smelling123

http://www.flickr.com/photos/76022002@N08/11015201966/ Original frame (modified). Lots of work but looks pretty and seems to ride well....

Normal to use a resistor type plug cap with a CDI ignition - you should use one on your PVL.

Paulmac - any idea of the jet sizes in your OKO?

5k is fairly standard - its used for noise (electrical noise/interference) supression. Should be used with CDI ignition - some of the older points ignitions dont use the resistor.

I swapped mine and it is a good improvement (and free). Personally I wouldn't be able to justify spending any money on a new 2nd gear set - although a high 4th might be nice. I run a small flywheel (electrex ignition) and that helped - it used to stall a little bit too easily in 2nd before. Here's how you do it...http://www.flickr.com/photos/76022002@N08/8583960396/ http://www.flickr.com/photos/76022002@N08/8582856835/in/photostream/

Trialsrfun - "Good idea that Stu, how have you secured the foam to the filter cage?" The filter element has a perforated sheet inside and I just cut the foam to the width of the 'gap' thats created when the paper element gets ripped off. So the perforated sheet holds it on the inside, and the chrome external perforated bit holds it on the outside. You can get foam sheet from Sammy Millers or trialsbits.co.uk. Ive put a picture here - you can just about see the blue foam http://www.flickr.com/photos/76022002@N08/8815764478/ cheers, Stu.

Just a sugestion - I run the pancake filter on my Bantam. Works OK but it isn't servicable - so when the papers dirty, you have to buy a new element. I soaked the paper in water, then ripped it off with pliers - this leaves the element without any filtration. I then bough some foam air filter material and cut to size. The filter is now servicable (wash the foam every couple of trials). I use the foam air filter spray which is supposed to keep it water resistant.

Good thing if you are 'girl pants'...

Worn primary chain/tensioner?

Old trials fanatic, I think as has been said, you might find your old sherpa springs are shorter than new ones.. I use the progressive magical ones and they are great, as pschrauber says they also make screw pre-load adjusters (although i think its a bit of a luxury as your unlikely to need them when you have the pre-load set correctly). You really want springs that are stiff enough not to bottom out all the time, and soft enough to provide a good ride over rocks etc. For the pre-load, if you can get about 20mm of static sag (the sag under the bikes own weight) and the laden sag (the bike with you on it) takes up about 1/3rd of the total travel, its about right. The Sherpa will be something like about right as your James will be similar weight. The oil will not matter regarding spring weight - unless you put too much in and use the hydraulic action to 'help' the spring at the end of the stroke - we used to do this when road racing sometimes. I don't know if the pursang springs are the same as Sherpa sorry...

Hi Bultacorock, Yes, Wigan Pier - I spent many nights there but in the 90s...brings back some fun memories! I have magicals progressive springs and they made a big difference - i found with the originals the front end dove too easily (actually I went over the bars twice on a tough trial in Wales once). I also have modern fork seals and dust covers fitted which are very good. I have only ridden a Bult with the standard old Betor shocks, with new gas filled Betor type and the Falcons on the bike now. The Falcons were much better than the new betor ones. I haven't tried Rockshocks or Magicals but both have a good reputation although I have read a few comments that the magicals have gone rusty quickly (though I dont know if this is true or not). cheers

Hi Bultacorock, I was intending to send my old Falcons back for repair but to be honest, when I costed it up it was not far off £90 - a new pair is £140 ish, so it didn't seem worth the repair. In the end I replaced the seals myself. The Falcons work really well on my Bult and I'd recommend them - if you can afford it go for the lightweight alloy ones. cheers

Matt, just measure the ID of the swingarm tube when you've cut it, should work?

Matt, I have some in the garage so I will measure them later for you. They are only £8 on ebay though - are you sure you want to go to the trouble of making some?

Where'd u get the 8 spring clutch plate Martin - Rex? Think I need one. Agree on the tensioner, I made mine but not worth it given the price to buy - rattle like hell without it (and snatchy). Also should have added, always fit new main bearings on a rebuild - because the crank seals are inboard of the main bearings, the lubrication comes from the gearbox oil and im not a fan to be honest - there's no flow/return it just relies on some being flung down the feed holes.

