FT: Frame (Twin) Grade of Stainless Steel

Herman-Handlebars

Well Known and Active Forum User
Non-VOC Member
Herman, I see you have my carb adaptors. If you are really going to race then I suggest that you go for one of the JE steering head mods as well.
Hi Norman,
Yes and lovely that are too, at the same time I purchased the steering head also Not sure if ill keep the Tupperware mod though
Cheers
 

Attachments

  • 20201108_134859.jpg
    20201108_134859.jpg
    114.7 KB · Views: 39

BigEd

Well Known and Active Forum User
VOC Member
VOC Forum Moderator
Hi Ed, as I gave bought the parts over around 7 years, I didn't have a preference until now realizing that steel is more suitable. Would you recommend a suitable steel grade to use?
Thanks
It sounds as if you built your bike in a similar way to me when I built my Rapide. I started off with a basket case and bought bits as and when I could afford them over three years. I've not built mine to be pretty and originality is definitely not my priority but I have replaced standard bits with stainless where they are visible. I was querying your choice of stainless steel for a part that is not visible and well protected from the elements anyway.
Others will be better placed to give you advice on steel grades. I would have thought maybe EN16 grade steel or whatever the modern equivalent (Grade 8?) Some stainless steel grades can also be quite difficult to machine. 303 stainless is listed as free-machining but I'm not sure of how it compares strength-wise.
Good luck with getting all your bits made. Keep at it. It will be worth the effort.
 

Bill Thomas

Well Known and Active Forum User
VOC Member
I mocked up the carbs on the stubs also which seem to work well
They look nice, If it's 14" from the valve head to the outer end of the bell mouth,
You may get the RAM effect !!, Mild Super Charging , I worked it out from an old tuning book from the USA,
 

Attachments

  • bikes 235 - Copy (5).jpg
    bikes 235 - Copy (5).jpg
    195.2 KB · Views: 32

Herman-Handlebars

Well Known and Active Forum User
Non-VOC Member
It sounds as if you built your bike in a similar way to me when I built my Rapide. I started off with a basket case and bought bits as and when I could afford them over three years. I've not built mine to be pretty and originality is definitely not my priority but I have replaced standard bits with stainless where they are visible. I was querying your choice of stainless steel for a part that is not visible and well protected from the elements anyway.
Others will be better placed to give you advice on steel grades. I would have thought maybe EN16 grade steel or whatever the modern equivalent (Grade 8?) Some stainless steel grades can also be quite difficult to machine. 303 stainless is listed as free-machining but I'm not sure of how it compares strength-wise.
Good luck with getting all your bits made. Keep at it. It will be worth the effort.
Thanks Ed, I'd imagine many vincent owners have said the same that its always taken longer than expected I'm going to stick with it, as I think now the engine is together, thats the hard bit done!! I would ring up Maughan's and pester them about parts, then order and wait! Then repeat..Mine won't have any originality as its a Comet cycle part with a new twin engine, but my main aim is to put it all together as best I can within what I can achieve (hopefully!).
I've ordered some 3/8 and En16 and 303 to experiment as well as a hss die to go in the lathe holder.
I am hoping to race it with Bhr, but we'll see how it pans out.
 

Herman-Handlebars

Well Known and Active Forum User
Non-VOC Member
They look nice, If it's 14" from the valve head to the outer end of the bell mouth,
You may get the RAM effect !!, Mild Super Charging , I worked it out from an old tuning book from the USA,
Thanks, they were from Norman. Really pleased with all the parts. Look the part, and like you say they should help with getting it to breathe well! Are they walt phillips fuel injectors? I have read they were all the rage at one point in the 60-70s
 

Gerry Clarke

Well Known and Active Forum User
VOC Member
S/less 303 and 304 will eventually rust as some of the fasteners did with ten years of every day commuting use on my Velo in the 1980's (it rains a lot where I live), 316 is much better in this regard. The 300 series are austenitic types and non-magnetic. For load bearing applications, a martensitic type in the 400 series is a better choice - like the front fork and wheel spindles that the club supplies, which I am guessing are likely 420? These will have some attraction to a magnet.

Gerry
 
Top