woody

Anyone out there who owns, or knows someone who owns an Ossa Pennine trials. Alan Wright is looking for one to display at Telford in February, so if you have one that you're willing to show or know of someone that might be, then Alan would be keen to hear from you

Press in, just two cups and a ball, same as those in your picture apart from no extensions either side of the middle component for O rings. Mine are a few years old now but assuming they still use the same set up. I'm not familiar with the latter set up you mention but I don't think I actually know what a 'proper' spherical bearing actually is... When I showed my local bearing supplier the bearing/bush from my Magical shock (referring to it as spherical) to see if he could supply them he said no and that they weren't spherical bearings

Very similar to the bearings fitted to the Magical shocks, except those fitted to the pair I had didn't have the O rings. Had them fitted for a few years and didn't give any trouble, no wear etc

If they're being fitted to a MAR then the top shock mount is bigger (at 14mm if I remember - it's bigger anyway) than the bottom mount which is the more common 12mm The way I'd do it is to just fit a normal rubber bush with 14mm id to replace the rose joint bearing. Falcon do different size bushes and as B and J Racing Products in the US are Falcon agents, they'd probably provide some

Slight problem in that I can't post new photos stored on my PC - these were old photos I'd put on from years back and are already stored in TC somewhere. You can see the forward/back positioning from the photo above (not saying it's correct but works fine for me) and in terms of height they are just on spindle height. I was told by Mick Andrews years ago not to go any lower than that (at all, not just a MAR). I have two MARs and on one the riser is 10mm (just 10mm thick flat bar under the bottom bar mount) and on the other I don't have a riser as never got around to it. Both have 6" bars Apico do a bar riser kit which I've used on some bikes and it gives between 20 and 40mm increase. The bolts with the kit are no use as they are 8 x 1.25mm 7mm are hard to find but I bought some from ebay, or maybe just found some from the net, can't remember now. Or maybe you could tap them out to 8 x 1mm fine thread as they are easier to find

One of mine - just lower, not back or forward. I don't begin to understand any of that percentage gobbledygook.... sounds like over analysing to me... PS - brackets are braced behind if they don't look strong enough

I'm 6' 3" and had no problem at all with riding position on Ossas, Montesas and Bultacos back in their era for the simple reason they had at least 8" high bars then... So although the footrests were relatively high in comparison to modern bikes, the riding position was ok. The bars now are much lower and I am bent over far too much with standard footrest position - and a lot older... So I lower them - and use bar risers Back in the 70s on a 159 Bulto (pegs are quite low already on Sherpas so you can't lower them by much)

The rim is normal Akront fitted to most bikes in 60s to about 1972 when Bultaco, as well as Montesa and Ossa all swapped to flangeless rims. On Sherpas, that style hub used a flangless rim but it's 40 odd years old and in that time could have been fitted with a replacement rim. A MK5 (maybe MK4 as well) Pursang used a flanged rim with that type of hub. You will have to measure the inside diameter of the hub. As mentioned before 125mm is Sherpa, possibly early Alpina also. Pursang will be 140mm I think from memory. They look the same in appearance. You're going to have to know which for the brake shoes your going to need as you can't use those...

That style hub was fitted to Sherpas in 1972 on the M91/92, but it had a normal rim, that flanged type was last fitted to the previous model 80 with full width hub (on the front) Pursang and Alpina also have that style hub but slightly bigger in diameter (on Pursang at least) Sherpa diameter is 125mm so if it is bigger it is Pursang or maybe Alpinaa

Not sure which needle roller bearings you mean? The MK1 mainshaft runs on normal roller bearings and the layshaft runs in bushes. On later MAR, TR77 on, maybe MK3, the layshaft runs in needle rollers rather than bushes but they won't work with the earlier gearbox as the shafts are different lengths and diameters on early / late boxes, even though they look identical side by side In all gearboxes there is a needle roller under the 1st gear cog on the layshaft - I've never had to change one of these as never seen one worn. There are two that the final drive sleeve gear on the mainshaft runs on. Never had to change these either. None of them have serial numbers that I've ever seen so you'd need to measure and obtain from a bearing stockist if you want to replace if none of the old Ossa dealers in the US stock them. Not aware of anyone in the UK or Europe that does

