monoshock

ok its late and im having thoughts about a monoshock.

to start with i want to ask you guys has anyone done a monoshock mod on a shaft drive xj?

i need to throw in a scetch of my idea but now its sleepy time in this part of the world.





any thoughts?


i have but i need to sleep over it..

 

ok i did a simple scetch



do we want a better drawing or can you see what im after?
is this doable or just plain stupid?

this mod would tidy up the rear for good

 

I'm in the same boat as you. I want clean, simple lines. I'll be doing something like this in the winter, and your sketch looks pretty straight-forward to me. I'm no expert, but it looks to me like you've got the right idea.

 

Did you do a search here?? I'm pretty sure the idea has been tossed around here. The main issue, if I recall, was how to properly beef up the spine of the bike to take the added stress ...that and finding room to add the needed reinforcement..

 

Check this one out:
http://xjbikes.com/Forums/viewtopic/t=1 ... art=0.html

 

interesting thread but im planning on reinforcing an original xj spare swingarm.

i have room for reinforcing the spine since my electric gizmos are gone,

i didnt catch on what axis the spine needs reinforcing?

 

bostonxj what do you mean straigthforward?

 

the 81 virago 750 had monoshock and the same wheels and shaft drive, maybe it would be easier than we think.

 

Virago swing arm & shock

 

That's a whole lot of fabricating, AND I think you lose the airbox.
What's wrong with some nice looking aftermarket shocks ??

They come in lots of flashy colors, and they actually work too.

 

padre and wizard, thanks for the idea, i have looked at that too but i came to conclusion that only the shock may be usable. it seems to me it is easier to weld support brackets on xj swingarm than try to fit a virago swingarm.




timetoride, no offence, but perhaps to some of us the names of the section and this thread in it indicates that the discussion will be about a whole lot of fabrication. if i would want to go with aftermarket rear shocks dont you think this thread would be about aftermarket rear shocks? some of us want to do a whole lot of fabrication and installing aftermarket parts just isnt fabrication enough.

are you really saying that custom monoshock swingarm wont actually work? then i have to suggest you to never try something like this.

AND only bad thing about loosing the airbox because of the shock is that im not loosing my airbox quick enough



whenever someone has a nice idea there is the other one saying "maybe you should just keep it stock"



stock is f****ng ugly if you ask me

 

.....and whenever someone says "stock is f****ng ugly if you ask me" there is another who says "I like to put things back to stock just like it came from the factory".

You DID say in your first post:

>any thoughts?

You DID say in your second post:

>Is this doable or just plain stupid?

You did say in your last post:

>timetoride, no offence, but perhaps.......

So don't take offense when someone give ideas, or says it's not doable, or suggests alternatives that may be different than just the ones you really wanted to hear.

That all being said, I am also one that has spent a lot of time studying the xv/xj parts interchange-ability. somethings work easy, somethings don't.

The mono shock presents a lot of challenges. We've already been through a lot of that through the forums. Someone said you may lose the airbox. If you prefer that, fine. That also means now you're getting into carb work....jetting, pods,etc.....and the associated nightmare with those.

Check to see if there's different off-sets for the bearings from centerline of the tire between the swingarms.

There's machining to do to the ends of the pivots. The measurements may not be the not the same. If you machine the swingarm, then you have to change to a different thickness bearings. If you machine the frame, then you may need to modify the pivot shafts.

Will the frame interfere with the shear size/shape of the monoshock swingarm? You may have to remove the inner fender?

If the idea is to "cleanup" the rear of the bike, how will putting a big bulky thing like that clean it up instead of clutter it up? If you modify an xj swingarm, how will that be any less cluttered than the mono-shock swingarm?

Here's an idea, if you're actually listening to ideas......

Go look at the how suzuki intruder 1500 swingarm is set up. that is a shaft drive, mono-shock system, and is as clean as an xj swingarm, and there's no clutter or frame to the swingarm like the virago mono shock has on it. That might give you a better way to go........modify your xj arm along that line instead.

dave fox

 

I test-rode a Goldwing for a friend and the seller said I ruined the motor- - in 300 feet.
That offended me.

This doesn't offend me.

I never said it can't be done, Chop away, my friend.
Keep pursuing your dream, and post-up some pics !

 

Time-- there's got to be a story going along with the Goldwing there!

Dave

 

I agree w/hog on this one... you ask for input..be prepared to take all input graciously. And don't ever assume you know what someone else has tried or hasn't tried based solely on their suggestion. (timetoride posts=2266 / venlis post=63) maybe time has tried this mod and found it's not worth the time/cost/effort.....in any event....
IF I were to wander down this path of fabrication insanity...I would probably pursue this type of design..


More along the softail approach. I've done enough engineering to know that a mono-shock setup is going to produce some extreme stress on the frame in weird places. And when you consider the xj frame was never designed to be subjected to those kinds of stress it makes it more of a challenge. As such I would try to localize the stress as much as possible. This design (I think) would localize the stresses more around the pivot area of the swingarm. What ever direction you decide to go I would have the welding done by a professional and check your frame every time you get on the bike...

