Velocette 500, 5 Speed conversion, part 5

At last, this is the gearbox assembly. Please note the deliberate error. I put in 2 gears on the main shaft. In fact, assembly of one gear on each shaft at a time is required. Also the selector plate must be positioned in 4th gear

[@johnkent449]

Thanks for your comment Alan. Yes, it will be hard to find a speedy and good chronometric repair.

[@stephenfeber394]

I loved watching this having rebuilt my velo box a few times back in the day. I must say when I ran the bike as everyday transport for several years the box was always faultless. I did change the levers to alloy ones which allowed removing metal from the clutch handlebar lever to get more movement and thus more lift at the clutch end. 😀

[@alanglen5902]

Thanks. I also have filed the alloy clutch lever to extend nipple travel. I was going to show this but editing and trying not to bore people meant that point, and other things, did not get mentioned. Currently I am working on video number 7 where the old gearbox is removed and replaced. Thanks Alan

[@terencerafter2408]

Layshaft end-float is critical! Anything more than a few thou can allow the Layshaft 4th gear to kiss the Mainshaft 3rd gear. This results in the 3rd gear and it's thrust washer being forced onto the retaining circlip. It then rubs against the splines, which act like milling cutters! Result is circlip failure and cheque book big-time! I know! See also KZbin "Velo gearbox breaks" by Paul Murley. When I finally got to speak with someone who knows these boxes, he recommended that having determined end-float, it should be taken up by a custom made shim washer between the kickstart gear thrust washer and the layshaft bush. I'm also toying with the idea of relieving the interfering portions of the offending gears by about 10 thou each, This would give 20 thou clearance and end-float wouldn't be so critical, I'm open to criticism and/or alternative suggestions on this!

[@alanglen5902]

Thanks for your comment. I am aware of the issue of location and end float, and am not finished yet. Currently working on video 6 I have not had real customer experience such as yours reported so far. I was initially disappointed with the selection mechanism function. Fortunately, I did not expect to just assemble it and have trouble free function. I am being very careful in the assembly. Feel free to comment further. Thanks Alan

[@petershacklock6457]

Hello, I am a recent “looker” I am rebuilding a 500 MSS gear box and your explanations are excellent. Regards Peter S

[@johnkent449]

Thanks Alan - very interesting set of videos. I should have watched them before I tackled my own Velo gearbox issue. I am not sure I will go down the 5 speed route, but the detailed approach to your Velo issues is helpful and illuminating. In one video you mentioned you had had the chronometric clocks rebuilt. Any recommendation on who can do this. I have a dev counter I need to get repaired.

[@alanglen5902]

Thanks for the response. I cannot remember who I got to repair the instruments. I have had a look on the web to see if anything jogs my memory, but sadly no. If I find a receipt I shall declare this, but basically all you can do is phone up the companies on the web. It took a few months for my instruments to be returned. Perhaps be suspicious of companies offering an “instant “ turn around.....

[@stephenfeber394]

Also having an engineering workshop I found very useful for the velo. As you do!

[@dducdude6315]

What a joy to watch over the Christmas break!! I redid my Venom box with all new stock gears and bearings last year with much issue as I had never done a gear box before. I thought about this kit , but the price was to dear at the time, now I am sorry I did not. A 5th gear would be juts what the Venom needs to crack the ton and keep up the the traffic on the motorway in the USA. Still with the new gear box internals and now a new bonded clutch I must say she is a treat to ride and shift. Many thanks for your efforts as I have really quite enjoyed the vids.

[@alanglen5902]

Thanks. Still more to do but making progress. Video 6 underway currently.

[@dducdude6315]

@@alanglen5902 Hi Alan, I really do enjoy the way you explain the function of the bits as I did not know how the outer cover bearing was oiled. If you are so inclined and since you have to put the box back in the bike and build up the primary I would love to see how you do that. As I had no end of trouble figuring out the the process. It was enough to make me think twice about keeping the bike. It took me a week or so till I realized that the spring carrier on the clutch was knackered and not free to spin so the springs would bend over when tightening . Then just getting the the darn springs compressed enough to start threading on the sleeve gear nut on was enough to cost a 1/4 bottle of single malt :( Not a lot of Velo fellows here in the States (in the Eastern Bits any way) so we can use all the help we can get:-)

[@alanglen5902]

Thanks. I have not finished yet. Video 6 in progress at the moment. If you engage top gear, the sleeve gear cannot get pushed into the gearbox while you attempt to engage the threads on the sleeve gear.

[@dducdude6315]

@@alanglen5902 Yup I figured out that top gear helps keep the sleeve gear from being pushed into the case but the spring rate was such that I could not compress them enough with out "the special tool" .. Just hard learned lessons

[@derekgee4223]

Thank you Alan very interesting and may I say entertaining

[@montyzumazoom1337]

Great stuff👍

[@Oldvelocette]

Hi Alan, regarding the selector plate. I am building a mac gearbox 4 speed. Do I need to put that in fourth as well, when rebuilding it? Thanks for the really great videos.

[@alanglen5902]

I have no experience of a MAC gearbox, the design philosophy is probably the same however. The most significant thing about engaging top gear is when attaching that threaded ring onto the sleeve gear which secures the clutch. Once 4th gear is engaged, the sleeve gear cannot move inboard(very much) and thereby make it difficult to engage those threads, as you compress the clutch springs. If the lay shaft and main shaft are meshed together and offered into the gearbox they should locate in the lay shaft bearing and also the sleeve gear. Then It should be possible to align the selector rods/ forks into the cam plate . That’s all I can suggest. In later videos I rebuilt the 4 speed which I removed from the bike. This may offer some clues. Thanks for the comment. Alan

[@davidatkinson3887]

where do you buy the screwdriver with hexagon shaft . thank you

[@alanglen5902]

I bought that screwdriver in the late 70,s from the Snap On man who called regularly. I imagine similar are still available today. Those Snap On tools have lasted a long time but the plastic handles on the screwdrivers are in poor shape and the chrome has worn off the sockets and extension shafts and ratchets.