Ian T Posted April 14, 2020 Author Report Share Posted April 14, 2020 (edited) 1 hour ago, lorenzo said: The frame-mounted tank is a chain oiler :- Ah of course! Why didn't I think of that? The frame tube has a threaded hole on top, behind the headstock, so that's how you'd fill up the frame. Still no idea what that's for. Edited April 14, 2020 by Ian T Quote Link to comment Share on other sites More sharing options...
lorenzo Posted April 14, 2020 Report Share Posted April 14, 2020 (edited) Ian - Re removing steering head lower inner race : these can be VERY tight on the stem (unnecessarily so, in my opinion) but if your lower yoke is like the one on my M85, Bultaco very thoughtfully provided two holes for this very purpose :- I use a Hilti nail - hard as hell and at 3.85mm. dia. exactly the right size - the more affluent/better equipped would use a parallel punch. Unfortunately, you may find that once you've removed the race from its lower position you have an equal struggle getting it off past the upper race position.... If your yoke doesn't have drillings, it's probably down to grinding away and splitting the race with a chisel. Edited April 14, 2020 by lorenzo Quote Link to comment Share on other sites More sharing options...
Ian T Posted April 14, 2020 Author Report Share Posted April 14, 2020 Ah interesting! Well as it happens the yoke I have is off an M85 because I can't find the original one from this bike. I noticed the two holes but they had been painted over and I assumed they were where it was pinned or something else. But still, even with heating the thing damn near red hot and smacking it via those holes, it still took me the best part of an hour to get the thing off. Can hardly believe it was that difficult. Anyway thanks, that was vital info. I think I'd have tried again to grind the thing off if that hadn't worked. Quote Link to comment Share on other sites More sharing options...
vintagenut Posted April 15, 2020 Report Share Posted April 15, 2020 On 4/14/2020 at 7:06 AM, Ian T said: Ah of course! Why didn't I think of that? The frame tube has a threaded hole on top, behind the headstock, so that's how you'd fill up the frame. Still no idea what that's for. Hi Ian, Firstly, I'm sorry to hear of your loss. I get it about the regrets of losing someone close so suddenly. Always seems like there's all the time in the world. Hope you and yours are all handling it as well as possible. As to the m49, how great is it that you have this project - your dad's - to work on. My own dad wasn't into motorcycles (loved his golf, though!) and, after his passing, I still feel profoundly connected to him whenever I even look at my golf clubs, as it was something special we often did together. I imagine you may have a similar experience as you work through your M49 restoration. Two things... as to the top tube mystery, I wonder if your dad ever found himself caught short of fuel while out on an extended ride back in the day? If so, what a resourceful way to pack along the extra gas without having to carry an auxiliary container! I don't know how many ounces one could carry or how far you could travel with a backbone full of fuel, but how clever if this were so. Running of fuel while on a long, solo ride has gotta suck and what a relief it would have been to know there was an emergency fuel reserve - even a small one - at the ready if needed. I ride Canams in vintage MX and have been tempted to try running fuel via the frame backbone (designed specifically for oil, in this case) instead of the fuel tank itself (mostly to preserve a painted plastic tank from becoming damaged by leaching fuel vapors). I may have to revisit this possibility... Second, what a cool Sammy Miller accessory chain oiler! I've never seen one before. Does it look like it was set up for actually oiling the chain?... or, again, an additional fuel cell? Does make one wonder, doesn't it? Regardless, that is one very rare and attractive accessory! Hey - best of luck with your build. I'm sure if you follow your dad's engineering advice of taking your time and using the right tools, etc., you'll be very happy with your results in the end. Please do keep the progress reports coming. It's been a very enjoyable read so far and I appreciate you sharing! Best regards, Christian BTW... attached are a couple of photos of a m49 I finished up a couple of months ago. A fair bit of motor work went into it including all new bearings and In Motion supplied rod kit, primary chain and gaskets. The exhaust is from an early m80. No muffler for this one... but thankfully it's not too loud. For the frame, I had to have a couple of tabs welded for the slimline (painted by the previous owner) and removed the older side panel tabs to clean up the look. Frame paint was done by myself... maybe a 6 on the 10 scale - depending on the judge or alcohol consumed! Otherwise, a fairly original bike. Very easy to work on. Quick pointer... do check the bronze bushes on your output shaft for excessive wear which can cause transmission issues. Mine were shot and I had to have some new ones pressed in. Shifts beautifully now. Cheers! C. 2 Quote Link to comment Share on other sites More sharing options...
