CB250RS café racer project

[NordieBoy]

My 5-speed has been going so well I havn't looked at dropping the 6-speed in yet.
It gets redlined in pretty much every gear before shifting.

Hmmm... spare engine... cafe racer... mmmmmm...

[mylittletony]

Hi guys,

I just joined this site so i can get more knowledge for my CB. Recently purchased for £190, straight through MOT and taxed for an extra 60, so it owes me £250, which is nice. It's currently in the back garden with bits missing while i transform it into one of these crossed with a cafe racer:

http://mulliganmachine.blogspot.com/...-trackers.html

much like some of the bikes above! I've just ordered a small battery to try and tuck up underneath a cut down original seat base which will have some free foam on top (thanks work!).

Other parts to be fitted include:
Bates style 4.5" headlight
Enduro rear guard and light (smallest, lightest ones i could find for cheap)
Universal speedo and rev counter
Tiddly indicators

I'm struggling to find a decent exhaust (got a Motad, but it's too quiet...) or even parts in the right size. I'd love a high pipe off an XL, but heard they don't fit?

Also very interested in the 340cc conversion as would like a bit more poke without getting silly.

Wobbles, where in London are you, I'm in Clapham...

Xwhatsit - you are a legend.

Apologies for the essay, i'll post some progress photos once i work out my stupid camera!

[xwhatsit]

Cool! Those Japanese street trackers are awesome. Have you seen Heiwa's site? Here's their Honda range, with an RS down the page a little: http://www.heiwa-mc.jp/dotnetnuke4/t...1/Default.aspx Their paint jobs (not that there's much to paint!) are absolutely beautiful.

The XL250S pipes; I dunno about how they'd fit along the frame, but I would think the main issue is that the header diameter is smaller. The XL250S engine was lower tuned with more restricted cam profile and exhaust ports.

I always thought the Motads had removable baffles? I always wanted to import one to the other side of the world here, they looked good. Ended up with a locally-made Cycleworks 'zorst (similar design to the Motad 2-into-1 but a little more agricultural) which after repacking is quiet enough but has a nice tone.

[lancerlot]

This has got to now be the best thread on the internet for caffing CB250RS's..
All of you guys are a great help!

A question tho that maybe you can help out on - how easy is it to fit other tanks?

I mean is it just a question of taking off the RS tank and slamming another one in - bolting it up at the base of the seat?

Or does research need to be done as to what particular tanks will fit on the RS frame?

Sorry - I know it's a really open ended and vague question - but i hope you all get my drift :-S

[HenryDorsetCase]

definitely a "suck it and see" proposal I'd say.

Hondas with spine frames of the era all had similar mounting I thik: two round rubber hockey pucks on the frame which slot into two semi circles on the tank, bolted or rubber strap at the rear. But from there the variables are endless: I think I would be spending a saturday morning down the local wreckers trying stuff out. Having said that, if you get "the" tank, it shouldnt be too hard to get some mounts brazed to it (by someone competent: petrol fumes, welding torch = fun for all the family).

the eyeball-ometer says something like a GB400 tank "should" fit... but....

[Ixion]

Biggest issue with changing tanks is always the crap mounted under the tank. Coils and what not. More often than not something fouls the underside.If it sits OK on the bike the mountings can be rangi'd easy enough

[vifferman]

http://mulliganmachine.blogspot.com/...-trackers.html

Cool! Those Japanese street trackers are awesome. Have you seen Heiwa's site? Here's their Honda range, with an RS down the page a little: http://www.heiwa-mc.jp/dotnetnuke4/t...1/Default.aspx T

Not a big fan of the large front tyre look - it's disproportionate.

[HenryDorsetCase]

they look in proportion in their intended use i.e. on a US dirt tracker.

something Ive always wondered.

US dirt track is kind of functionally equivalent to speedway (half mile dirt or cinder oval, go out, turn left......)

yet the bikes are SO different: speedway bike has a big front wheel, rigid rear, small but fat rear tyre, 500cc alcohol, no brakes

dirt tracker: default setting is 19 inch wheels front and rear, much less apparnet rearward weight bias, rear suspension and the 750cc air cooled V twin.

Which is faster-er? which is "Better"? my opinion is the dirt trackers are better looking bikes but thats the two year old in me going "WANT"

[lancerlot]

definitely a "suck it and see" proposal I'd say.

Hondas with spine frames of the era all had similar mounting I thik: two round rubber hockey pucks on the frame which slot into two semi circles on the tank, bolted or rubber strap at the rear. But from there the variables are endless: I think I would be spending a saturday morning down the local wreckers trying stuff out. Having said that, if you get "the" tank, it shouldnt be too hard to get some mounts brazed to it (by someone competent: petrol fumes, welding torch = fun for all the family).

the eyeball-ometer says something like a GB400 tank "should" fit... but....

Yep - so i had a look see last night - and turns out you are spot on. Just the bolt at the rear of the tank, and the rubber pucks holding it on (presumably so theres no sideways movement - the weight of the fuel keeps it moving up and down) at the front...

As long as the tank you fit on later has room for the bolt - perhaps something like this

http://cgi.ebay.com.au/HONDA-750-4-C...3A1|240%3A1318

Then as long as you can get the front side from moving laterally, you should be in business...

[jester_parks]

So, back from my short stay in Sardinia, I am proud to show you my latest addition to my RS-parts: tank and seat to beat Hilton`s UK-racer....who by the way "founded" the "CB250RS appreciation society"

Can`t help it, but brits can give always very nice names - sound far better than any german titel!!

[xwhatsit]

WHAT! How'd you score those? You lucky bastard

[Wobbles]

Damn fine looking bit of bodywork there Lester!

With that hot motor, your bike's gonna rock!

How long do you reckon til it's together?

[dandandan]

Loving this thread. I bought my RS in 2003 as my first bike, went to a RGV250, CBR400, GSXR600 and now returning to the RS to cafe it.

(by now I mean it has been sitting at my parent's place for a while now as I live in an apartment on the other side of town and it is near impossible to find the time to get over there to play with it).

A few years ago I did the ultra-cheap psuedo-cafe conversion (dropped the pipe off, flipped the bars) but that just got silly after a while. Got some grand plans for this one but trying to do everything myself.

Thanks to everyone in this thread for all the helpful input. I'm not heaps mechanically minded but there is lots to take away from this.

Going to read the thread from the beginning again to try take it all in. No doubt lots of questions to come. Thanks in advance.

Dan

[jester_parks]

@xwhatsit:

Its off an old CB72/77 racer and it took me long to find it - always searching for those old-period-racer-parts and you will be lucky one day too...

The pacel with the piston hasn`t arrived yet??....seems that you are really living on the other side of the world, don`t you?

[xwhatsit]

@xwhatsit:

Its off an old CB72/77 racer and it took me long to find it - always searching for those old-period-racer-parts and you will be lucky one day too...

What a rare thing to come across! Hopefully it mounts easily without too much hassle, the problem with the RS is the shape of the frame is high at the front and back and dipped in the middle for standard seat.

The pacel with the piston hasn`t arrived yet??....seems that you are really living on the other side of the world, don`t you?

Not yet, I was wondering about that today. Then again, ordering things from England has in the past taken just as long. David Silver had me scratching my head!