Danny's XS Hardtail...

[Prof]

Danny brought his XS Special up today to get a hard tail installed. We had prevously discussed the pros and cons of me hardtailing it or him buying in a hard tail for me to attach. At the price he could get one from Trojan, I suggested he buy one. I installed a premade hardtail on an XS some years back and it went ok, so I expected the same of this one, but such was not the case.

Now don't get me wrong. I am not criticising another manufacturer or supplier (Trojan get theirs from USA). I am hoping this is just one bad apple. the problem with it being that it required heating and stretching to fit and most painfully, the axle plates are tilted 3mm to one side. Otherwise, the welds are neat and the frame tubing 30mm diameter and heavy walled.

First step with any hardtail addition is to get the bike level and tied down firmly. Levelling is best done off the side of the rear wheel. XS frames can be a bit touch and go as they are said to have often been bent out of the factory. I have found some interesting things on these frames including missed welds and really crooked gussets,but this one seems good, possibly because it is a later model. Notice centre line drawn on the 25mm particle board...


Because we have to cut off the rear of the frame close to the back of the motor, we mount the bike on just the one cross piece and then tie all down with four anchors of soft (not high tensile) fencing wire. Once all are installed, they are twisted with a screw driver. This not only pulls it all down tight, but allows fine tuning of centring the bike...


Plumbobs front and rear are used to centre the bike.


Swing arm is removed and then the rear subframe cut off. Paul happened by and as he is a wizz with the sabre saw, he got the job!..


Hey Danny! While the back half is off, let's rake the front half! Just kidding! (But I have to say it; would be much nicer to ride) Anyway stop dreaming, Hardtail ready to go on...


Centre found on hard tail, by installing the axle and marking it as well as cross piece...


Front of hard tail is off centre and too narrow by 8mm...


Left arm heated and bent out 5mm. To get it centred right side needs to be bent out 3mm...


Danny cleaning off paint with a flap disk in preparation for welding. Paint will contaminate the welds...


After tack welding the bottom left rail, top rails are stretched upwards 15mm to fit around the back bone. At this point we also check the angle of the bottom rails and calculate how much drop we will have. I set up the hardtail with a slight upward tilt to get sufficient drop of the bike. Rear will drop 80mm at the axle which will bring the ground clearance down from about 8" to 6" inches... still a bit too high for a rigid with a narrow motor, should be 4" - 4.5" in my books. Legal minimum in SA if you are interested is that no part of the bike will touch the ground when both tyres are flat!..


Bottom rails have to be stretched apart about 20mm. Scissor jacks are really handy for this stuff...


Alignment and levels are checked with every action. Here the right seat rail is pulled outwards with a bit of heat and a very useful tool easily made in the workshop...


More checking. Getting the whole thing square was a bit of a rigamarole, but we got there...


Looks can be deceiving when looking down a backbone that is at a different angle to the seat rails. Although we have the rear end centred over the centre line with plumbob, we check by this method. Measure the diameter of the steering head and run a stringline back to the axle, marked at the same measurement... in this case 49mm... 24.5 each side of the axle centre. Because the axle is below the line of the the backbone, I place a thin steel ruler across the high point and lift then drop the string lines under pressure. That way they find their true straight line. We can now see it the string lines run parallel to the back bone... which thankfully they do...


Now for the main problem; the tilted axle. Blue line on right is same length as the one on the left and shows that there is a 3mm difference to the seat support, which itself has been checked for level as we have been setting up the frame. I should mention here too that to two front ends of the seat rails were checked for level before welding. Left was welded in place and then a clamp was used to square up the right one. Important to be patient and check level before every weld. Up the front we will be welding in a large gusset to stiffen up that area and also to provide a locating surface for a sprung saddle. The last thing you want is a crooked base on which to mount the pivot...


Hard tail tack welded in place. 80mm clearance from bottom of tyre to floor. The only solution to the crooked axle plates is to die grind out 3mm olong the bottom of the left slot and then weld in a piece of 3mm flat bar to the top. Danny will be thrilled with that job tomorrow morning when he comes...

