Racetech spring installation

[giantkillerrobo]

Hi All,
I'm a reasonably new member here, with an 06 Silver that I picked up new several months back. I've put ~1200 miles on the bike, with my wife stealing it for the other 300 miles, we both like the tractability of the motor and the overall ease of riding the beast - it intimidates her much less than my SV1000 used to. Smooth power delivery, all day ergos, and good handling have really won us both over to Triumph, she is considering a Tiger as an all-day alternative to her SV650S.

The praises having been sung, there have been a couple of minor improvements I've been wanting on the bike. Wanting to put a bit more Sport into this Sport-tourer, I started looking at suspension and handling to increase the fun factor of the bike. The triple makes more horsepower than I can reasonably use, so brakes and suspension are the orders for the day. I installed 6-pot calipers after the 500 mile service, I plan on riding for a crummy 4-5 month Portland winter in rain and muck and do not want to deal with any brake issues. Likewise, the front end has always been a bit soft for my tastes, I've given myself a good scare a couple of times getting into a corner and having it push a bit where I didn't think that I'd turned up the heat level enough for that sort of thing to be happening. After checking sag and playing with preload I made the decision to install new, stiffer springs to see about improving the front end performance. After checking the board here I also decided to go with 10w fork oil, save for a couple of track days maybe next summer I don't plan on riding the Sprint hard enough to warrant a valve kit in the forks.

Racetech delivered a 0.95 kg/mm spring kit last week so I set about installing these bits today. Installation is about a 2.5 hour process and requires a couple of special tools and the shop manual. The forks come off the Sprint easily enough, suspending the bike on the centerstand and hanging the headstock to the rafters in the garage allowed for removal of the front wheel as per the factory manual. Once the front wheel and fender are off the fork clamps may be loosened - this is pretty easy to do, with the exception of the top bolt on the left fork tube lower clamp. Space is tight between the clamp and the coolant reservoir, I ended up chopping down a 6mm hex wrench so that it fit into the tight confines better.

The fork top cap (end with the pre-load adjuster) and the damping cylinder bolt are also best loosened while the forks are in the clamps - Godzilla must have been touring Hinkley the day my Sprint was assembled, both required a fair amount of grunting to get loosened.

With the fork top and damping cylinder bolt loosened the forks may be dropped out of the bike. The top cap can then be fully unscrewed (the spring won't be under much compression at full extension of the fork) and most of the oil drained out. To get the old spring off you completely remove the top cap from the damping rod - a couple of 14mm wrenches as per pic 4 below will do the trick. Once the top cap is off the spring can be removed, and the damping rod exercised to further drain any remaining fork oil. I left both forks upside down on the oil pan to give them some time to empty out and moved on to preparing shims for the new springs.

Triumph is using a full length progressive spring in the forks on the new Sprint. The springs Racetech sent were quite a bit shorter, requiring a shim to be cut to length. The last pic shows the original Triumph spring on bottom, as well as the new Racetech coil with the shim and shim washers. Racetech provides enough shim tubing (some sort of thin wall Aluminum alloy) to re-cut shims if you make a mistake. I cut the shim long enough so that the new spring, shim, and washers total length equaled that of the old spring. Cutting the tubing was done using a thin-wall tubing cutter bought at the local Home Despot for ~$20. This cutter assures a square cut of the shim end, if you use a saw be extremely careful to make the cut at 90deg otherwise the spring might flex sideways and wear on the inner sidewall of the fork tube. After cutting two shims and getting all the parts ready it was time to re-fill the forks with new oil and install the new spring stack.

Re-filling the oil is straightforward, just pour in roughly the amount called for in the manual. The oil level is set using a special tool, I bought a Motion Pro model as the local Triumph dealer was out. The tool consists of a syringe hooked to a long needle with lengths marked on the side. Pic 2 shows the tool set up prior to setting the fluid level on my first fork. The basic idea is to overfill the fork when the springs are out and the fork is fully compressed. Work the fork tube and damper rod a bunch of times to get rid of any air in the system, then use the marked needle to draw the oil down to 120mm from the top of the fork. You can tell when you've removed all the air from the lower damping assembly when both the rod and fork tube move smoothly through their range of motion, any jerkiness is a sign that you are pulling air through the system still. The only trick is to remember to pull the damping rod up prior to trying to drop in the new spring, if you don't then you won't be able to reach the rod, and you'll have to pull the spring out again which gets oil all over the garage if you are not careful.

