trackin xv750

MJPriceisright said:
saw this bike the other day and its exacting the inspirating im going after.. this bike is simply amazing in my opinion, and you can easily replicate this to an extent using the xv. have a great new year!

whoa...do they make/sell brakes like that or is that a concept bike??
 
thats a newer buell xb braking system.. pretty awesome. this xr1 is a kit they will be selling for the buell xb, for the first time in my life i can say id like a buell to buy this kit. lol
 
How much stiffness do you expect to lose by cutting the frame section out? That would seem to put all twisting forces through the head of the bike, hope you plan on a rather leisurely riding style!
 
I believe this modification was originally done by Sep Koch, tons of people have done the mod and have experienced zero loss in structural strength. And to answer your question, yes this will be a leisure rider, not sure if any virago has found its way out of that category of bike and riding style.. I'll leave the aggressive riding to the litre bikes I ride at the track.
 
MJPriceisright said:
I believe this modification was originally done by Sep Koch, tons of people have done the mod and have experienced zero loss in structural strength. And to answer your question, yes this will be a leisure rider, not sure if any virago has found its way out of that category of bike and riding style.. I'll leave the aggressive riding to the litre bikes I ride at the track.

This question is a perennial over on the Virago Tech forum !

Take a look at what Loek has done with his to STRENGTHEN the swingarm area. Also Pat Cowan of this parish who is no mean racer of old, subscribes to the "don't do it" brigade.

Not sure about the Virago, but on the TR1 [ same ? ] the footrest hangers are humungous, and tied in via the seat frame [ again substantial ] and then back to the main frame.

I've done a lot of work with cars using engines as stressed members - there's the stress they were designed to take - and then the stress WE subject them to !

Sepp has reported No problems whatsoever with this mod, and his bikes don't get an easy life !

When I originally started playing with TR1s I came up with a tubular footrest carrier, but after I fitted it I was a little concerned at the strength I'd lost by removing the OEM footrest hangers. Still working on it.

Eventually it comes down to personal choice, and riding style. Leisure riding is I suspect fine for this mod - I intend to ride the wheels off mine, but then there's always Sepp Koch !

Picture375.jpg
 
great post, very informative. thank you.. yeah your right when it simply comes down to riding style. those stock footrest hangers have some thickness to them, not quite sure what im going to do about those just yet.
 
MJPriceisright said:
great post, very informative. thank you.. yeah your right when it simply comes down to riding style. those stock footrest hangers have some thickness to them, not quite sure what im going to do about those just yet.

MJ - I started the final strip of the donor bike yesterday and had a good look at the area in question.

Without question the whole assembly is tied in one to the other. Footrests [ via engine cases ], to seat frame, to main frame.

The footrest hangers are far more substantial than required for just hanging the footrests - have you felt the weight of them ! They are bolted securely to the cases and then there is another substantial chunk - the seat support frame. This acts as a girdle around the cases [ via the footrest hangers ] and then is bolted directly back to the main frame. Take ANY one part out of the equation and it makes for a far less substantial structure.

In my very early days as a design engineer I was taught by a very respected tutor to exagerate ALL forces and stresses to see what the outcome could be - then dilute the findings down to the working level. A sort of safety factor if you like, but exagerating the design allowed you to easily see the "what ifs" and show up any marginal design.

The frame IS fuggin uggerly, no question. In my aplication - no problem as I will have side panels inkeeping with a 60's look. IF I were looking at an alternate for a modern take on a Cafe Racer [ and I did at one time] I think I'd go for a Duke style trellis frame.

I even went so far as to look at the frame on a spare BMW K1100 with relevant forks, 4 pot Brembos etc.

I'll take some pix of the area in question in the next few days - food for thought.

Would the cut down system fail ? Probably not. Would it put additional strain on the integrity of the engine cases - undoubtedly.
 
oh yeah man no doubt they play a huge roll in the structural integrity of the bike.. just picking it up and moving it around the garage it shakes without them there.. i never planned on running the bike without them, was just thinking about making some custom mounts to replace them, seein on the throttle side it has like mounts for the battery etc.. idk we'll see. anyways, i did however pick up the rear wheel today for the front end, attached is a pic. im thinking im going to pass on the rear to front conversion kit, as i really want to run a front drum. keep those handlebars nice and clean without the master cylinder. im sure with some proper mounts made etc it will work alright. looks good though with a big front meaty tire on the new forks, will look awesome all black like planned.
 

