big rear tyre conversion?

i want to put on a massive rear tyre, well compared to the original anyway. i ve just had a wornout xj900 thrown at me and want to do some mods to it. fixing a larger rear whell would be one of them. but ofcause the shaft drive does limit it.
has anyone replaced the original swingarm with a chian drive item? is it possible, with or with out the original motor?

 

Forget it. It's nearly impossible without spending a lot of money. If you want a chain drive model sell the 900 and buy one.

 

why do you say that?
have you tried it yourself. what problems did you encounter?

 

How are you going to convert the output of the transmission from a drive shaft parallel with the bike to a sprocket at right angles to the bike?

You can't.

You'd need to replace the engine with something with a chain - the 550 or the secaII.

You'd then need to figure out if the swing arm is going to work with the new rear axle, brake system and the rear sprocket.

Sorry - too expensive to be worth it for most people.

 

well thats what i mean about if you cant do it with the original motor can another be easily bolted in that will do the job. i have very little knowledge about yamahas let alone xj's.other that the wreak i have before me ive got nothng to go on. ill have to look up the secaII and the 550 and see if its a go'er.
the only problem ive had with had with changing rear tyres is having the sprockets lining up. a few spacers in the right place normally does the job.
if you keep all the braking system of the donner rear rim all is good.

 

well you know yourself - with enough work any frame could be modified to fit any other engine; that said - we're not talking fitting an engine to a stock frame and it working... we're talking about completely gutting a frame to make it work.

If that's the case - then why not use the frame the engine came from, the rear wheel the engine came from etc... you could more easily mount the maxim gas tank and seat to the new frame that work the other way around

it's a slippery slope - at what point is it no longer a maxim and does that matter to you? We've come a long way from just a rear rim swap...

 

time and effort is not a problem. i much prefer to ride something that noone else has, or at least gets people to ask 'what the hell have you done to that'!.
i only started modifying the xj cause i was given it. but maybe your right, it would be easier to start with something easier...... but whats the fun in that?

 

Another possibility for a chain driven engine swap would be the XS650's (parallel twin), chassis is somewhat similar to the XJ's, and at least you'd be staying all Yamaha, and not have to drop the engine size...

 

Now Joel just gave the best starting point... although you're going back a generation in engine design it seems reasonable.

 

i have thought about that. esp. about keeping it all yamaha. but im finding it a little hard to find an xs motor. seems its a fairly popular engine. but if i can ill do it that way, as ive seen some good examples of that conversion.

 

That conversion just seems a poor use of both a motor and a bike. What is wrong with the ride you just scored (I'm assuming for free, best price of all)? Is the motor bad enough to warrant the conversion? I'm with Woot on this one. If you want something different, buy something different. Changing accessories and chrome goodies is one heck of a lot easier than hacking up a frame or shoe horning a motor where it doesn't fit. Tonnes of engineering there as well as the following trial and error. If you have nothing but time on your hands and a welding torch, I'd stick to the least expensive route. Buy what you want. I've done vehicle mods (conversions from automatic to standard transmissions, motor upgrades, front wheel and rear wheel) and I can tell you that when I'd finally finished the desired improvements, I tallyed up the cost and time and realized I'd have been so much further ahead if I had just bought the bells and whistles already installed by the factory (this is why my wife drives a new Passat with all the toys, no more mods for me!). I can understand an upgrade to improve reliablility and to customize something but unless you have the "monster garage" and the finances to back it up, leave heavy duty mods to the pros (and in some cases, the nutcases). I expect that a used 900 motor with some life in it still can't be hard to find and that will of course bolt right in. No fuss, no muss. Then detail and customize to your hearts delight. Now, that said, you want to create something no one else has, look around on these pages. There are photos of some darn impressive mods and finishes that really make an otherwise ordinary (by that I mean run of the mill, looks like everone else's) bike stand out on it's own two tires! I'm all for making it your own, but I guess I'm trying to save you a LOT of time and headache. The case on your machine would have to be machined out and a custom output shaft assembly made to mod your engine to chain drive (reads: EXPENSIVE, VERY). Then there is the issue with the swing arm. It would probably be best to get one off a similar model that is designed for the chain and mod it rather than start from your shaft swing. This too can be very expensive. I think your money is better spent sourcing another motor. Heck, if you have the means, have the bores punched and a fresh set of pistons, rings and bearings chucked into it. That would be a little more money, so the used engine sounds like your best bet and investment. Good luck and happy hunting.

