"CBass" -- Yamaha Virago XV750 Cafe Build (Finished!! Updated with Pics and Vid)

Re: "CBass" -- Yamaha Virago XV750 Cafe Build




Finally have a roller!!!!!!!!!

Pictures taken last week. I've been battling some electrical issues....


- Test fit rear wheel and measure rear alxe bolt to machine.
- Measure clearance for swingarm and wheel to center of frame

Re: "CBass" -- Yamaha Virago XV750 Cafe Build



- Machined rear axle
- Installed front wheel (still needs a thin spacer on one side)
- Installed rear wheel


The front wheel needs a 2mm spacer on the right side so the rim sits center to frame. I have 4-5mm clearance from tire to each side of the forks. Now I can get ready to install a fork brace

The rear driveshaft fits fine, final drive housing mates to the swingarm seamlessly, and rear axle bolt is machined correctly the first time. I think I shaved off/down 13.5mm's in width and matched to 15mm O.D. I was warned that the rear wheel will be off center from frame spline. I had Bucannans lace the hoop as far left (towards the driveshaft) as possible but they were only able to move it about 5mm. They said anything more would be unsafe due to the original drilling of the holes in the hoop and difference in spoke tension. If I were to purchase new undrilled hoops (I bought my used D.I.D. hoop on ebay), they would be able to move it a little more.

I used the old string and weight method at various points to measure and when all said and done, the rear wheel is about 9mm from center of frame which is about 3/8 inches. I asked several custom bike frame builders and a retired F1 engineer who also served on several pit crews for superbikes in the 90's regarding my rear wheel being off center to the left by 9mm's...... they said unless I was tracking my bike competitivly, then that I was to enjoy my project build and ride it. Frankly it's more of a fun/looker rather than "performance".....obviously.

Re: "CBass" -- Yamaha Virago XV750 Cafe Build

T.Stanley said:

.......................................
I used the old string and weight method at various points to measure and when all said and done, the rear wheel is about 9mm from center of frame which is about 3/8 inches. I asked several custom bike frame builders and a retired F1 engineer who also served on several pit crews for superbikes in the 90's regarding my rear wheel being off center to the left by 9mm's...... they said unless I was tracking my bike competitivly, then that I was to enjoy my project build and ride it. Frankly it's more of a fun/looker rather than "performance".....obviously.
...................................................................my edit - Beachcomber

Click to expand...

This offset track subject is a Red Herring ............. BMW have been offsetting their rear wheels for years - ON ROAD BIKES.

The BMW Kay range uses IDENTICAL frames and swing arm setups for the cooking tourers through to the RS / sports models K75 / K100 / K1100.

The rear wheel widths vary from 3" to 5.5" !!!!!!!!!!!!! There is a slight offset in the wheel casting for the larger widths, but never the less the offset according to the OEM workshop manual is around 3/8".

There is NO requirement in Europe for either construction and use [ official build regs ] OR our annual MOT / TUV / Service des Mines tests for the front and rear wheel to be on the same axis. They HAVE to be parallel of course.

I first discovered this when I was building my K100 Steetfighter and as an auto design engineer of some 45 years standing was horrified. To the point where I was going to re-design the frame pickups to move the power train over to compensate for the much wider [ 2.5" ] rear wheel. Fortunately I hooked up with a guy from the BMW comps dept. who put me straight before I got into it !

Initially I took things very nervously, but soon realised that it had made not the slightest affect on handling or tracking. The bike was eventually used as a test mule for the RAM shox and was ridden to very respectable speeds on a closed race circuit. Road or track makes NO difference, just seems weird.

Ben Kingham [ BMW K100 ] is currently running [ and winning ] in the BEARS race series with a K100 modified using the same wheel set up as my Fighter - and RAM shox !

Here's my initial checks from stock 3" wide wheel to the 4" - later switched to 5.5" [ see next pic for Ben Kingham's example ]

Re: "CBass" -- Yamaha Virago XV750 Cafe Build

Ben Kingham's K100 is badass!!!

Thanks for your reply beachcomber. Gives me a piece of mind.