[TriNortchopz]

It looks like that was a tricky hardtail install; well done Prof. The photo with Paul holding the 'chop saw' is great! Good that Danny got involved too. It looks so much cleaner with that hardtail installed. Would it have been any easier in the frame jig?
So, when is Danny coming back for the rake job?

[Prof]

In retrospect would have been easier in the jig. Also extra time due to inaccuracies means we may as well have started from scratch. I have done a couple of others and had no problems hence the reason for suggesting he save money and buy a hard tail.

He definitely doesn't want any rake... will be to whip down to BWS and the supermarket he says.

[Prof]

Danny, being a patient man; and a gentleman besides, did not throw up his hands in horror the next day, but straight into the arduous task of sorting out the tilted axle plate. First, the bottom of the higher plate was gouged out with a die grinder and then levelled up with a coarse flat file. Final measuring showed we had to actually take out 4mm...




Biscuit was in meanwhile working on his Vulcan trike and Kevin rolled in with a broken rear muffler bolt. This is the second time it has snapped even though it doesn't seem to be under any real tension. Last time we added some reinforcing around the bolt head which is welded to the muffler. This time, I get Kevin to make up some fishplates out of 25x3 stainless flat bar which I welded to the muffler and went for a 3/8 rather than 5/16 bolt. Will see how it lasts this time...


Back to the XS. Here with filing completed, a piece of 4mm bar is shaped to fit the axle hole. Bar and upper edges of plate slot are chamfered so once welded it can be ground back; wooden wedge holding bar in place for welding...


Wheel in place and centered. Now to check whether chain will line up. If the countershaft sprocket is tight on the shaft a straight edge can be run along it to see how well it meets the rear sprocket. I'm usually happy with it being within 3mm.


The way I prefer to do the alignment is to run a straight edge off the side cover picking up off a couple of bolt heads or off the machined surface of the engine cases; which is what we do. Tool is easy to make...


Sprocket alignment comes up fine with the wheel centred. But a new problem confronts us. The distance between the axle plates are 15mm narrower than stock and the stock left spacer is too long. I am aware of the extra cost this messy hard tail has been and suggest Danny just machine off some of the spacer. Doing this gets us within 3-4 mils of alignment and the sprocket bolts almost skimming the axle plate. Not really happy, but it is bearable.

Next step is brake mounting. We are using the stock XS special rear disc and caliper which fits snuggly against the right axle plate without modification. Now for location and anchoring. I could stand up straight up, tilt back or hang underneath. We settle on as far forwards as possible for neatness and unobtrusiveness; just need to work out anchor...


I suggest a slotted anchor on top of the frame rail (needs ot be slotted to allow for chain adjustment) which we may later incorporate with the rear guard strut. I collect all sorts of bits and pieces that might come in handy for chopper jobs, slotted metal being one of them. I can do slots on the mill, but why spend customer's money when I can provide something already made. Here marked out for cutting...


Bolt holding anchor needs to not turn when tightening so we cut two flats on the head of a bolt in the mill. Could also be done with an angle grinder with care and patience...


Caliper mount is set up on mill and the bolt hole slotted to match the bolt head. I you need to do this and have no mill but do have a bench drill you can use a router bit in aluminium. An XY table needs to be used (less than $200 at a tool place)...


While I am doing the milling, Danny alighns the rear wheel and measures for a brake anchor spacer...


... and knocks up a spacer on the lathe...


Slotted anchor welded on...


Time for Danny to head for home, but pretty happy with it so far...

We then had to have to have a break for a while due to family requirements on my part...

Well, it's been a month since we last worked on Danny's XS. He came for the day on Sunday and we got some more progress happening.