Ian T Posted April 17, 2020 Author Report Share Posted April 17, 2020 On 4/15/2020 at 6:17 PM, vintagenut said: BTW... attached are a couple of photos of a m49 I finished up a couple of months ago. A fair bit of motor work went into it including all new bearings and In Motion supplied rod kit, primary chain and gaskets. The exhaust is from an early m80. No muffler for this one... but thankfully it's not too loud. For the frame, I had to have a couple of tabs welded for the slimline (painted by the previous owner) and removed the older side panel tabs to clean up the look. Frame paint was done by myself... maybe a 6 on the 10 scale - depending on the judge or alcohol consumed! Otherwise, a fairly original bike. Very easy to work on. Quick pointer... do check the bronze bushes on your output shaft for excessive wear which can cause transmission issues. Mine were shot and I had to have some new ones pressed in. Shifts beautifully now. Cheers! C. Hi Christian, thanks for the kind words! The chain oiler is pretty neat, but I'm yet to actually try it and see how effective it is. Your bike's looking tidy, always inspirational to be reminded of the finished result I'm aiming for! The paint looks good, but this is something I've stalled on for the minute (deciding which type of paint to use) but hope to get moving with that next week. I have a compressor and spray gun, but had a minor disaster earlier this week when the swingarm fell down after being painted, at which point I got disheartened with the whole project. Took the dog out for a walk and felt better later! I am ordering some parts from inmotion later today. Unfortunately they don't have any of the output shaft bushes in stock but I will see about making some (I have a lathe), if not will try to source elsewhere. Given how worn out the rest of the bearings were I expect the bushes are hammered too. I do have a rod kit brand new in its box but I've never rebuilt a crankshaft before. The crank is probably ok, but close to being on the limit for sideplay in the rod. Another thing to consider is whether I have the old fork uppers replated for £200, or buy new ones from inmotion for £95. On the one hand I want to keep as much of the bike as possible original, but on the other it seems like a no brainer - half the cost for new parts. That's assuming they're as good quality as the original ones. Quote Link to comment Share on other sites More sharing options...
vintagenut Posted April 17, 2020 Report Share Posted April 17, 2020 1 hour ago, Ian T said: I have a compressor and spray gun, but had a minor disaster earlier this week when the swingarm fell down after being painted, at which point I got disheartened with the whole project. Took the dog out for a walk and felt better later! Hi Ian, Wow, now this sounds familiar! I had a very similar experience on my 49 rebuild as well. I picked up a new HVLP mini gun, bought some PPG paint I found the color recommendations for here, and even went a little crazy creating an air line cooler out of copper with a desiccant filter (Devilbiss) etc. to make sure I did this paint job (my first with this setup) as best as possible. I thoroughly removed the old paint, cleaned and prepped the surface to almost OCD levels, then hung the frame on a makeshift open air booth I prepped using a canopy-less EZup frame and some 2" water pipe zip-tied atop the structure. Worked like a dream! Well... almost. Worked perfectly right up the point I'd finished the most beautiful paint job I'd ever produced and, while slowly spinning the frame to admire my fantastic work, the wire "coat" hanger I'd twisted into a makeshift "motorcycle frame" hanger chose that exact moment to cut loose, releasing my gorgeous (for the moment) frame, crashing onto the dirt below. The good... it still looked beautiful, laying there in the dirt at my feet. The bad... well, I'm sure you already know. I chose to let the paint dry with the dirt in place, then sanded through the dirt, wood chips, insect husks etc. to the clean primer beneath and re-sprayed. Not as magical an experience as with the first time but not too bad either. The experience did once again hammer home the importance of using the right tools for the job, though - in this case... coat hangers are best saved for coats. As to your approach following your own moment of crisis... nothing like the company of a good dog to help one feel a whole lot better! I fully endorse that! Regarding the bronze bushes... I purchased mine through Lynn Mobley here in the US https://bultacoparts.com/ Lynn's a great guy - very nice, personally - and has been a great resource for NOS and used Bultaco parts for me. The bushes I bought from him went in beautifully and required nothing further reaming-wise, according to my friend who did the install. Now I will say that I had to replace the entire layshaft because the wear to both the shaft and original bushings was so severe (see attached closeup). The shaft had a significant step worn into it and the inner bush was chipped from misalignment. Hopefully, your layshaft isn't as worn as mine and replacement bushes (bushings?) will work out well... otherwise, a custom set to fit your existing layshaft might be the better option - especially if you already have the machinery and skills to produce your own set. BTW... thought I'd share a before shot of the 49 as received. It came with the original tank and a few other original pieces but, as you can see, she was left to rot for years in the open and was a challenge to justify the purchase the moment I loaded her into the truck. Still, it is very fulfilling to get these old bikes back into running condition for me, despite the obstacles (such as the main bearing photo) encountered along the way! Have fun and enjoy the process! C. 1 Quote Link to comment Share on other sites More sharing options...
