Lefty DLR 2000 Servicing Notes

Disclaimer:
For the safety of you, your Lefty, everyone and everything else on this or other planets, in any dimension, only a fully qualified Cannondale mechanic should attempt a service on a Lefty. Needless to say, but I will... these notes are purely just for informational purposes, certainly not educational purposes, and should definately NOT be used, partly or completely, as a guide or even as advice to servicing a Cannondale Lefty, in any way, shape or form. What the heck are you thinking? If you don't already know how to service a Lefty, DON'T do it now, and if you do, certainly don't attempt it based on any information you find here. I didn't write it, so I'm unsure about it's completeness or correctness, I can't even recall where I found it, but probably in some forgotten corner of the Internet... under a pile of old socks... you know, those really stinky socks that were used on a 12 day trek in the rain and subsequently forgotten at the bottom of your kit bag. 3 months later you find them and in a moment of madness, you boil them with some old cabbage then lightly sprinkled with some blue cheese then left to dry in the sun, so they've now become a bit crispy around the toes but still a bit moist around the thread bare heel. These are the kind of socks that flies wouldn't touch.
...but I digress.
Although, I do suggest you to take the same philosophy to a Lefty as those flies did to the socks... Don't touch it, don't even think about touching it!
So if you break or damage something/anything/everything, including yourself, in the process of servicing your Lefty based on any information here, or anywhere for that matter, you've only got yourself to blame for everything. From the moment you look, touch, even think about your or anyone else's Lefty directly or indirectly... you're on you own and reponsibility lies with you... just you... nobody else but you.

Remember servicing a hydraulic suspension system such as a Lefty requires unique tools and substantial expertise and training. Only an experienced mechanic at an Authorized HeadShok Service Center should perform them. Based on praise and reccomendations from the www.mtbr.com Cannondale forums, one of the best is Craig Smith at The Mendon Cyclesmith.

YEAR 2000 LEFTY FORK TELESCOPE SERVICE

TOOLS REQUIRED FOR GENERAL SERVICE

• Lefty Castle tools (for cartridge removal) # HDTL200/
• Lefty clip removal / expanding plug tool
  
• 2x 10mm wrench for Lefty expanding plug tool
• Metric hex key set
• Park green pin spanner tool
• Small thin blade screw driver
• 3/8” ratchet or Park blue pin spanner
• Zip ties (HD175/BLK) or rubber bands (can be cut from a 700 x 35c inner tube)
• Double headed zip ties (HD185/BLK)
• Zip tie gun or diagonal cutters for zip tie cutting
• Needle bearing grease (Finish Line White Teflon grease, Slick 50 One Grease, or Royal Purple synthetic grease)
• Cable cutters
• Loctite 242 (blue)
• Micrometer or digital calipers
• Torque wrench

REPLACEMENT SPARE PARTS

• HeadShok needle bearings, pack of 4 HD161/
• Lefty lower collar HD207/
• Inner race retainer clip HD165/
• Outer race retainer clip HD208/
• Lefty frame bumper HD215/
• Lefty air cylinder saddle HD211/
• Lefty lockout dial HD213/BLK
• Lefty damping adjuster knob (red) HD214/
• Lefty dial plug assembly HD201/
• Lefty boot kit HD204/BLK or HD204/YEL
• Lefty filter and filter hood kit HD209/BLK
• Lefty upper crown clamp HD205/
• Lefty lower crown clamp and steerer HD206/
• Double headed zip ties, pack of 10 HD185/BLK
• Zip ties, pack of 50 HD175/BLK

