SR500 Forks extension options

[flamesnm]

Hi All. I can see a few SR500 questions on here, so thought it was worth an ask. I'm looking to raise my ( new to me, and now running ) SR500 up as it's a new project that I want to make into a taller custom scrambler. I appreciate the better move is to start with a TT/XT but this bike came to me unexpectedly so I'm moving forwards with what I've got. I had originally thought it would be a straight swap for a TT/XT front end, but the those are 36mm to the SR 35mm and are a hub front brake.

The dumb question is whether it's just a case of getting longer fork tubes, appropriate springs and maybe spacers to accomodate ? It's never that simple. I appreciate long tubes will change the geometry without other changes, but I want to keep it simple for now before I look at more complex options.

 

[jetmechmarty]

https://franksforks.com/

 

[arcticXS]

Hi All. I can see a few SR500 questions on here, so thought it was worth an ask. I'm looking to raise my ( new to me, and now running ) SR500 up as it's a new project that I want to make into a taller custom scrambler. I appreciate the better move is to start with a TT/XT but this bike came to me unexpectedly so I'm moving forwards with what I've got. I had originally thought it would be a straight swap for a TT/XT front end, but the those are 36mm to the SR 35mm and are a hub front brake.

The dumb question is whether it's just a case of getting longer fork tubes, appropriate springs and maybe spacers to accomodate ? It's never that simple. I appreciate long tubes will change the geometry without other changes, but I want to keep it simple for now before I look at more complex options.

Do you just want more ground clearance, or also increase suspension travel? I see that the SR, just like the XS650 has 6" of suspension travel. It is possible to increase this slightly by extending the damper rods, but that will decrease overlap between fork tubes and sliders.About the only vintage road bikes with longer travel forks are 70s BMW. These have 8" travel, but have 36 mm tubes and are leading axle. And a very awkward caliper mount. Generally, longer travel forks have leading axle, in order to maintain sufficient overlap between tube and slider. Using a leading axle fork requires different triple trees, otherwise the trail may become too short.
I guess you could also look at newer, smaller offroad bikes/ playbikes for fork and wheel options. 250 cc and smaller.

 

[flamesnm]

Thanks arctixXS and jetmechmarty for getting back to me. I'll get in touch with Frank's Forks to see what he advises.

The aim is to get more ground clearnance and more suspension travel. I want to raise the bike some because I'm tall and it looks like a kids bike under me But I'm also looking to give it a little more suspension travel to give it a little light offroad capability.

Definitely up for swapping out the front end for something more recent. I got into the alls balls conversions, but it assumes road bike to road bike conversions so there's no real info on there I can use.

 

[jetmechmarty]

There’s a bunch of stuff on Sportster to Dirtster conversions on the internet. Low Brow did a video series on building one. I’m sure that’s a lot of transferable information.

 

[arcticXS]

If you end up just using longer tubes, I definitely recommend looking into springs and emulators (adjustable compression damping valves) from RaceTech. In fact, the KTM 390 Adventure does not have much more fork travel than the. SR and XS. A well set up stock SR fork may work better than a random fork fitted as is, without specific setup for bike and rider weight.