Hydramatic Posted April 17, 2020 Report Share Posted April 17, 2020 Does anyone make a set of spokes for the M49 rear wheel ? Inmotion don’t. I reckon I’ll have to get a set made. Andy Quote Link to comment Share on other sites More sharing options...
Ian T Posted April 17, 2020 Author Report Share Posted April 17, 2020 (edited) 12 minutes ago, Hydramatic said: Does anyone make a set of spokes for the M49 rear wheel ? Inmotion don’t. I reckon I’ll have to get a set made. Andy Hi Andy, I asked inmotion about that today on the phone actually and as you say they don't have them. This might be because they have odd bends in them or something. I have written to Central Wheel to see what they might be able to do - I will report back with what I find out. From the parts book: 18 x 195mm, 9 x 165mm, 9 x 167mm (these last 9 described as 'outer spoke' rather than 'spoke', not sure if this means more of a bend), all diameter of "4" which I assume is mm and not 4 gauge. However the Spanish bit shows slightly different info, e.g. "4 x M3,5 x 165". Obviously the 18 longer ones are on the non-brake side. I suppose the outer ones are longer on the brake side as they have to bend round from the other side of the flange, if that makes sense. Like an idiot I didn't measure the spokes or look carefully at them before cutting them all off... Edited April 17, 2020 by Ian T Quote Link to comment Share on other sites More sharing options...
Hydramatic Posted April 17, 2020 Report Share Posted April 17, 2020 Like an idiot I managed to undo all mine ( there are better things to do with ones time ! ). The outer ones on the drive side do have a small ‘kick’ in them to clear the flange. It hadn’t occurred to me that they might be slightly longer though. I too have spoken to Central wheels so we can compare notes soon. Andy. Quote Link to comment Share on other sites More sharing options...
feetupfun Posted April 17, 2020 Report Share Posted April 17, 2020 2 hours ago, Ian T said: Hi Andy, I asked inmotion about that today on the phone actually and as you say they don't have them. This might be because they have odd bends in them or something. I have written to Central Wheel to see what they might be able to do - I will report back with what I find out. From the parts book: 18 x 195mm, 9 x 165mm, 9 x 167mm (these last 9 described as 'outer spoke' rather than 'spoke', not sure if this means more of a bend), all diameter of "4" which I assume is mm and not 4 gauge. However the Spanish bit shows slightly different info, e.g. "4 x M3,5 x 165". Obviously the 18 longer ones are on the non-brake side. I suppose the outer ones are longer on the brake side as they have to bend round from the other side of the flange, if that makes sense. Like an idiot I didn't measure the spokes or look carefully at them before cutting them all off... There are two different rear hub types used on M49 and the early type is rare. The difference between the outers to the inners is the shape of the spoke on the end so the outer can wrap around as you suggest. The original spokes are "double-butted" which means that the hook end is a larger diameter than the rest of the spoke. It is possible to get spokes made like this if you want it to look totally original but most modern spoke kits have spokes that are the same diameter everywhere. I also have the gearbox shaft that is a size that In Motion don't have bushes for and found that the bush OD is a standard size and was able to get some sintered bronze bushes easily that were a bit small on the ID and machine them to size once fitted in the output shaft. 1 Quote Link to comment Share on other sites More sharing options...