 

it seems that i may have either offended some people by wanting to tear this bike apart or not not expained myself very well. the only reason i want to completly remodel the bike is because it really is a mess. the motor is a complete loss. totaly knackered. everything i take off the bike either crumbles in my hand or the bolts snap. the frame and forks and swing arm are the only really good items on the bike. and as im a fabricator and have my own workshop i have access to all the good tools.
i was just hopeing for some more sugestions for extreme modifications that people have done to get some insperation.
this isnt my first bike ive built, the last one was a suzuki. 1200 bandit motor in a 90 model 750gsxr frame, with gsxr1000 sub frame, vfr750 swing arm, r6 rear shock, 96 gsxr 750 front forks and a host of all sorts of gear. planing on putting nitrous on it later this year,just because i can.
maybe this isnt the site to question these things? i just though people would want to see whats possible to do to a motor bike. that doesnt involve just buying a bit and bolting it on. not that i think there is anything wrong with that. i just like making my own stuff when i can.

 

It's not that you offended people... it's just that most of us don't understand why you'd want to do it. Most of us have small motorcycle budgets and we try to get the most bang for our bucks - most of us would rather ride our bikes than cut them up.

As Robert says - to do this you'll need a lot of experience. Your intitial presentation of your understanding of the problems seemed to suggest you didn't know what you were talking about. In your most recent post you say you know what you are doing... which is great. In that case I heartily say - GO FOR IT.

Don't be offended that a bunch of people behind computers don't know what you are capable of - instead bring back pictures of your progress and we'll be interested. At the moment you seem to be the pro in this area, so why don't you try and show us how it's done? I'm not sure why you'd ask us about the bike and if it was possible if you seem to be so sure it is possible... that's a bit like Tiger Woods asking the crowd if he could make a simple 2" put.

Now - you have to understand something about our position. I've had someone ask how to change the rear indicators into DRLs. I explained how and then that person went off on some tangent about how he worked for NASA and didn't need my electrical help - it cuts both ways. I could tell you that I am a professional hockey player... I do play hockey but I'm no professional... In that same vein, I doubt that this person knew much about electrical wiring - if they did then why did he ask how to do a simple DRL job and then retort with credentials? The web is a strange and wonderfull place.

Cheers,
woot.

I hope you see this as a semi-humerous twist on things - this certainly isn't me trying to make it personal... I don't do that because I'm here for the bikes and the community and not to stir shit. I've got enough of that in my life that I'm not here looking for it - take that as my word that I'm not trying to knock you down.

And for the fun of it - two quotes from you in the same thread:

If you could re-read those two posts and then think why we might have been confused by your presentation of the problem...

 

ok u can do it...

just show us the pics!!

 

Another tidbit: was poking around looking at some V-max stuff (want one soooo bad!), and apparently there's a chain drive conversion available for those. From the looks of it, the V-max's driveshaft setup isn't all that different from ours...

 

thats cool, even though i have owned and modified alot of bikes i dont consider myself a pro in motorcycle modification. thats why im hear to learn something new, being, xj yamahas. sorry if my first post was a little vague. i didnt want to write some long winded question.
even though i know what can be done with some machines dosent mean it can be done with xj's. i was just hopeing some out there had performed some of the mod's i want to. it just makes it easier and cheaper if you have someone to bounce questions off.
but the posts you quoted, im not seeing what you ment about them being confusing.

 

this whats left off the bike after i removed most of the broken gear. apart from the tank seat and clocks, there isnt much left. im pulling out the motor tomorrow cause its shot as well.

