Fork rebuild

[UKDave]

I read all the comments about fork bush wear and can't believe it. 12,000 miles? No way! I've done 40,000 and 30,000 on two successive FJRs and the forks were fine. Virgin (of airline fame) offer a "Limobike" service in London using FJRs and they expect a service life of 60,000 miles without any problems. Of course, we don't have desert dust and dirt roads here but we have some shitty weather and plenty of corrosive winter road salt. You will get a slight hands-off shimmy at some point between 30 and 50mph, especially if the side cases are fitted. That isn't unique to the FJR and it doesn't mean the forks are faulty. I wouldn't trust that dealer!

 

[bramfrank]

Shimmy is at 30-50 because that is the resonant frequency of the front end.

If your wheels are even slightly out-of-true or out of balance you get this, which is why new tires generally roll true - they are in balance when they leave the shop but may wear slightly unevenly - hence not running in-balance and perfectly true.

Forks are fine if you don't have any looseness or leaking.

 

[radman]

48K on the Frank, yearly changes on fork fluid, tight as a virgin so far. All parts can fail prematurely, this is why warranties exist.

 

[donaldb]

I would like to do this to my bike, it has original fork oil still in it w/28k miles. I have bought new fork oil to flush and replace, but never having done such a thing it looks a bit complicated. I have printed out the directions from fjrtech and every time I get the urge, I then sit and read over the directions and get discouraged again. Anyway, a day will come, likely this winter when I can risk having my bike broke apart and have that what the f*#k do I do now look :blink:

 

[cadman]

can one take a fluid extractor and suck out the old oil instead of a full tear down of the forks?

cadman

 

[Geezer]

can one take a fluid extractor and suck out the old oil instead of a full tear down of the forks?
cadman

It is really not difficult to remove the fork tubes, pour the old oil out, and pour in the appropriate amount of new oil. Do it at the same time as a front tire change while the wheel is off.

 

[luvtoride]

Or, as Jeff Ashe has always told me... while torquing the head bearings is a perfect time to flush ye' ol forks. He tells me that it should be done yearly... or every 20,000 miles.

He changed mine for me @ about 36,000. Yeah, it looked & smelled gamey.

 

[Kevin Daly]

Not to hijack but is there a perfered replacement oil genus and species??

 

[Aasland]

Not to hijack but is there a perfered replacement oil genus and species??

I've had good luck with Motorex in other applications. On the FJR I've used 10W but think that may have been a bit too fluid (I'm not noticing a lot of difference playing with rebound) and may go for 12w or 15w next time.

 

[Big Sky]

If the forks get disassembled, make sure those washers that pull the fork seals out are flattened or replaced before reassembly or you will do the whole process over. They will likely come out somewhat cone shaped. Don't ask how I know this.

 

[keizerken]

Lots of intersting comments and they are all appreciated. I still have the shimmy some two months after my first post, but it hasn't gotten noticeably worse. Just annoying at times. I did talk to a different dealer about it and they recommended installing an upgraded, stiffer spring. Said thay had done several FJR's and that it had made a difference in the shimmy and improved handling. I think at this point I'm going to run the life out of the Contitental Road Attacks and get a different make of tire and see how that turns out. If that doesn't fix it, then I may have to dive into the forks like it or not.

Anyone done a fork spring upgrade? Worth doing?

Thanks.

 

[rickysnickers]

Lots of intersting comments and they are all appreciated. I still have the shimmy some two months after my first post, but it hasn't gotten noticeably worse. Just annoying at times. I did talk to a different dealer about it and they recommended installing an upgraded, stiffer spring. Said thay had done several FJR's and that it had made a difference in the shimmy and improved handling. I think at this point I'm going to run the life out of the Contitental Road Attacks and get a different make of tire and see how that turns out. If that doesn't fix it, then I may have to dive into the forks like it or not.
Anyone done a fork spring upgrade? Worth doing?

Thanks.

Yes, I have. I put the Eibachs in from the group buy that W.C. put together last time. They made a big difference. I am right around 200#, without gear. It made the bike much more fun to ride. It's easier to control as well. I think for about $100, you cannot go wrong. BTW, the shimmy you have sounds like the tires are just worn. I doubt that you would need a fork rebuild, unless you are going to upgrade the entire inner workings, ala GP Suspension, or Traxxon.

Rick

 

[just roy]

if you do choose to have your forks rebuilt i recommend race-tech i have had a lot of dirt bike forks and one set of street bike forks done by them and have always been very satisfied. you tell them your weight and riding style and they will custom build your fork and shock. i have found their gold valve to work well in every application i have had it in. no connection just a very satisfied customer.

 

[DaveFJR]

According to the factory service and owner's manuals, there is no scheduled fluid replacement required for the fork oil. "Check operation and for oil leakage" to me means you change if seals fail or need a rebuild only.

