180 on an SV

[hardhat_harry]

Can a wider rear wheel be fitted to the SV, from say a GSXR?

Is it a good idea?

Ta!!

[barwel1992]

yes it can be done but theres a lot of work involved like machining the brake mount and wheel spacers, it is usual a gsxr 750 rear wheel that is used not sure which one though

also some people have sead that it make the sv handle worse

[Aquila]

I thought this was a speed thread!!!:D

[SV650Racer]

If you have an injected bike then a CBR600 1995-1998 model rear wheel fits in. You need to take a few mm from the spacer and then everything just fits in fine. You need the CBR sprocket carrier, sprocket and disc too. Whole lot can be had from ebay for £40-£80.

You can fit a GSXR rear wheel say from a 600K6 but you need to have the sprocket carrier hub machined down to get the sprocket carrier to line up correctly with the chain.

Steve runs a 180 section rear on his race bike and it works very well and improves tyre wear on track as the load on the tyre on the edge is spread over a larger footprint.

[hardhat_harry]

Bugger just sold a set with my Steely

[plowsie]

Bandit 1200 rear wheel fits.

[Jay-ninja]

Just buy an SV1000 and be done with it.

[Tallguy]

There's a gentleman in the USA advertising in the For Sale section:
http://forums.sv650.org/showthread.php?t=143904

[johnnyrod]

Sarah everyone says it makes it turn slower, what have you found?

[SV650Racer]

Sarah everyone says it makes it turn slower, what have you found?

No difference in turn in at all. We are running a 5.5" carbon rim for the dry with the 180 and a CBR 5" rim on the inters and wets.

Turns in great in fact when i rode Steve's SV after riding my supersport bike the SV had me in the kerbs mid corner as it turned so quickly!.

The bike does run a lengthened Ohlins and GSXR front end so quite different to a stock road bike geometry wise anyway.

If your running a 180 on the 5" CBR rim for the road then you will more than likely find it will turn as quick if not a little easier to to the profile of how the tyre sits on the 5" rim.

I ran a 190/55 on my supersport 600 bike for a while and it actually aided initial turn in as the rolling circumference of the tyre was taller than that on the 180/55 so it sat the bike up by a few more mm at the rear and gave a larger side footprint.

[yorkie_chris]

Ever heard of someone putting ZX6R B1 wheel on back? Is 5.5" and looks similar.

Anyone here got one to take some preliminary measurements?

[SV650Racer]

Ever heard of someone putting ZX6R B1 wheel on back? Is 5.5" and looks similar.

Anyone here got one to take some preliminary measurements?

Havent heard of that one. The CBR one fitted so well barring the spacer it looked like it was made for the SV! LOL. Very cheap too off ebay. Just make sure if you get on that its the post 95 model one with the 5 inch rim as the pre 95 wheels look the same but are 4.5 inch on the rim and will flatten the profile of the 180.

[fastdruid]

Biggest advantage IMO is that 120/180 'pairs' seem to be in the sales all the time, hardly ever see any 120/160 pairs for sale. :-/

Doubt it would make much difference to turn in, while it mght slightly, the turn-in speed is more dictated by the geometry[1], what it does do is reduce the speed you can carry a certain speed at. Or to put it another way, if you were to take a corner at 40mph on two identical bikes, one with a 160 rear and one with a 180 rear you'd need to lean more on the bike with a 180 rear. As to the actual amount and if it makes a difference in reality I don't know.

Druid

[1] The SV is a lardy bus compared to for example an NC35 which has a 10cm shorter wheelbase, even when the NC35 is wearing the same size tyres (std NC35 is 150 rear but a 160 fits).

[yorkie_chris]

SV has cruiser geometry as stock. Shorter forks and a 350mm shock soon sort that.

I don't believe you about the lean angle. Surely F = mv^2 / r and the F is a sin of the weight at some angle to the vertical.

[N8te rider]

I thought this was a speed thread!!!:D

Me too lol. 180mph!!! Who's done it? :rolleyes:

[fastdruid]

SV has cruiser geometry as stock. Shorter forks and a 350mm shock soon sort that.

It's still 10cm longer wheelbase and you can't do much about that! My SV is ~1 inch down at the front and ~1 up at the back, to the point where it is twitchy but not excessively so, it handles fantastically and it still isn't a patch on how the NC handles.


I don't believe you about the lean angle. Surely F = mv^2 / r and the F is a sin of the weight at some angle to the vertical.

Lol, its more to do with the difference between your real angle and the contact patch, wider tyres move the contact patch away from the centre line of the bike.

