Suspension heaters

[FROSTY]

I never really thought about this before. Ok you rock on up to a track day and first session you go out and the bikes as stiff as a board. So you head in -soften everything off and head back out.
The shocks warm up and now everythings spongy pud.
Especially for winter racing/trackdays I could see shock heaters of some sort being the ducks nuts.
Ok either I'm nuts or This has been thought of and done well n truely already

[CookMySock]

Ok either I'm nuts or This has been thought of and done well n truely alreadyShit I might just go patent that. Why tell everyone?

Steve

[Kickaha]

Ok either I'm nuts or This has been thought of and done well n truely already

Both of those options are true

[Tony.OK]

Too late fullas............already available.

http://traxxionstore.com/detail-68.aspx

[FROSTY]

no mate--going is present tense--GONE is past---more likely methinks

[Robert Taylor]

Too late fullas............already available.

http://traxxionstore.com/detail-68.aspx

Ive had one of these Traxxion shock warmers for more than a few years. Frankly, on TTX36 which have hydraulic preloaders on them ( shrouding the main body tube ) its a waste of time. All you are doing is heating the hydraulic preloader, unless you perhaps had it on the shock for maybe 90 minutes or more....
Especially during winter series racing shock response is very lethargic at cold ambient temperatures, considering that their optimum operating temperature is in the 50 to 65 degree celsius zone. Going out in first practice on a cold lethargic shock can often overstress your tyres, especially when there is already trouble enough precluding cold shear in the often cold temps we race in.
Hayden Fitzgerald in fact came up with the best and most obvious idea, place a cheap fan heater underneath the bike and shock! The next worry then is the antiquated electrical supply system in the old pit sheds at circuits like Manfield....

[FROSTY]

RT Im thinking more the front shocks. -theyre pretty stiff when cold

[Robert Taylor]

RT Im thinking more the front shocks. -theyre pretty stiff when cold

Ok, the reality is that forks run at ambient temperature or slightly below because there is so much mass of metal and its always in the cooling airstream. So on a cold FROSTY ( ! ) morning even though you may have preheated them they will be back down to ambient within a lap or two.
Cartridge forks are less susceptible because they have much more control and run much thinner oils that are less susceptible to thickening at colder temps. Dependent on the internal valving and some other factors the cartridges themselves will run with some warmth.
Damper rod forks such as we have in pro twins SV650s, ER6s etc are horribly susceptible to colder temps as they have to run much thicker oils in the range of 35 to 50 centistrokes at 40 degrees celsius . This because there is so much uncontrolled bleed and poor tolerancing and alignment issues in such low cost mass produced forks. The forks are VERY letahrgic first thing on a clear frosty morning but in the middle of the day when the sun is out they feel okay, the ambient temp may have shifted as much as 12 degrees or so.
Most effect is on rebound speed and arguably slow rebound is one of the biggest causes of crashes.
The answer is to have the forks proffessionally built so that internal clearance and alignment issues are minimised as much as is possible to reduce uncontrolled bleed, that then further reduces the need for thicker viscosity oils that are most affected by temperature shift.
And dont run cheap $20 bottles of oil! Theres a reason its cheap including in laymans terms a problem with it thickening too quickly as the barometer drops.
Of course I will be accused of saying ''you would say that'' but we have found the very best suspension fluids to be supplied by Ohlins and believe me we have tested almost everything readily available. We did some very subjective testing of fork oils in colder temps a few years back when we first started importing Ohlins oil, with Craig Shirriffs. He found he could go harder in the very first two laps because the forks were responsive straight away, this practically confirmed what we were told, that the flow properties at colder temps were excellent. Given that Ohlins manufacture a lot of snowmobile suspension units it is clear that they are very attentive to cold flow properties.
Hope this helps.....

[Pussy]

CHOPPA or Frenchy would be able to install a heat pump on the front of your bike.....

[Tony.OK]

Just as a point of reference and a little of track....and no Dr Bob didn't bribe me........when I put the stock cartridges back in my 08 Blade I used the same Ohlins oil as in my race forks. I was very surprised at the difference and compliance having "good oil" up front. I was expecting the same harsh feeling from the factory delivered bike, even more so having had the 25mm cartridges in prior.

For $60 odd bucks I'd not hesitate in future if I get another road bike in swapping the oil............great bang for your buck!

[quickbuck]

place a cheap fan heater underneath the bike and shock!....
Heat Gun fits nicely in the Swing Arm Brace of many bikes ;)

Yup, the Hydraulic adjuster did indeed make for a new challenge :)


Theres a reason its cheap including in laymans terms a problem with it thickening too quickly as the barometer drops.!....
Oh, yeah, you would say that..... :lol:

[quickbuck]

Too late fullas............already available.

http://traxxionstore.com/detail-68.aspx

Thanks Tony....
Bloody good Blurb in that link too!

[vifferman]

FWIW, if anything v-twins and v-fours tend to have the opposite problem, with heat from the rear header(s) overheating the rear shock.