 

disfigured, try to track down a used V-Max swingarm. That would be your easiest route to attempt what you want to do. There are a bunch of companies making modded wide tire arms for the "Max", and you might be suprised to find out the fit isn't far off. You can (barely) fit a 170 tire in the V-Max swingarm, but I've seen where they cut the arm where the tire rubs and put a plate in. That increases it to a 200.

Hope this helps. And yes, I too would love to see pics of it finished!

 

Dang. Disfigured, if I could swing the shipping costs, I'd take that knackered motor off your hands, I would love to see the jugs on that thing. Good luck on your mod, please don't feel I harbor any grudge, I'm just a purist at heart. As with Woot, I gathered that you were just dipping your toe in the pool for a mod and I was doing my darnedest to dissuade you from jumping in head first. Seeing you've experience with this sort of thing lets me breath a little easier, you know what your getting into. Looks like you've little choice if 900's are few and far between. Your resume on mods sounds good too. Good luck to you on this one, I expect we'll see the pictures as you progress.

 

hey man good luck, cant wait to see the pic's. i bumped into a guy the other day and he told me that one of his mates changed a xj into a trike by using a datsun 1200 gearbox mounted to the rear axle-shaft drive.
cheers brenton

 

my fisrt major hurdle: couldnt get the engine out. the front right mounting bolt was bent! not sure how that happened. not even smashing the thing with a rather large hammer would budge it. so ill be borrowing a grinder from work to cut the thing out.
im thinking that when i get it out i might strip it and swap/sell it for parts. so if anyone needs any engine covers or internal parts, let me know and ill see if there ok or not.

 

oh, seca9, any chance you could post a picture of that vmax swingarm with the cut out in it?
thanks

 

I've never had a picture of one, but I've seen a few on the 'net and at some local bike shows. I remember being told that the modded arm is available already done. That's really all I can give you on that one.

 

alrighty, thanks anyway, ill see if i can find one and see if its possibility.

 

well from what i gather here is my answer you could cut the shaft off close to the trans weld a gear on the shaft that on the trans yet set it up like a rear end just only one side and have that run to a sprocket and then you could stretch the swing arm or change it witc ever. if you do go that rought i think it would be cool to run it just like a rear end and run dual chain and sprocket's to the back tire/rim would require alot of fabing but would look cool you would proebely need to add the the back of the frame though id say about 6 to 12inches would be enougfh i saw somthing similer done to a custom chopper. I'm kinda with you on this it's fun to have a project to go out and work on but im sure there has got to be an easyer way to put a bigger rear tire on thease bikes. But hay id love to see progress pictures to if you still plan on doing this

 

well it can be done and on the chep. a guy on the xs-xj owners site has a working bike with chain drive conversion done at home in his garage! requires some nerons and a little forethought. cut the mid gear housing for chain to go into output shaft needs to be splined for a sproket,swing arm needs to be custom made or fabbed , (he used two of the stock units cut and welded back the same two sides added an adjuster for chain stretch............ you get the picture.

 

i hope theese come out good for you.



I say go for it, this mods are on an 1100 xs yamaha, so hey anything is possible

 

for the non belivers,how bout this custom made xs1100 yamy 500 rear wheel horse power.



i love it when someone says it can't be done :lol:

 

It's not really a can't be done - but more - what are the chances the person asking actually can do it...

I bet the person who did it never asked if they could - they said they would.

Neat mod I guess - I still want to know why?

 

Because it might be hard to put 500hp down through a 130 width tire... :lol: 8)

 

Alright - just to be clear here - we've gone from stuffing a big tire on a bike to a fully blown engine with a car tire mounted to a wide swingarm with some crazy chain drive adapter...

