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Mar Wheel Bearings


basketcase
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Hi all, just stripping down a 1972/3 MAR and was wondering if anyone could tell me the serial number for the bearings. I`ve found the number for the steering head bearings (30204) but can`t seem to find any for the wheels.

Also are the hubs supposed to be black?The bike is 99% original and the spokes don`t appear to have any overspray. All the bikes I`ve seen have alloy/silver hubs but mine are black!

Cheers in advance, basketcase.

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I use 6201 2RS the 2RS being rubber sealed both sides

2 in the front wheel and 3 (iirc) in the rear or 4 if your using the flat sprocket adapter

Not sure if you have a mk1 or mk2 but I'm fairly sure the mk2's had all black hubs and brake plate

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Many thanks amo and woody, sorry but I`ll be asking quite a few more questions in the near future. I was told by the previous owner that it was a 1972/3 bike but not registered until 1976. The engine and frame numbers match,231673 and it still has the dished rear sprocket. I guess that the bike hasn`t been messed with very much apart from the frame being painted black, it`s now powdercoated silver again.

The only thing that I`m having problems with is getting an original rear brake cable, I suppose that I can send my old one off to Venhill to get one made up, but no one stocks them.

I thought that getting spares for my 1965 Matchless was hard but nowhere near as hard as for this!!

Cheers, basketcase.

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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.

post-71-0-17761100-1389040593_thumb.jpg

On the MK2 the shock mount appears further forward due to the arm being longer pushing the spindle further back

post-71-0-54710400-1389040693_thumb.jpg

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...

Edited by woody
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Wow!!!! Thanks woody, you`re a mine of information! Looks like I have a Mk2. I`ve not seen any rear brake cables listed on Inmotions website but they do list the new dished sprocket, £55. I`m sure that my tank is steel not alloy, feels too heavy. I`ve also noticed that the footrests fitted on the Mk2 in the picture have springs fitted to them....mine don`t! Are they supposed to have them? Saying that the ones on my bike are on a different mounting. The paintwork on mine has the hockey stripe and not the straight, diagonal wide stripe, is this right?

Sorry for all the questions but I like to get the bike right...my last bike won awards. (it did take me almost 5 years to finish though :))

Cheers, basketcase.

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Excellent reply as always Woody

Who's selling the dished sprockets? I didn't notice any available last time I was looking for ossa bits on the net

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.

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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

post-71-0-50570300-1389087164_thumb.jpg

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.

post-71-0-72894500-1389087590_thumb.jpg

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Many thanks....again! I definately have a Mk2, alloy tank (not as heavy as I first thought), 2 retaining bolts on the front forks, no split in the cylinder head, swing arm as shown in your photo.

There is a company on fleabay selling tank and side panel decals, £25 a set. Did all Mk2`s come with the Mick Andrew side panel stickers?

I`m putting in an order with Inmotion for the usual stuff, fork seals, chain tension pad, brake shoes, cables etc. The bearings I`m getting from a local suppliers, they`re cheaper!

Have you bought anything fron Ossa World in America? I can`t get them to answer any e-mails. I need a few things that Inmotion don`t stock.

When I work out how to upload pictures I`ll show you work in progress, powder coated frame etc. A company up in Staffordshire did the powdercoating, less than half the price that I was quoted down here in Somerset, and they did a lot more things like both parts of the exhaust in satin black, wheel spacer frame brackets.

I`m picking up all the replacement nuts, bolts, washers etc tomorrow....all in stainless.

Cheers,again, basketcase.

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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.

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Hi Woody, it`s just the small things, the plastic washers on the side panels, the tank mount kit, cable guide on the front forks and their gear lever is a good price ($24.95 + p+p). I e-mailed them to check on the price for shipping to the UK, still no reply. My tank was held on with a jubilee clip at the rear which was a pain to undo, and it has worn the paint off the frame. I can`t work out how the rear fixes and Ossa world shows a piece of rubber, still can`t work it out!!

I watched a front headlamp on fleabay just before Christmas, I gave up when the price kept going up!

I`m sending some bits off to be rechromed in the next few days. I had loads done for my Matchless and Honda with Bob in Stafford, cheaper than anyone else and a better job too. Hope that the front pipe comes up ok.

Going to pick up the stainless bits now.....can`t wait!!! I`m like a kid at Christmas when it comes to this!!

Cheers, Nigel.

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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

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Yes, I was thinking of a cable tie and a piece of rubber between the tank and frame. I won`t be using my bike as much as most, just the odd wobble around a local field or quarry.

Are the handlebar bolts (handlebar to mounts) M7`s? Couldn`t match them at the suppliers. Might get them chromed :)

Still trying to work out how to upload pictures. Modern technology isn`t my strongpoint.....I`m not sure what is my strongpoint!!

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