See http://books.google.co.uk/books?id=84hF-qoR5I8C&pg=PT5&dq=motorcycle+handling+book&client=opera&cd=1#v=onepage&q=motorcycle%20handling%20book&f=false

Page 2-17 and 2-18, which says
figure 2.5 shows how the contact patch moves away from the centre plane of the wheel or the steering axis as the bike is banked. A greater angle of lean is necessary to maintain balance, and this may require a slightly higher centre of gravity to restore cornering clearance. It may be necessary to add around 5 degrees more to the lean angle when cornering at 1g to compensate for the width of modern tyres.

Druid

[barwel1992]

just dropped mine 5mm at the front at jacked the back up buy 38mm not sure how the 5mm at the front will make a diff but the back made a huge difference

at some point i would like to put a 180 on the rear but not at the moment

[yorkie_chris]

Ok so I missed that part entirely:smt095

A short wheelbase isn't the be-all and end-all of good handling though. You could probably get some good improvement by getting rid of the 'busa forks and fitting some revalved GSXR6/750 ones.

What shock have you got? Is it meant for SV or is it a SRAD one?

[fastdruid]

I've got some GSXR6 forks to go on[1], The shock is a proper SV Ohlins one.

But that won't appreciably change the speed at which you can turn in[2]. The NC is insanely quick to turn in. While wheelbase is not the be-all and end all it makes a *huge* difference as to how quickly you can turn in.

I'm once again going to refer back to the book I referred to before, page 3-16 now;
http://books.google.co.uk/books?id=84hF-qoR5I8C&pg=PT5&dq=motorcycle+handling+book&client=opera&cd=1#v=onepage&q=motorcycle%20handling%20book&f=false


Wheelbase


The distance between the wheel centres has several effects but, in general, the longer the wheelbase the greater the directional stability and the greater the effort needed to negotiate bends. There are three main reasons for this.

1) Required steering angle
Figure 3.20 shows how, for a given bend, a long-wheelbase machine needs the front wheel to be turned further into the bend. Consequently more effort is required for cornering; also, a given deflection of the front wheel (say, from bumps) will have less effect on its directional stability.

2) Rear-wheel angle
It is also clear from figure 3.21 that, for a given sideways deflection, the angle of the rear wheel to the direction of travel is smaller with a longer wheelbase, this improving directional stability

3) Inertia effects
The wheelbase has an effect on load transfer under braking and acceleration; for a given centre-of-gravity height, the longer the wheelbase the smaller the load transfer. In addition, the moments of inertia in the pitch and yaw planes are increased, which makes a long-wheelbase machine more sluggish and stable.



Druid

[1] I just need a GSXR6/750K6-K8 front wheel & discs.
[2] Except maybe at high speed, the GSXR6/750 wheel is lighter than the TL and runs smaller lighter brake discs.

[yorkie_chris]

But speed of turning is not the be all and end all of handling, everything is a compromise. I bet the SV can put its power down without wheeli-ing more easily for example.

Was that ohlins fresh out of box or has someone revalved it?

[ophic]

I don't believe you about the lean angle. Surely F = mv^2 / r and the F is a sin of the weight at some angle to the vertical.
I had to think about that statement. Easier to visualise if you imagine an insanely wide tyre - wider than the height of the bike. As you lean, the contact patch could move so far that the bike "falls" in the wrong direction, so you'd turn the wrong way.

You'd have the bike equivalent of a weeble :D

[zadar]

I'm once again going to refer back to the book I referred to before
That book is great but keep on mind it breaks down things in to individual aspects. Many of those work against each other when put together in one package as motorcycle. So, even though it is correct real world experience can be different. Simple thing like tire profile can negate your shorter wheelbase turning.

[fastdruid]

But speed of turning is not the be all and end all of handling, everything is a compromise. I bet the SV can put its power down without wheeli-ing more easily for example.

Absolutely, its all a compromise, if the SV had the same wheelbase it would be impossible to keep the front end down.

Which is where one of the advantages of the NC comes in, it has no power, so it doesn't wheelie even with a silly short wheelbase.
http://www.fastdruid.co.uk/albums/cadwell2006/thumbs/640x480DSC02093_2.JPG
*ahem* ok so it needs to be really provoked to wheelie ;-)

Was that ohlins fresh out of box or has someone revalved it?

Freshly serviced 3 trackdays ago, dunno about revalving.

There is nothing _wrong_ with the handling of the SV, I've tried a lot of bikes and mine is the second best handling bike I've ever riden, its just that the RVF400 is better.