Re: "CBass" -- Yamaha Virago XV750 Cafe Build

beachcomber said:

This offset track subject is a Red Herring ............. BMW have been offsetting their rear wheels for years - ON ROAD BIKES.

The BMW Kay range uses IDENTICAL frames and swing arm setups for the cooking tourers through to the RS / sports models K75 / K100 / K1100.

The rear wheel widths vary from 3" to 5.5" !!!!!!!!!!!!! There is a slight offset in the wheel casting for the larger widths, but never the less the offset according to the OEM workshop manual is around 3/8".

There is NO requirement in Europe for either construction and use [ official build regs ] OR our annual MOT / TUV / Service des Mines tests for the front and rear wheel to be on the same axis. They HAVE to be parallel of course.

I first discovered this when I was building my K100 Steetfighter and as an auto design engineer of some 45 years standing was horrified. To the point where I was going to re-design the frame pickups to move the power train over to compensate for the much wider [ 2.5" ] rear wheel. Fortunately I hooked up with a guy from the BMW comps dept. who put me straight before I got into it !

Initially I took things very nervously, but soon realised that it had made not the slightest affect on handling or tracking. The bike was eventually used as a test mule for the RAM shox and was ridden to very respectable speeds on a closed race circuit. Road or track makes NO difference, just seems weird.

Ben Kingham [ BMW K100 ] is currently running [ and winning ] in the BEARS race series with a K100 modified using the same wheel set up as my Fighter - and RAM shox !

Here's my initial checks from stock 3" wide wheel to the 4" - later switched to 5.5" [ see next pic for Ben Kingham's example ]

Click to expand...

Just read the above and I must say I was in the red herring camp and thought they had to be inline and parallel. If they are not parallel wont they prescribe a different arc around a bend? Although as I type that I'm thinking why does that matter, I suppose it might if our bikes where two wheel drive it might.
This might make for less machining being needed on my next project.

Re: "CBass" -- Yamaha Virago XV750 Cafe Build


Update --

Sorry for the delayed updates. I've been battling electrical and starter issues. Thanks to the help of everyone on this forum, I've solved most of my issues. Proper grounding of this bike IS key to a proper running bike. I've installed 2 grounds, one to the frame/engine and one to the regulator/rectifier bracket.

Starter and "box of rocks" issue was also addressed. I ordered a new Caltric 4 brush starter to fix the ring gear issue and ordered new clips and #2 idler gear as spares...just in case. I initially thought I may need to replace the ider gear and it's corresponding components but upon inspection, the wear wasn't extensive. I also took my time cleaning the carbs for the 3rd time (lemon boil method, different gauge E guitar stings) and now it starts within one full crank of the starter button being pushed. Countless time members here address over and over again is true...... FRESH battery, thorugh cleaning of the carbs, and SOLID GROUNDS will solve most of your issues you'll ever come across.



Some fine tuning will need to be done and jet kits on hand. Will update again once I get around to taking more pictures.






Tarozzi front fork brace :













Cleaned coils, new spark plug (AP63) and new wires :








Front calipers rebuilt and EBC Organic pads installed :






New Avon grips w/throttle tube, New right control switch:

Re: "CBass" -- Yamaha Virago XV750 Cafe Build

notlob said:

Just read the above and I must say I was in the red herring camp and thought they had to be inline and parallel. If they are not parallel wont they prescribe a different arc around a bend? Although as I type that I'm thinking why does that matter, I suppose it might if our bikes where two wheel drive it might.
This might make for less machining being needed on my next project.

Click to expand...

They MUST be parallel - otherwise you'd have all sorts of weirdness. However, the twin track information is CORRECT. Like I said, BMW do this as a matter of course from the factory design ! Ben Kingham's bike runs almost 3/4" off centre front to back [ as does my Fighter ].

It does seem totally wrong when I've spent all my life designing and manufacturing chassis [ albeit car ] for racing and road to the minutest of tolerances.