Once the oil level is set and the damper rod is pulled out the new spring can be put into the fork. The shim needs a washer on both ends to prevent abnormal wear and possible malfunction, so drop a washer on top of the spring, followed by the shim and final washer. At this point the slotted washer that goes on top of the spring stack can be installed, and the top cap screwed back into place and torqued accordingly (pic 3). Getting the fork tube screwed onto the top cap can be a bit of a trick, I ended up leaning on the top cap whilst pulling up and turning the tube, this got the threads started and I was able to finish up sealing the fork with a socket. the fork can then be reinstalled in the bike, and the wheel/fender reinstalled. The whole process took about 2 hours. I then spent about 1/2 hour checking static sag as per the racetech website. By cutting the shims to match the original spring length I was able to get a front static sag of ~30mm with the preloaders dialed all the way out.

Results:
I took the bike for a ~40 mile jaunt across town, up Germantown and out Skyline (both of which have great twisty sections and a full range of pavement from new to bumpy/potholed). Handling with these springs is much improved - the old springs were so soft that the front end felt vague. With the new springs the bike is much more agile and feels much more flickable, I felt much more comfortable driving around and changing lines in corners. Feedback is immediate and brake dive is much reduced. I ended up dialing in a bit more rear preload to bring the rear sag back into line, this has resulted in the bike feeling slightly taller. Coming through downtown I did feel a whole new class of pavement bumps that the old soft springs soaked up, however the low speed handling is much more confidence inspiring and makes the bike much more usable in the city. I was only able to do a short speed run at ~70MPH, I didn't notice any ill effects. The most significant effect comes into play when entering/exiting corners, the feedback is much better with the stiffer spring rate and the front end feels more solidly planted.

Overall I'm quite happy with the improvement to the handling. I'd recommend this upgrade to anyone interested in improving the front end feel and tractability when cornering.



Cheers, JJ

[steventhechef]

Firstly, welcome to the forum giantkillerrobo,

Secondly, great write up on the spring upgrade. It's more than I would tackle but a good guide nevertheless..

I have toyed with increasing the oil to improve front handling but wouldn't know where to start!!

well done..

[DaveM]

Hi giantkillerrobo,
welcome to Triumphrat.net and the Sprint forum.

When you can post a pic of you and your sickle in the sticky thread at the top of the page.

Quite a few have carried out your upgrade. Myself I am happy with heavier fork oil and an upgraded rebuilt rear Showa unit.

Mine handles like it's on rails and corners like a Rhino on heat.

Yes I'm in love with my '04 for the same reasons you love your '06.

DaveM

[oldndumb]

Originally Posted by DaveM

Mine handles like it's on rails and corners like a Rhino on heat.

DaveM

Now that is a phrase certain to strike fear in all men.:

[roadduster2]

giantkillerrobo - nice article on the front fork rebuild, and I am sure you are enjoying your 'new' ride.

I have a 2000 ST that I just did a complete suspension update on. I took a 7500 mile tour last year of the Northwest/Western United States. I was maxxed out on GVW on the way back from Seattle to Chattanooga, TN, as my girlfriend flew out to Seattle and rode back with me. With a gross weight of 990 lbs. on the Sprint for 3800 miles, I'm afraid that, plus 34,000 total miles on the bike wore out the original fork springs & rear shock.

I replaced the fork springs with Hyperpro Springs & Hyperpro 5w oil. The rear shock was replaced with a Penske Sport Shock/Hyperpro Spring set to my specifications.

I now have a 'new' ride as well. It is quite compliant, and handles as never before. I am very satisfied with my ST as it provides the touring bike I want, and definetly now puts the Sport portion of the ride in as well. These ST's have progressed nicely as time has gone by and fill a niche in motorcycling that makes them an all around fantastic ride.

Keep the shiney side up and enjoy your ride.

Roadduster2

[CLB]

Germantown? Skyline? Sounds familiar!

I installed 0.9kg springs after reading reports that the 0.95 and 1.0's may be a little stiff. I am happy with them but I am an old slow geezer (and ok with it).

I ordered the Gold Valve kit at the same time but didn't end up using the valve body. RaceTech suggested drilling a bleed hole that left me with no damping. I reinstalled the Triumph body with the RaceTech C34 digressive shim stack and no bleed. I am running a ~7wt mix with a bit of MoS2 powder mixed in. Stiction be gone!

I did not pull the fork tubes to revalve/respring.
Support the front end. I used a hoist to a rafter.
Pull the front axle and wheel.
Reach up from the bottom of the tube and remove the damper fixing bolt and brass washer (have a drain pan under the forks).
Pull the caps and everything comes out the top.

For springs only you can leave the bottom end intact, no need to pull the damper cartridge.

[pushr0d]

Yep, the only reason to pull the fork tubes is to drain the oil.

It's much easier than trying to flip the bike upside down

[keo1050]

Welcome,
Great writeup and great upgrade. Had mine done at the dealer about 500 miles ago and love it. Kudo's to you for being able to do it yourself...I would still be in the garage cussing and screaming.