Just a cut at an angle, diagonal to the length of the tube (if that makes sense?) - the weakest point will likely be either side of the weld but by cutting it diagonaly the weld is spread along a longer part of the swingarm and therefore the force on the weld is spread. like this http://www.flickr.com/photos/76022002@N08/8586722762/in/photostream

I lengthened mine by 1.5" and it still turns great. I used to feel it wheelied too easily up steel hills and it seems to grip better with the longer arm. Used a scarf cut for strength and inserted a tube for strength - used for 2 years and lots of drop offs/rocky sections and no problems. Stu

Hi Higgo, Ive taken a lot from Trials Central forums so I think its time I give some back - hope this helps... You can have a competitive motor without spending much. The 185 big bore piston helps but remember to make sure the head is machined to match the new bore (squish gap should be set with gaskets at about 0.75mm/30 thou"). Compression ratio is fine between 10:1 and 12:1 - 12 will make more power but 10 will be a bit 'softer'. You can get a cheap suzuki TS175 piston off ebay for about £30 but you need to make a phosphor bronze busg for the little end as the gudeon pin is a different size to the Bantam. You also need to shorten the Suzuki piston to stop it hitting the crank wheels at BDC (shorten carefully with a hacksaw and tidy with a file to the same skirt length as the Bantam). An easier option is to buy a big bore piston from Rex Caunt racing (they are on ebay) - think they're about £45 but are built to suit and have a needle roller small end bearing. The iron barrels are fine for power (but heavy and run hot) either D14 or B175 but the ports are a bit smaller on the D7. Ive raised the transfer ports on mine but it isn't noticably better. Buy a smaller primary drive sprocket (again Rex Caunt) to gear the engine down - when this is done the clutches can slip so also need stiffer springs. There are several ways to improve the clutch action - the main problem is that the cable gets full of mud and the clutch action goes heavy. I will post a picture of what I think is the most simple method. Change the gears over (2nd and 3rd) - this is FREE and gives a useable 2nd - see previous post from a few days ago. I find the standard amal carb is good, some use Mikuni. I also fitted my own boost bottle which helped tickover and really made the low down response crisp. A good ignition helps - the ratio of engine revolutions per kick of the kick start is less than other bikes so most Bantams seem to need a good kick to start (and a good flood of the carb). I haven't seen anything radical in any of the alloy barrels ive seen - so I haven't bought one yet but they are a LOT lighter and will no doubt run cooler. If I think of anything else I will re-post. cheers Stu

THat should do if Keith

Ive just done my Dads Bantam gears so I took a piccy and did a little drawing to illustrate it. Click the links here>> http://www.flickr.com/photos/76022002@N08/8583960396/in/photostream http://www.flickr.com/photos/76022002@N08/8582856835/in/photostream/ Hope this helps Stu

Even some silicone sealer (from halfords - not the bathroom type) will seal a small hole.

Martin, take a picture or do a drawing before you start - its very easy but if you're like me you'll end up confusing yourself half way through!!! Basically you move the 3rd layshaft gear to the mainshaft in place of the 2nd gear and vica versa. Remember that the gears that mate originally (i.e. the 3rd gear pair and the 2nd gear pair) will still mate when you're done - its just that youve moved them to the opposite shaft and moved position. hope this makes sense...? It's worth doing as you get a useable 2nd gear. cheer Stu

You're quite right old trials fanatic, plus lots and lots of time..

Here's my Bant. I reckon I built it for about £1200 but my old man does have extensive machining, welding facilities etc. The swingarm is lengthened (made from a Bantam and a C15) and the loops moved to suit the Bantam frame. Forks have suzuki internals which I fitted myself. http://www.flickr.com/photos/76022002@N08/8553104754/in/photostream http://www.flickr.com/photos/76022002@N08/8552001115/in/photostream/

As far a I know 'Stiction' is an amalgamation of the words 'Static Friction' - friction, or resistance to movement, is significantly higher when the item is static (so when it starts moving, it becomes 'dynamic/kinetic friction' which is usually lower).