However, looking at the bike prior to his return, the hard tail still doesn't look right and I spend some time doing more measuring from different angles. It definitely looks canted to the right and we know the axle plates are narrower than stock. Further checking shows that the left axle plate points inwards slightly which will make tightening the axle difficult as it will want to slide forwards on the right side. Man, definitely a Monday job and a very inebriated operator doing this hardtail! I definitely need to do another modification! No charge to Danny on this operation as this project has cost more than to have built one from scratch already.

I cut the two cross pieces so I can spread the left side of the frame out 20mm. When cutting square tube, mark with a set square. When cutting round tube use a decent quality pipe cutter to mark your cut. Angle grinders are too hard to keep straight by eye...


Jack used to begin spreading the axle plates. Right one will spring out too, but once heat is applied on the left the left will move to its rightful position and the right will spring back...


Heat applied top and bottom rails where the bend will least show...


Spacers machined (4mm at top and 7mm at bottom). I'm just using flat discs to weld in because a rear guard mount will be welded in hear and reinforce this joint and a battery box is weing welded in at the bottom.,,


Ready to weld...


Of course the axle plate is now pointing out slightly (measured with a square) and heat is applied right in front and the plate pulled across with an F clamp...


So what did we get up to this Sunday?

Danny brought up a couple of mudguards he'd gotten off a friend to try. He also found an interesting brake master cylinder that can be used with a pull style brake lever. He'd machined up a mounting bush for the standard brake lever at work. He wants mid controls as he is not used to forwards and wants to keep linkages simple. We played around with locations and will use the original exhaust mounts under the engine for the footpegs...


There is limited space to mount the foot brake, but we find a place to tuck it right under the kicker with just enough clearance for the lever...


... that is with a few mods of the lever. I trim it back to a minimum for clearance. Pin hole is counter sunk and Danny machines the head of a small shoulder screw to fit. This will allow us to fit the footbrake in, close but still dismantle the linkage. We had to make sure the engine would still clear when it needs to be removed/installed and the rear starter bolt will be a bit less accessable, but still ok...


A bracket is made to be welded in and support the foot brake pivot...


A spirit level laid over the bottom frame rails allow us to eyeball the pivot to ensure it is level as we weld it into place. It is also checked for square, so it is parallel to the centre line of the bike...


The master cylinder has to be mounted so a bracket a bit like this will be fabbed and welded to the back of the brake pedal pivot. The two white circles represent the cylinder mounting holes. It will then be all boxed in to make for a neat and strong set up...


Rear guard next. Flat guard is chosen. A panel beating mate of Danny's will weld in all holes for him. First step is to align the wheel... and bring it to its most forwards position. Err! I forgot the latter and we had to remake the mount. Pays to pay attention and double check everything. Cost us 15 minutes!


Guard diameter is too large and we tighten the curve but tapping along the valences with a brass hammer on a soft surface. Brings it in nicely...


For tyre clearance we tape some 12mm wooden blocks inside...


Most aftermarket hardtails seem to put their cross pieces too far forwards necessitating what I think is an ugly and unnecessary mount... here the parts formed by Danny and welded by myself in bronze...


Weld it in and put the wheel back in. Bugger! Too close. So have to cut off the flat part of the bracket, shorten the tube and reweld. Here a piece of angle cut and clamped to keep it square while I reweld...


Guard is put in place and first hole marked and drilled. Take time to line the guard up accurately when you do this. It needs to be evenly spaced and front and rear and top of wheel. Second hole is marked ready for drilling... a bne sharpened bicycle spoke is spot on for job like this...


Front mounts done, Danny makes a cardboard pattern for the top gusset and then cuts it out of 3mm steel sheet. It is cut so that when welded the top of the plate is level with the top of the seat rails. This will also carry the front mount for the sprung saddle...


Getting dark outside so time to stop. Off the blocks and see how she feels. Danny likes a large comfy saddle I have in stock, but wants me to chase up a black one. Here, the brown one in its approximate location...


Well that's it til next Saturday. We also started on an electrics box, but that will be in our next installment.

In the meantime; keep safe and don't let the rain and cold stop you riding...

[Prof]

We spent Saturday afternoon and Sunday on the XS again. Danny spent much of the time machining various parts while I worked out what was needed, did fabrication and welding.

