woody

It's not about getting involved. I was interested in the original question as, not being an engineer or mechanic, I hadn't a clue what it was about, which I'm quite happy to admit. I know absolutely nothing about balance factors. I was interested to hear others' opinions, that's all. I read your first reply and thought maybe you must know each other and were taking the pee. With your next post it became apparent you weren't. So my only purpose in commenting was to wonder why, if you have the knowledge to help, you didn't and instead preferred to seemingly belittle a person's question - a response that if your honest and objective about it, was unprovoked - unless there are issues I don't know about. Other than it being on a public form, I accept it's none of my business and won't comment any further. I have no issue with you, just confused at your response to the question as if I'm in a position to help someone, I will. The last comment in my last post was tongue in cheek, not derogatory.

Jesus H Greeves, what's gnawing at you? Jon (whom I don't know) asked what seems to me, a perfectly reasonable question in his original post. I haven't a clue what he was on about technically, but understood that all he wanted was for his bike to run as smoothly as possible. Straightforward enough. Don Morley may not know his a*** from his elbow technically for all I know and he does make a few factual gaffs in his Spanish trials bike book, but he may well have got that percentage from a factory rider from that era. Who knows? As for name dropping, you're joking, surely? As for people having trouble following the thread, read it again. Your first reply was sarcastic within its first sentence and you've carried it through ever since. You chide people about wanting to quantify themselves whilst all the time treating everything they say with a fair amount of derision, itself suggesting they're talking crap and you know better. Hypocritical !!?? You never once tried to help, you went straight down the sarcastic route. If you have an opinion on whether there is any benefit in trying what he suggested he'd like to do, or if you have a suggestion for the percentage required for smoother running, or how to do it, then why not just help the man? And if you must pick issues with people's standards, I'd suggest you spell check your last sentence...

Rear Shocks - Betors are inconsistent in their performance, you buy one set they're too soft, buy another, too hard, buy another, they may work ok. It's a lottery. The gas helps add a bit of pre-load to the springing and doesn't affect damping so if it is the damping that is too stiff, letting gas out won't have any affect, unless a previous owner has messed with them and gassed them themselves. Should be about 90psi. Leave it in. Don't check the pressure unless you have a proper screw on guague. A normal push on type will expel all the gas before you can do anything about it. I'm never sure with Betors whether they are supposed to work either way up. Check with Millers, as they are the agents and if not make sure you have them fitted the right way up. Once you know the answer to that, take the spring off and push the damper rod fully home, slowly. If the shocks are designed to work upside down, put the top mount on the bench and just push down on the body. If they work conventional way up put the bottom mount on the bench and push the rod down. Either way, you should be able to push it home easily by hand. If not, the damping is probably too stiff. If you can, then check the spring rate as there are two or three different spring rates for the Betors. You may have too hard a spring. Front forks - sounds like too much oil which will stop the fork travelling through it's full distance. Drain them and refill with the correct amount. Also check nothing is twisted and that wheel spacers are correct as if the forks ar being pulled in or pushed apart at the bottom through incorrect spacers, that will also affect their travel. 10W oil is usually a reasonable weight to go with for older forks.

Hi Martin, it was 4 years ago that I rode it, so not sure if / how it may have changed. Can't remember if they had 3 or 4 routes. Back then I rode the hardest route and it was on a comparison with the harder of the Normandales in terms of difficulty. In other words, the sections were rideable, there was nothing you looked at and thought 'no way' but they were difficult enough that it was easy to lose a lot of marks, not overly tight, but very little room for error. To get a good result you had to be on line and everything timed right. Get it wrong and it could easily be a 3 or 5. Your bike needs to be well prepared too as the hard route puts a fair bit of emphasis on clutch brake control and the motor needs to pick up quickly and cleanly to clear ledges, steps etc in the sections. The run ups can be short so acceleration needs to be clean. The approaches are enough, but shorter rather than longer and if the bike is gasping or slow to pick up, then life gets a little harder... The 200 Fantic is more than capable. I was riding my standard 340 Sherpa and it was set up for our local trials, lazy motor, soft suspension (plus poor clutch action and little in the way of brakes) I noticed the better riders were all clutch / brake, lively suspension and their motors picked up quickly (be a nightmare in our local trials) I had a go on a few Pumas afterwards - chalk and cheese... The next route down I would say is somewhere between the Miller 'A' route and the lower end of the Normandales. On a scale of 1 to 10 with Miller being 1 and Normandale 10, I'd say a range of 4 - 6. Depends on whether you'd like to get a result near the top of your class or just enjoy a challenge and not bother about the result. On the hard route, there are some very good riders, so a 'result' doesn't come into it, it's about your own personal challenge with the sections On the next route down, if you ride at the top of your game, you'd stand a chance of getting near the top of the awards. Love to do it again, and Santigosa. As ever, it all depends on work so can't make any definite plans.

Yes, that's the one. Look very neat when fitted to the bike with the dished sprocket.