CARTRIDGE REMOVAL

1. Unlock the cartridge by turning the large lockout knob counter-clockwise. Loosen the top clamp bolt and remove the lockout dial assembly. It may be easiest to pry it out with a thin small screwdriver.
2. Insert the tall castle tool into the fork leg and using a 3/8” ratchet or a Park blue pin spanner, unscrew the outer cap of the cartridge.
3. Completely compress the fork. This may be easiest to achieve by placing the bike upright on the floor. Slide the shorter castle tool onto the square flats under the cartridge outer cap.
4. Release the air from the Schrader valve at the bottom of the fork leg. Engage the teeth of the tall castle tool into the cartridge outer cap and use the tall castle tool to press the outer cap down into the fork leg. If you can’t push it down, the cartridge is locked out. Hold the cartridge outer cap and use a 19mm wrench to unlock the cartridge.
5. Applying slight downward pressure, rotate the tool counter-clockwise until the teeth of the smaller castle tool (under the outer cap) engage in the top of the cartridge body.
6. Unscrew the cartridge from the Lefty leg. Turn the bike upside down, and remove the cartridge, making sure not to drop it. Note the orientation of the cartridge body (top), the air cylinder (bottom) and the 25.5mm cylindrical plastic spacer between the two. Also be sure to keep track of the black plastic saddle which supports the air cylinder in the Lefty’s axle spindle.

FRONT WHEEL REMOVAL

The Lefty front hub uses a self-extracting bolt to attach the wheel to the Lefty's axle spindle. The bolt is held into the hub by a cap which is screwed into the non-disc side of the hub using a pin spanner tool. The self-extracting bolt and cap combination is very similar to that used on cranks, except that the Lefty hub cap has left hand threads. The cap should not be removed, it is there to hold the axle bolt into the hub. If you do need to remove the cap to replace the bolt, be sure to reinstall the cap with a drop of Loctite 242 (blue) on the cap threads. Remember that the cap will need to be turned counter-clockwise to be screwed in.

1. Using a 5mm Allen wrench, remove both disc brake caliper bolts from the fork. Take care not to drop any of the brake spacing shims which go between the fork's disc brake mount and the brake caliper. The wheel cannot be removed without first removing the brake from the fork.
2. Using a 6mm Allen wrench, unscrew the axle bolt which attaches the wheel to the fork's axle spindle in a counter-clockwise direction. Note that the bolt is held in the hub by the self-extracting cap, and will stay attached to the hub even when the wheel is removed from the axle spindle. There is no need to remove the cap from the hub.
3. Pull the wheel off of the axle spindle.

NOTE: It is not necessary to remove the front wheel from the Lefty fork to change an inner tube or tire. Simply remove the tire from the wheel as you normally would using a tire lever, making sure to pull the tire off of the nondisc side of the wheel.


NEEDLE BEARING SERVICE

1. Remove the front wheel as instructed in the Front Wheel Removal section. Then remove the brake caliper, and brake lines by carefully cutting the zip ties on the fork leg.
2. Loosen the three clamp bolts securing the Lefty leg and slide the fork down out of the clamps. You will need to remove the old style foam bumper between the clamps by sliding it up and off of the leg, the new style "C" bumper can be separated and removed.
   
3. Clamp the Lefty leg in a work stand.
4. Remove the inner race retainer clip from the top of the inner telescope using the Lefty clip removal tool. The technique is to completely compress the fork and slide the tool down into the Lefty leg so that the four angled tabs go into the “corners” between the four flat inner bearing races. Then turn the tool clockwise 1/4 turn while applying downward pressure. Pull the tool straight up out of the leg, and the race clip should be on the end of the tool. It may also be loose inside the Lefty leg. It may take several attempts to get the clip out, but with practice can be achieved in the first try. If having difficulty, try practicing on the inner race retainer clip in an in-head tube fork such as a Fatty.
5. Cut the tip ties on the filter hood and the top of the accordion boot. Pull the filter boot up and the accordion boot down, exposing the lower collar on the outer leg assembly.
6. Loosen the lower collar counter-clockwise with a Park green pin spanner and unscrew it completely.
7. Use a zip tie or piece of wire to tie the lower collar to the top disc brake mount hole, to keep it and the boot out of your way.
8. Slide the telescope down to the point where the bottom of the outer leg is just below the bottom of the inner race flats on the inner steerer tube.
9. Use a tip of one finger to press one of the outer races inward. Then move to an adjacent race and using a small thin screwdriver, press it inward and pry the outer race retaining clip out. Moving your way around the fork, release the other outer races one by one until the clip is free.
10. Extend the Lefty leg until the bottom of the needle bearing strips just show below the outer leg. Then insert the expanding plug tool in the top of the fork leg and use two 10mm wrenches to hold the upper nut while turning the lower nut clockwise. This will expand the rubber plug at the end of the tool, holding the outer races in place.
11. Use two zip ties or the rubber bands cut from an inner tube to hold the inner races in place against the inner steerer tube. Then put a mark on the outer tube where it lines up with the axle spindle to be sure that the orientation is correct when you reassemble the leg.
12. Slide the outer tube up until 6 needle bearings on each bearing strip protrude from the bottom of the outer steerer tube. Use another zip tie or stretch another rubber band over the four strips of needle bearings to hold them tightly against the inner steerer tube.
13. Make one final check to ensure that the inner races are secure to the inner steerer tube, the outer tube races are secured within the outer tube, and the needle bearing strips are held to the inner tube. Then slide the outer steerer tube off of the end of the inner steerer tube.