 

i guess i need to apologise. my head was tired and my pen was too sharp. i never ment to bash veteran members of this fine board.

by asking "any thoughts" i did mean thoughts on this particular subject: monoshock modification, not rear suspension in general. i appreciate opposing opinions yes, but in this thread i wanted to ask about this type of fabrication. by starting a thread titled like this thread one might assume that i think something doesnt suit my eye on the stock swingarm setup. so in my opinion, questioning why is not going to be too fertile for the discussion.

hogfiddles we are talking about differences in taste, those things cannot be argued, and sometimes someone, when tired, will think expressing a different taste is arguing. ill try to behave in the future.

mad_bohemian, based on timetorides post, i would assume he has not tried this. usually people say a lot more than they write. but thats all in the mind of the reader of course. so i may well be wrong.
on your scetch wouldnt the shock be expanding instead of compressing under load?

thank you everyone for your valuable input.




dont viragos have 16 inch rims?



adding a little steel tubing on a swingarm and hooking it to the frame with a suitable shock will definitely clean out the rear section, leaving the whole rear frame useless ---> cutting time.............

 

Me thinks if you duplicate the lengths and angles that the factory did with the virago on the xj swing arm and either beef up or fabricate an anchor point on the frame in the same fashion that the factory did. If your a good welder and maybe have the welds magnafluxed or ex-ray'd you'd get what you want. On thru the fog!!!!!!!!!!!!

 

Guys.. What's with all the agression? This is the mods section after all.. Maybe you think its sacrilage to chop up a XJ.. But it's not like they're rare bikes, don't be so precious, wish I had the means and the skill to do summit like this. Although I do agree, peeps have the right to ask why you don't do something a certain way.

Anyone who's seen an R1 recently can't possibly say that duel shocks look nicer (this aint mine btw.. Wish it was!!)


keep it going.. I'm watching with interest (outta my league, but I love this idea)

 

My own PERSONAL opinion.....yuck. I don't like it. IMNSHO

Dave

 

Correct. The softail shocks don't dampen compression like a standard shock, they dampen expansion of the shock. You might need two (not sure how much pressure it takes to expand the shock) but could probably easily fabricate a mounting system where the center stand on the maxim is.

 

I have thought about this myself for my bike. I no longer have the gigantic airbox but do have pods and a jet kit with a pipe, little tuning required and I ran neck and neck with a maxim X to 130mph. So monoshock away, your swingarm makes sense and inside of the frame I would say there is room if you find the right length of shock. As far as stress on the frame? It is steel and the welds from the factory are sloppy at best. Bracing wouldn't be bad the frames are kind of like black spaghetti, look at a book on designing race car frames more stress there then on your bike. Take pictures lots of pictures I must see.

 

Where is Rice-Burnarr when you want him?

 

i have been thinking of cutting the whole rear frame off, and adding some steel to the 'new' backend of the frame and the shock mounting point. wish id have time to draw a picture.

ok now i get the softail approach. it would look even cleaner than the '1st gen' monoshock style, and would maybe require less strenghtening on the upper frame.. but no, i would see that the rear hub needs to be supported so it would be supported by something else than only the swingarm bolts. what do you think?


swissjon you are right. and this is a discussion board, all discussion should be welcome. but with that r1....

i had a similar r1, absolutely loved it. but that one with all that chrome.... id have to shout RAPE ! ! ! ! !






bottom line i really like this idea and only things possibly stopping me are finnish authorities, who hate garage built bikes. i would like to keep my bike road legal and these kinds of modifications might be too much for them. i have to ask...

 

RAPE? This is a visual masterpiece lol

I guess it takes all tastes to make the world turn. Personally I love it.

I'm curious, why have you gone from an R1 to an XJ?

 

yeah well i can totally appreciate the work on the r1, i just have something against chrome on motorcycles. chrome only where its supposed to be, on the forks. even though im thinking of getting those rubber protectors to hide the crome on my forks

yes swiss again youre correct, things would quickly get boring if everyone would suddenly agree on everything


i had a 03 r1, regrettably i had to part with it because i couldnt afford keeping an apartment, a car, a bike, a useless unemployed woman and a kid. so the bike had to go, unfortunately the woman had to go a week after that, meaning i just might have been able to keep the bike after all. well f***.

a litre supersport bike is extremely expensive to keep in finland because of the ridiculous insurance costs, on top of those i lost my licence many times with it and collected more than 2000 euros worth of speeding tickets.

an old xj on the other hand is insured for 1/10 of the cost of r1. besides theres a lot more to do with an xj almost as old as me

 

i think theres no room to fit softail type shocks so im going forth with my original plans heres a new scetch what do you guys think?

 

That is very similar to what I was thinking would work although I want to keep the stock look. I like things to look like they haven't been messed with. But the bracing on the swing arm is good I think, the more direct the shock is compressed the more efficient it is.

