I agree with proper fork oil and not engine oil - the latter foams when pushed through damping orifices, and then air does not a good damping medium make.
But 30W! ... ummm, how can I put this politely?
Alright, I'm an obviously-sylph-like 170-odd lbs. After much experimentation, my twin-front-disc T160's (100-odd lbs. heavier than a TR6) run 25W Bel-Ray fork oil and this works even two-up with luggage in up to 100-degrees ambient. My T100R runs 20W.
Originally posted by 649: triumph owners manual til 1970 (preOIF) recommends 30w engine oil...but what would they know
As I have pointed out in another thread, depending on which Triumph last updated "til 1970" manuals:-
1. Triumph as part of the BSA Group went out of business in about 1972;
2. Triumph as part of NVT went out of business in about 1976;
3. Triumph as the Meriden Co-op went out of business in about 1982;
4. Triumph built by L.F. Harris under licence went out of business in about 1988;
5. JR Technical Publications are currently licensed by the current (Hinkley) Triumph company - which owns the copyright to *all* publications bearing the Triumph logo; aiui, the licence specifically prohibits changes to the original text.
You will note that the aforementioned dates are all some years ago; you may be surprised to learn that people who actually ride old bikes have either continued development in a number of areas or have taken developments done by others and adapted them to old Triumphs. Fork damping fluid is one such area.
Originally posted by PLUG: Auto trans Fluid ATF
ATF is something recommended by one of the Triumph incarnations after 1970. However, afaik, it is of one viscosity, which means that it is ultimately suitable only for a narrow range of conditions.
For example, Triumph (as part of NVT) recommended ATF for the forks on a T160. However, if an owner (say, me) subsequently fits a second disc brake to the front wheel, loads the bike up with another adult and sufficient stuff to make being away from home for a week or two reasonably civilised, ATF is pretty hopeless as a fork damping fluid and the riding experience becomes less of a pleasure. As there is (and has been for a couple of decades) something both specific and better, why would one not use it?
No need to make a big issue out of it. I use 20 or 30 weight fork oil in my external spring forks. Rock oil and Silkolene make something suitable. 30 may sound heavy but it is for a certain design of fork. If you put 30 in another fork it may well be stiff as ****.
As 649 says 30w engine oil will be ok because the forks are the same as they were when made and if it worked ok then it will work alright now and I bet modern oil doesn't froth so much anyway. No need to tear him to bits Stuart.
You guys are missing the obvious. Fork oil is for forks that go up and down. Mine don't at least not very much. I ride on smooth roads. So, I use engine oil but not just any engine oil. I would have to drive all the way over to the other side of the island to get fork oil and I'm just not that annal. I can get the "purple" synthetic oil in or Syntech in any viscosity I want locally. I use them in the forks of my Triumph and my Norton. I just took apart the forks of my Norton after 6 years of use and the seals and bushings look brand new. Plus the forks are very smooth with almost no "stiction" I think I used 10-40 Syntech if I remember correctly. Cheaper than fork oil, too. Aloha, Bill
Bikes 1974 Commando 1985 Honda Nighthawk 650 1957 Thunderbird/T110 "Flying Tiger" Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
well Ive been actually riding for 40 years,and still happy to use engine oil for everyday riding...Ive got the original manuals and handbooks and am happy to use the info in them as I dont believe it suddenly went wrong in 1972, and technological advances on a 1930s design probably arent going to make a great deal of difference...Im happy to be stand corrected if Im actually wrong (and giving out incorrect or misleading advice) but not really interested in being taken to task for giving out the original recommendation that is still quite valid and useable, tho others may have decided there are more modern alternatives...if you want to use 30w fork oil or experiment do so by all means, its a whole 190cc per side of oil and 4 screws to change but for everyday riding 30w engine oil is fine..this is my OPINION, as are all the other answers here..but ATF is definitely not right for the pre 1970 nonOIF forks phrases such as "how do I put this politely" arent really necessary and usually meant as a putdown ...its just a sharing of info/ideas here and anyone who asks a question should weigh up the answers and decide if its valid info....simple stuff, but grown mature adults can still make a big issue out of what grade of oil to put in 40 year old motorcycle forks...hopefully none of us work in the military decision making dept isnt it...sir I disagree with what fork oil they're using we must invade now..
Originally posted by htown: What weight in a 1978? Generally a single rider, 200+, no luggage.
All Triumph & BSA aluminum fork leg bikes (1971 - until) came specified for ATF, which is approx 8W. What is best for YOU depends on your weight, your riding style, and your road conditions. So only YOU can find out.
Luckily, we're not talking more than $20 to answer the question.
People... please no spitballs here! There are as many "correct" answers here as there are different bikes; and people who weigh 150 pounds to 400 pounds; who ride the superslab; or have a driveway which consists of 3 miles of gravel and dirt.
Some of us ride bikes with different suspension systems... some "period", or considerably more modern. Thus each bike/rider combination must be considered as an individual... and each owner/tuner should listen without predjudice to the opinion of fellow owners/tuners, and make an informed choice from the shared wisdom.
If that choice is less than adequate... so what? As RF says... oil's cheap... experiment until you are happy and please don't "dis" anyone who got good result from another choice.
Also remember that volume of oil is a valid tuning device as well... if 190cc of say... 30WT engine oil is a bit stiff... 175cc may be just the ticket. Or 200cc if too soft.
I am reminded of a friend who shopped for new stereo speakers online using published "consumer reports" as a guide toward evaluation. He bought a very expensive pair of speakers without listening to them first... even though a pair were available at a local dealer for him to sample. He HATED the sound... and I have them now for 1/2 price because I think they were designed with my particular hearing range (loss) in mind.
Every owner must try different combinations of bits on your bike to determine the best fit for you. That is part of the journey, and finding the "magic combo" is part of the reward!
I use 20W synthetic fork oil with new L P Williams progressive springs, works well as the springs have a lot more to do with rider/load weight than does the fork oil. Anyone running original springs after all these years would be well advised to toss them in the scrap bin and start off afresh with a known quantity rather than confusing dampening with springing. Trumpetloon is exactly correct, this is a job for the informed individual. With OIF forks you can slip three "O" rings over each fork stanchion, one set at max travel [bottomed] and the other two to gauge differences in travel during tuning/setup. Overdamped and undersprung forks are a recipe for losing the front and that is the quickest way to the ground and pain, trust me on this.
A little under 200lb stark nekkid, happy to send pictures if you like ? If I were you I would use #20 oil and work from there, not keen on engine oil for reasons described by Stuart, cavitation is a real issue and proper dampener oils would have a very low vapour pressure to combat this.
Originally posted by Tiger: A little under 200lb stark nekkid, happy to send pictures if you like ? If I were you I would use #20 oil and work from there, not keen on engine oil for reasons described by Stuart, cavitation is a real issue and proper damper oils would have a very low vapour pressure to combat this.
I'd guess handlebar choice is also a factor. I tried 20W on my T140 and found it too harsh with Progressive springs (I weigh about 190LBs). Have gone to Silkolene 10. I have Western (?) bars - about 6" rise and wide, on my bike. Flatter bars would probably put more weight on the front wheel and require heavier oil.
Hmm, yes, mine has US bars so little weight on the front except when braking when the weight would be exaggerated by the height of the bars. Maybe I'll start even lighter maybe even ATF? My understanding of it is that you would use a lighter oil in progressive springs to get the 'finesse' whaddya reckon?