help fork tubes

Energy One

bruce

Active Member
I started my winter maintenance, I am doing the front front seals, etc. well when I got the first fork apart I noticed that the fork tube has wear marks enough so that you can feel them, so I am assuming that I have to replace them. I called bigdog and it was suggested that I buy them from forks by frank. does anyone have any other info, and is it normal for these to wear with only 17000 miles. thanks you in advance.
bruce
 

Raywood

The Pirate
Staff member
Calendar Participant
Troop Supporter
Bruce, I'm moving this to the appropriate section.

As for the forks mine are shot also so I would ask if you them serviced at the 10,000 mile mark as required? When the seals wear out they start eating into the tube and it's just "wear and tear"! Mine are worn to the brass or copper coating and leak like hell. I stuff the caps full of blue paper shop towels to collect it.
By the way, DV on here has suggested that we even increase the amount of times we re-build them due to the amount of friction/leverage they receive due to there length.

Forking by Frank is a well know company and you can google their address. Or shop on eBay for tubes sold by Shovelheadkicker.

:cheers:
 
Last edited:

Sparks

Chopper Junkie!
Bruce, I'm moving this to the appropriate section.

As for the forks mine are shot also so I would ask if you them serviced at the 10,000 mile mark as required? When the seals wear out they start eating into the tube and it's just "wear and tear"! Mine are worn to the brass or copper coating and leak like hell. I stuff the caps full of blue paper shop towels to collect it.
By the way, DV on here has suggested that we even increase the amount of times we re-build them due to the amount of friction/leverage they receive due to there length.

Forking by Frank is a well know company and you can google their address. Or shop on eBay for tubes sold by Shovelheadkicker.

:cheers:
Forking by frank will also do custom lengths for any bike. I've had him do a several sets for me over the years. here's a link
Frank's Maintenance and Engineering, Inc.
 

dogvet

Banned
I haven't seen a set of forks go 10,000 miles without needing the bushing seals and lower legs in need of replacement. It's not the seals wearing out, the bushings wear out (they're teflon coated) once the coating is compromised, the bushing wears into the aluminum lower leg). If you see copper on the bushing, Damage is already done!

The scoring on the fork leg is also the result of bushing wear (and the fact that on many of the front ends I've disassembled at the factory, typically the washer under the seal is installed upside down.

This was an issue I had been trying to get BDM to address for years. They did start using H-D bushings and seals as repair items. Since I was let go today, I thought I'd give an additional :zz2cents:
 

TCALZ06

Well-Known Member
Bruce, I'm moving this to the appropriate section.

As for the forks mine are shot also so I would ask if you them serviced at the 10,000 mile mark as required? When the seals wear out they start eating into the tube and it's just "wear and tear"! Mine are worn to the brass or copper coating and leak like hell. I stuff the caps full of blue paper shop towels to collect it.
By the way, DV on here has suggested that we even increase the amount of times we re-build them due to the amount of friction/leverage they receive due to there length.

Hi Ray,

What was your mileage when this happened?
I've had my fork oil changed as required in the manual and my seals don't leak or leave residue on the fork tubes more than they did when it was new.
I just had my neck bearings done and was told they looked good.
 

Loafington

Active Member
I haven't seen a set of forks go 10,000 miles without needing the bushing seals and lower legs in need of replacement. It's not the seals wearing out, the bushings wear out (they're teflon coated) once the coating is compromised, the bushing wears into the aluminum lower leg). If you see copper on the bushing, Damage is already done!

The scoring on the fork leg is also the result of bushing wear (and the fact that on many of the front ends I've disassembled at the factory, typically the washer under the seal is installed upside down.

This was an issue I had been trying to get BDM to address for years. They did start using H-D bushings and seals as repair items. Since I was let go today, I thought I'd give an additional :zz2cents:
Can you show in a diagram the correct installation?
 

stig

cycomutha
are there part numbers for all the wear items that need to be replaced? seals,bushings etc. was gonna do mine this winter, and replace all the wear items, but would like part names and numbers to make it easy..was hoping to get them thru nelson?
 

dogvet

Banned
Can you show in a diagram the correct installation?
Its a stamped washer, the curved (concaved) side of it goes down towards the bushing.

BDM just uses cool CAD drawings to make their manual look cool but it's quite lacking in useable content.

I happened to be in engineering the other day and their "tech" was overhauling a set of forks. the bushings were shot and I asked him if he ever looked inside the fork tube to see what's going on and he said no. I had him take a look in the fork leg (slider) to see where the wear in the leg was from the lower fork bushing wearing out the aluminum. Boy was he surprised.

As senior test technician, I would have oil samples analysed and in every case, aluminum wear metal was off the scale (over 999 ppm).

Once this wear occurs, your front end needs a new set of lower legs and if the tubes are scored, they need to be replaced too.
 

Raywood

The Pirate
Staff member
Calendar Participant
Troop Supporter
I happened to be in engineering the other day and their "tech" was overhauling a set of forks. the bushings were shot and I asked him if he ever looked inside the fork tube to see what's going on and he said no. I had him take a look in the fork leg (slider) to see where the wear in the leg was from the lower fork bushing wearing out the aluminum. Boy was he surprised.

As senior test technician, I would have oil samples analysed and in every case, aluminum wear metal was off the scale (over 999 ppm).

Once this wear occurs, your front end needs a new set of lower legs and if the tubes are scored, they need to be replaced too.

Those may have been my forks. :D
 

Raywood

The Pirate
Staff member
Calendar Participant
Troop Supporter
Hi Ray,

What was your mileage when this happened?
I've had my fork oil changed as required in the manual and my seals don't leak or leave residue on the fork tubes more than they did when it was new.
I just had my neck bearings done and was told they looked good.
TCAL, if I remember right I never had them done till about the 19,000 mile mark or so..... So was my fault that they are worn out. I had them done again this year in Tampa and they told me the forks were shot and would need replacing.

I would heed DV's advise and have then done regularly as there is a lot of stress on them longs fork legs.

:cheers:
 
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