CB250RS café racer project

[avgas]

1960s road racer.

You must be too young - i got told off for saying 1960's...turns out the whole ACE thing started late 40's early 50's.
Doing a ton under the bridge nearby was a common thing in the 50's. As were the cutlery chained to the tables.
So I've been told.
As for the TM auction, very nice - pity I've been told that the 650 was a dog. Mind due soon as i will lotto 1 of the 850's back home is getting the cafe' treatment.

[Bonez]

Yeh i suppose MDI's would be fine on a 250 - as your prob only going to keep it a few years. Good call Bonez

Ment to be suitable for up to 750cc(old school of course) Bought a set for the GB400 and GSX750EX. Haven't tested the gasaxe ones out yet( one of the original shocks had too much striction for comfortable riding). Springs can be a bit stiff for lighter bikes. But its easy enough to change them over if needed. Turns out if I don't like them on the gasaxe I can swap the Konis on the CB550 over.

MDI make a variaty of replacement monoshocks as well.

[xwhatsit]

Wo0o0o0o0 for bungbung. I'm buying some XL250 instruments off him. They don't look exactly classic right now -- unless you mean in an 80s sense. But think it should be easy enough to have some new face plates printed up.

I like the fact the redline is at 8500rpm -- at least I'll feel comfortable revving out to the redline, hahaha. In general practice I avoid anything over 7000-7500rpm, a lot of vibes seem to appear, and I don't really feel like replacing bent valves again.

[TygerTung]

I've got a CB250RS which I race, well I've only done one event, well not really, the shitty old rotton exhaust fell off in the practice!!!!

Does yours like to rev HARDOUT? Mine does, the redline is at 9 I think, but it pulls hard around to about 11, which seems fine to me, did your one crap out or somthing?

If it starts to vibrate hardout it may be due to the balance shafts being wrong or somthing, I took mine out and it vibrates quite badly, I think I might put them back in....

If you are gonna get rid of that front mudguard let me know I'm missing one!

[xwhatsit]

I've got a CB250RS which I race, well I've only done one event, well not really, the shitty old rotton exhaust fell off in the practice!!!!

Does yours like to rev HARDOUT? Mine does, the redline is at 9 I think, but it pulls hard around to about 11, which seems fine to me, did your one crap out or somthing?

If it starts to vibrate hardout it may be due to the balance shafts being wrong or somthing, I took mine out and it vibrates quite badly, I think I might put them back in....

If you are gonna get rid of that front mudguard let me know I'm missing one!

I bought a CB250RS parts bike off another KBer a little while ago, so I've got plenty of parts. I've got a front guard -- will go and check the condition, give you a PM.

Mine doesn't like to rev heaps, really. It doesn't seem to make much more power after about 6000, so I don't bother stressing it beyond that. Around town it's happy sitting on 5000, changing gears at 7000 for quick acceleration. On the motorway I've had it up far higher, but that's only because the gearing seems quite low. Wouldn't mind changing the sprockets. It doesn't vibrate excessively, it's just it's normally fairly smooth up until 7000, until it hits some sort of `resonance'. If you get to 8000, the vibes seem to settle back down to normal. Racing would be a different matter of course.

If you need engine bits for your race bike, I've probably got most of what you need as well.

Would love to see a CB250RS racing! Wish I lived a bit closer so I could watch

[TygerTung]

Maybe there is somthing wrong with yours as they are a very revvy engine?

I don't need any parts for the engine at the moment, if you want a new piston go to www.motoequip.co.nz they are cheap! there.

I'll send ya some pics of me racing once I get it going!

[Dodgyiti]

I think the tank and the seat lend themselves to the cafe style quite well.

Probably not good advice, but when I was a poor apprentice I once padded out some clip ons with beer can ali. Terrible eh?
Is there no way to file a bit off the clamping face to let them bind up more?
They better be really tight before you go riding. And jeese they look low, I know of a good orthopedic wrist doctor, PM me when you need him.

Cafe Racers Rule!

[xwhatsit]

I think the tank and the seat lend themselves to the cafe style quite well.

Probably not good advice, but when I was a poor apprentice I once padded out some clip ons with beer can ali. Terrible eh?
Is there no way to file a bit off the clamping face to let them bind up more?
They better be really tight before you go riding. And jeese they look low, I know of a good orthopedic wrist doctor, PM me when you need him.

Cafe Racers Rule!

The seat is definitely going -- I hate it, lol. It's very comfortable, the most comfortable seat on any bike I've ridden, but it just doesn't look right, so I'm trading it for a hard bit of fibreglass with some leather stretched out on it

You think I can pull off the tank? Me too -- if you close your eyes and squint a bit, it's got the same sort of profile as one of the 1960s Honda CRs

I've got some Tommaselli replica clip-ons that are 32mm on the way from 'Merika, so then I'll be able to throw out my coke-can shims haha. They are bloody low though, you're right. I've actually got used to it now though. Quite comfy, as long as you're moving. At traffic lights I stick it in neutral and sit dead upright, like I'm standing up, so my back gets a rest haha. As I said earlier, though, the current position is just a compromise until I fix up the headlight/indicator arrangement up front.