I feel some Kenny Loggins in the back ground something about a danger zone

 

no the fully TURBOed bike is an xs became xj in 1982, has a wide tire on it,thats what the question was ,to do that you have to go chain drive conversion on the shaft drive bikes. which includes custom swingarm,etc.,etc. the other bike is just to show how one person went about fitting a wider tire on his shaft drive bike thats all,no more no less....By the way aren't you the one that said IT CAN NOT BE DONE?ye have little faith,the guy just got two examples of it BEING done,not just buy a chain drive bike for an anwser.So sorry for posting in the MODIFICATION section. I should have looked in the can't be done section, or the buy a different bike section.by the way woot,you drive a non modified stock bike? Including stock exhaust,stock air cleaner and no jetting?I was just curious. I like things that go fast...or faster if possible i thought modifiying a bike was also meant for performance gains? i could be wrong?that turboed bike was bought new by the guy who still owns it,he owns a company that makes custom parts for i think valkerys or something like that. He moded and made all the custom stuff you see on that bike. Sure he has the means but i take nothing away from his vision.. I think that bike is cool as all ..... I don't mean anything personal here to anyone.

 

I think the deal is that with bikes, like cars, there's always gonna be some people who just enjoy the way it is supposed to work from the factory, and there's some who want to customize it. Be it for looks, speed, comfort, whatever. One person's taste will never perfectly match another's. I guess I fall into that second category. I'm never happy with the way something came from the factory, I like to personalize it to suit my own tastes. BTW, I think that XS1100 is B-A-D!!! 8O

 

LOL - called?

There are two issues. Can it be done, and can this person do it.

It was done - so that's a yes.
They haven't done it yet so that's a maybe.

The turbo'ed bike is a nice bike. It proves it can be done. Not my taste for an everyday bike, but it certainly is interesting...

Me? My bike is mostly stock in terms of engine parts... if I wanted a faster bike I'd go back to the sport bikes. Performance is a multi-edged sword as there is no simple solution - each gain comes at a cost. Going to 500hp means that bike would be a handful in the twisties, but would eat up a drag strip. Going to say 200 hp could make it easier to ride in the twisties, but not as good on the strip.

My mods? Storage, comfort and practical road worthiness...

1 - (Not done yet) The spin on oil filter for example is brilliant - easy oil changes on the road.

2 - (Not done yet) 750 tank instead of 650 tank. Longer range - great for out of the way places with no gas stations and getting down the slab quickly.

3 - The lower seca bars I find as comfortable as the maxim bars and I get a better feel off the front end. This really helps (IMHO) sling this bike around the twisties

4 - Shift the forks up 3/8" - made a big difference in handling.

5 - GT 501 tires. I like them - others like other tires...

6 - ( On my work bench ) - custom seat. I have two saddles, I'm converting one to a solo only seat... the pillion seat will accomidate more luggage, the rider seat will be tractor seat like.

7 - (To be done) - new brake lines. I'm holding off on this mod as I'm slowly looking for a suitable donor front end... this is a pricey mod and I'm not sure if I'll do it as I am looking at a new bike.


For me - I look at it as a can this bike do what I want and if it can't - then what are the options and is a different bike a better solution. Radical customization is nice, it's interesting. The trade off is potentially reliability and as always difficulty sourcing parts on the road. Say I road my chain drive adapted bike to PA - say the adaptation broke - how do I get home? On my stock maxim I'm pretty sure I could source a part from a dealer or a scrap yard and I'm also pretty sure there is lots of life left in my stock parts... I couldn't say the same for a part that I fabricated to adapt to a chain drive. I have no idea how long the part will last or how it would fail.

To word it simply. You've proven it could be done. Is it practical? Probably not. Should a bike be practical? Probably not... one certainly has to ask if it makes sense for you as a rider and your unique needs and whether you have the nessisary resources to pull this off. It certainly isn't cheap (prohibitively expensive for most XJ riders) and it certainly isn't an out of the box solution requiring indepth knowledge in a number of fields most riders do not haev.

So instead of saying it's impossible how about I say - it's not likely, it's expensive and it's really not going acheive any practical gains.

