Freshening up a 2006 Sherco 290

[KTM39]

I've been commenting in Craigus' Beta thread, so I thought I should post some pics of mine in a separate thread.

I bought this bike nearly 3 months ago with the intention of buying a cheapish trials bike to learn some new skills on. I knew that the forks needed work, but I was hoping to get away with about $600- worth of repairs and go riding.
It didn't turn out that way.
Every bolt that I've touched was either loose or seized. Most of the bearings were dry, full of rust and worn out.
The spokes were loose and the threads seized so that they couldn't be adjusted.
Wheel bearings were dry and worn out.
When I removed the airbox, I found that the manifold connecting the carb to the airbox was perished and cracked, not all the way through so as to allow dust to bypass the air filter, but not far off.

The bottom line is that I should have been more patient and waited for a better bike to come along. At least now I know that this one is ready to ride and should be a good thing.

It wasn't all bad. I've learned the bike's history and the owner before the guy I purchased it from was very fussy and had done a lot of work to it, including rebuilding the engine with an oversized piston, fitting the fat bars and some of the S3 bling as well as the Cabastany graphics kit. The motor seems very sound with strong compression and no rattles.

This is how it looked the day I picked it up.

[KTM39]

I'm posting this info as it might help out someone else one day. I've had difficulty finding this sort of info on the various trials forums from around the world.

The biggest problem was the forks. They've obviously been thrown down the rocks several times and there were deep gouges in the chrome stanchions which would have been chewing out the fork seals in minutes. The forks weren't holding oil at all. The previous owner talked it down and said that he'd been quoted only a few hundred bucks for new fork tubes from Sherco, or that I could "just put some defcon in the scratches and sand them smooth, then fit new fork seals". I should have walked away then and there.

I took the forks to two local suspension tuners who I've used before for my race bikes and I trust them. They both took one look at the forks and told me to take them away and either come back with new forks or new stanchions.

After several weeks of research, I found the following:
New fork tubes are available from Sherco Australia for the 2006 forks. They are about $400 for the left tube and $600 for the right.
Complete new forks are no longer available for the 2006 models. You can buy the 2009 or later complete front end from Sherco Aus for about $2,700- including triple clamps. Sherco USA list the complete 2013 front end for about US$1,300. It would have cost about Aus$1,800- for a new front end delivered to Aus. The later model Tech forks are 39mm and the fork offset is different to the older 38mm Paioli setup.
Rechroming the stanchions was discussed. IF it was possible, it would be $300 to $400 per tube. They wouldn't know if it was possible until the forks were disassembled. And if it could be done, they would be silver and not black (not that I really care about that).

Here are the damaged 2006 Paioli 38's:

[KTM39]

I ended up getting lucky and finding a complete front end from a 2003 model 290 on eBay in the UK. It cost me $485 delivered including the triple clamps.

The earlier model forks are non adjustable 38mm Paioli's. They were in much better condition than the forks that came with the bike, but they did need a service and clean up and they have some serious scratching on the lower/outer tubes. There's one tiny nick in the chrome, but it should hopefully not cause the seals to leak in less than one season, at which time I'll service the forks again anyway.

Why don't more people run fork guards on their trials bikes? It seems obvious to me that for stuff all money, all of these problems could be avoided.

I received some very helpful tips from the nicest guy you'll ever meet - Greg from Sherco SA. He told me to make some fork guards out of 50mm Poly Pipe. He even gave me a few lengths of old pipe to get me started. I also purchased some neoprene upper fork guards from Sherco SA for $30-. After about an hour of careful trimming with a Stanley knife, this is what I ended up with:







This is my new/second hand front end with triples and new head stem bearings.

[KTM39]

I replaced the triple clamps because I had to drill out one of the pinch bolts from the original clamps due to it being seized in there like nothing I've ever seen. Drilling a steel bolt out of aluminium triple clamps is not easy, and of course I stuffed it up. Luckily the replacement forks came with triple clamps.

[KTM39]

The next problem was the rear spokes. As I mentioned, they were loose and one was already broken. The nipples were rusted and seized solid.

I cut them off and (as I would later learn) made the big mistake of not recording the rim/hub offset before disassembly. I recorded the spoke lengths and pattern, but stuffed up on the offset. Another lesson learned.

I had new spokes made by a local wheel builder. The first lot had faulty threads and when I tried to assemble and true the wheel, they were busting threads and popping off under the slightest tension.

[KTM39]

Long story short, the rear wheel has been reassembled three times now. The spokes have been replaced (3 times) with zinc plated high tensile steel spokes and new nipples. The hub/rim offset is now correct so that the tyre does not rub on the inside of the swingarm. FYI, the offset is about 30mm towards the brake disc. I think it was 27mm from the edge of the rim to the inner edge of the brake disc.

