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PostPosted: Sun Jan 27, 2013 10:26 pm 
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Indeed, the stash included a longer steel spring, and it was a 450. Bingo! You can just about make out the felt pen markings:-

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You can see here clearly the tool I made to hold the shock body firmly when unscrewing the top clevis or seal head:-

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I have also set the air gap at 5mm with the shock compressed:-

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Here you can see the difference in the lengths of the springs. I had to separate the preload spacer from the preload nut to allow it to fit. I love the way these shocks seem to be modular, the top spring perch is identical to the bottom one. :)

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And assembled:-

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I have ridden the bike home this evening, and it feels so much better with the heavier spring. I could just get the sag correct with the first spring with four turns of preload, but it is correct with just two turns now, but feels so different. I suspect part of this is down to the reduced air gap, so next time i will try a larger gap, maybe 15mm, to feel what effect that has. My friend had a spin around his driveway to get feel for the bike, he reckoned that the rebound was too fast, I thought it was too slow! This confirms I have the correct weight oil in, the 2.5wt was a guess based on the condition of the oil taken out. I have it set now at one and a half turns out, and is a setting we both agree on.

Really need different forks though, the front end is holding me back now.


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PostPosted: Sun Feb 10, 2013 8:07 pm 
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This image I took last week, before a bit of a ride.

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You can see clearly that the forks are too short and the bike is sitting on its nose. It rode ok, but far from perfect.

Earlier this week I ordered a set of Rockshox Revelation forks for the bike, and set about fitting them. I knew I wanted the travel reducing to 130mm, but had no idea that the supplied 10mm spacers were not compatible. I have reduced many pairs of Reba's/Rev's in the past but these were all dual air models. The new RS forks are all solo air, and require a little bit of work to shorten the travel. To reduce the travel the air spring shaft needs to be shortened by the amount of travel reduction required.

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I removed 20mm from the top end of the shaft, and redrilled the shaft for the roll pin. Once I was happy with the outcome, I decided to make a new shaft in titanium to save a tiny amount of weight but more importantly produce a very smooth and slippery shaft. The finish on the oe shaft is simply as the aluminium is drawn, and far from smooth.

Here you can see the difference, the ti item is smooth. :)

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The other little mod I did was to the already fantastic new lockout lever.

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It is supplied with a torx headed bolt which makes servicing a bit of a ball ache, so I swapped out the bolt with a stainless allen head bolt. Also turned the head down on the lathe so save hardly any weight.

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And, as she stands this weekend:-

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:)


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PostPosted: Sun Feb 10, 2013 8:41 pm 
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Good work. It does look better with the slightly longer fork.

Have you had chance to ride it yet?


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PostPosted: Sun Feb 10, 2013 8:50 pm 
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I have commuted on it a few times, but only ridden off road the once, and that wasn't a fair test as there was still snow on the ground. Plus that was with the old forks.


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PostPosted: Wed Feb 13, 2013 12:49 pm 
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:D Looks great


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PostPosted: Fri Feb 15, 2013 12:01 am 
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Had a proper ride this afternoon. It got dark, but that made it more fun.

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I have fitted a reverb seatpost, and I am impressed. I have played with them before but never had a full ride on one. Its the ossum. Also took the cranks form my Yeti, i wanted to try the 2x setup on the 26er. i think i will leave them on here to be honest, and get some 3x cranks for the yeti....

Also picked up some titanium hardware for the shock. Not fitted them yet, should get around to that tomorrow.

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PostPosted: Sat Feb 16, 2013 7:05 pm 
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Hose routing of these dropper posts has always been the part that put me off. I have installed a couple on friends bikes and they have always been a compromise of cable ties and heli tape. I wanted to make a proper job of mine.

Started with a Thomson seat clamp, as this is not only the most modern design, but it uses a barrel nut in the same way as a Salsa unit. I like this idea, but the Thomson also has the floating washer much the same as the seatposts feature, full of win.

Although the Thomson part is pretty low profile, certainly smaller than a Salsa, it still was very close to the reverb hose on the lowest setting. So i machined away a very small area, not so much for clearance as it still touches, but at least the hose won't rub the anodising off now.

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The other part is fabricated from 6/4 titanium. It is actually the second try as the first item was a bit ugly. Fitted:-

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There is still a patch of heli tape, and I will leave it on, but the hose doesnt touch the frame in any position. :)


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PostPosted: Sat Feb 16, 2013 8:40 pm 
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That is a cracking solution. I really want a dropper post, but the cable routing really puts me off. Ifi used a stealth system and drilled the last front mech cable guide out, I think I could use the cable guides under the down tube on the SX. Downside to this s theres a rear shock in heway! The other option is to just use a post with a lever under the saddle.

How does the bike ride with the longer forks and th serviced / tinkered with rear shock?


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PostPosted: Sat Feb 16, 2013 9:12 pm 
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Much better. I have gone back to 10mm air gap on the shock, and have learned that you need to be very careful when bleeding the shock to get the best performance. The forks set at 130 are perfect for this weather, tho I might try 140 when the trails dry out and get faster. :)


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PostPosted: Fri Feb 22, 2013 12:04 am 
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I have managed to fit a couple of steady rides in this week, the light is holding on more and more as winter turns slowly to spring.

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I am also starting to become an expert at removing and refitting the shock, and then rebuilding it. It has been out of the bike for one reason or another three times this week alone......

Lessons learned are that the IFP height should be about 10mm, this seems to make a noticeable difference to the rebound damping. With a smaller IFP volume/height, the shock had erratic damping, most noticeable in the rebound stroke with an audible 'clunk' that could be felt through the frame. Now I know that nothing could be touching inside, as it was in the rebound stroke so the piston&shaft would be travelling away from the IFP....

Lesson two is that careful bleeding is rewarded with much better quality damping. Goes without saying, huh? The best way I found was to fill, to the brim with oil while the shock was compressed. Refit the top cap, not tight, just so the seal is working. Then extend the shock and leave for a couple of mins. This should introduce a vacuum inside the body, and make any air bubbles hidden inside the damping circuit very big, and allow them to escape. Then, after a few mins, very slowly compress the shock. A slow compression is vitally important here as it keeps turbulence in the oil to a minimum. Then unscrew the top and you should be greeted with oil free of bubbles.

The damping is now very controlled, and the rebound adjuster makes very tangible differences to both the rebound stroke, and a little to the low speed compression.

I really like this shock. :)


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