Danny has chosen a comfy sprung saddle that is 15" x 13". It comes with a pivot which I think is way under strength and not tightly enough toleranced for secure seating. I pick up pivots that might be suitable whenever I can and it is one of these that we use on Danny saddle. It is strong with a decent size shaft that is a close fit.

A tab needs to be made to mount the saddle and I use some 50 x 5 flat bar. Here measuring distance back from pivot for first hole...


Quick diagram with rest of measurements. Always measure centre to centre for bolts. Centre line marked with a marking gauge (You can use an 'odd leg caliper' or your verniers); set square also for accuracy...


Always good idea to double check...


Tab cut and drilled and set in place. Set square lines it up accurately...


Seat attached to mounting tab. Tried a couple of different length springs. These 4" ones just sitting in place...


If there is one thing I hate is the inconvenience of mounting sprung saddles with nuts and washers. I bolt the springs to the saddle, but use a catch at the bottom. Seat is secure, but can be lifted in a jiffy. Right spring is mounted and left spring left off so you can see how I do it. Firstly blue arrow shows machined ridge on the stock seat mount to better locate the spring. Red arrow shows a 3mm plate welded in level with the bottom of the upper frame rail. Orange arrow shows the bottom fixing bolted in place. Next photo shows a diagram of the bottom fixing...


Fixing shaft is curved at the top to allow the spring to easily locate. One side of the shaft is notched. To fit over the shaft, the spring needs to be pushed to one side so that when the bottom coil locates in the notch it is under pressure and won't release unless pushed aside. Works really well and easy to make...


Now to some frame tidy up. We will pull the motor out next weekend so we can finish welding. Open end of original frame needs closing off. A cardboard pattern is made followed by the piece of 3mm flat bar you see here...


It is then bent to final fit ready for welding. When he originally cut the frame, Danny got a bit careless and cut a couple of inches along the frame. I have opened the cut up slightly so a piece of 6mm rod can be welded in to return the tube to its original strength...


Plate welded in. If you are aware of the concept of 'fishplates', the next sentence will make instant sense to you. Fishplating is a method of joining or strengthening metal by spreading the join longitudinally. A weld around a piece of tube should not be square to the length, but spread along the length like a fishes open mouth or an arrow head. In this pic, red arrow shows end of joined tubes. Although the join is at an angle, it is wise to extend the top gusset along the dotted line so both top and bottom welds do not finish at the same distance along the tube. I will continue this gusset later when the motor is removed. For the same reason on stock bike frames you will see welds are as much as possible longitudinal rather than across the frame tube...


While I have been doing these jobs, Danny has been machining up some guard mounting bungs to fit the M8 socket heads we will be using...


Tabs need to be welded to the axle plates. I use a bung as a pattern...


Cut the paper pattern out and now have something to draw around and to locate the centre of the threaded hole with an automatic punch. Tabs are 8mm thick so there is sufficient thread depth...


It is easiest to drill matching brackets before they are cut out...


Here threaded and cut. Bungs are installed to make sure the tabs wil be cut out right. Note that I have not cut all the way through, but just left a sliver, so one does not drop to the floor...


Tab and guard stay needs to clear the rear brake. Tested with axle full forwards and here fully back...


Pieces of bar are clamped to axle plates to keep the tabs in the right position and level with the inside of the axle plates. Inside top of each axle plate is chamfered to match a chamfer on the tabs. That way weld will fill the 'v' and can then be ground back flat. Piece of rod helps with alighment and...


... allows me to measure back from a fixed location (red arrow) to ensure the stays are square...


Welded in place...


Guard stays are made from 12.5mm tube. To provide a tight bend to match the guard requires a small former, which I machine up on the lather and mill. Takes 1½ hours, but will be used again. I made one some years ago for a customer who was making a rack for his cruiser, but he took it with him...


