Vintage Road Racing Association

The 70 is a B25.Last of the old style frame.(not oil in frame) These where high compression,decent motor with good bearings.Has a high pipe & steel tank,the early tanks were fiberglass,the 71 on were aluminum.It has the 69/70 bsa/triumph front end(good & fairly light) triumph 8"tls drum & 19" rim will fit right on.It has a 7"tls 18" now.No difference between the 250 bsa or triumph accept the badge.These bikes handle good for the time.I am going to run a 19" on the front with 8" tls & tt100's front & back.I beleive these bikes handled the best the way they were built.You can stick the top end from a 441 on this with a little work & it becomes a P1 350


Brad

It should look like this

Rearset mounts Tig welded

Nice welding...Have to do mine soon. Coming to Montreal Rick??????

These bikes were fairly light for their size.The 250 motor reved higher than 500 (about 8200 red line I think) A twin plug head is a period mod & with the pipe & biger carb they run quite well.If you raise the compression a roller starter will be in order.You will need to work on it,it's not a jap bike.I'm sure Peter would be able to tell you a lot more.
I have a b25 & a 441.I'm not sure which way to go.These bikes a very easy to work on & fairly reliable if kept maintained & not overreved.They are very torky & the 250 should hit 80mph with stock gearing.The

Brad is right on the money. The dual plug head is a good easy mod plus there are some oiling mods for the bottom end that will help with parts lasting. I would suggest you check out this website, tons of good info on these bikes: http://www.b50.org/index2.htm

The BSA's have a certain charm and do have lots of torque which is an advantage on some of the short tracks for sure. They do require attention but can be made reliable if you don't go too crazy with mods (ask me how I know this ). A roller starter is a must, tough bike to bump start.

Peter

Almost on it's feet....

Hey Rick,Love the wheels,I think I want it back now.

Brad

The quest for (more) fire.....

Wasn't that a movie???? Looking good Rick. Enjoy your Holidays. All the best to you and yours...

Good call running the later steel rotary valve - that's a KE175 steel valve and collar, right? The fiber ones break apart too easily at high rpm, especially when they've been modified, though I did cut back the one on my 100 Kaw and it seemed to last okay, but I was extra careful and polished the edges of the modified valve.
Are you going to cut or mill all that crap off the back of the engine cases - the original air intake? It looks like there's a ton of metal there.
I don't know if the F7 has the same problem with the cylinder sleeve blocking part of the intake tract like the Samurai 250 twin and my 100 did (you've probably cut it back already) but worth looking at.
If I could have found an F7 cheap, probably woulda gone the same route as you, but the ersatz CB92R has been a lot of fun to work on so far. It hasn't cost a lot of money (yet), there are bits around my shop that can be used on it and besides, I don't want Stan to be the only guy out there with leading link front forks. If I ever get my computer working right, will post a few photos. Hopefully, it'll look like something on the grid from 1963.
Great work so far. I look forward to following you around the track next year.
Have a Merry Xmas and a Happy New Year.
Pat.

Getting my desktop rebuilt so I'm not able to post any photos of the CB92R just yet, but checked the frame and engine numbers today and found that I have a '63, not a '65 like I thought I'd bought, so I guess I can run pre-'65 as well (have to check with the tech committee)?
Don't know what I prefer - getting my arse handed to me in pre- 65 or bumping to P1-250 for a second class and getting my arse handed to me there.
I have a set of NOS Honda pistons and rings and some "pre-enjoyed" front suspension bits coming from the USA and still trying to figure out what fairing to use - all the stuff I have seems a bit big, but looking at another fairing mould next week to see if it'll work. Might just end up being a Norton nose bowl and screen initially, though...
The purple metalflake paint is sloughing off almost by itself, so should be easy enough to strip to bare metal and check for any needed repairs before repainting. The original frame, forks and swingarm were royal blue underneath the purple metalflake, but I may go to a black frame so I can pick any fender / tank / seat colour(s) I want to.
I'll try to get some photos posted after the bike show and then the head shaking can really begin.
Have a Happy New Year everyone.
Pat

Expansion chamber done...my 1st one ever.... 22 gauge steel rolled in a borrowed slip roller...







Raised compression ratio to 10.8:1
Squish set at 0.050"
Rotary valve modified

Waiting for my carb adapter and some oil seals.....

We have spark!

NICE !!!!!!!!!

Sorry gang, still no photos available to post - the computer repair has turned into buying a new one so I'm currently looking for a new unit and using a borrowed one right now...
Anyway, received the front fork suspension bits, some of which will work fine but a few bits, not without modification which is to be expected working on 50+ year-old bikes I guess.
Got my brand new Honda pistons and rings the other day, great stuff, in the original Honda boxes, makes me wonder how much NOS factory stuff is still out there for these bikes (Honda made over 68,000 CA95's and I don't know how many C92's and CB92's).
Have a CB350 front wheel and brake on it right now, the backing plate needs machining to accept a bushing like the original had to allow small amounts of rotation during fork movement (leading link fork, remember?). Slapping on a bigger front brake is a little more involved than with telescopic forks but still, a pretty straightforward fitment as it has the same axle diameter and the wheel was pretty much centered in the forks using the CB350 axle spacers. I have a shouldered Akront WM1 rim for the front, correct spoke angles drilled for the Honda drum but with the next guage size up spokes so will have to work my magic with the drill on the hub to accept the bigger spokes before lacing it all together. Would have liked a bigger brake but probably okay for now...
Yesterday, I fitted a complete rear wheel from a CS3 Yamaha - 18" rim, a lot lighter rear hub and better brake, too once a few mods have been made. Same axle diameters and same chain pitch (#428) so again, pretty straightforward conversion once spacers have been machined for chain alignment. The conversion also allows me to buy a pretty good assortment of CS3 rear sprockets "off the shelf" - the CA95 only ever had one rear sprocket listed for it. I'm looking for a WM2 shouldered alloy rim and I think I've got a spoke set already, but if anyone has got something like it, let me know - doesn't have to be shouldered, just 36 hole and alloy with the right spoke angle pitch.
Going to start going over the rest of the motor in the next week or so far, I'm absolutely amazed at how good the condition of the majority of the motor parts is.
Regards,
Pat

And on other breaking news, friends in "high places" may have some "real" CB92 bits for my project. So far, a front brake stay has been proffered (if it can be found, been in storage these many years).
I feel 5mph faster already.
Pat