slogger Posted September 27, 2009 Report Share Posted September 27, 2009 (edited) Have just attempted my first front fork seal change (oh what fun!) One of the jobs to sort after buying the bike was to sort the "Normal" rings of oil on the fronts forks following no attention being given to this matter. Following the Beta manual and some great advice form the forum I have been able to replace the seals, but I am still not happy with the movement? The oil coming out was no different to the engine oil oil coming out of my MG so it was replaced with Rock oil SVI 5 suspension fluid (as this was all my local off road dealer had). The only way to describe the front action is "uninspiring". Basic measurements (from the bottom of the bottom yoke to the top of the dust seals) are as follows: resting - 160mm fully extended = 180mm with my weight on the bike in a central c-o-g postion = 150mm fully compressed = 140mm I am concerned that the total amount of travel (based upon tests in my garage) is only 40mm. I know in sections this would be more, and I am going to get out next week to give it a field test...... Preload and rebound has been set at a midpoint althought at both extreems I saw little difference So questions: 1) What is normal pre-load and rebound settings 2) When filling the spring stantion, this was straight forward, but when filling the cartridge side, obviously fluid kept running into the lower tube. Beta quote a fill level but, is this a quick pour and measure of after the lower tube has been filled 3) Are the travel measurements about right. Im 5 ft 6 and 74kg 4) As an newbie at front forks have I done something stupid that I need to check ! Its very difficult to describe what I mean as "uninspiring" but even prior with the seapy seals their was a level of resistance. Its not juddery but it just seams "flat" and sloppy! Any thoughts?? Edited September 27, 2009 by slogger Quote Link to comment Share on other sites More sharing options...
nzralphy Posted September 28, 2009 Report Share Posted September 28, 2009 Normally 5wt would be about the correct weight. Normally you fill the forks with some oil, pump them up and down to fill chambers/cavities then lower them to max travel (just leave off both caps) and measure the height to the top of the oil. Actually over fill it and put a tube to the correct depth then suck out the excess with a syringe. the forks should have 165mm travel and, with some effort, you can get close to max travel in the garage. Have you got too much rebound adjustment turned on on the RHS leg? or have you got too much oil in them?, or do the springs need a little more preload on the LHS leg? Quote Link to comment Share on other sites More sharing options...
slogger Posted September 29, 2009 Author Report Share Posted September 29, 2009 Cheers for that, started checking last night. Like a right muppet I took BOTH fork leg caps off at the same time!!!!! Obviously by compressing the fork legs to check the RHS all of the fluid spiled ouit of the left...doh! Anyway, the RHS (cannister side) was low so I have topped that up. Getting more fluid so I can reset the level of the LHS and see how it is. Quote Link to comment Share on other sites More sharing options...
slogger Posted September 30, 2009 Author Report Share Posted September 30, 2009 (edited) Still not right! Have refilled both tonight and can only get limited travel (as measured above). Measurement from top of front mudguard at highest point of arch and bottom of lower yoke is 165mm. Cant get anywhere near full compresion. Next logical step is probably to remove both fork legs and see which one is restricting the travel............. Just to check basics.... RHLeg (cannister) - measurement is taken with fork fully compressed, then cap attached to slider and tightened down LHLeg (spring) - measurement is taken with fork fully extended and spring in, then 2 spacers inserted before cap is tightened down #####edit note##### - just read 2 other articles that say LHS should be measured with spring out and fork fully conpressed, another says spring in and fully compressed???? Im confused now ????? Edited October 1, 2009 by slogger Quote Link to comment Share on other sites More sharing options...
grahamjayzee Posted October 1, 2009 Report Share Posted October 1, 2009 Couple of things to check: Take the caps off both forks and ensure you can get full movement with the wheel in place. If you can't, you may be missing a wheel spacer meaning the forks are not parallel and progressively nip up. It's an easy mistake to make! Secondly, the oil level should be measured with the forks compressed. Again, both caps off, compress the forks and fill to roughly the level in the manual (can't remeber exacltly what that is off the top of my head; 85mm one leg, 100 the other rings a bell. John Lampkin will know!) and then suck out the excess by using a syringe and a tube poked into the fork to the required depth. If you do this with the fork extended, you will only have 85mm or so of air gap at the top and 150mm of fork play! It is never going to happen! Good luck Graham Quote Link to comment Share on other sites More sharing options...
slogger Posted October 1, 2009 Author Report Share Posted October 1, 2009 Secondly, the oil level should be measured with the forks compressed. If you do this with the fork extended, you will only have 85mm or so of air gap at the top and 150mm of fork play! It is never going to happen! Graham, thanks for the final validation......I suspected this was the case. The Beta manual specifically cites fork compressed for the RHS but not for the LHS. I assumed (incorrectly!) that this one needed to be extended. As you state, the maths just dont add up!!!!!! Other movement is OK. Nothing getting in the way when the caps are off. Will empty the fluid on the LHS tonight and reset the level with the forks compressed cheers Rob Quote Link to comment Share on other sites More sharing options...
grahamjayzee Posted October 1, 2009 Report Share Posted October 1, 2009 You don't need to empty it; just 'suck out' any over the amount it should be. The way I do it is to get one of those spray bottles that contains cleaning products. Wash it out thoroughly and thow away the bottle part. Keep the lid/ squirty bit and put a tie-rap around the tube. Slide this up the tube to the level of the fluid specified in the manual. So if it says 85mm, set the tie rap so it is 85mm from the end of the tube. Then simply put the tube into the fork leg until the tie-rap rests on the end of the fork leg and squirt out oil until no more comes out. Job done! Reset the tie-rap for the other leg, re-assemble and go down the pub happy in a good job done! Graham Quote Link to comment Share on other sites More sharing options...
slogger Posted October 1, 2009 Author Report Share Posted October 1, 2009 Graham, Job sorted, thanks for the tip. Was able to use a syphon tube with a tap on the end but marked the level as you suggested and "job was a good un". Think what has thrown me was the picture in the Beta manual. It clearly shows the spring inside the fork leg BELOW the tube top and UNDER the fluid level. With the forks compressed the ring protudes the top of the fork leg by about 2 turns??????? Hence my assumption - fork extended! Cheers for your help, I now have a very nice front fork action Rob Quote Link to comment Share on other sites More sharing options...
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