[hellmet]

I made a mistake. I let a local mechanic deal with a fork oil change. That guy messed it up totally. The second mistake was that I didn't RTFM. So when he said he'd pour in the entire 175ml of fork oil into my forks I thought, OK, this guy must know his stuff. I immediately noticed the forks wouldn't travel more than 1.25inch and I would get nearly get thrown off small bumps. The story that follows is unnecessary but I just wanted to let you (and the web) know that you need to read your manual and let the mechanic know how much fork oil to put in or you'll have a terrible ride and possibly ruin your motorcycle.

The amount of oil according to my manual (it was right there!!) for my TVS Victor is 125ml. Yes, a full 50ml lesser. I'm taking the bike to the dealer tomorrow for a fork bearings change so I'll be replacing the fork oil with the right quantity this time.

Any how, what the heck is it with these mechanics calling it "forak" ? Someone please put some sense into them.

[ArizonaJim]

You are absolutely correct. Overfilling the fork with oil will cause problems.

The limited fork travel you noticed caused by overfilling can be very dangerous, causing the tyre to lose contact with the road. While this is uncomfortable and not good for the mechanical parts of the motorcycle while riding in a straight line, in a corner it can cause a loss of control and result in a collision.

To make matters worse, overfilling the fork with oil can damage the fork seals causing them to leak. If this happens, the seals must be replaced.

Filling the forks with a insufficient amount of oil will reduce the forks ability to dampen the fork movement allowing wheel "hop" after hitting sharp bumps which can also result in a crash. A lack of oil will also cause a loss of lubrication for the moving parts resulting in rapid wear of the forks.

Knowing what the Owners Manual or Shop Manual says the fork oil requirement is, is good but should be used with caution. Manuals have been known to be incorrect.

IMO, the best approach to determining the correct value is to carefully measure the amount of oil that has been drained from the fork. Then, using that amount of new oil to fill the fork should cause no harm unless the fork seal has been leaking.

[scorpian]

This is one of the most common blunders mechanics do to bikes,fill the entire and then the front suspension is ridiculous.

I would suggest you fill in exactly what you drain by measuring in a measure cup.Thats what i do,however the new oil would be thicker and the old oil would be thinner and more murkier.

For my last change in my karizma i measured and then filled in a little less oil to keep my front suspension soft,i like it that way.
Another mistake mechanics do is they dont pump the tubes enough to let the air out,if you just fill the oil and tighten the top nut,the air inside again causes resistance.To avoid this after filling the new oil,the cap should be kept loose and the tube pumped several times by hand,if you pay attention you can hear the whiff of air escaping and at the same time you can feel how soft the suspension is.

If you have to replace oil seals do them in a pair,reason being the mechanic will replace oil in just the affected tube and then you will have new oil in one which is harder and old oil in the other which is softer causing improper tyre wear.

[braindead]

The forks should be filled to a certain level. ( Free height from the top )

The best procedure is to first measure the level of fork oil before draining, then match level after refilling. Also its very important to precisely match the level in both forks.

Excess oil the forks leaves too little space for air at the top and effectively increases preload. Rate of progression of compression for air is very different from the springs. ( much more progressive) This can be used as a tuning method for certain (rare) situations. The changes are usually made in 5ml increments.

Too little oil in the forks will pressurize the fork oil too little under load and will cause cavitation and eventually emulsification of the oil at the valves. this will degrade damping performance.

Moral of the story: Fork oil level - Very important.

[braindead]

Bit of additional info:

Yamaha states fork oil level in the R15 to be 126 mm from top of fork leg with suspension compressed and spring removed.

Info for other bikes may be present in their service manuals.

[abhipuru16]

Yes, I know about this.
When I got my P200's for oil changed, I insisted on using a syringe and filled in the required amount. The result was absolutely original ride quality that I had when I first bought the bike.

[ArizonaJim]

While on the topic of changing fork oil I might mention that with the Royal Enfield the difficulty depends on which one is being worked on.

The Electra UCE models involve removing the drain at the bottom of the fork to drain it and the removal of the top plug to add the new oil.
The mud guard and front wheel can remain in place.
This is a simple job that should not take over 15 minutes.

The Classic UCE models have a different front fork and the draining/refilling involves totally removing the wheel, mudguard and front forks to drain and refill them. The forks, mud guard and wheel must then be reinstalled.
This is a fairly major undertaking and can take a considerable amount of time.

I mention this because obviously the cost of having this done may vary widely and I feel you should know the reason for it.

[hellmet]

Originally Posted by ArizonaJim

While on the topic of changing fork oil I might mention that with the Royal Enfield the difficulty depends on which one is being worked on.

The Electra UCE models involve removing the drain at the bottom of the fork to drain it and the removal of the top plug to add the new oil.
The mud guard and front wheel can remain in place.
This is a simple job that should not take over 15 minutes.

The Classic UCE models have a different front fork and the draining/refilling involves totally removing the wheel, mudguard and front forks to drain and refill them. The forks, mud guard and wheel must then be reinstalled.
This is a fairly major undertaking and can take a considerable amount of time.