Tubing bent and fitted. Always cuts things like this over length by 10-20mm, then trim to fit. Safer than trying to cut exact and find you are 3mm short! tube is flattened at each end to allow welding to the small bungs...


Marked for final cutting and shaping. Required two cuts to get right...


Bronze welded in place. Then taken off and finished at the welding bench...


Finished job. I had Danny help when doing the initial final fitting and welding to ensure the guard was not twisted and was centred over the wheel. He made up an 8mm threaded steel plate to fit under the guard. Nuts are a no no cos they are such a pain. Welded nuts are a possibility but don't really spread the stresses enough and eventually the guard is likely to crack especially on a vibrating XS650...


Danny has very definitely opted for mid mounts. We consider a variety of options (drawn on concrete) and decide on using the bottom part of the original mounts. One end will be bolted to the front exhaust mount with a tab welded on to locate in the second hole. The other end will carry a turned footpeg...


The holes in the footpegs have an inner ridge to retain the stock rubber mounts. Danny drills them out. He then turns up two bushes out of aluminium and we press them in. Bottom done...


A pair of aluminium footpegs are turned and knurled. The inner end is slightly smaller diameter to fit the mounts.Here one is fitted. It is purposely shorter and threaded.. A button head and washer will pull it into place..


Try out. Yep. Good...


There is not a lot of clearance on either side. Left side is governend by gear lever and side cover; right side by brake lever and side cover. Finally find a spot to suit both and do a final measurement with a calipers to get both spot on. This is basically is completed by Sunday arvo, so tabs will be made next week...


The pegs are not perfectly square and need a bit of heat with some downwards and forwards twist...


A double check for square is done with meter rule across the bike and lined up with a straight section at bottom of frame. Not square here as I went up the workshop after hours and grabbed a quick pic to show the process...


Danny was given a stainless oil tank and will use it as an electrics box. One side needs cutting out for access and last week we whipped down to the local Mitre 10 a grabbed a bigger bi-metal hole saw. Danny rode the CB750 and I took the shovel. We swapped on the way home and took a bit onger route as the weather was pretty good. Meant to get a pic and forgot.

A bracket needed to made on the pedestal drill to mount the tank for cutting the hole...


I used some 3 x 50 bar for the pair of electrics box mounts. Drilled one and then clamped the second to it to drill. While swapping the clamp for drilling the second hole I keep the drill bit in place using the lock on the drill (red arrow)...


Clamps bolted on. These two M10 bolts are a fixture on the telectrics box and will be cut off and replaced by threaded plates so just a button heads can be used. Box is set in place under the top frame rails and marked. Right one has been cut...


Tack welded in place. To make welding easy a couple of spacers (arrow) are stuck under the frame rail so the box can be pushed up tight to weld, but will not be touching the frame when it is bolted in place. In this pic you can just see the notch at the bottom of the seat mounting pin...


Finished location. I kept the electrics box close to the seat post to minimise wiring exposure and also so we don't have to do a cutaway for the chain, but it does mean the carby air filters may be a tight fit. Danny is bringing his after market carbs and filters next week to test whether we may need a couple of cutouts at the front of the box...


Now for the side stand. Stock stand is way to upright now that the bike has been dropped with the hard tail. XS stand mounts are substantial. but very steeply angled. I usually cut them off and make a new one towards the rear of the bike. Danny wants to use the stock location. We cut off all the stock junk and Danny turns up a piece of round bar to match the end of the stand. Here welded on. The ends of each piece of bar where they are to be welded, are ground to a 'point' (actually a flattened point) so when welded they stand will be solid steel all the way through the join...


Stand is fixed to bike and Danny puts some weight on the bike as I head the stand. Final bending done with a piece of pipe to give us a nice curve. Original for comparison...


Bike now on its own stand. Stock stand is also a bit narrow, so the bike can tip a bit too easily, so I always make the stand at least 3" - 4" longer. Bike needs to be tilted enough to the left to allow the front wheel to be swung on full lock to the right without the bike tipping...


XS stands in stock position end up with a bit of a funnry bend part way up to get them leaning over enough...