Re: "CBass" -- Yamaha Virago XV750 Cafe Build

As Beachcomber has said the offset is not an issue. We've been racing with wheels offset in supermoto for years. My KTM rear wheel is offset 1/2" from the centerline of the rest of the bike with no handling issues.

Great build btw, very tidy.

Re: "CBass" -- Yamaha Virago XV750 Cafe Build

Like almost everyone else I was under the impression that the wheels had to be on the same axis front to rear, very interesting, I know in the UK they test the wheels for alignment on the MOT test, I presumed that was to ensure the wheels are parallel and the reason I thought that was that the use a straight edge from rear to front and check the gap between the edge and front wheel is equal on both sides. However now that I don't need to worry about the wheels being on the same axis gives me more tolerance on my build.....happy days!

Re: "CBass" -- Yamaha Virago XV750 Cafe Build

Beautiful fork, subscribed!!!

Any updates?
It's been almost two months...


M.

Re: "CBass" -- Yamaha Virago XV750 Cafe Build

johnu said:

As Beachcomber has said the offset is not an issue. We've been racing with wheels offset in supermoto for years. My KTM rear wheel is offset 1/2" from the centerline of the rest of the bike with no handling issues.

Great build btw, very tidy.

Click to expand...

I had a major "discussion " with my MOT guy on precisely this subject as my back wheel is some 3/4" offset. He would not conceed the point until I showed him the BMW OEM workshop manual giving the offset for the RS [ sports] version vs the Tourer [ 5 1/2" and 3" wheels respect. ]

Re: "CBass" -- Yamaha Virago XV750 Cafe Build

fantastic looking build so far! Can't wait to see the final thing!

Re: "CBass" -- Yamaha Virago XV750 Cafe Build



Cut out stock airfilter to fit open K&N filter -









Mac 2-1 Header but ended up using a Cone Engineering Stainless Steel Exhaust -





Tank and Headlight bucket from "Paints by Smokey" in San Clemente, CA. I wanted to stick with vintage colors so I went with classic Ivory Porsche White and Porsche British Racing Green. Font on the tank is also from the classic 911's. Petcocks are from an Itallian moped -

Re: "CBass" -- Yamaha Virago XV750 Cafe Build



Update:

Hey guys!!! The bike was finished a few months back. The weather was amazing this spring and summer here in Southern California so I have been riding any spare chance I get..... :cl: :cl:


Once the bike was 70% assembled, I rushed to finish it and did not take enough pictures during the process. There were a lot of little things done that weren't documented and those were the most tedious.

* Tarozzi Rearsets
* Custom endlinks and linkages (local hardware store)
* Refinished wiring harness
* New headlight with internal LED turn signals in housing (eBay)
* DDM Tuning 4300k H.I.D. kit
* XV920 Carb Boots with Metal Covers
* Relocated rear damper controls, starter solenoid, new safety switches, eliminated kickstand switch etc.
* Custom made Yamaha Tank Decals

Re: "CBass" -- Yamaha Virago XV750 Cafe Build

Re: "CBass" -- Yamaha Virago XV750 Cafe Build

Re: "CBass" -- Yamaha Virago XV750 Cafe Build

Turned out beautiful!

Re: "CBass" -- Yamaha Virago XV750 Cafe Build

johnu said:

As Beachcomber has said the offset is not an issue. We've been racing with wheels offset in supermoto for years. My KTM rear wheel is offset 1/2" from the centerline of the rest of the bike with no handling issues.

Great build btw, very tidy.

Click to expand...

On my R100 Café I thought that the subframe was off because the wheel did not line up with the fender/seat. I took the complete rear end off and reassembled it in proper alignment only to find out that the rear wheel was still off. A waste of time except that it was a good lesson, haha.

Re: "CBass" -- Yamaha Virago XV750 Cafe Build


http://youtu.be/KuS26oYfSpk

Re: "CBass" -- Yamaha Virago XV750 Cafe Build

Very very nice, well done!

A few things I thing I've missed:
- What's that exhaust on the bike (headers + muffler)?
- What size tires are you running?
- What's the front brake rotor off, it's not original, is it?

M.