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fork oil

kevin71kevin71 Posts: 12
edited September 2010 in MTB workshop & tech
The service guide for my Tora coil fork says to use 130cc of 5wt oil what would be the difference if I use 7.5wt or 10wt instead?

Posts

  • gnusmasgnusmas Posts: 167
    i used 10wt oil in my forks instead of the specified 5wt and found it to be better. it is a lot smoother and seems to even out the bumps better IME. I used Castrol motorbike fork fluid as it worked out cheaper and i have had no problems since doing it at the start of this year
  • Thanks, did you use 10wt in the oil bath as well?
  • gnusmasgnusmas Posts: 167
    yep, i stripped them completely, cleaned them and changed the oil in both legs. if i remember correctly it takes about 40cc in the oil bath (i am probably out but that springs to mind)
  • joshtpjoshtp Posts: 3,966
    its best to use the recomended weight really.... some heavyer riders can get away with 2.5 wt more.... but as a general rule, stick to the 5wt... also get the real rockshox, or other mtb fluid...the moto stuff can be harmful to seals.


    Rockshox red rum is dirt cheap on CRC
    I like bikes and stuff
  • *AJ**AJ* Posts: 1,080
    joshtp wrote:
    its best to use the recomended weight really.... some heavyer riders can get away with 2.5 wt more.... but as a general rule, stick to the 5wt... also get the real rockshox, or other mtb fluid...the moto stuff can be harmful to seals.


    Rockshox red rum is dirt cheap on CRC

    Not convinced that intirely true!

    I spoke to Marzocchi about some forks I have and the problems I was having and I got told, by them to up the oil weight from 7.5W to 15W... They also recommended using oil from a motorcycle shop.

    I suppose rockshox could be different. Marzocchi do have a motorcycle background i guess.
  • joshtpjoshtp Posts: 3,966
    *AJ* wrote:
    joshtp wrote:
    its best to use the recomended weight really.... some heavyer riders can get away with 2.5 wt more.... but as a general rule, stick to the 5wt... also get the real rockshox, or other mtb fluid...the moto stuff can be harmful to seals.


    Rockshox red rum is dirt cheap on CRC

    Not convinced that intirely true!

    I spoke to Marzocchi about some forks I have and the problems I was having and I got told, by them to up the oil weight from 7.5W to 15W... They also recommended using oil from a motorcycle shop.

    I suppose rockshox could be different. Marzocchi do have a motorcycle background i guess.

    yep, iv used all sorts of oils in my Zocchi's, they are totaly happy with it, and you can tune them in intresting ways using it.

    RS though are a little more fussy, and iv heard bad things of playing around with other oils.
    I like bikes and stuff
  • gnusmasgnusmas Posts: 167
    I serviced my RS without any problems to seals or inners with the 10wt oil from my old judy's to my oldish tora's. have used motorbike oil previously on all manner of forks previously and never had any problems.

    BTW my old judy's are still going strong after 7 years (yearly oil change) with 10wt motorbike oil and seals are still intact.
  • OK Thanks. Going to get some decent 10wt semi synthetic (same as Red Rum) from Halfords and give that a go.
  • cavegiantcavegiant Posts: 1,546
    oh this thread made my head hurt, so much bad info.

    Fork oil weight is a lousy measure, performance rarely corresponds in the same line, let alone different manufacturers.

    http://www.pvdwiki.com/index.php?title=Suspension_Fluid

    read that, realise the error of your ways and get teh right stuff.
    Why would I care about 150g of bike weight, I just ate 400g of cookies while reading this?
  • maddog 2maddog 2 Posts: 8,114
    I've played around with oil weights (and volumes) a lot more on my motorbike* than mtb but the basics are straightforward. Thicker oil leads to slower damping (compression and rebound) so effectively re-calibrates the range of adjustments.

    In other words if you want more compression and/or rebound than your current settings allow then go for a heavier weight.

    Personally, I think that light weight oil (5W) is fine for Pike forks, as you want fairly quick response on a mtb. Can't say whether Toras are the same, for your weight, for your riding type/style.

    *IMO motorbike fork performance is much more important/sensitive than mtb.
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • sorry to high jack this thread but is this oil suitable for lubing fox float seals and foam rings?
    http://www.opieoils.co.uk/p-827-silkole ... uctDetails
    float fluid is very expensive
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