Cheers

[Dodgyiti]

The seat is definitely going -- I hate it, lol. It's very comfortable, the most comfortable seat on any bike I've ridden, but it just doesn't look right, so I'm trading it for a hard bit of fibreglass with some leather stretched out on it

Heehee, good onya. Practical is not in the cafe racer build list. But lightening and drilling out and discarding everything not absolutely vital kinda is..Your on the path to enlightenment, and don't forget that doctors number.

[xwhatsit]

Well, the stories you have heard about me are true; I am a tit.

Got my beautiful clip-ons today. Opened up the package to be greeted by mouth-watering shininess. Gorgeous things, wonderfully made. Anyway, pull off the old clip-ons, juggle the controls and forks and all that stuff around (horrible job). Put on the new ones... oh bollocks. They're too small.

Yep. So now we have the reverse of the original problem. By prying them open with a screwdriver, I could get them to go on as a very tight fit (had to use force to make them go down the forks). I can get the bolts in to tighten them up, but they only go in a couple of threads, and I don't like that one bit. Don't want to put too much torque on the bolts when they're gripping only a couple of threads.

What are my options here? I have the reverse problem now. Can I take the clip-ons to a machinist, and have him bore out perhaps half a mm? I think there's enough meat, please correct me if I'm wrong. I've enclosed a photo from the ebay auction, so you can see if you think there's enough to chew out.

Longer bolts wouldn't help, as the problem is the thread and the opposing hole the bolt tightens on to are at different angles because they're stretched open.

I would really like to avoid buying a new pair, or trying to swap these -- it wasn't cheap to buy them, and shipping takes forever. Can it be done?

[xwhatsit]

Oh yeah, by the way, this time I dropped the triple clamps down on the forks, then put the clip-ons on top of the clamps. Had to use reams of Nitto tape to secure the headlight assembly (why did Honda use such an ass-backward way of holding onto the headlight + indicators? What's wrong with fork clamps?).

Feels weird to be sitting up so high now, lol. Still lower than the original bars though. A side effect of dropping the bike down through the forks is that it's changed the geometry slightly; the forks now have a steeper rake, and the bike now has brutal turn-in. It pitches you screaming towards the apex without you even having to think about it. Quite fun in it's own hair-raising way. I'm sure I'll get used to it. Probably will increase the chance of a tank-slapper, so I'll keep the front wheel on the ground (has it ever been off the ground?), and once I've got new headlight + headlight clamps I'll put the forks where they should be and the bars just under the top clamp.

[Ixion]

Personally I'd get one of those little grinding wheels you put in an electric drill, and carefully take a bit off the inside . Or one of the "wrapped in emerypaper cylinder" gizmos if you can't find a grinding wheel wide enough. Half a millimetre is only 20 thou that's not much to remove. You caould do it with a rattail file (or even a half round) if you have a good hand and eye.

Also, can you take a few thou off the staunchion, using a strip of emerycloth run around the staunchion and pulled back and forth ?

[xwhatsit]

Personally I'd get one of those little grinding wheels you put in an electric drill, and carefully take a bit off the inside . Or one of the "wrapped in emerypaper cylinder" gizmos if you can't find a grinding wheel wide enough. Half a millimetre is only 20 thou that's not much to remove. You caould do it with a rattail file (or even a half round) if you have a good hand and eye.

Also, can you take a few thou off the staunchion, using a strip of emerycloth run around the staunchion and pulled back and forth ?

I've neither a good hand nor a good eye. Playing french horn ruined both I'll find one of these grinding wheels you speak of.

I'm not overly keen on playing with the stanchions as I'm not completely sure yet where I'll put the bars yet.

Ta for the advice. Half a mm should be sufficient, as that would make the bars the equivalent of 1mm bigger, and that seems to be heaps if I've gone from 34-35mm to 32mm with such a vast difference. These 32mm ones are much closer.

Thanks to Spankme for not booting me off his site for being such an utter twat

[Ixion]

Meh, half the fun of such a project is dealing with all those little quandries that arise

(In reality, of course, it's not fun at the time, it's a proper pain in the tit. But, once done, you can put on side about "the problems I overcame" and wax pontifically and smugly . Which is fun)

[xwhatsit]

Meh, half the fun of such a project is dealing with all those little quandries that arise

(In reality, of course, it's not fun at the time, it's a proper pain in the tit. But, once done, you can put on side about "the problems I overcame" and wax pontifically and smugly . Which is fun)

You, sir, speak the voice of experience. I'm already beginning to smugly tell stories about when I seized my top end, and crap on about how I wrestled the engine back together with my sheer manly brute strength. I must be becoming a biker.