Now, the races may be removed for cleaning, inspection, and possible replacement. Remove only one race at a time, clean it, and then replace it. It may be helpful to number the steerer tube faces and corresponding races as shown. This will make sure that the fork is reassembled with the races arranged originally. If you forget, inner races can be identified by the oval hole in the top of the races, while outer races have a tab at the bottom of the race. If you have trouble removing the outer races from the outer leg tube, you may need to reduce the compression on the rubber plug using the two nuts at the top of the expanding plug tool.

It is very important that the races be reassembled exactly as they were originally positioned!


INSPECTION AND RACE REPLACEMENT

1. Clean and inspect the races as you remove each one individually. Pitted or corroded races must be replaced with the same thickness and length race. The thickness must be measured with a micrometer or digital caliper, as the thickness must be precise to within .001”. See the list of available needle bearing races for replacement part numbers.
2. If there is any sign of corrosion or pitting, all four needle bearing strips should also be replaced. They should be coated with one of the needle bearing greases named above, and then installed with the angled corners facing out from the inner steerer tube (the wider side facing in towards the steerer tube).
3. If bearing migration (loss of travel) is the reason for the telescope service, note whether one (or two adjacent) bearing strip(s) have moved down the inner steerer. If so, replace the corresponding inner races with a race that measures .001” thicker. You should only need to replace one, or at most two adjacent races with the next thicker race to increase the preload on the needle bearings.
4. If you want to replace the accordion boot, it is easiest to do so now while the outer tube is removed from the inner steerer tube. Make sure that the lower collar and lower race clip are in place before you start to reassemble the Lefty.

REASSEMBLY

1. Make sure that the races are correctly positioned. This means that the inner races should have the bottom of the race clip hole flush with the top of the inner steerer tube, and the top of the outer race clip slot in the outer races is flush with the shoulder inside the bottom of the outer tube. This will allow the outer race clip to be positioned correctly.
2. Coat the needle bearing strips with one of the above named greases. Needle bearing strips should be held to the inner steerer tube using a zip tie or rubber bands so that 11 needle bearings are above the edge of the inner steerer tube (not the inner races) and 11 are below the top of the inner steerer tube. Make sure that the shaved corners of the strips are facing outward.
3. Align the axle spindle with the mark you made on the outer tube and slide the outer tube onto the inner steerer tube very carefully. Make sure that the needle bearing strips align with the outer races correctly, and that all four needle bearing strips stay in alignment at the same relative position on the steerer tube.
4. Once the two tubes are overlapping, remove the rubber bands or zip ties from the bearing strips and inner races. Slide the outer tube down until it stops, then loosen and remove the expanding plug tool.
5. Slide the outer tube down to the point where the bottom of the tube is just below the bottom of the inner race flats on the inner steerer tube.
6. Using your small thin blade screwdriver, reinstall the outer race retaining clip. The bottom of the outer race retaining clip should sit flush with the bottom edge of the outer tube.
7. Apply a drop of Loctite 242 (blue) to the threads on the bottom of the outer leg, and screw on the lower collar using the Park green pin spanner wrench.
8. Pull the accordion boot up over the lower collar, and slide the filter and filter hood down to the boot. Use new zip ties to secure the boot and filter hood in place. One standard zip tie should be used to secure the bottom of the filter hood and the top of the boot simultaneously. A double headed zip tie should be used to secure the top of the filter hood. Do not run the zip tie tail back through the locking mechanism, you will need to do so after reattaching the disc brake.
9. Position the inner race retaining clip on the Lefty clip removal tool as shown in Completely compress the fork and insert the tool into the fork leg so that the square tabs of the race retaining clip go into the “corners” between the four flat inner bearing races. It may take a bit of wiggling to get the tool all the way down into the fork leg. Turn the tool clockwise 1/8 turn while applying downward pressure. Then pull the tool straight up out of the leg, and look to see if the race clip is in place. You may need to insert the tool again and rotate the clip clockwise a bit more until the square tabs of the clip are correctly located in the holes in the top of the inner races.
10. Reinstall the Lefty leg into the fork clamps, making sure that the rear brake and rear derailleur cables run through the clamps, between the head tube and the Lefty leg. Also make sure that you reinstall the bumper on the leg, between the two clamps. Tighten the two lower leg clamp bolts to 55-65 In-Lbs (6.25-7.25 Nm).
11. Reinstall the front wheel as instructed in the Front Wheel Installation section. Then reinstall the brake caliper and brake lines using new double headed zip ties. Make sure that the loop in the zip ties for the brake tubing is not cinched tight, but left open to allow the tubing to slide freely through as the fork is compressed and extended.