woody Posted April 17, 2020 Report Share Posted April 17, 2020 Sid's Wheels in Stafford will rebuild them if that's what you're looking to have done, he makes his own spokes. He is busy as he has lots of trials riders sending wheels to him. He's done the wheels on my M10 and M27 Sherpas. He can also get hubs / rims anodised, painted, polished, whatever is asked for 1 Quote Link to comment Share on other sites More sharing options...
lorenzo Posted April 18, 2020 Report Share Posted April 18, 2020 (edited) Ian T, Hydramatic - Re the rear wheel spokes, the originals were (single) butted stainless steel , M4 X 3.5mm and used on models 27, 49, 80, 85, 91 & 92:- (from the top) r.h. inner/ outer - 18 off length 189/195mm ? ) l.h. inner - 9 off " 165/167mm ? ) depending on which parts book you are looking at l.h. outer - 9 off " 162/165mm ? ) The stumbling block for obtaining replacements is that l.h. outer - I couldn't get any for years until I found a seller in the US with NOS. (I don't think spoke suppliers are very keen on replicating the double bend in stainless, a pretty unforgiving material). The double bend is to allow sufficient offset of the rim/tyre to clear the chain line and chainguard. Ultimately, these are the first spokes to suffer damage, or breakage if the chain derails............... The alternative would be a set in single gauge galvanised, similar (but not identical, unfortunately) to Pursang fitting. Let us know how you fare. Edited April 18, 2020 by lorenzo missing text Quote Link to comment Share on other sites More sharing options...
Ian T Posted April 18, 2020 Author Report Share Posted April 18, 2020 (edited) 22 hours ago, vintagenut said: BTW... thought I'd share a before shot of the 49 as received. It came with the original tank and a few other original pieces but, as you can see, she was left to rot for years in the open and was a challenge to justify the purchase the moment I loaded her into the truck. Still, it is very fulfilling to get these old bikes back into running condition for me, despite the obstacles (such as the main bearing photo) encountered along the way! Have fun and enjoy the process! Wow looks like you really had some work to do! Looking good now though. Funny that you had a near identical paint spraying incident. I definitely learnt a lesson there. I do indeed have some gearbox wear, see below 18 hours ago, feetupfun said: The original spokes are "double-butted" which means that the hook end is a larger diameter than the rest of the spoke. It is possible to get spokes made like this if you want it to look totally original but most modern spoke kits have spokes that are the same diameter everywhere. Yes it seems the ones with the double bend (see Lorenzo's post) are the problematic ones. 1 hour ago, lorenzo said: The stumbling block for obtaining replacements is that l.h. outer - I couldn't get any for years until I found a seller in the US with NOS. (I don't think spoke suppliers are very keen on replicating the double bend in stainless, a pretty unforgiving material). The double bend is to allow sufficient offset of the rim/tyre to clear the chain line and chainguard. Ultimately, these are the first spokes to suffer damage, or breakage if the chain derails............... I do have some packets of spokes kicking around, genuine Bultaco ones, but I don't think any of them are the ones I need. Today I managed to use a hybrid of two bearing puller sets to get that last 'blind' layshaft bearing out... Then I got to looking at the mainshaft and sleeve gear, with a view to making new bushes... However I found the wear on the end of the shaft to be uneven to the point of having quite a taper on it. I invoked questionable engineering practices and set about trying to grind the shoulder so that it was consistent for the length of the outer bearing, mindful that the shaft looked hard chromed and there wouldn't be much thickness to play with... ...and ended up going through the chrome. There was virtually nothing left anyway. So that pretty much consigns the shaft to the junk pile. I have two other engines I could use bits from but both have a different (later) type of shaft. One even has needle bearing races for the sleeve gear, so presumably Bultaco did learn. I do have a complete M49 engine which I could strip down, but something tells me the main shaft will be equally worn. Edited April 18, 2020 by Ian T 1 Quote Link to comment Share on other sites More sharing options...
Hydramatic Posted April 18, 2020 Report Share Posted April 18, 2020 Pic of my M49 as purchased. Why oh why did I go to the pub that night. Andy Quote Link to comment Share on other sites More sharing options...
delberto Posted April 18, 2020 Report Share Posted April 18, 2020 Cracking topic this is, i am doing a model 49 as well at the moment ill try and get some pics up. ? Quote Link to comment Share on other sites More sharing options...
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