View Full Version : FXR forks
RDjase
21st February 2010, 17:30
Hi all
a mate has just bought a FXR for a bucket, It has been a road bike and needs fork seals, he has dropped off the seals and forks for me to do
What is the fork oil amount, weight and level? he weighs around 80kg ish
and do I need to make some preload spacers on standard FXR forks for race use?
I didnt feel what the forks before he took them out so have no idea what they felt like.
Thanks in advance
Jase
speedpro
21st February 2010, 18:34
I can't help you with info you want. I only have a question - why does it need preload spacers? Is the static sag too much? If it dives TOO much under brakes maybe when you have them apart you should be looking at adjusting the compression damper holes down a mm or two. My forks are real soft spring-wise but I still have about 10mm movement to go before they bottom out. I have played with the compression damping and it works well.
RDjase
21st February 2010, 18:44
I can't help you with info you want. I only have a question - why does it need preload spacers? Is the static sag too much? If it dives TOO much under brakes maybe when you have them apart you should be looking at adjusting the compression damper holes down a mm or two. My forks are real soft spring-wise but I still have about 10mm movement to go before they bottom out. I have played with the compression damping and it works well.
Havnt had them in the bike, he just bought them around. Just thought the FXRs being a cheapy road bike may be set up soft in the spring rates and may need spacers for race use. I can fit the seals and give them back and try on the bike to get better setup and rider sag. I know with the LCs (my post classic bike) the 1st mod on standard forks is raise the fork oil level 10mm and and make preload ajusters out of the standard fork cap,
What are FXR forks like in standard condition?
Kendog
21st February 2010, 19:03
What are FXR forks like in standard condition?
I think they are fine.
Plenty of FXR bucket info at fxr.co.nz (http://www.fxr150.co.nz/discussion/)
RDjase
21st February 2010, 19:12
I think they are fine.
Plenty of FXR bucket info at fxr.co.nz (http://www.fxr150.co.nz/discussion/)
cheers, thanks for the link, will check it out
Got my sons freashly bought TF powered FZR and my RX to get going too. Hope to have them ready for the next pacific round at Roys Hill
Yow Ling
21st February 2010, 19:20
I think they are fine.
Plenty of FXR bucket info at fxr.co.nz (http://www.fxr150.co.nz/discussion/)
that would be www.fxr150.co.nz (http://www.fxr150.co.nz/discussion/)
it still went to the same place, just being pedantic
Damien_Toman
21st February 2010, 20:46
Hi all
.... What is the fork oil amount, weight and level? he weighs around 80kg ish
and do I need to make some preload spacers on standard FXR forks for race use?
...
Jase
Hi Jase. It brought a big smile :) to my face hearing about the RD mods - still the same eh?! I've still to start rebuilding my 350 YPVS - it WILL happen this year.
I can help with the FXR150 as I have one and I had front end diving issues. Henk can also add some advice if he reads this. Henk suggested I go for a depth of 100-110mm from the top of the forks (I hope I'm quoting him correctly), with no spacers (I also asked about spacers! - being an RD guy from way back). When I topped the forks up I finished with 100mm and it was great. But, I don't know what oil was in there (probably 10wt) and I used 10-40 engine oil! It was all I had and this was Sat night after practice and I needed it to be ready for Sunday 14Feb racing at Mt Wellington - it works well - see photo - link below :)
http://www.flickr.com/photos/dty1/4371909301/sizes/l/
I used a wooden lollypop stick attached to stiff wire as a dip. Remove existing FXR tube spacers before measuring. My next mod will be to add a coin or two as additional spacers! Just like we did years ago. Speedpro is an expert and his suggestion sounds better but involves more work. If I decide to dis-assemble my forks I might try that approach.
I'm looking forward to doing Roy's hill in the Nth Island bucket series :). Will be in touch once we have dates.
Regards
Damien
F5 Dave
22nd February 2010, 09:51
Havnt had them in the bike, he just bought them around. Just thought the FXRs being a cheapy road bike may be set up soft in the spring rates and may need spacers for race use. I can fit the seals and give them back and try on the bike to get better setup and rider sag. I know with the LCs (my post classic bike) the 1st mod on standard forks is raise the fork oil level 10mm and and make preload ajusters out of the standard fork cap,
What are FXR forks like in standard condition?
Adding more preload will not change the spring rate one jot. The physical spring will stay the same, preloading it will just adjust where you start compressing it. Just as on the RDs & YPVS the best thing to do is increase the spring rate. My 350s springs were quite long (many coils) & I took off 6 coils from memory (don't quote me) from the tightly wound area, then made spacers to replace the length.
F5 Dave
22nd February 2010, 09:57
I can't help you with info you want. I only have a question - why does it need preload spacers? Is the static sag too much? If it dives TOO much under brakes maybe when you have them apart you should be looking at adjusting the compression damper holes down a mm or two. My forks are real soft spring-wise but I still have about 10mm movement to go before they bottom out. I have played with the compression damping and it works well.
Yeah but you put emulators in didn't you?, (or where they other forks), but that largely negates the negative consequences of fixed orifice dampers. Have to be careful with that last 10mm, that is where the hydraulic cones live & they lock up on those to prevent hard bottoming in extreme situations, so you don't always 'get' all the travel + if they do get onto those cones they will 'stick' down there going on & off (for a very short time, but long in the world of traction).
