| Author | Message | ||
     Thefleshrocket |
My fork seals and fork spring compression tool arrived, so I'm goin to change my fork seals this weekend. I have a couple of questions. First, what should the fork oil be set to? Second, I assume it should be checked with the cartridge installed but not the fork spring or spacer. Is that correct? Third, what is the stock fork oil weight? I have my rebound damping set 1/4 turn out from full stiff and am going to go one weight thicker so I won't be at the limit of the adjustability. Thanks! | ||
| Kicka666 |
94mm fully compressed no spring, I would use a good quality synthetic 7.5w for better rebound. Make sure you bleed your cartridges well. Hope this helps | ||
| Dcmortalcoil |
Not 100mm, with the outer tube fully collapsed? | ||
| Kicka666 |
Manual says 94mm, outer tube fully collapsed yes, 100mm would be fine. | ||
| Thefleshrocket |
7.5wt? Is the stock fork oil 5wt? I read somewhere (of course I didn't save the link) that the stock oil was 10wt, so I was planning on using 15wt. As far as bleeding the cartridge, that's pretty much just pumping the cartridge up and down until only oil comes out the top (the rebound side), right? | ||
| Thefleshrocket |
Here is the thread that says stock is 10wt. http://badweatherbikers.com/buell/messages/290431/ 425037.html?1230564036 | ||
| Thefleshrocket |
This chart seems to support that Harley Type E is approximately a 10wt. http://www.spectro-oils.com/pdfs/techsheets/Shock_ Fluids_Comparison_Suspension_Oils_Chart.pdf (Message edited by Thefleshrocket on July 09, 2011) | ||
| Rodrob |
I run 120mm in my bikes. Helps me get the sag I want and I get less chatter. All depends on your weight. | ||
| Kicka666 |
Yes 10w is standard & the rubbish they use in the factory is a mineral based oil once it gets some heat into it, it may as well be a 2.5w, a good 7.5w synthetic oil will make a big difference. I changed mine out to an Ohlins 7.5w @ $50 a litre well worth it, running oil level at 110mm. | ||
| Thefleshrocket |
$50 a liter? Wow.. it's probably great stuff, but there's no way I can justify spending $100 on fork oil. I ended up using Spectro 15wt. Sort of. I bought 1 quart of Spectro 15wt from a local shop and filled up the first fork tube. It ended up taking about 3/5 of the quart to get the oil level set to 96mm, after bleeding the cartridge. I used the rest of that quart on the second tube. I had another mostly full quart of Spectro 15wt on the shelf, but the oil looked super thin. But then I compared it to the Spectro 15wt that I'd already poured in and it looked like it flowed like water too. So I used the rest of that but also added a little of the Spectro 20wt I had on the shelf too just in case I had something thinner than 15wt in there. (A while back, I did a bunch of mixing and matching of fork oils while tuning the fork on my SV650, and some of the quarts might not have in them exactly what's labelled on the bottle.) So, what's in the second fork tube? Probably something that's mostly 15wt but I'm not positive. I've just taken a short commute to work so I can't really comment, but with the rebound damping set two turns out from full stiff (previously set to .25 turn out) and the compression damping set 1 turn softer than it was previously (I don't know how many turns out), the bike felt firm but compliant. Obviously I'll need to do some tuning. Next time, I'll be sure to buy TWO quarts. | ||
| Zac4mac |
Flesh - 2 Quarts? I just did the forks on my Uly and only used 3 PINTS of Type-E. Haven't seen a Spectro product in 20+ years, so I have no idea what size/quantity they come in.... Z | ||
| Thefleshrocket |
Zac, the Spectro stuff comes in the same size as pretty much any other fork oil, as far as I know. It was either a liter or a quart that I bought. Google says that 1 pint = 0.5 quart, which means that if you used 3 pints on your Uly, that's a quart and a half. I probably used a little less than that, overall. Every standard fork I've ever worked on has taken just under a quart (or a liter--one bottle) to get both tubes to the proper level. The 1125 has the first upside down fork that I've worked on and I'm guessing that USD forks simply take more fluid than non-inverted forks. | ||
| Kicka666 |
1 qt(US Liq) = 946.352 mls which I work in being the metric system in Aus, I am a bike tech & probably do 3 or 4 sets of seals a week, there is no way that your forks hold 2 quarts. Did you check your oil level with the outer fully collapsed, I did a XB12R last week & they only held 486cc of oil per fork & they are a Showa fork very similar to the 1125's. | ||
| Thefleshrocket |
No, I didn't use 2 quarts. The first fork took about 600 ml. (I got that measurement by looking at the fork oil bottle--it indicated that it had 400ml left, and assuming it was 1 liter, then 600ml was used.) I poured the remaining 400ml into the second fork tube, along with a bit of oil from the 15wt and 20wt bottles, so I'm not positive how much was used in the second fork tube. I measured the fork oil level with the outer tube fully compressed, after bleeding the cartridge, and without the fork spring installed. | ||
| Mountainstorm |
That sounds kind of crazy putting different weights in the two forks. | ||
| Thefleshrocket |
Not at all. Some bikes have rebound damping adjustments on one fork and compression damping adjustments on the other. That means that each fork tube will inherently have different damping characteristics. But since both tubes are tied together at several points, the damping effect affects the front end uniformly. In my case, the overall weight of oil in my fork would be the average of what's in each tube. That said, I generally prefer to keep each tube with identical oil for the sake of consistency. | ||
| Mountainstorm |
Uh yeah...the fork tubes on the 1125r are independent so using the same weight and volume of oil is a necessity...maybe I misunderstood your post because it sounded like you filled one tube then used whatever was laying around and filled the other...which sounds a little bit off...it might not make much difference...but I would want both forks to have the same exact action. | ||
| Dannybuell |
f_rocket >>the limit of the adjustability. One part of lighter fork oil is that it takes less time to heat up. Some see this as a benefit and others as a burden. Going up in weight means your forks may not do so well at the start of your ride but as the front fork oil warms up your bike will do better. On the road and track most want a bike to perform consistently. Follow the factory suggestions and you will be happier on turn one. If you want more distinct compression and rebound responses consider getting better valving. gpsuspension.com's 3 cnc machines make nothing but suspension internals for sport bikes. The first thing I did to the CR was get gpsuspension valving. I am a big guy and this made a distinct improvement to the CR. I started using gpsuspension on my S1 after using a HD dealer installed G&^% valve. That lasted for one season when I learned through motorcycle racers about gpsuspension. |