 

[Ignacio]

Anyone done a fork spring upgrade? Worth doing?
Thanks.

Yes. Immensely....if you do more than just do springs. I tried the spring thing years ago and it helped, but not like a true upgrade.

The Soqi upgrade transformed my bike.

Worth it regardless of a group buy or not.

Call or visit the GP Suspension website. I'm having them redo things again this winter mysefl...with 90K on the odometer.

 

[SkooterG]

According to the factory service and owner's manuals, there is no scheduled fluid replacement required for the fork oil. "Check operation and for oil leakage" to me means you change if seals fail or need a rebuild only.

Yeah, well the manual is wrong in this case. The oil gets *nasty*. I don't do mine very often, but it's a good ideal to replace the oil on some sort of schedule. Also of note: I changed the oil in my forks at 30k when I put new Wilbers sprnigs in. Then, at 91k I had them opened up for seal replacements (from a wreck) and the bushings had almost *ZERO* teflon left on them. I have put 63k on the FJR since then and am WAY overdue for fork oil change. Mine will get done again soon.

 

[DaveFJR]

I can live with a 50Kmi fork oil change interval.

 

[Ignacio]

and the bushings had almost *ZERO* teflon left on them.

I'll add to that. The folks at GP Suspension noted that Gen 2 bikes seem to be even harder on the teflon bushings than the Gen 1 bikes. They noted that even low mileage Gen 2 bikes seemed to have worn the bushings...as in this is a new bushing.......GoooooD:

And a bushing from a Gen 2 set of forks last Winter Not So GoooooD:

Not much can be done about it, but it is something to think about.

Meanwhile, now that it's cooling off I'm gonna be working on a thread to catch up on a photo visit I did to GP Suspension last winter in the next couple weeks.

 

[ahchiu]

Anyone done a fork spring upgrade? Worth doing?
Thanks.

Yes. Immensely....if you do more than just do springs. I tried the spring thing years ago and it helped, but not like a true upgrade.

The Soqi upgrade transformed my bike.

Worth it regardless of a group buy or not.

Call or visit the GP Suspension website. I'm having them redo things again this winter mysefl...with 90K on the odometer.

+1 on GP Suspension, Dave knows his stuff he works on race bikes,I'm going have him do my front and rear (Penske) it will cot around $1,500.00,this will transform you ride.

Marcus

 

[Baz]

Changing fork oil & especially changing viscosity can help with fork performance. You can notice differences in viscosity changes, but I would doubt if the average Joe like your or I would notice a difference in changing the fork oil under lets say 50,000 miles.

Unless you feel some funky things going on in your front end and your steering head bearings are in good shape, I would suggest that playing with forks is a non issue unless they are leaking oil, or the bike is really old, or has been sitting a long time like 2-3 years. Yes, new springs & valves can help with shock performance but you have to sake yourself if you need this. Unless you are hanging off the side, probably not. If you are, you should have bought a true sport bike.

Your front end shimmy is tire related. Front end upgrades may mask it, but it is due most of the time to actual tire tread design or cupping.

 

[Mikesgts1000]

Did they check the steering head nut torque? I checked mine at the first service, and although it was tight (about 40 ft-lbs), the spec is 85 ft-lbs.

Rebuilding forks at 12000 seems early unless you're running in really dusty environments.

Motion Pro is selling a little plastic/synthetic wiper tool that they say can clean up a seal and stop a leak. No first hand experience with the product, so I can't vouch for it.... but its cheap enough to be worth a try if you actually have leaking. My sense from your post is that you do not have an obvious leak.

Time and type of use can be more important than miles on fork oil seal life, but on 07 is pretty young.

I have seen older low mileage ST1100s that needed fork rebuilds.

You could check the fork oil. If there are parts that have worn to the point of needing a rebuild, I would think the fork oil would be showing some signs. In a one year old bike with 12000 miles one would expect the fork oil to look "ok" rather than the sludgy grungy look it gets after several years and a bunch of miles.

FWIW, its a messy job in my experience, and you usually need some special tools to get the fork fully disassembled (special socket on a long extension). Sometimes the Haynes manuals will give you tips on making special tools so you don't have to shell out the bucks for the official tool.

It could be a tire issue that they're avoiding because they sold you the tire and they would rather charge you for another job rather than fix the last job.

If the fork rebuild turns out to be necessary at 12000 miles, it would seem that it would be a warranty issue. I suppose technically bushings are "wear parts," But most folks would agree that bushings ought to last 12000 miles.

Hi, I've used those fork seal "thin plastic" cleaning tools on my old ST1300 and it cured my leaking left side fork seals. Road it for many years after and didn't see any more leaks! Was worth the $5.00 and wasn't that difficult to do, I'd use it again on my FJR but can't find it anywhere!