front fork bottoms on hard decel at stop lights

[elader]

Well when I bought the bike, my buddy told me that the bike (07 GS500f) was known to have soft front springs and I should get progressives. However the shop suggested i ride for a while and see if I had issues. As a new rider, i don't know what issues are I suppose. But in the 1200 miles i have driven the bike, I have made a few aggressive stops at stoplights due to the light changing suddenly. If the surface is rough, I have had the fork clunk clunk - i assume it was bottoming out. Yes I am stopping with both brakes.

So is this what the shop was suggesting I 'watch out for'? I also assume there is no way to adjust the preload on the shocks? Is there a specific thing that GS500 owners do? Should I just bring it to the shop for it's next service and just have them swap the springs?

[Homer]

Yes.

[sledge]

WB Homey 

[rger8]

Just put 20 wt. oil in the forks for a significant improvment That just might do it!

[Homer]

Thanks.  Fresh air, and all that.  

[kman]

different springs can help.  Longer spacers can be installed, the equivalent of more preload.  There are a number of threads on front end mods ranging from changing the fork oil to changing to the katana front end. 

I have noticed the same thing braking hard on rough roads but I have not tried anything to fix it.  I be hesitant to change the oil without changing the spring rate since it will change the damping ratio.

[Jeff P]

I switched my '96 to Progressive springs 5 or 6 years ago.  I don't exactly recall what the bike was like before them, but it certainly doesn't bottom out with these, even during quick stops.  I'm 185 lbs, not sure how much rider weight affects it.

If you have the tools and are feeling a little adventurous I'd recommend trying this out yourself.  It's not that difficult and can be a fun learning experience.

jeff

[burning1]

Kman, the spacers are what give the fork pre-load, so lengthening them isn't just the equivalent of adding preload. :teeth

Going to 20 weight oil probably won't prevent the forks from bottoming out. It can help slightly, but the stock springs are almost certainly being overloaded by the forces generated by braking, not by the inertia caused by brake dive (which is what fork oil would correct.)

Stiffer springs (and oil) are the correct solution. Stock, the GS already has lots of pre-load on the forks.

[lamoun]

Also you could try filling the forks with some more oil. (10 - 20mm more)

That way you increase what is called "air spring" resulting a stiffer "spring" when approaching bottom out.

The other thing you can do is either cut a bit of the spring, flatten the top and add the appropriate spacer (hard) - or better find some way to bind a number of coils.

That way you effectively increase the spring rate for free!

[mass-hole]

I was having similar problems to what you are experiencing, not so much during braking but the tiniest bumps would just absolutely crush the front and it would bottom out. I just installed new, non progressive springs in the forks that are like .85 kg/mm compared to the stock ones that were something around .60 kg/mm and the difference is amazing. no bottoming, handles much better and it causes the front to ride a tiny bit higher. I was having trouble staying back on the seat but because the seat is not slanted so far forward its much more comfortable. I also did 15 mt fork oil but i cant attest to that since i did the springs at the same time. Anyways i highly recommend looking at some sort of springs for the front.

Jay

[fraze11]

For me it was night and day.  I rode my first 1000kms with the stock springs and by the time I hit my first 1000 service I was getting annoyed, the stock ones are no doubt "mushy".  I put a set of progressives in and it was the single greatest thing I could have done.  Love it.  Do it.  

Sniff around on ebay, I picked mine up there for 65 bucks new....even if you dont them for that, they can be gotten for under 100 at several places.  Its well worth it in my opinion.