XJ600 engine in xj550 frame.

Andy, re gsx750es swingarm

by memory...i had a round alu tube made for the swingarm pivot to go through as the swingarm is fork design this end..
i trimmed a few mm off the frame inner bosses carefully with an angle grinder and got this square much to my relief and to retain the end caps of the swingarm i remember having the innner shims of the caps surface ground ...

still need to get shock mounts welded on..its on my to do list

 

@tobar wow sounds an interesting project. I like the way you have engineered the swing arm. I mentioned in an earlier post that I have a Bandit 400 swing that I thought would not work so well, however I've had rethink and I'm going to try and shorten it, it's about 75mm or 3" to long. I'll post photos when I attempt this. Hopefully it should work well and it's steel so it'll be easy to weld.

Cheers Andy

 

yep done that...another xj im working on has a bandit 600 swingarm in it...
again i cant really remember exactly but it does need fettling to fit...possibly a bit off either side..i cut up a damaged and bent bandit 600 frame just for the lower shock mount and had it welded on to an xj600 frame..still work in progress but it works in mock ups...
its a bandit 600 wheel but for some reason someone put a 180 tyre on it..that will be coming off for a 160..gs500/gsx750f front wheel with axle same size as xj one...15mm from memory..but need to work out brakes or discs that will work with it..

 

going back to the gsx750es swingarm that may have had a bit trimmed off either side too???
but when it was fitted it was a bit stiff going up and down so the machine shop surface ground the shims for that reason to make it smooth...probably easier and cheaper than taking more off the swingarm..but i think originally that swingarm is 220mm, maybe 222 and with end caps 226mm wide so its close to xj5/6 frames

 

That looks good, I too have a B6 swing arm, again I thought it was too long however your set up looks fine. I also thought about a B6 rear wheel, they are cheap and readily available. The main reason I decided against a B6 rear wheel was the alignment of the sprockets. I don't know about XJ/FJ600 frames but there's not a lot of room on the Radian frame for the chain.

Cheers Andy

 

@tobar Again I'm not sure about pivot width for the swing arm of XJ/FJ600s are, but the Radian is 200mm. So that means getting creative with the hacksaw so I can use either a B6/B4 swing arm.

Cheers Andy

 

200 is that all..hmmm..what about original fireblade swingarm? off the top off my head 180mm width fork design at the pivot end so get a tube in the middle and sleeve the fireblade pivot down to use your spindle, space out the 180 to 200mm which should make chain run easier and maybe a slimmer cbr600 wheel spaced out....
is radian twin shock..may have to cut the brace off the arm if it is to get mounts welded on..if monoshock then that will need working out too

 

ps..thats me thinking out loud,,may work or may just be a load of bollox..lol

 

just looked on ebay
cbr900 swingarms are tubed at the pivot end not fork design and 50 quid and under...dont know what the spindle width is but just a bearing swap may work if the od and id works..
if you think it may work and cut off the braced arm to weld shock mounts on..i'll have the brace off ya..lol

 

@tobar No worries, I did think of a Fireblade swing arm, a bit extreme for me perhaps, although a good idea. And yes the Radian is twin shock which I would like to keep, maybe some XJR 1200 piggy back rear shocks just for the looks. I might have a look at the B6 swing arm again at the weekend.

Cheers Andy

 

well good luck with it all....as far as shocks go i'd recommend YSS twin shockers...so many different lengths,combinations and connotations in their catalogue at a good price and they look good to

 

isnt 200mm the same pivot width as rd350's..have a look at what swingarms they are getting put in those frames

 

@tobar this is a useful link https://www.xjrider.com/viewtopic.php?t=3136 although not a complete list. According to that list RD350s are 200mm at the swing arm pivot point and presumably RD250s would be the same.

Im sure I've seen somewhere of RGV250 swing arms used on RD250/350s.

The Radian frame is essentially a slightly modified XJ550 frame so it stands to reason that an XJ550 frame is 200mm at the swing arm pivot point.

YSS shocks do look good, I was thinking of using them but maybe a little longer for a nice stance, so that it looks like it's braking from 120mph even when it's stood still.

Cheers Andy

 

i'll try and measure up my xj550 frame with gsx750es arm which will be post modded of course....at the mo its buried at the end of the garage, im working daylight hours..and its snowing so wont be straight away

 

@tobar thanks mate, there's no rush and you never know someone might post the info here.

Cheers Andy

 

Yeah, well watch the steering angle if you go too far with that idea.

 

Thanks for the tip, however I won't be doing anything too extreme, maybe 20mm, it won't be like Motocross bike.

Cheers Andy

 

Check the rake (camber) angle 24* is the Sport Bike norm. Buell used to go to 23* SV650 25* old school bike 27* and more. Short S/A and slack rake was the rule of the day.
Modern is steeper, and longer S/A, just a few numbers for those that may be interested in how steep is steep? If you go too steep without a corresponding change in trail
you can get into oddball handling. Triple clamps on modern bikes typically have less offset keeping trail in proper range.
Cheers, 50gary

 

@50gary thanks for the heads up. As far as I can tell modern bikes have longer swing arms because they are mainly monoshock and need to be longer to allow space for the shock absorber. If I understand what you saying I could perhaps leave my Bandit 400 S/A stock and drop the forks through the triple clamps or yokes as we know them in UK and I could achieve somewhere near stock geometry or am I barking up the wrong tree.

Cheers Andy

 

the pics arent great but what they show is the alu needs cleaning..lol
so you have the centre tube made up to fill the gap
the frame inner bosses cut 5mm either side with angle grinder which worked out great taking my time..measure and mark out 10 times cut once
im sure this frame was 205mm at the pivot which i took out to 215mm as the ruler shows sort of
i think a gsx750es swingarm is 222m with cups...
the engineer guy took some off either side cos i remember him pushing the needle bearings into the swingarm a bit more..
the outer cups have been reduced and the cups have shims in them and they were played with to get a good swing..ground a bit flatter i think...
so not the easiest install but we got there