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hey guys spent a little more time in the garage over the weekend and was toying around with ideas for the front drum brake setup.. ive attached a couple pictures, they are giving some ideas of the bar support to keep the drum in place.. which looks better? i think the one with the bar would probably work better, because of the forward motion pulling against a bar, instead of a bolt going through the fork arm and into the drum mount like the second picture shows.. although the bolt setup would put my brake arm in a good spot to connect to the fork to make a cable setup.. any thoughts?
 

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The 2nd setup looks better, but a) is that fender mount on the fork strong enough for the cable mount (looks like it should be OK) and b) is the brake cam lever itself shorter in the 2nd setup? Optical illusion? You'd likely want a little more travel but that can be adjusted easily enough.
 
I must be missing something here. The bike weighs like 1,000 pounds stock and the brakes weren't exactly MotoGP class and you want to go with a SLS drum? I couldn't bring myself to do that on any bike that will be ridden. A 250mm Fontana - well that would be a different discussion :)

What I did on my last project was to fit an FZR master cylinder with integrated reservoir and black braided brake lines for a clean minimalist look.
 
tim that fender mount is pretty bulky, appears that it would be able to handle the pressure of a cable mount, then again i have no research to support that statement other than visually... yeah must be an optical illusion cause its the same lever.

teazer im not building a race bike here, its got large front and rear wheels, its an absolute joke performance wise and i dont plan on beating the hell out of it.. i can understand your concern via the weight issue but this is definitely lighter now without all the garbage parts all over it.. idk like i said before i dont have any research to back this situation, ive seen everyone use the rear to front conversion kits and use the disc brakes, and i also am aware im taking a step backwards when it comes to performance, technology etc.. but i dont want a rotor, caliper, master cylinder on the front, im thinking the cleaner the better. of couse if its not safe on the other hand, ill do what is necessary to make it safe. thus, ive posted and appreciate your questions regarding the issue cause i respect your point of view!
 
Did some work tonight in the garage, got the arm on the front fork ground down and flat, drilled the hole and mocked up some washers to see how wide the bushing will need to be. Turned out good, just needs to be ground down some more and make it look nice. Also took apart the drums and cleaned everything up in order to get good quick release.. Was all gummed up before I took it apart.
 

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IMHO, i think that is not safe. I would not ride it with that setup. The fender brace was never designed to handle such power, torsion-wise. Therefor, i think it will break. Might not be at first ride, but it will.
 
did you take a peek at the picture i made of the two setups? any thoughts on that? thats not a fender brace fyi, thats the caliper mount, im sure they did some testing to make sure that a caliper mount can handle some pretty large stress loads, agree? pretty darn thick and rigid.
 
it should hold up not sure if you'll stop as soon as you want to .....It does look like a fender mount because of the inverted forks
 
yeah i can see how it looks like a fender mount, maybe should have put up a before and after. hahah yeah if i wanted to stop on a dime id just buy the conversion kit for the caliper and be done with it all.. but just tyring to do something different here, while keeping the handlebars clean. these bikes are 500lbs stock, thats 100lbs heavier than your honda small cc cb's with dual drum.. minus the weight ive removed (rear tail, exhaust which was surprisingly really heavy) i think it will be good to brake.. this wont be a track bike by any means, but i do want it to be safe to ride.
 
In reality, we can only guess that you will need more than a SLS drum to haul that beast up safely in traffic. You will know if it's adequate when you ride the thing and if not it can be changed. That's the nature of the beast and of building bikes.

We get ideas and test them and if they don't work, we chalk it up to experience and change them.
 
thanks teazer, puts things in perspective no doubt.. and yes, we will see. priority will be safety of course, so if it doesnt stop, ill make adjustments so it will stop.
 
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