gazza7965

http://www.bsaotter.com/pre_65_rules.html

Try Paul at Cambridge Trials Centre, he specialises in these, last time I spoke with him about them he wanted around £200 for a half decent one, the plastic lugs all break off normally. I think he was looking to reproduce them.

Niponn, I believe you will find that the Repsol version of the 4rt still uses the same forks as the later 315's, I have a 2002 315 and I removed the rainbow stanchions and replaced them with new black stanchions for a Repsol 4rt into my 315 fork bottoms so I would expect the damper system to be the same as well. Worth looking into. Hope this helps.

Ken, You are correct, no big rocks around here either! You are also correct, just remove the shoulders on either side of the primary drive sprocket, this will enable the taper to fit on the shaft and give enough thread for the nut. With regard to the slimline seal carrier, i was not impressed with the cost the local engineering company I used wanted to charge me so that did not end well, so I cannot recommend anyone to make one. However, the design is very simple, it is basically a thicker version of the original plate (BSA part 90-133 I believe) made from 6 or 7 mm thick aluminium plate and a 6 or 7 mm width seal to suit. I had the screws recessed into the plate so you could use the original screws and not have them protruding.

Hi Ken, I have done exactly what you are looking to do with my '65 D7. I reduced the primary drive socket down to 12 as you are wanting to do, I used one of Rex's sprockets. He quite correctly states that in its original state as purchased, the gears will not line up, I had to have it machined to fit, the sprocket will not go on far enough to allow the chain to line up or fit onto the taper of the crankshaft, it needs the overhang on the back and also the front removed, then it will fit, and allow the nut to be fitted,. You are then faced with what gear ratios to run. I started off after having a custom seal carrier (a lot thinner machined from billet aluminium), this enabled me to have a 12 front sprocket and 64 rear in 420 chain size. I found this far too low geared, so after going up to a 13 on the front and 60 on the rear, found it still too low. I am now running a 14 front and a 60 rear, however this is still a little lower geared than I would like and as you only have one usable gear, I am looking to either go bigger on the front or smaller on the back. If you go bigger than 14 on the front I dont think you have the chain clearance issue with original seal carrier. So a 15 front and 64 rear may work and remove the need for seal carrier alterations. I am probably now looking at 14 and 56 rear to have i usable gear. Hope this of some help.

Hi Can anyone recommend someone to widen a rear bantam hub by 35mm? Really struggling to find someone who is comfortable doing it. I am in the south east but do travel north regularly thanks

I think you will find that the ones with red/ yellow graphics are the aftermarket Gas Gas UK kit.

Hi Bert, I completely agree with PeterB comments, the only additional advice I would give based upon my own experience is to apply some heat. I have experienced this issue multiple times, the best way I have resolved this is to remove the disc completely hopefully not snapping the heads off any more bolts, I find a heat gun is the best way to approach this and some WD 40 or alike, they do seem to undo much easier, I believe they all have some type of thread lock on these from new for safety reasons and they also make a nice mess of your caliper if they come undone. You really do need a very good quality drill bit and if you are going to try and re tap the thread using a 5 mm drill, this has to be exactly in the centre of the broken thread or it will destroy part of the thread if not and then you are looking at a helicoil! I have found the easy out method with heat the best solution. Drill a hole to suit the easy out size, ideally around 3mm. Spray WD 40 on the broken bolt area, heat using a heat gun (not a blow torch), repeat 2/3 times, then whilst still hot remove broken bolt with the easy out, this has ALWAYS worked for me and you will find that when it is hot it will not take a great deal of force to remove it.

These bikes do seem to suffer badly from pre-ignition or "pinking". You cannot retard the iginition as there is no movement on the stator. The only way I could get my 2002 to run to my satisfaction was to add a 1mm head spacer. This lowers the compression without upsetting the port timing with the addition of additional base gaskets. I tried to do it through carburation using differing size pilot jets and changing to a Keihin and different fuels and octane boosters but by far the biggest improvement was achieved with the head spacer. Pinking gone and no noticeable loss in power.

I have always used: PJ1 Motorcycle Motorbike Engine And Case Paint 400ml Spray Satin Black Aerosol Gives a very good finish and very durable if oven cured as per instructions.

I found Derby Road and Race very reasonable and very good quality

I understand that Gas Gas have changed the clutch pack height on the latest models from the 9.75 - 9.85 tolerance to something above 10. Does anyone have any experience of this or know the new tolerances. Been looking around the internet and I can find no details on it. Many Thanks

Hi barnesy The white and orange are painted, the only decal is the black 4RT style one. I did deliberate not painting the tank cover as it seemed a shame to paint over the carbon fibre but it would not have gone with the colour scheme Regards

Renthal Fat bar conversion Raptor pegs Keihin Carb 1mm head spacer to cure pinking issues 4rt Showa fork stanchions Boyeson reeds Mitani carbon fibre fuel tank H & D racing rear suspension linkage plates

I am not sure about the weight difference but I don't think there is much in it. I would say that the 315 feels much lighter than the 4RT and for me is a much nicer bike to ride.