I wasn't sure if the Vega was another name for the Europa to be honest as I've never seen one. I had an original 323 with the Tau engine and later I had a 240 Europa. About that time I remember a budget version of the Europa coming out called the Weekend which was red and had a rear drum instead of disc I think. I also remember the SR as Rob Sartin was riding one. But never heard of or saw a Vega at the time.

This is the Vega but the Europa was pretty much the same bike but finished in white, not red.

Yes, they're still available here for the flat sprocket conversion but there used to be one for use with the dished sprocket as well, different from that one. I think I might still have one somewhere, it was 'put away' after the dished sprockets were no longer available. If I can find it I'll post a picture but it may be long gone now.

Try Brian Griffiths Motorcycles in (or near) Hereford. He had a fair bit of JCM stock years ago. You'd need to google for the number / email etc. Joel Corry speaks good English so if you email the shop in English you should get a reply Steve Goode was also a JCM dealer so may have some old stock The Europa engine is I think pretty much the same as the GasGas aircooled motor and, I think, derived from the Bultaco, so not sure if Bultaco rings would do the job?

Or there used to be an aftermarket replacement spacer that doubled up as a 4th bearing carrier for use with the dished sprocket. Can't remember who made them, may have been Keith Horsman, who sadly died a few years ago now. Never seen a swingarm that allowed different shock positioning. They were experimenting with shock position on Evertson's works bike, moving the bottom mounts forward for more travel, but that never made it to production as the swingarm would bend / break (don't think they reinforced it at all) They settled on laid down shocks for the next bike, the MK3.

On the In Motion website wheel bearings are priced as pairs but they'll sell you as many as you want

Checked again on two wheels and as per Mrb505, the offset from brake drum to the edge of the lip on an original Akront rim is 14mm. The measurement of 18mm I had was for a flat sided rim with no lip

I've got an offset of 18mm written down from a previous measurement, which was from the edge of the drum on the brake side to the edge of the lip on the rim (original Akront with the lip around the edge, not a flat sided rim) It can be difficult to get an accurate measurement from a used wheel as the rim may have buckles and even an average of several measurements from around the rim can still get it a little out. I think I have a newly built wheel somewhere, if so I'll check the measurements on that tomorrow.

To be fair to In Motion, I can understand the question because these bikes are now 40 years old and any number of components can have been changed by previous owners, so you can't always be sure that a bike is actually fitted with it's original components. I use 1 10mm seal in each leg.

I don't remember the post you mention but with an Ossa, the problem could be anything, shimming of the shafts, shimming of the selector drum, worn pins on the selector drum, damaged selector fork(s)... I have heard of people managing to remove the engine from the frame without taking off the cylinder, but I've never managed it. I take the cylinder off and them remove the engine. To take the cylinder off, remove the two front engine bolts, remove the rear upper bolt and them push the front of the engine down slightly, pivoting it on the lower rear bolt. You can now get the head and cylinder off. With the engine in its normal position there isn't enough room to get the cylinder off, it hits the top tube. Or you can tell us how to remove it as a complete unit if you manage it... Steve Sell is down your way, he has a lot of knowledge of Ossas, he'll be at the Telford show trading as Marlimar.

Useful info, thanks for that. I've always struggled to find someone that sells the allen bolts / capheads in M7

Yes, bar clamps and yokes are both M7 and really difficult to get as allen bolts in the UK

ok, yes, you'll probably only get stuff like that from them or from suppliers in Spain. I've never seen a proper rear tank mount, even on the bikes I had back in the day that were relatively new. I'd guess that the rubber slips over the tab at the rear of the tank to stop it chaffing on the frame. What actually holds the tank is the front edge of the seat. The original seat is chunky enough and reaches far forward enough to push against the rear of the tank and they 'dovetail' together. This works even with the UK alloy tank. Aftermarket seats that are slimmer, or custom made seats, won't perform this task so well and things such as jubilee clips can be used to hold the back of the tank in place. I use a releasable zip tie to hold mine Don't forget also that the rear rubber will be manufactured to fit the original style fibreglass tank, not the UK alloy one

I remember seeing Norman Hanks on his Bantam on occassions at our local sand/gravel quarry (actually quite near to the centre of Brum) back in the early seventies. I don't know when he would have first built it (I'm assuming he'd built it himself) so don't know if it was a late 60s build or not. Nice looking bike as I remember finished in chrome and alloy, and went pretty well too. Happy days in that quarry as a kid, first watching Arthur Browning practising on his Homerlite Bultaco, then later Dave Smith and Steve Wilson joining him before getting bikes ourselves. It spawned 2 or 3 generations of off-road riders, that old quarry. I imagine Norman's Bantam is still tucked away at the back of the Hanks workshop somewhere.