FRONT WHEEL INSTALLATION

1. Make sure that the front disc brake is not attached to the Lefty disc brake mount. It is not possible to install the wheel with the brake installed on the fork. If necessary, remove both disc brake caliper bolts from the fork using a 5mm Allen wrench. Take care not to drop any of the brake spacing shims which go between the fork's disc brake mount and the brake caliper.
2. Apply a light coat of good quality bicycle grease to the flat bearing seats on the tapered axle spindle of the fork. Also smear a little grease on the axle bolt threads inside the end of the axle spindle. Take care not to get any grease on the disc brake or brake rotor attached to the hub.
3. Slide the front wheel onto the axle spindle with the disc side of the hub closest to the fork leg. Make sure to press the wheel straight onto the axle spindle so that the bolt threads will correctly engage with the threads in the spindle. Using a 6mm Allen wrench, tighten the axle bolt to 80 In-Lbs (9 Nm).
4. Reinstall the brake caliper to Lefty's disc brake mount. You will need to first slip the caliper over the brake rotor so that rotor runs between the brake pads. Check to be sure that both brake pads are in the caliper. Remember to include the correct number of shims between the disc mount and the brake caliper to center the caliper over the brake rotor. Be sure that the shims are on the inside of the fork's disc brake mount, not directly under the head of the caliper bolts. Using a 5mm Allen wrench, tighten both brake caliper bolts to 69-78 In-Lbs (8-9 Nm).

CARTRIDGE INSTALLATION

1. Make sure that the smaller Lefty castle tool is in place under the top cap of the cartridge, and slide the cartridge up so that the teeth on the tool engage the cartridge body. The hex on the top of the cartridge must be unlocked (rotated counter-clockwise).
2. Check that there is an O-ring in place on the cartridge body above the cartridge threads. Also, apply a drop of Loctite 242 (blue) to the cartridge threads.
3. Assemble the two halves of the cartridge together, making sure that the white plastic spacer is placed between the air cylinder and the oil damper.
4. Insert the cartridge into the Lefty leg
5. With the fork completely compressed (easiest if the bike is still sitting on the ground), use the tall Lefty tool to screw the cartridge into the fork.
6. Inflate the air spring to about 50 psi, so that the top cap extends above the fork leg.
7. Remove the shorter castle tool, and completely extend the fork. This may be easiest if the bike is now hung in a work stand so that the weight of the front wheel pulls the fork down.
8. Use the tall Lefty tool to screw in the top cap of the cartridge.
9. Reinstall the lockout knob and damping knob assembly, and tighten the top crown clamp bolt to 55-65 In-Lbs (6.25-7.25 Nm).