I mention this because obviously the cost of having this done may vary widely and I feel you should know the reason for it.

Well, it would be so much more better for all of us to have motorcycle manufacturers go to using top and bottom plugs so we can avoid visiting the mechanic for this job as well. It would then be a simple job of draining, measuring and refilling!

[interc00led]

Oil level plays a very important role and most of the mechanics neglect it.
Manufacturers specify two ways to check the oil level/capacity during different cases.

1. Amount of oil needed when the fork has been disassembled and cleaner completely is the Fork's maximum recommended capacity.
For Unicorn/Xtreme/Hunk it is 150ml.
For Splendor/Passion/Cd-Dawn it is 135-150ml.

2. When the oil was just drained and re-filled - Manufacturer specifies the level from the fork top with the fork inner tube fully extended.
For Unicorn/Xtreme/Hunk it is 165mm.

With the top nut and spring out, the fork inner tube has to be pumped several times to remove any trapped air.

Please avoid using local oils, Motul and Veedol make good fork fluid. Recommended grade for the above mentioned bikes is 20W

Yes, all Hyderabadi mechanics call forks as FARAK.

[adrian]

Originally Posted by ArizonaJim

While on the topic of changing fork oil I might mention that with the Royal Enfield the difficulty depends on which one is being worked on.

The Electra UCE models involve removing the drain at the bottom of the fork to drain it and the removal of the top plug to add the new oil.
The mud guard and front wheel can remain in place.
This is a simple job that should not take over 15 minutes.

@ ArizonaJim : The fork oil change for my Standard 350 UCE is overdue. I have done 16k now where the oil change should have been done at 12k. The UCE Bible says nothing about forks and I don't want to take my bullet to RE service and get more bad than good. I was searching the forum and came across this post. My bullet has allen key nuts on top of the fork and the bottom of it. So I presume that all I have to do is drain the fork oil by opening the bottom ones and refill 195ml per fork over the top hole. Am I right here ? Do I have to pump the forks before closing the top allenbolts to remove air bubbles ? Kindly advice.
regards adrian

[sagarpadaki]

Here is a detailed information on the fork oils .

http://www.xbhp.com/talkies/universa...fork-oils.html

[ArizonaJim]

adrian
Because there seems to be several different front forks used by Royal Enfield I suggest you first try to remove the allen key bolt on the top of the forks. Do this before attempting to drain any oil out of the fork.


As I recall, on some of the forks, removing that top allen bolt will not open a passage to refill the fork. It will be a blind hole leading nowhere.

If this proves to be the case, you will not be able to simply drain and refill the fork.

If the top allen bolt is just a plug to allow the fork to be refilled, drain the oil and pump the forks several times to blow out any remaining oil. Then replace the plug and add the measured amount of new oil.

Here is a link which deals with the "C5" model being exported to the USA. It is the one that uses a fork that is a major hassle to change its oil so there is quite a lot of reading. There are 8 pages in this topic and many of them may have information that will be useful to you.

http://www.enfieldmotorcycles.com/fo...c,10813.0.html

If possible, you may want to print the information in the link and the other posts out for future reference.

Added: Another link to posts about changing the fork oil

http://www.enfieldmotorcycles.com/fo...c,17367.0.html

[adrian]

Originally Posted by ArizonaJim

adrian

If the top allen bolt is just a plug to allow the fork to be refilled, drain the oil and pump the forks several times to blow out any remaining oil. Then replace the plug and add the measured amount of new oil.

Thanks ArizonaJim. Is it necessary to pump the forks after filling oil to remove air bubbles or is it a simple fill it shut it process ?

I am yet to open and check the top allen bolt (keeping my fingers crossed)
regards adrian

[ArizonaJim]

I suppose if you were going to put it on a race track for the next event you might want to pump the forks after adding the oil but for doing everyday riding, don't bother pumping them.

Nature will allow the new oil to end up where it belongs without you exerting yourself.

[adrian]

Originally Posted by ArizonaJim

I suppose if you were going to put it on a race track for the next event you might want to pump the forks after adding the oil but for doing everyday riding, don't bother pumping them.

Nature will allow the new oil to end up where it belongs without you exerting yourself.

Thank you ArizonaJim. Have checked with several service personals as well with our famous local mechanic Mr. Murugan and they all sing in unison : "The forks have to come off the bike to drain oil". So for the time being I feel that the job is out of my league. So I have decided to take the machine to Mr.Murugan so that I can see the procedure right before my eyes and decide if it would be a DIY job next time


IF ANYONE FROM ROYAL ENFIELD IS READING THIS : "WHY ARE YOU DOING THIS TO US? A 45 MINUTE HIGH PAID JOB EVERY 12000 KMS WHERE ALL THE FRONT END OF THE MOTORCYCLE HAS TO BE STRIPPED FOR A SIMPLE FORK OIL CHANGE. WHY DON'T YOU MAKE SIMPLE FILL AND DRAIN FORKS LIKE THAT OF G5 FOR ALL BULLETS ?

OT : Is the front forks of G5 available for purchase in India and would it suit a Standard UCE 350 ?
regards adrian