fork bump stops?

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Jun 14, 2014 | 07:44 PM

hdkev

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Joined: Dec 2009

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fork bump stops?

I recently lowered my forks about 2". To me it looks like if I hit a bump hard enough the fender will hit the crash bar. Anyone know if there is some sort of bump stop inside that will limit travel before hitting? I put in the progressive drop ins with no spacer.

Btw, the directions said no spacer would only drop it 1" in a 2010 streetglide.

Jun 15, 2014 | 05:38 AM

Campy Roadie

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Joined: Aug 2011

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From: SW Ohio

There's a spring on the damper tube, underneath the lip, but it's for the forks topping out, not bottoming. So the short answer is, bottom is when springs are fully compressed and/or the full length of travel has been used. I can't answer about the "will it contact?" part of the question.

Last edited by Campy Roadie; Jun 18, 2014 at 04:31 AM.

Jun 15, 2014 | 05:43 AM

petdoc94

Outstanding HDF Member

Joined: Jun 2007

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From: St.Pete Beach

I was considering lowering my SG, but I think I will listen to a few stories before attacking the beast...

Jun 15, 2014 | 05:47 AM

Lowcountry Joe

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Joined: Sep 2007

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From: Near Myrtle Beach, SC

Harley's are already plagued with limited suspension travel, lowering only exacerbates this problem. You are wise to be concerned.

Jun 15, 2014 | 07:10 AM

shakrr

Road Master

Joined: Sep 2008

Posts: 799

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From: central Il

I lowered mine 1" with race techs and stock fender, and hit a big bump and dented my fender a little on the crash bar. I am now back at stock height with my new fender

Jun 15, 2014 | 07:24 AM

Iceman24

Seasoned HDF Member

Joined: Sep 2009

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From: Eastern NE

Just like lowering a cage...steer clear of large bumps and speed traps...they'll bite.

Jun 15, 2014 | 07:50 AM

FastHarley

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Joined: Apr 2007

Posts: 5,360

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From: Davie, FL

Differences

The OP's system is a cartridge system. I have no idea if they either do or not have bump stops. By removing the spring (if you can) and collapsing your fork to hard bottom out and making sure you do not have a softer spacer between the piece that is over the damper rod (if in fact they have this in their system) and the body where the piston is. Measure the fork L.O.A. in both fully extended (to see if your brake lines are long enough) and fully collapsed (to see if there is any interference) This should have been done prior to installation.

This is an Ohlins 30mm cartridge I make for Harleys for example of the bump stop. Look at the top cartridge and look at the spring guard (white), length spacer (aluminum) and the hard rubber bump stop. It does not matter if the fork shell is an inverted XR1200 or a conventional fork as the cartridge works the same.

It is very unlikely that the bottom of the piston/damper rod has a bump stop on it where it could hit the bottom of the cylinder tube. Those are non-rebuildable (by the customer) gas shocks.

The damper rod (OEM) system used also with RT emulators do not work as aforementioned. The stroke is limited by the oil lock stopping against the check valve that is inserted during manufacturing and compressed inside of the bottom of your fork. The only way to to provide more space between your fender is either by dropping your fender in relationship to the fork fender mounts (shorting the distance) or raising your forks by purchasing a longer fork tube or, if you can & the top tree clamps around the fork such is in Dynas, Sporters, and the 2014 bagger, raise the fork tubes.

Your damper rod system and OEM cartridge emulator (2006~2013 FLT) below.