The MK1 and MK2 both had the Mick Andrews Replica decals on the side panels, yes (and the MK3) They differed very slightly by the dates. Mick won the European championship in 1971 and the SSDT in 1970 and 1971. Therefore the Replica decal on the MK1 MAR which came out in '72 mentioned winner of the European championship in '71 and winner of SSDT in '70 and '71 In '72 he won both again but then left for Yamaha for '73. When the MK2 MAR came out in '74 the Mick Andrews Replica decal now included the '72 wins as well for both the European championship and the SSDT. ie: - winner of the European championship in '71, '72 and winner of SSDT in '70 '71 '72. The Replica decals are available but they are listed seperately from the tank stripes. One thing I've noticed though on the Replica badges I've seen for sale for the MK2 is that they have missed off the '72 date from the European championship wins. I've not bought anything other than a pair of alloy mudguards from Ossaworld so can't comment on their stuff in general. The front mudguard stay broke from vibration in it's first trial, so I wasn't too impressed with their robustness. Looked good for a show bike but no good to ride with. Someone I know bought one of their remanufactured kickstart knuckles and it sheared in two with little use, so he wasn't impressed with that either. What can't you get for it? Most, if not all parts can normally be found in the UK now, unless it's things like grommets and rubber bits you're after, like headlight mounts etc.

Re: rear brake cables. In Motion probably have them even though they aren't on the website. They can definitely get them for you or you can order from Venhill direct. If you do the latter it's better to go onto their websit and get the part number - saves you a bit of grief when ordering... The footrests and their positioning on the bikes in the pictures have been altered by me as they are too high in the standard position. They were ok when the bikes were new as the handlebars were so much higher than today's bars which are 6" max. If you're over 6', then riding with modern bars tends to tip you up too much so lowering the rests gets you somewhere back to the original riding position. The original Ossa MAR rests didn't have springs fitted. Your tank should be alloy, maybe it's got a lot of filler in it which is why it's heavy.... The hockey stripe is right for the NK2 yes, the broad green stripe across the tank was for the MK1. If you're going to repaint the tank make sure you get the right decal as there are several suppliers and not all are the right shape. The picture below is about as near to original shape as you'll get Also make sure you buy from a UK supplier as if you buy from abroad, their stripes will be shaped to fit the fibreglass tank which is what the bikes came with. Only the UK bikes had the alloy tank and as it is a different shape from the fibreglass tank, it has its own stripes made to fit. As you can see from the MK2 catalogue picture below, the fibreglass tank stripe has a different bend. You can also see that the MK2 in the picture is fitted with a MK1 head with the split fin.

In Motion - interestingly, they are now manufactured as 44 tooth whereas the originals were 46, then 42. 46 always looked a bit big and cumbersome but worked fine with an 11 tooth engine sprocket. Using a 42 tooth with an 11 tooth made the gearing a little too high and the 10 tooth engine sprocket can give problems with the chain catching on the nut which is almost as big. 44 tooth sprocket should be a good compromise and work with either engine sprocket.

Venhill manufacture the rear brake cable so you shouldn't be having any difficulty getting one. In Motion should have them in stock. There are two, one for the MK1 and the other for the MK2 onwards as the MK1 swingarm is shorter. You need to know which swingarm is fitted to your bike to get the right cable. Your chassis number suggests MK2 not MK1 but it could still have a short swingarm as you never know what previous owners have done. The NK1 swingarm is like the one below, where the shock mount is right above the snail cam stop. On the MK2 the shock mount appears further forward due to the arm being longer pushing the spindle further back Whichever of these swingarms you have determines which cable you need as Venhill list them for the 72/73 bike or the 74 onwards. Other visible differences from MK1 to MK2 are: MK1 cylinder head has a vertical split in the outside fin of the cylinder head MK1 usually had the valanced 'mud catcher' wheel rims MK1 hubs plain alloy and where the spokes hook in and locate, there are 3 steel shims per side on the inside of the hub. The hub is recessed slightly to house the shims and they aren't noticeable unless you know they are there. MK2 hubs black and don't have the shims and there is no recess where the spokes hook in, they're flat. MK2 hubs use wider brake shoes than MK1 MK1 cylinder uses a bolt on carb, NK2 uses a rubber hose MK1 forks have flat bottoms with 1 pinch bolt per side, MK2 have a rounded casting where the spindle fits with 2 pinch bolts either side MK1 came with a fibreglass tank, by the time the MK2 came out fibreglass had been outlawed and they had a replacement alloy tank fitted by the importer. MK1 was fitted with a 46 rear sprocket, MK2 had a 42 as original equipment (means nothing now though) When the MK2 replaced the MK1 you may find crossover of parts such as a MK2 with some MK1 parts such as cylinder or cylinder head fitted. Differences you can't see are the smaller crank assembly in the MK1 engine and the MK1 and MK2 cranks had a different handed thread on the ignition side, but I can't remember which was left and which was right...

Not powder coated or painted, they're anodised red

MK1 had polished hubs which had the narrow brake shoes MK2 on had black hubs with wider brake shoes Dished sprockets are available again.