[Robert Taylor]

FWIW, if anything v-twins and v-fours tend to have the opposite problem, with heat from the rear header(s) overheating the rear shock.

High shock temperature is not so much of a problem if a high quality shock is fitted that has exacting tolerances and material choices with differential rates of expansion that compensate for thinning out of oil , to temperature compensate. There are many ways that this is done, for example in many single tube shocks with a rebound adjuster at the bottom of the shaft the internal rebound rod that it is attached to is made of an alloy that expands at a slightly faster rate than the main shock shaft itself. As it expands it closes off the internal rebound bypass needle incrementally, maintaining as closely as possible the same damping performance as when the shock was colder. If you check the number of clicks when the shock is cold and when warm it can amount to 1 , 1 and 1/2 or sometimes 2 clicks less when hot.

In a road / road race bikes rear shock temperature will typically run between around 50 to 65 degrees celsius, sometimes warmer as Vifferman has correctly stated, if closer to the engine and headers and if there is shrouding and not too much airflow. Other variables that affect peak temperatures include how aggressive the internal valving is and if the shock is getting a real workout on bumpy surfaces. If also the spring rate is a little too soft and its riding lower in its stroke in the more accelerative part of the motion ratio implied to it by the linkage...
But in the mainstream the application in motorcycles is a lot less stressful than the rear dampers in formula cars. These will sit on top of very warm gearbox / differential casings and will opeate at 100 to 125 degrees celsius with no problems.
Consider also that a typical motocross shock will be subjected to 17000 compression cycles during EVERY SINGLE LAP of a typical MX track.

The message is the same, only use high quality oil and change it often, every 20 to 30 hours in an MX rear shock.

[quickbuck]

Consider also that a typical motocross shock will be subjected to 17000 compression cycles during EVERY SINGLE LAP of a typical MX track.

The message is the same, only use high quality oil and change it often, every 20 to 30 hours in an MX rear shock.

Mmmm, Another reason not to buy an MX bike that was "Never Raced".....
Also a very good reason for regular servicings of the shock.

[CTD]

Just as a point of reference and a little of track....and no Dr Bob didn't bribe me........when I put the stock cartridges back in my 08 Blade I used the same Ohlins oil as in my race forks. I was very surprised at the difference and compliance having "good oil" up front. I was expecting the same harsh feeling from the factory delivered bike, even more so having had the 25mm cartridges in prior.

For $60 odd bucks I'd not hesitate in future if I get another road bike in swapping the oil............great bang for your buck!

Tony, was the ohlins oil the same weight as the factory oil?

[Robert Taylor]

Tony, was the ohlins oil the same weight as the factory oil?

Yes, the centistroke rating at 40 degrees celsius is very close to oem. While Tonys findings are not as controlled as ours were with Craig Shirriffs he has noticed the same difference.

The only correct way to rate the flow properties of suspension fluids is by either the centistroke scale or the saybolt scale. SAE ratings that we see on bottles are misleading and are definitely not apples for apples but that is what the market is conditioned to. Its a flipping motor oil rating, not a suspension fluid rating. Consumers are fickle and wont always accept what would be a correction. Motul had multigrade ratings on many of their suspension fluids a few years back, nothing incorrect there except there was buyer resistance because consumers did no understand it.

For example, drain your SAE 5 Maxima out of your forks and instal SAE 5 Silkolene ....See how much you have to withdraw the compression and rebound clickers outwards to achieve exactly the same feel and performance. The Silkolene 5 ( a good quality oil ) has approximately the same centistroke number at 40 degrees celsius as Maxima 10. Its a ''thick'' 5.

We ( CKT ) do not even talk the SAE language for suspension fluids, only centistrokes. Its time manufacturers of suspension fluid all universally labelled the centistroke rating on the bottles. Ohlins do it and to the best of my knowledge only they ( my beloved viking friends ) do this...

[Pussy]

It's "centistoke", Robert!

You're welcome! :)

[Robert Taylor]

It's "centistoke", Robert!

You're welcome! :)

I deliberately mispelt it as you speak that language and I knew youd pick up on that!

[Pussy]

I deliberately mispelt it as you speak that language and I knew youd pick up on that!
You're picking on me now... not my fault I have a mild case of Tourettes. Fuck it!!

Back on topic... one 750 that lives in the shed here has the 20mm Showa cartridges in the forks (with the rebound mod)... and operate appreciably smoother with the Ohlins oil they have been filled with.

[Yankee Doodle Dandy]

I remember reading that a lot of NASCAR teams were using them as it helped them get up to speed and set up the shocks quicker.

[vifferman]

Back on topic... one 750 that lives in the shed here has the 20mm Showa cartridges in the forks (with the rebound mod)... and operate appreciably smoother with the Ohlins oil they have been filled with.
It's amazing how smooth the action is on my CKT-fettled forks too - courtesy of the expensive Ohlins BabyAfghaniLesbianFurSealPeguinWhaleOil, and some attention to making sure the internals have concentric and well-spec'd bits'n'bobs.