Yes, as above, there is a thin cover plate that fits over the spoke heads, just prise it off. It's probably stuck on with a bit of corrosion

Once you start tinkering with these babies, you have to hoard.... re: front wheel, the spindle diameter is larger on the older type wheel so to fit the later wheel you'll need the later spindle and need to sleeve the spindle housing in the forks, maybe just on the brake side, but can't remember. Just a thought, if you can find a later type torque arm they have an extension for the outer cable locator which is a bolt on part, as there is no lug on the brake plate on the later wheel, With that, you might be able to reverse the brake arm if that's what you want to do. Not something I've ever done on my own bikes but I understand the point s/s was making

The front end is the same on M27 49 and 80 so it would suit any of those for someone wanting an original set up. Some later bikes also ended up with the tapered forks as well. At least with that front brake you won't have the problem of chrome peeling off

Re: front tbrake set up - the front end is from an early bike like the M80

From what I can see of it, it looks like the hub used on the Sherpas from 1975/6 M159 up to the last 199b model. Off the top of my head I don't know the diameter. I'm not familiar with Alpinas so don't know what hubs they had, but don't think they used hubs like that. There should be a steel ring plate cover that fits over the spoke ends and is held in place by the sprocket

Not production, someone has added those messing with shock position. The original mounting point is still there with the big headed slot screw. It also has the later type wheel, the 151 had the Pursang type split hub. Nothing wrong with the later wheel of course, smaller and neater hub. Make sure the chrome lining is intact in the hub and check the bearing housing on the brake side as they can wear leaving a loose fitting bearing and if it is slack allowing the bearing to move or 'chatter' a bit, the housing can crack and open up rendering it useless and needing repair

MZ forks

The Haynes manual should give you all of the info you need for your bike as the early 70s 5 speed models are pretty much the same. The bike pictured on the front cover is actually a 151 If you look for another cylinder it has to be from the early 325, models 92, 125 or 151. The cylinder was a new design from 159 onwards and won't interchange with the earlier engines

Yes

The Drayton frames aren't actually that light (they aren't sold as such either) The frame for my C15 is a fair bit heavier than the Faber frame I had before. But standard Bantam frames aren't that heavy either, I've ridden a Bantam with original frame (I don't mean a standard bike, still modified) and the Drayton and there's little in it, Alan Whitton's Cub that I tried a few years ago was around 160/170lbs I think, so a Bantam is going to be very near that taking into account the Cub frame is probably lighter but the engine heavier than the Bantam A sad subject at the moment though as Drayton builder Jim Pickering passed away last night after his battle with cancer. A lovely bloke who will be very much missed in these parts

Not sure if I can explain it any better than I have but whatever colours you find on those frames, you're asking what the original colour was for a 198 and that is silver. Remember how old those frames are, they may have been blasted clean of paint in the past and repainted any colour, and more than once. Originally, the B was white, the A was blue and the rest were silver (excepting the smaller capacity models)

I'm not sure hammerite keys very well to aluminium. I used smoothrite spray on a frame once and it chipped easily, which is the very thing I thought it wasn't supposed to do. If you're looking to paint your frame the original colour, the only Sherpa to have a white frame was the B model 198/199. The 198/199A was bllue, the rest were all silver

The swingarm bolt rusting solid is not an uncommon problem. It's unlikely you'll drive it out, normally the spindle has to be cut through either side of the swingarm which can them be removed, then you can set about removing the spindle

The change to a 39 rear was a strange choice on the A and B models as it makes the gearing quite high compared to earlier bikes. The internal ratios never changed on the 5 speed models, which used 11/46 final drive, until the 199 when 1st to 4th were lowered with the change to 13 teeth on the front. With the A they changed the ratios back to the earlier models, or, depending on what you read or who you believe, changed 2nd to 4th back up to the ratios used on all earlier models, but left 1st as the lower 199 ratio, Whichever, with standard gearing on the A it is running 7 teeth less than earlier models which is a lot although the final drive ratio of 11/39 is the same as the 13/46 of the 199 I haven't ridden a 199 or an A for a very long time so can't remember the feel of the gearing but on my B I run around 43 on the back as 11/39 makes the gearing too high and 1st on the B is the same ratio as the 199. On my 49 and 92 bikes 11/46 makes 1st a bit higher than ideal for tighter going