I learnt more about how to correctly seal the rim strip and how to set the bead on the tubeless tyre each time (having fitted that bloody tyre three times).

Now the rim is perfectly true, with lubed spoke nipples, a well sealed rim strip, new wheel bearings, silicon inside the rim drop centre, a new valve and new Dunlop tyre.
It is holding air pressure perfectly. I also replaced the sprocket and disc bolts/nylock nuts and ran a thread tap through the disc bolt threads to clean them up before fitting the disc with Loctite.

I can highly recommend the guys at GC Motorcycles for wheel building. Their prices were excellent and they bent over backwards to sort the problems out.

[KTM39]

While all the wheel problems were happening, there were also some major issues with the rear suspension.

There was a massive amount of lateral free play in the swingarm. With the bike assembled and on a stand, you could move the rear wheel up and down about 30mm without the shock moving at all.

I stripped it down and found that the swingarm bearings and shaft had actually been serviced and lubed previously and weren't in bad shape. I cleaned and regreased them with a mix of water proof grease and anti seize compound and refitted the swingarm.

The linkage bearings were not the worst I've seen, but they hadn't received any grease for a very long time and were full of rust and mud.

I also decided to remove the lower shock bearing as my research suggested that these are prone to failure. Removing it was an absolute mongrel. I couldn't budge the bushes or the complete bearing assembly, so I took it to a mate's workshop and we pressed it out. It took so much force that I was expecting the shock to break (I was googling the price of an Ohlins shock while we were swearing at this silly Olle' setup - about $800- ).

We eventually got the bearing and bushes out without damaging the shock, but we completely stuffed the bushes. I also found that the outer race of the spherical shock bearing was cracked. This would no doubt have been contributing to the excessive free play in the rear end.

Sherco Aus told us that the lower shock bearing bushes are no longer available.

All Balls sells a rear linkage kit that includes the lower shock spherical bearing. I was assured that it includes the bushes. It does not.

I learnt that the lower shock bearing kit from 2002 to 2011 Sherco's are all the same and ordered a kit from Sherco USA. The kit arrived with what appears to be an updated lower shock bearing. It is definitely made of different material than the original bearing. Hopefully it is a stronger part and the problem will not recur.

This is the linkage fitted with new bearings, again packed with a mix of marine grease and anti seize.



This is the new spherical lower shock bearing that came with the All Balls kit. It looks the same as the old one that I removed. The new one from Sherco was silver/chrome and was branded Olle' (sorry - I didn't take a pic of the new one, after waiting 3 weeks for it to arrive, I just wanted to assemble the thing).

[KTM39]

I removed the carby and stripped and cleaned it. It actually wasn't too bad inside (which surprised me) so I cleaned and lubed all the fasteners, reassembled the carb and refitted it with a new rubber carb to airbox manifold. The old one was perished and cracked. It wasn't due to sun exposure as you can barely see the thing with the bike assembled. I suspect one of the previous owners may have sprayed Inox on the engine and surrounding components thinking he was doing the right thing. Experience has shown me that Inox is great for metal and terrible on plastic or rubber. I use only CRC 556 to protect the bike as it leaves a safe oily film (unlike WD40 that just evaporates away to nothing).



New rear brake and gear levers as the old ones were completely flogged out. I also replaced front and rear brake fluid. They really did fit that rear brake fluid reservoir in a pig of a spot.

[KTM39]

The previous owner had lost one of the adjuster screws and replaced it with a convenient cable tie as his long term solution. This was all the excuse I needed to buy some bling.



I also had an issue with the side stand. It was very loose and had been rubbing on the rear brake disc for a long time (judging by the grooves in the side stand foot). I wedged a washer between the sidestand bolt and swingarm bracket to remove the free play, but the stand would still touch the disc when retracted. My band aid fix was to fit a hose clamp onto the side stand to act as a stopper and keep the stand away from the disc. Has anyone else had this problem or know of a more permanent solution?



This is how the bike looks now. It doesn't look much different to when I bought it, but a lot of work has gone into fixing some avoidable problems. I rode it for the first time on the weekend and learnt very quickly that I won't be setting the world of Trials on fire any time soon!

[Craigus77]

Great thread man, as I said previously it's good to see (at your expense) that I wasn't the only person entering trials with a bike full of drama.

You've done a sensational job on the repairs to the GG, looks like you had more severe issues than I did though. I had a good laugh at the cable tie replacing the lever adjuster I tell you.. This must be common practice? Both mine were the same, I bought the same bling to replace them.

Thanks for sharing!

Cheers
C.