 

I think if you would fit an r1 or r6 tail on that, it'd look the dogs b*ll*cks. (That's an English expression for very nice )

Hmm. Well I ain't gay, so I'm afraid a woman is as necessary part of my life as a bike. As they say... Sh*t happens. Next time find one who earns her own spending money

 

yeah brewer, i plan to make this look slick and not messed with too



adbrewers notion of the direction of the bracing and shock is a good one, and thats what i was thinking too. since its a moving object would it be good to try to adjust it in such way that the angle of the shock/brace is near 180 wet weight with the rider? or am i on the wrong path?

theres not much i know about rear suspension geometry yet, but if someone of you really knows, let me know.

swissjon im afraid all factory tails are too big and wide for my particular taste, i have to make my own. its going to be 2 up, only a seat, not much of a tail..



continuing about women: that was shit im glad happened.

nowadays im married to a stunning top quality northern beauty from lapland. she looks after herself and supports my hobbies. in some of our discussions she said "theres nothing wrong with having three bikes."

 

You lucky bleeeeeep. You've found the perfect woman. funny how they seem to turn up second time around. Mine is the same, only I have three bikes, she says I have to sell the car if I want a forth. only trouble with Switzerland is that it's like finland. Biking in the winter is a no go, a car is essential. Oh well. Going to sell off this little Honda I have and buy a norton project bike.

I know what you mean about the tail. Wish I had the skills to fabricate something like this.

Loadsa photos please!

 

i think i have more will than skill, but that counts too..!

winter is good for two things: no insects and downhill skiing.

i will be posting a thorough coverage of all i have done with my bike in the future, the build process is slow due to so few hours in a day.



any knowledge on the geometry?

 

Are you wanting to go for the Harley Softail look so your bike looks like a rigid? If so, then in my opinion, it's not worth the effort unless you just want to do it for the sake of saying "I did it". I completely understand that and say there is no better reason for doing something. If you're wanting to get the clean lines of a rigid while not sacrificing riding comfort, then you're doing it for all the wrong reasons. The Softail type suspension doesn't work nearly as well as the dual shock set up you have now. In reality, it just plain sucks. You're willing to sacrifice comfort for looks, and again I totally agree with that. But why not go all the way and make it a rigid with a sprung solo seat? You'll have less engineering/fabricating and the difference in ride won't be all that much.

If you're going for the street fighter look, then completely ignore what I have said and do your thing.

 

I believe I have a book on fabrication for race cars still kick'in around somewhere I'll have to look. I look at the lists of bikes some of you own and wish I didn't live in North America I would love an XJR.

 

no bud i am going for the 'streetfighter' looking ducati supersport type of setup.

the idea is to try to make it work and look better. i believe a monoshock is a lot easier on the shock than a twin shock.

 

Check out what I just found - -

http://www.youtube.com/watch?v=t6WDE4pZ ... re=related

This thing even sounds like it runs good with no airbox and open header !

 

yeah ive seen that before.. thats exactly the setup im after.

may take me years though

 

It was a tad easier for them to pull off, the 550s are chain drive.

 

but only a tad..

 

I think you have a pretty good plan to brace and monoshock your swingarm. If it was me, I would probably get a Virago swingarm and shock to cut the pieces off and weld to the XJ swinger. That way I wouldn't have to fab a lower shock mount or jig up the bracing. If you have the time, you might want to take a look at Tony Foale's site if you haven't seen it before. He really knows what he is doing. He is a nice guy to talk to. I raced against him at Mid-Ohio this year and he has a custom framed Aermacchi that he built that is really cool.

http://www.tonyfoale.com/



Ken

 

thanks ken, i wasnt familiar with tony foales work before. theres a lot of information on the page that just blowd my mind. a lot of motorcycle theory. id like to dig deeper but it seems he wants some $. maybe i can send him an email and ask for some SIMPLE directions to shoot for

the virago swingarm is for a 16 inch wheel, therefore pieces needed are too short. i need to fab everything anyway and i need to weld the bracings where i want them, not where i can get them to go, if you know what i mean.



came to my mind that being a shaft drive bike the limits of wheel travel have to be critical? so i may need a shock off a bike that had linkages, since the shock travel on linkage type shocks is less than on shocks that dont use linkages.

does anyone know what would be the maximum rear wheel travel on 750 secas? a wheel travel to aim at when planning this, i dont want to ruin my shaft drive. or does it even move to a position where damage would occur?

 

i want that 550 with the monoshock

 

I might do a monoshock for my cafe later. monoshock cafe bikes are hawt.

 

The XJ series was all chain driven in Australia and Monoshock, so there's the trade off

 

could i swap over to an australian rear end to gain a monoshock?

 

Yup

 

Only the 600

 

Hey Venlis - -
have you seen this one??

http://www.bikeexif.com/honda-cb550-cafe-racer-2

And 100 more pics here of Cafe Overkill - -

http://www.vinmoto.org/gallery/v/VinMot ... +Overkill/

 

thanks time, that bike is awesome.. i have seen some bike that had dual shocks under the seat but im not sure if it was this.. the thing looks like you wouldnt want to ride it cause u want to keep it shiny



kevin isnt that a virago with a 16 inch wheel?

 

Its My Virago 500, 1983 the only year made. Monoshock, and yes 16" rear