Next Saturday our plan is to make a chain guard, finish securing the footpegs, pull out the engine and finsih the frame welding and mount the fuel tank. Then he can take it home for final tidying and painting etc And soon one more cool bobbed yammy will be on the road...

[Prof]

After mounting the electrics box, which I kept as far forwards as I could to clear chain (which it just does) and reduce exposed cable coming from the front, I realised the carby air cleaners would most likely foul the front of the box. So I asked CAnny to bring his carbies and air cleaners so we could check.

Sure enough they fouled by about 10mm!


Moving the box back to the second bolt on the mount did the trick...


Meant welding in an extra piece for the second bolt...


All tidied up and looks better than the original...


Battery box next. Measured up the rubber 'box' the battery fits in and did up a development drawing. Forgot the pic but looked like a german cross with the base being the centre and the four sides the wings. Bending up the first two opposite sides is easy...


Next two are done in the vice with a couple of 75 x 300 x 12 'tongues' that protrude far enough above the vice to clamp each remaining box side and allow them to be bent without fouling the vice...


Drill and weld in a piece of 30 x 3 flat bar against the rear lower cross member. The threads are M8 'threadcerts' which I've described prevously. They are quite adequate for a job like this...


Rear brake is next. A fair bit of discussion went into this. We settled on an 80's HD cylinder which is a tidy unit and fitted nicely on the side of the box. Step one was to make up a plunger off to operate off the brake pedal. This was turned up in the lathe and then the two flats done in the mill. Angle grinder would work for the flats, but less accurate and would take longer...


Will be bolted to box side. Mounting holes marked...


...though they won't be drilled...


Master cylinder needs to be 12mm from box, which is perfect...


... as we will thread a piece of 12mm bar and wled it to the box...


Marking location of bar with a custom bent scriber (bicycle spoke)...


Will fit like this...


A bunch of holes are drilled in the side of the box and the bar is plug welded. Strong and real neat...


Bolted in place...


Here you can see how it lines up with the brake lever...


Rectifier mounted to the rear of the battery box with nutcerts. Solid state rectifiers regulate current by converting the excess voltage to heat, hence the fins. Always mount them outside of electrics box...


Hole saw makes hole for ignition switch...


Danny has used a Toyota switch which includes the starter as in a normal car, saving a second switch...


An electrics box like this offers the challenge of being able to access all the components and wiring connections. We finally decide to mount the coils side by side. They need to clear the switch so have to be mounted at an angle...


Pattern of angle mounting plate needs to be...


At this point Rayne and Julie rock up and its down tools for half an hour. Caught this shot of them leaving...


Coils mounted and bolted in place. Coils are bolted to a 3mm plate with captive nuts (welded) which is spaced out with a piece of 25 square tube that has bolts welded into it. Two holes in the top of the electrics box are capped with dome nuts...


Then the familiar rumble of Jason's S&S Evo chopper... passed Rayne just down the road! Down tools again for a bit. Jason has only just run the new motor in, and is still checking a couple of bolts that have come loose in the past... here checking the front drive pulley nut...


Back to work. This bracket for the starter solenoid. Counter sunk bolt welded in. Other hole is threaded for an M8 bolt that will come in from front of electrics box. Two heavy cables will go through the same holes as the coil leads... which was the filler neck and will just clear the right air filter...


Here ready to be mounted in the box...


Danny has chosen a 8 fuse, fuse box (I use four fuses at most) and this needs to be mounted just inside the cover. 5mm bracket is bent accurately by cutting half way through and slowly bending...


Then welded with MIG or gas; this time gas...


Finished bracket with fuse box mounted...


View from in front. We use an M8 button head through the existing drain neck (green arrow)...


Fuses mounted. The electrics box will have a removable cover. We found a stainless base off one of my old submersible pumps what is just the right diameter and will finish it all off very nicely (forgot pic, Drat!)...


My bedtime folks! Will finish the story off tomorrow night I hope, so stay tuned...