Lindemann Engineering Fork rebuild/revalve/respring

Lindemann Engineering Fork Services

My fork seals finally gave up the ghost after 20K miles and 22 years. I called up a couple shops about getting a rebuild, and the quotes were all in the $250-$270 range. I'd been thinking about either springs or valve emulators. One shop wouldn't touch them (rebuilt only), another would only charge an extra hour of labor for the emulator install (but I'd need to buy them from RaceTech). The first shop, however, recommended that I talk to Jim Lindemann if I was going to go for any sort of respring/revalve.

I swapped a few e-mails with Jim, and he explained his views on why he prefers to rebuild damper rods vs. trying to use a cartridge emulator. He sold me on his expertise, so I took the bike apart (surprisingly easily), and dropped them off at his shop (which incidentally turned out to be closer than any Honda shops are to me).

When I dropped them off, Jim asked for my weight (without gear), and where I rode it, street/track. Since my daily commute includes 16-17 miles of CA Hwy 9 (google maps link), some of the best riding around, I further specified that I rode up there (vs. city/highway).

The springs were upgraded from the stock ~0.5kg/mm rates to 1.0kg/mm ones, and I'm not sure what they ended up doing with the damper adjustments, or the weight oil they used.

They had the forks for 10 working days, up from the estimate of 4-6. I called on day 10, and they were "just finishing up", so not sure if they got lost in the shuffle, or just busy. Either way, it wasn't going to change when I got the bike back together (work's been rough recently, lots of long hours to hit a deadline).

I did have one hiccup in the whole process. I put the bike back together last Sunday, which was almost as easy as disassembly was. Except that I didn't have a clutch when I was done. The left clip-on had been on it's side on the upper triple-clamp while the forks were in the shop. This resulted in the master losing it's prime, and needing to be bled. Remembering my previous experience bleeding the clutch master (and rest of the clutch system), I built my own adapter for my Motive Power Bleeder (link here), and used that.

Finally today, I had a chance to get out riding on it. Um.. Wow. :smile::smile::smile:

The difference is simply astounding. I was worried that with the stiffer springs, it would be really harsh (as my stiffly sprung truck was), but the damping is just perfect. The bike lets you feel the surface, but doesn't beat you over the head with it. Big bumps are far more composed, and small ones are noticed, but not bothersome.

But it's reaction to my inputs is what's most changed. There's less hesitation before it starts turning in than before, but it's not at all twitchy. It very much goes where I point it. Mid-turn, it's far less reactive to my ham-fisted inputs (this is good), but making small corrections is easier than before.

Hard braking is where the new spring rates really shine. The dive under braking seems to be less than half (doubled rate + better damping), but it's the rebound which is wonderful. Instead of popping back up, it's nice and gradual as you come off the brakes and lean it over into a turn.

In general, I found myself carrying more speed, and feeling like I had more control, and FAR more of a margin of safety than before.

I can only hope that the new struts for my WRX are going to have this much of an effect. (replacing 100K mile blown stock units with Tokico D-Specs, but keeping the stock spring rates).

 

nice write up.

i've wondered what all the fuss was about new suspenders.

you describe a desirable effect.

thx
bob

 

desirable is an understatement... :smile:

 

Lindemann has built all my race bike front ends and has helped greatly with the rear shocks on them. I never thought to have him do anything with the "junky" damper rod forks. I should have known he could do magic with them, too.

 

Apparently the SV650s run damper rod forks, and he works on a bunch of privateer AMA SV650 race bikes.

 

'Most' SV's around here on the track have GSXR 600 front ends on them. Nice fully adjustable forks. If you run in SS and have to run the stock externals, then they have all new internals that are adjustable. I don't think there is a single 'stock' damper rod fork in the lightweight village at our races.

 

I wasn't certain exactly how much modification you can get away with. I was assuming AMA Pro was similar to SCCA GT1/2/3 with the modifications that you can run.