Bent Fork Tubes

[SacramentoMike]

First of all, I don't post much in this sub-forum 'cuz I'm not a very technical guy, which means I don't understand what the heck you're talking about most of the time. But maybe if I ask my specific question, I'll learn something.

I got a pair of almost new Gen 2 fork springs a while back, and today I took them to Roseville Yama to switch with my old ones (and switch my old shock too). Dean comes back to me looking sad and calls me in to look at the worn bushings at the bottom of the fork tube. Worn on ONE side, but OK on the side 180o away. So yes, replace the bushings, sez I. A while later, here comes Dean again, looking even sadder. Shows me the disassembled fork tube, and the rod that comes up inside it is way off center, instead of riding right in the middle where it should be. Well, the tube's bent like a piece of elbow macaroni. Which explains why the bushing wore down, for one thing. I've got NO idea how [it or they] got bent, or how long it/they have been like that (they didn't disassemble the other fork to check for straightness). Since they didn't have a spare set of tubes handy, they just reassembled from there and sent me packing with my front end the way I brought it in. I've got the new bushing and the new spring in my tail bag right now.

So here's the question. Or questions. How safe or unsafe is it to ride around with this slight bend in my fork tubes? (The macaroni thing was an exaggeration, but if you roll it on a flat table you see the gap under it appear and disappear.) Is it anything but automatic that if the right tube is bent, the left one is going to be equally bent? What I'm really wondering is whether I need to rush to get this fixed as soon as I can, or is it just kind of "not perfect," but OK till some more convenient time? Like the end of the summer? After a couple planned long rides? It's another $500 or so that I'd just as soon hold off on spending for a while, for one thing, but of course I will for safety. Appreciate your thoughts.

 

[allrider]

First of all, I don't post much in this sub-forum 'cuz I'm not a very technical guy, which means I don't understand what the heck you're talking about most of the time. But maybe if I ask my specific question, I'll learn something.

I got a pair of almost new Gen 2 fork springs a while back, and today I took them to Roseville Yama to switch with my old ones (and switch my old shock too). Dean comes back to me looking sad and calls me in to look at the worn bushings at the bottom of the fork tube. Worn on ONE side, but OK on the side 180o away. So yes, replace the bushings, sez I. A while later, here comes Dean again, looking even sadder. Shows me the disassembled fork tube, and the rod that comes up inside it is way off center, instead of riding right in the middle where it should be. Well, the tube's bent like a piece of elbow macaroni. Which explains why the bushing wore down, for one thing. I've got NO idea how [it or they] got bent, or how long it/they have been like that (they didn't disassemble the other fork to check for straightness). Since they didn't have a spare set of tubes handy, they just reassembled from there and sent me packing with my front end the way I brought it in. I've got the new bushing and the new spring in my tail bag right now.

So here's the question. Or questions. How safe or unsafe is it to ride around with this slight bend in my fork tubes? (The macaroni thing was an exaggeration, but if you roll it on a flat table you see the gap under it appear and disappear.) Is it anything but automatic that if the right tube is bent, the left one is going to be equally bent? What I'm really wondering is whether I need to rush to get this fixed as soon as I can, or is it just kind of "not perfect," but OK till some more convenient time? Like the end of the summer? After a couple planned long rides? It's another $500 or so that I'd just as soon hold off on spending for a while, for one thing, but of course I will for safety. Appreciate your thoughts.

I don't know the definitive answer here but i do know two things that might help. These forks wear bushings and they do it unevenly, according to the experts at Racetech that replaced mine at 7000mi. Slightly bent fork tubes can be straightened fairly easily, given the tube itself is not scared beyond repair and can't seal, which i don't think is an issue with yours or you would have mentioned it.

I haven't done this in a while, but you could try turning the tubes so the bend is curved forward and then run it against a solid wall a few times. That's what we did when we smashed the **** out of our dirt bikes when we were kids. It worked once in a while...

 

[Bustanut joker]

Good question Mike. I have to wonder if it's unsafe as they have no doubt been bent for awhile..

More like an unneeded expense kinda thing as the bushing may wear unevenly.

I would think if it got so bad you noticed the handling adversely effected it might become unsafe. :huh:

 

[rogdeb]

I rode on slightly bent fork tubes for a year before a mechanic found they were bent when I was in for a re-build of them. I couldn't feel they were bent -- wouldn't have known what to feel for anyway :huh:

 

[FJRBluesman]

IMO Mike, now that you know, don't push it, get it fixed. I wouldn't chance any suspension or controling part of the bike being bent, broken, etc.

Good luck.

 

[FJRay]

Bushings will tend to wear on one side because of the loading. If there wasn't any rake to the front end then the wear would be more uniform. If you were riding it before it isn't any more dangerous now than it was then. The forks on the FJR are pretty big and quite strong so I wouldn't worry about it a lot.

To find out just how bad they are you need to get them in a lathe or on a precission straight edge and measure the run out. I have straightened a number of them and have had good results. Ther is a guy in the midwest that does a good job. I think its called Forking by Frank. He is well known for his work on BMW forks.