If I wanted a fast bike I'd buy a fast bike ( zx14 is quick)
If I wanted a nimble bike I'd buy a zx6rr
If I wanted a sport touring bike I'd buy a sport touring bike ( vfr is nice)
If I wanted a touring bike I'd buy an ST1300...
If I was house poor and paying student loans? I'd buy a maxim and treat it like a sport bike while I tour

Meaning - if I had enough spare cash to turn the maxim into something it wasn't - then I'd buy what it was I didn't get from the maxim... youth, range, sportiness and ergo's.

I ramble - hopefully people don't mind too much

 

Holy Cow! Beautiful, but what do you need it all for? Where would you use the potential? Race track maybe, but on a street? I'm a wunderin'... Nice to put those photos up for Disfigured, I'm sure he appreciated it. Good on ya Chevy. I learned something too. I'm not messing with anything to that extent. What a pain. What is to be gained by the conversion? I understand having something different, but is there any other justification for the hack? Lot of work for a minor gain in to the ground power. Wouldn't a little "giggle" gas be cheaper? Bigger tire looks cool and all but more contact patch=more friction. Guess I'm just going to not get it. I'll accept my fate. Good luck to you Disfigured, it looks like the answer you were looking for! That 1100 is beautiful! I wonder how long I could send my kid to college for with all that is wrapped up in that thing? Looks like the front end was sourced off a Radian. Bit of a rake on the head, don't see any rear suspension (ouch, my kidneys, I'm whizzin' blood), nice job on it!

 

I'd haf to agree with the new info why you would want to i guessi would see it as cool to say ya you did it but outher than that i cant see apoint for the shaft to chain driving part. I mean if you relly want more power to the ground then just jet it up change cam bore it out or put different jugs or head's on i mean i know that you cant (from donor bike's from junk yards and some elbogreese) make thease bikes get 200hp and save your self the trouble of self fabing a hole lot of parts and hafing to worrie about it breakind down. I would also like a bigger tire but not at the coast of chain driven because i got my bike for the shaft n oil slop to clean up not hafing to chang the chain checking it for ware and so on. If i had access to a dyno i'm sure id have proof that even with my bike's mods that a bigger tire is only for look.


Hope not to make you not put it on if you want to but what i would relly like to see is a way to do it with out getting rid of the shaft. or shrinking the shaft because when i was talking to my dad he said cut the 4 or 5 inches out where the tire would rub and put a pice of bar stock in. Witch i guess would work with some good fabing but then you still have the thing of bigger tire on a small rim.

 

it's all about personal choice! I think if the guy likes winning custom bike shows he's spot on if he likes the drags he's right on if he likes hanging out with the chopper people and doesn't want to be like everyone else i think he got that nailed down pretty good also.So actualy that bike does or can suit a niche. Me i think a chain drive should have been an option on my brand of bikeXJ1100. to have one would be pretty cool. the other bike the guy has over 8,000 miles and not a glitch (knock on wood) it's all about choice,America gotta love it. (or any place that has freedom of choice anyway

 

Right... He's perfectly free to do what ever he wants to do to his bike and if his results are anywhere as good as what you've presented it will be a thing of beauty.

To get there he needs alot of money, time, and skill. I'd like to learn something out of this so if the orginal poster could keep us up to date that'd be cool.

I think I'm yelling too loudly - - I don't think I expressed my point particularily well it seems... ah well I'll try next time

Peace,
woot.

 

Your point is not lost Woot and I'm simply rambling. Shame on me. Woot, choice is a beautiful thing and that choice makes the beautiful bikes we get to enjoy looking at! I'm done mucking up this post. Disfigured has his hands full and I'm certain he'll post as progress continues, he promised. Good lad, hope you turn out a beauty. I am supportive of your endevour, what ever it may be. It is more important to ride than what it looks like after all.

 

I was thinking this same thing about upsizing the rear tire but i am starting with a chain drive 550. I can understand some of the budget minded answers because some mods get out of hand quickly if you find out all thats needed to get the look you want. thank you SECA9 for the info about the 170 and 200 tire fitment....i was hoping i could go up a little in size and that notching and plate idea i might look into

 

This is a many-year-old forum.....and seca9 hasn't been seen here since 2006, fyi.

Dave

 

thank you