Druid

[fastdruid]

That book is great but keep on mind it breaks down things in to individual aspects. Many of those work against each other when put together in one package as motorcycle. So, even though it is correct real world experience can be different. Simple thing like tire profile can negate your shorter wheelbase turning.

Too true but only to a certain extent, I take it back though, it's not 10cm, it is 8.5cm shorter (1335mm against 1420mm). It is *also* claimed 165kg dry weight, identical to the SV[1].

Now I'd accept that you could get tyre profile to work against it but only if one was on something with a stable profile and the other on something sporty. As it stands both are on road/trackday rubber, BT090's for the NC, D209RR's for the SV. If anything the Dunlops have a more pointy profile. The NC still turns in quicker than anything else I have ever ridden.

Druid

[1] and my SV is *much* lighter than stock.

[zadar]

The NC still turns in quicker than anything else I have ever ridden.


It is different bike :)
Wheelbase alone may not be reason, it is ratio between wheelbase and cog, and than you have trail and rake, swingarm, tires, weight distribution and even rotating parts inside motor.

[fastdruid]

It is different bike :)
Wheelbase alone may not be reason, it is ratio between wheelbase and cog, and than you have trail and rake, swingarm, tires, weight distribution and even rotating parts inside motor.

:) Too true and it *is* a combination of everything, but the biggest single difference is still the wheelbase.

NC35 dry weight 165Kg
SV650S dry weight 165Kg

NC35 25° Rake, 92mm Trail
SV650 25° Rake, 100mm Trail

NC35 150/60R17
SV650 160/60R17

NC35 swingarm length 540mm
SV650 swingarm length ???

NC35 wheelbase 1335
SV650 wheelbase 1420

Druid

[zadar]

That is huge difference in trail, even my race sv does not have that low trail number with rear up 3/4" at shock and front down 1".

[SVXR650]

SV650 swingarm length ???
Druid


SV650 swing arm s 545 mm to the middle of the adjuster...

535 mm is the shortest it can be with axle all the way forward...

Luis

[fastdruid]

So nearly same length swingarm then.

Druid

[Grumpy]

Can someone tell me something. I have a standard k8 sv 650. I need to change my tyres. At te rear it has the 160 70 17 and i want to put a 180 55 17 because i can the buy a combo for like r1700 where if i buy a cr2 size 170 70 17 i will pay 1449 for the rear and r1049 for the front. Anyone done this cause the bike shop says it will affect cornering etc. I use the bike for driving to work and back. thats about it. Thanx in advance

[fastdruid]

Unless you change the rear wheel you should stick to the 160.

Druid

[SVXR650]

Can someone tell me something. I have a standard k8 sv 650. I need to change my tyres. At te rear it has the 160 70 17 and i want to put a 180 55 17 because i can the buy a combo for like r1700 where if i buy a cr2 size 170 70 17 i will pay 1449 for the rear and r1049 for the front. Anyone done this cause the bike shop says it will affect cornering etc. I use the bike for driving to work and back. thats about it. Thanx in advance


You can 180/55R17... You just need to buy a wider wheel.

I fitted a wider GSXR rear wheel on my SV650. Generally I use 180/55R17... But, the one on the picture below is a 190/50R17...

http://pic20.picturetrail.com/VOL16/628080/21825355/379784825.jpg

On the stock SV650 wheel the 180/55 profile would be distorted and handeling will suffer.

I would not do it!!! If you do it anyway, be careful cornering... Remember crashing is expensive!!!

Luis

[yorkie_chris]

Can someone tell me something. I have a standard k8 sv 650. I need to change my tyres. At te rear it has the 160 70 17 and i want to put a 180 55 17 because i can the buy a combo for like r1700 where if i buy a cr2 size 170 70 17 i will pay 1449 for the rear and r1049 for the front. Anyone done this cause the bike shop says it will affect cornering etc. I use the bike for driving to work and back. thats about it. Thanx in advance

go shop somewhere else, I bet you can find some tyres for similar price in correct sizes.

I did not like how 180-55 felt on SV standard rim.

[hardhat_harry]

Ok Ive got my F3 wheels and I have had a quick look but the spindle (measuring the hole in a spare spacer I have) on my curvy looks to be narrower that the hole on the CBR wheel centre. When someone said that it needed new spacers was it just to pack out the distance from the wheel / sprocket carrier to the swingarm or do I need to look at spacing the spindle itself and new bearings.

I have not taken the SV rear whell out yet as the front is already off the bike waiting for the GSXR bearing kit from TWF (anyday now!!),

Any advice

[yorkie_chris]

Measure it, curvy is 17mm