Damien_Toman
22nd February 2010, 18:45
My FXR is around 7 years old (2003) and the springs will have lost some springyness and will have compressed a little over time. The idea of adding a few coins as spacers is just to compensate a little and provide some adjustment mechanism to otherwise very basic forks. It's an old, simple, cheap, but tried and tested approach. I will be experimenting with mine as I start to brake later (just getting back into the feeling of racing a road bike so not started braking hard yet) :)
F5 Dave and speedpro, great to have your expert input on suspension. When I need to fine tune things (inevitable) I know who to ask for help :).
Regards
Damien
CookMySock
22nd February 2010, 19:27
I'd just boof some adjustable emulators in there and some stiffer springs. End of problem, and hello front end handling!
Steve
Yow Ling
22nd February 2010, 20:29
I'd just boof some adjustable emulators in there and some stiffer springs. End of problem, and hello front end handling!
Steve
Why fit stiffer springs when the stock ones are adequate. Emulators are probably 50% of the purchase price of the bike. Most of the FXRs running down here are just stock, the biggest performance mod most get is new seals or straighten the fork tubes
RDjase
22nd February 2010, 22:08
Cheers for all the info guys,
I havnt even had a chance to strip the forks yet and check spring free lenght to see if they have compressed. All the LC springs I have are old original ones but all are still on standard lenght, bar 2 of them which are 3mm under max but still in spec. Can springs be on spec lenght wise and be low on tension?
What is the free lenght? what oil grade? oil amount and level height? Is the 100mm Damian said the standard height/level or a bit higher for HD use?
i will just replace the seals and fill with oil. fine tuning later
Funny having a look at the FXR forks , 33mm compared to 32mm on my LC lol
Bloody match sticks dipped in chrome
RDjase
22nd February 2010, 22:13
Hi Jase. It brought a big smile :) to my face hearing about the RD mods - still the same eh?! I've still to start rebuilding my 350 YPVS - it WILL happen this year.
I can help with the FXR150 as I have one and I had front end diving issues. Henk can also add some advice if he reads this. Henk suggested I go for a depth of 100-110mm from the top of the forks (I hope I'm quoting him correctly), with no spacers (I also asked about spacers! - being an RD guy from way back). When I topped the forks up I finished with 100mm and it was great. But, I don't know what oil was in there (probably 10wt) and I used 10-40 engine oil! It was all I had and this was Sat night after practice and I needed it to be ready for Sunday 14Feb racing at Mt Wellington - it works well - see photo - link below :)
http://www.flickr.com/photos/dty1/4371909301/sizes/l/
I used a wooden lollypop stick attached to stiff wire as a dip. Remove existing FXR tube spacers before measuring. My next mod will be to add a coin or two as additional spacers! Just like we did years ago. Speedpro is an expert and his suggestion sounds better but involves more work. If I decide to dis-assemble my forks I might try that approach.
I'm looking forward to doing Roy's hill in the Nth Island bucket series :). Will be in touch once we have dates.
Regards
Damien
Cheers Damian, Sounds like you were having fun, I was at the BFTP rally that weekend too. you would have been racing when I was on my LC road bike on the forgotten Highway heading to whangamomana
Looking forward to seeing and racing against your powervalve Damian ;-) While your at the track you may as well race in Postys and buckets/ss150 aye mate. 2 bikes is twice the fun
Hoping to have my sons bucket ready for the track day at Taupo on the 13th
CookMySock
23rd February 2010, 06:56
Emulators are probably 50% of the purchase price of the bike.I wonder what the cheapo chinese copies are like. Probably ok for a bike that does about 1500km a year.
Steve
RDjase
23rd February 2010, 16:24
I wonder what the cheapo chinese copies are like. Probably ok for a bike that does about 1500km a year.
Steve
They will copy anything, we get chinese knockoff pneumatic parts come into work when there machines dont work properly or at all, some dodgy crap out there. cheeky pricks ,the parts look genuine(ish) till you take them apart
But then there must be some chinese companys THAT do make good parts and want resale and supply back up service and spare parts
RDjase
18th March 2010, 19:29
Hi Jase. It brought a big smile :) to my face hearing about the RD mods - still the same eh?! I've still to start rebuilding my 350 YPVS - it WILL happen this year.
Hey there Damien
I bought a 83 YPVS350, best you get started on yours so we can race each other. The engine may end up in my TZR for a pre 89 bike, not sure yet
Jase
Damien_Toman
18th March 2010, 21:22
Well, mine's an '87. The handling is way better than my old '82 (I think it was '82 - the original). I have and XR400 valve regrind to do this weekend then work on my FXR150 (crash damage from last weekend). RD comes after all that! Looking forward to racing with you.
Damien
RDjase
19th March 2010, 15:31
Well, mine's an '87. The handling is way better than my old '82 (I think it was '82 - the original). I have and XR400 valve regrind to do this weekend then work on my FXR150 (crash damage from last weekend). RD comes after all that! Looking forward to racing with you.
Damien
LC's were 80 to 82, RZ or RD YPVS(UK spec) were 83 on.
The 87 F2 YPVS are definatly the better bike, nicer suspesion, brakes and looks.
Are you doing the last round of the pacific series? Your RD/RZ will be eligable for postys and Pro Twin open. There is alot of 2 stroke twins running in pro twin open now. Had 2 LC's, 2 TZ 350's, a RD350 YPVS(UK model F2) and RGV's and RG's running. Cool fun !
Damien_Toman
31st March 2010, 21:06
When and where? The web site is not up-to-date.
http://pacclub.co.nz/press/f4-f5-buckets/
The RD is not a priority at this stage so I'm not sure.
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