Thanks!

xcdhboy

The viscosity of any oil will be higher (i.e. thicker) at lower temperatures. I don't know alot about the oils used for suspension systems, but there may be some oils that are less sensitive to temperature than others over the range of temperatures in which you plan to ride. But any oil is going to be different at 90 degrees versus 30 degrees. The air pressure will also be lower at 30 degrees if you last filled it when it was very warm out...the same thing happens with your car tires.

So yes, you have to re-tune things for cold weather riding.

antman3249

same with my fork and my friends fs. my fork is stiffer and my friends bikes rebound sux.

Ricardo

Definetely oils are sensitive to temperature. Obviously it changes according to the oil formulation but in the case of internal combustion engine lubrication the oil is made so that when the oil is colder it gets thinner and viceversa.

Ricardo

Back2Kill

My biggest gripe is having the rear shock bottomed out just sitting on it. It was originally adjusted for my 235lbs at 75deg and rode great. Now at 30deg it's got nothin'?

When I made the jump to FS I never learned I'd be adjusting the air-pressure before (and during) every ride based on temperature!? Never had this problem with my coil-sprung motorcycles. Guess I'll be purchasing a shock-pump earlier than I was planning.

Raiyn

Your tires probably lost pressure too. Alert the authorities! Jack Frost is stealing air again! If you've lived above the frost line for any length of time you should know that devices that rely on pneumatic pressure lose pressure simply due to the change in temperature and that it's more dramatic the colder it gets.
Common sense would dictate that you should have purchased one when you bought the bike. It's not the bike's fault at all

Quadzone.com

my RST GilaT5 acted like a rigid fork at 30 degrees. It didn't hardly move at all about a week ago when I had it in PA. Glad It's been replaced.

nathank

i personally have never found the difference to be noticeable enough to warrant my re-adjusting anything -- but from Back2Kill's description sounds substantial.

it hasn't been clearly stated yet, so i will:

in general with cold:
a) air shocks become softer (i.e. air takes up less volume at lower temprature so like lower pressure)
b) oil forks become harder as the oil gets thicker with lower temperature

i would an air system you could simply adjust once for the winter season and then again for summer when it gets warm again. for coil/air forks you could change the oil (as most people in cold areas change the oil in a car for the winter) but this seems like a lot a effort...

pinkrobe

My $0.02... I have been out in temps down to -15C on a Stump Pro FSR with a Fox air shock, and it did get soft, but it certainly didn't completely go away. After I took it back inside and let it warm up, it would get a bit stiffer, but not back to the way it was. My guess is that the air seal became less "supple" as the temp drops, allowing the leak. The higher the air pressure, the bigger the gradient, and the more dramatic the change in pressure. This didn't happen with my Fox fork, but maybe the seals are better as its 4 years newer.

Back2Kill

Well, I do run a really high pressure to hold my weight and any slight loss makes a huge difference. It took along time to get the pressure dialed in when first purchased.

Suppose I'll make a personal pressure chart based on current weight and temperature. That way before every ride I can refer to it and be happy about its performance.

Thanks for the input. I'm an old-school hard-tail guy and I'm still trying to get comfortable with rear suspension.

jscott

I agree with Nathank no real noticeable difference. I actually slowed down the rebound a bit on the rear.

EXR PRO Marrazochhi and Fox Float R.

Just a thought, may be some of the change is more due to maintance. I clean and check and repressure about every 200 km.

Raiyn

It doesn't work that way. I know for a fact from personal experience you can't expect to adjust an air shock once per season and not have to deal with it again. The original poster or ANY rider should always take the time to check the pressures at the tire and suspension before any ride. On a side note the should also do a quick once over to include quick releases and brakes before you take off. Better to find a problem before you start out than mid-ride. I know I'd rather fix my bike in the relative comfort of my garage with easy access to the proper tools than being forced to fix it trailside with a multi-tool.

Back2Kill

Was able to spend 3hrs tearing up some singletrack today. I first stopped by the LBS and aired up the rear shock to 260lbs. Finally some support! Granted it was a warmer 50deg today, but the added pressure made all the difference. My ride included 15 miles of super-fast downhill singletrack strewn with rocks, drops, water crossings, and washouts. The suspension performed awesome. I would say it doubled my speed and control from my previous hard-tail. Yeah, I know I need a shock pump. But, Christmas is coming soon (hint, hint).

Anyway, thanks for all the pointers on the topic!

iamthetas

I rode Sat. morning( 32 deg.) and my bike was stiff as heck due to the oil being thick. I compensated by lowering the fork air . I rode today(75 deg.) with the same settings to start with and felt like I was climbing with a flat front tire and having a marshmallow for a fork, so I had to raise the air to compensate. the rear shock( FOX TALAS) had only a slight bit more sag on Sat than today and no difference in pedal bob while climbing. that is why I carry a shock pump in my water pack.

StonedGeologist

funny, I got the exact opposite just by leaving my bike out when at 11 degrees Celsius!

skoda2

Because it was 13 years ago!!😪

CabezaShok

temperature does not significantly affect true coil suspension. For a while they were making quality coil forks which worked fine in any temperature and were as plush as air forks. Sure they were a bit heavier, but if you don't race who cares...And they were a lot more reliable...a lot, but thats another topic

StonedGeologist

"at this very moment, I knew that I just ****ed up"