 

[madmike2]

Mike, I think there's a guy in Sacramento who will straighten forks. The Frame Man, just off Business 80 near El Camino or Marconi. I think the guy just works on motorcycles (motorcycle frames, etc.). You could use Google or try the phone book and give them a call.

 

[SacramentoMike]

I rode on slightly bent fork tubes for a year before a mechanic found they were bent when I was in for a re-build of them. I couldn't feel they were bent -- wouldn't have known what to feel for anyway :huh:

But once you knew they were bent, what did you do? Never mind, I'll ask you at breakfast Saturday. Right now it's replace, repair, or ignore.

Agreeing with Simon, can't really relax with no. 3, and at least with the first option I don't have to worry about how good of a repair job somebody does. But I will do some price comparisons too. Thanks for the replies, and feel free to add more.

 

[charismaticmegafauna]

...Right now it's replace, repair, or ignore. Agreeing with Simon, can't really relax with no. 3, and at least with the first option I don't have to worry about how good of a repair job somebody does. But I will do some price comparisons too.

Thanks for the replies, and feel free to add more.

I see you're in the 'crash club' -- do you think that was the cause of bent fork-tube? If so, you may also want to check for a broken steering stop (do the h/bars turn more in one direction than the other?).

The FJR's fork-tubes are relatively large diameter but thin-walled. They get strength, in some areas, from the diameter -- but lose, in other areas, from the thin-wall. Still, many m/c fork-tubes have been successfully straightened over the years. Thin-wall being a bit more susceptible to damage from the press/tools.

A good, old-line/machine-shop-style, motorcycle shop should be able to easily handle the job.

 

[exskibum]

I see you're in the 'crash club' -- do you think that was the cause of bent fork-tube? If so, you may also want to . . . .

Not on the present bike, charisma.

The crash club incident was on his previous FJR, which was totaled on the way to NAFO in '08. Mike then rode a KLR 650 for a year or so before finding and buying his present FJR.

 

[charismaticmegafauna]

I see you're in the 'crash club' -- do you think that was the cause of bent fork-tube? If so, you may also want to check for a broken steering stop (do the h/bars turn more in one direction than the other?).

Not on the present bike, charisma.

The crash club incident was his previous bike, which was totaled on the way to NAFO in '88. Mike then rode a KLR 650 for a year or so before finding and buying his present FJR.

OK, that helps -- (I assume?) he bought this one used? How much does he know of its history? Hit a pot-hole? Curb? Bent rim?

(we know the fork-tube is bent -- just trying to 'flesh-out' the whole issue, if there is one...)

 

[FJR-RemingtonRider]

Well just having experience this just last week, I'll chime in.

On my 08' I took the tubes off the bike and took them to a Yama shop in Conroe, Tx.

It was difficult getting the axle out, the pre-load would not release and I had to tap the axle out with rubber mallet.

They were to change the oil and the seals, because one was leaking.

I had purchased the seals and fork oil already from their parts dept. $70.00

Turns out, they let me know that both tubes were bent, the right more than the left, and the left bushing was worn.

They quoted me $398.00 on New tubes($190.00 per) and one bushing + $160.00 in labor (remember forks off the bike).

.

I don't play with forks, so I chose to order the parts myself from Babbitsonline.com

Paid $138.00 each per fork and bought bushings for both sides. (With savings, bought some FZ-I mirrors..another story)

.

Waiting is hard, Babbits took 6 business days...better than they quoted on delivery time.

Spent that wait time cleaning the calipers and rotors which were covered in brake dust and fork oil.

Took the parts in and had the shop put it together.

.

They feel fine and I can ride with much more confidence than before.

So my .02 is get it done.

 

[charismaticmegafauna]

...Turns out, they let me know that both tubes were bent...

Do you know why (what was the cause...)?

(sorry, didn't you buy this bike used...?)

 

[SacramentoMike]

I see you're in the 'crash club' -- do you think that was the cause of bent fork-tube? If so, you may also want to check for a broken steering stop (do the h/bars turn more in one direction than the other?).

Not on the present bike, charisma.

The crash club incident was his previous bike, which was totaled on the way to NAFO in '88. Mike then rode a KLR 650 for a year or so before finding and buying his present FJR.

OK, that helps -- (I assume?) he bought this one used? How much does he know of its history? Hit a pot-hole? Curb? Bent rim?

(we know the fork-tube is bent -- just trying to 'flesh-out' the whole issue, if there is one...)

Really don't know the cause (except that my crash is definitely eliminated ). The PO is a friend who took very good care of the bike, but who knows what pothole or whatever could have caused this? I know I've hit some holes and kept riding--everything seemed fine. Didn't shake any teeth loose or anything. One good thing is I do have faith in the shop, and they had their top dog on this job (many here know Aaron). I know he looked carefully for related problems. That's one reason I'm leaning toward the replacement option. "Better safe than sorry."

Now I just saw the last post from FJRRR--another "replace" vote. And there's one more thing, and another reason we like our Roseville boys. Without going into the whole story, they're going to give me a break on the labor cost and even the parts cost for what I had done today since it will involve two separate trips and separate teardowns. I feel like I've been treated very fairly, which of course is great for "customer loyalty." And I know they'll do it right.