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Is 5th gen rear wheel perfectly centred or off centre?


Stray

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Hello All, 

 

I seem to recall reading somewhere that the VFR 800 has an off centre rear wheel. 

 

Does anyone know know if this is true and by how much? Can’t measure mine as swingarm is stripped right now (should have measured before disassembly - silly mistake).  

 

Thanks in advance, 

 

Stray

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My spare 5th gen rear wheel measures 98mm from the mounting flange to the >outside< of the rim on the machined side.  I don't have a spare 5th gen wheel without a tyre, so I cannot measure it properly (which would be to the >inside< of the rim, given that wheels are still measured in inches for some unknown reason...)

 

Using my best fuzzy logic, therefore, the correct measurement is probably 3.75", which (given the 5.5" internal wheel width) means that there is probably a "positive" offset from centre of 1.0".  

 

I have previously measured other Honda SSSA wheels and found that they had the same offset (e.g., my 5.5" NR wheel and a 4.5" NC24 wheel), so without measuring those wheels again, I would guess that they all have a 1" positive offset.

 

Ciao,

 

JZH 

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Thank you for the reply, JZH. 

 

My initial question could have been phrased better: are the front and rear wheels of a 5th gen in perfect alignment? 

 

In the fog of distant memory I seem to recall you saying the wheels are not perfectly in line. Can’t find the post now. 

 

Stray 

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I can't speak for the 5th Gen, but I'm pretty sure I read that when HRC went to a 6" rear wheel on the RC45 it was offset to the front wheel (because of swingarm clearance issues) and apparently it made no difference whatsoever to how the bike tracked.

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I don't think it was me.  We know the front wheel is in-line with the frame.  So the only question is whether the rear wheel flange, when the swing arm is mounted, is 1" offset from the frame's centre line or not.  I haven't measured that...

 

Ciao,

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Thanks again for your replies, gents. Really appreciate the input. 

 

I’ll be doing the string test on Tuesday to measure alignment and report back. 

 

In the meanwhile does anyone have exact measurements for a 5th gen rear rim width from edge to edge? Mine has a tyre on and it’s hard to measure with vernier calliper. You’d need a naked rim to be exact. 

 

I think VFR rim is 157mm but tyre makes it hard to be accurate. Ducati 848 rim is 159. Both are 5.5 inch.

 

If you’ve got a loose 5th gen rim I’d be very grateful for your help. 

 

Stray 

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Thanks Terry - VERY helpful! 

 

This means for a Ducati 848 rear wheel conversion we don’t need a spacer for the wheel - it mounts in exactly the same spot! 

 

Still need a shim for the hub (VFR swingarm clamp is 77mm wide and Ducati hub is 80mm wide). 

 

Thanks again Terry! 

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not gospel, but the accumulative knowledge and work of several really sharp guys, you results may vary.....

 

Honda SSSA wheels are offset 19mm from wheel center. That is vfr/nc30/nt650/nc35/rc30,  never measured an rc45 wheel. That is so they center to the frame and front wheel.
Ducati Brembo wheels are offset 21.5mm.

Therefore to center the wheel to the frame, stock position, a 2.5mm shim is required when using a modified Honda spindle.

You can center the wheel by adjusting the thickness of the shim when installing the Duc hub, although a 2.5mm offset would probably not matter to most. If you are OCD like me, it might.....

 

in the picture, Ducati parts, you can see the eccentric has a 1 piece sleeve/shim on it for installing in a Honda swing arm.

 

 5kIleE.jpg

 

and a Honda nt650 spindle modified for Duc wheel use with a 2.5mm shim. These have been used on 4th gen vfr's and nt650's.

 

Duc_Spindle_(1).thumb.JPG.05f9399c4376ddbeff4ac58dbc9e37ce.JPG

 

 

 

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Thanks Slo1, that’s some seriously helpful info there! 

 

I was unable to measure the VFR swingarm’s centrality (is that a word?) because the whole motorcycle is quite lopsided. Engine isn’t central in frame, so cushion mount can’t be central, right? 

 

I just assumed the Honda engineers had made it central and went from there. 

 

My figures for VFR vs Ducati offset are slightly different to yours (doesn’t mean mine are right!). Here they are: 

 

Ducati 848 figures: 

Wheel hub from left - 101mm

Wheel width - 159mm

Wheel offset - 21.5 (we agree!)

Hub width - 80mm

 

VFR800 5th gen figures: 

Wheel hub from left - 99mm

Wheel width - 157mm

Wheel offset - 20.5mm (we differ here!)

Hub width - 77mm9931FEBA-6EB1-40A4-B437-FB3351B64693.thumb.jpeg.09081be1581968e6a169711a9b8f3f2f.jpeg

 

The crucial difference is that Duc wheels are 2mm wider than VFR so the offset needs to be adjusted by 1mm (half of 2mm as we are only measuring from one side). 

 

By my calculations that means no shin required?

 

On the the other hand, if your offset figures are correct, does it mean your 2.5mm spacer should be 1.5mm? You haven’t accounted for the difference in wheel width. 

 

That also leaves the question of sprocket-to-wheel hub distance. If you’re shimming the wheel outwards (to the right) are you not also moving further away from the sprocket?

 

Do the sprockets now line up properly? Misaligned sprockets cause frictional power losses, accelerated wear and possibly weird handling (I can’t verify the third point).  

 

It’s a bl00dy minefield! Will have to revisit my measurements for the 100th time and report back. 

 

Big thanks for alerting me to these measurements, Slo1. My brain hurts now...

 

Stray

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8 hours ago, Stray said:

That also leaves the question of sprocket-to-wheel hub distance. If you’re shimming the wheel outwards (to the right) are you not also moving further away from the sprocket?

 

With the SSSA the sprocket is not affected by the wheel spacing when it is shimmed on the wheel side of the spindle.....

It would be with the eccentric spaced out from the swinger, but the spacer in the pic causes the sprockets to line up spot on. Ducati cush drive mounts the sprocket further in than the Honda one when installed on the Ducati eccentric.

 

a wider or narrower wheel does not affect the offset, as it is in relation to the wheels center. Center is center no matter the width.... Once centered there will be more, but equal, overhang on each side with a wider wheel.

 

I don't think 1mm, or 2.5mm, off center will really matter to the average rider. Harleys were always WAY out of line front to back....... BUT, shimming the wheel out 2.5mm centered it and increased clearance to the swinger and caliper, on the Hawks and vfr750s..... 

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