GSXR Rear Wheel Conversion (pointy)

[CheGuevara]

I recently picked up a set of '07 GSXR600 wheels recently -intending to use the front for my conversion and selling the rear... but then I spotted the thread on the svrider forum about the rear wheel swap.

It seemed pretty basic - machining of some spacers (and possibly a little off the sprocket carrier) and it drops right in. The guy who figured it out sells the kit on US ebay -but it's fairly expensive (not to say he's making a bunch of money on it, but it's well over what my budget allows). I decided to contact him and ask for his measurements and... he said no. Can't say I was terribly suprised really, but it was worth a shot asking.

He did offer to sell me the specs for a sum and the stipulation that it was for my use only. I'd probably have jumped on it but I'm not too keen on the "for my use only" part -and I'm sure I can figure it out for myself and share my results. I know someone who can do the machining for much less money than it would cost me to buy.

Anyhow I've started measuring up the GSXR wheel assembly this eve and here's my results. If anyone has any additional information (or can point out any mistakes) as the thread progresses, please pitch in.

First was to measure the total width of the spacers and bearings. From the disk side to the sprocket side (and not including the caliper carrier) is as follows:

OutrSpcr > Brng > CntrSpcr > Brng > InrSpcr > Brng > OutrSpcr

15mm > 12mm > 127.5mm > 12mm > 19.5mm > 17mm > 17mm

TTL: 220mm


I also measured the distance from the bearing to the edge of the hub on each side to get the total width of the hub:

Disk side: 8mm

Sprocket side: 20.5mm

8mm + 12mm + 127.5mm + 12mm + 20.5mm = 180mm

Still need to measure up the SV stuff and then figure out how much to machine off of the caliper carrier and the inner sprocket carrier spacer (and possibly the sprocket mounting surface).

-Mike

[CheGuevara]

So I've decided to aproach this from a slightly different perspective. I figured that the critical primary measurement was from the centre of the rim to the outside of the RHS outer spacer. With that I can get the wheel centred, and then determine how much the LHS needs to move.

With that in mind, I figured my best method to find the rim centre was to remove the tire from the wheel (on both wheels), mark the edges of the rim on a piece of paper on the floor, and then use a straight edge as a plumb line to mark relative reference points (spacers, sprocket etc) down to the paper. And this is without the need to remove bearings, possibly destroying them in the process.

I've done this once now, and I'm happy with the results, but will start again from scratch to verify my measurments:

1) I get 8mm total difference between the SV & GSXR, from the outside of the LHS spacer to the outside of the RHS spacer.

2) From rim centre to the outer edge of the RHS spacer there is just 2mm difference between the SV & GSXR - so mill this amount from the outside of the brake caliper carrier (and the locating bar on the swingarm as well if necessary to alllow the carrier to sit flush against the swingarm).

3) The wheel will now be centred, but we need to remove 6mm total from the LHS to fit it into the swingarm.

4) Remove 2mm from the inside edge of the inner sprocket carrier spacer. If you also remove the little bridges and nodules from the cush rubbers this will allow the entire sprocket carrier to move inboard 2mm.

5) Remove 4mm from the outer LHS spacer. The wheel should now fit in the swingarm (we've narrowed it by the 8mm difference).

6) We still need to make sure the rear sprocket is in line with the front. The difference between the measurements of the rim centres to the centreline of the SV's 525 sprocket, and a 520 sprocket on the GSXR, is 2.7mm. We've already moved the carrier inboard by 2mm, so we're dealing with just 0.7mm. I think I can live with that, but if you can't it's possible to mill this much(or more -up to about as much 3mm if you decide to stick with a 525 sprocket) from the sprocket mounting face of the GSXR sprocket carrier.

Now just to be clear, when I'm suggesting "remove 4mm from the outer LHS spacer" what I mean is that a new sleeved spacer must be machined 4mm amount narrower than the stock LHS spacer, that will also take up the difference between the diamer of the SV axle, and the GSXR bearings & centre spacer etc. A sleeved spacer is also machined for the RHS, and both spacers should (I believe) overlap the centre spacer so that the entire assembly is stable.

I'll get some diagrams off to my machinist (that'd be a friend with a lathe and a bit of skill) and see how it goes. I'l post up my results of course.

IMPORTANT NOTE: As mentioned above I've measured this just once, and need to do it again to confirm my measurments and calculations. Even then, please make sure you confirm these figures for yourself before you start butchering your parts.

[Red Herring]

Is the GSXR spindle not bigger, you need to enlarge the holes through the swingarm as well......point of no return? ...or is that being done with the "sleeved spacer"?

[CheGuevara]

Yup, sleeved spacers, so no changes to any SV parts other than the brake caliper carrier.

On another note - I think I've spotted a small error in calculating the distance the sprocket needs to move inboard, so I'll double check that later today and edit the post as necessary.

[CheGuevara]

I've done some more measurements, to a point where I'm happy to start machining (also done some drawings for the new spacers). I'll post those up later on, but just did some quick weight comparisons:

Complete = spacer to spacer including sprocket carrier, but no sprocket or retaining nuts (but including studs), and tire (or tyre if you prefer) removed.

W/O Carrier = without sprocket carrier (and without both sprocket carrier bearings), but cush rubbers still installed.

Carrier = weighed the parts removed (sprocket carrier and carrier-spacers) and should be the difference between the above 2 weights.

K6/K7 GSXR 600/750 Wheel

Complete = 16.4lb

W/O Carrier = 14lb

Carrier = 2.4lb

K5 SV650-S Wheel

Complete = 18.2lb

W/O Carrier = 14.8lb

Carrier = 3.4lb


So the complete GSXR wheel assembly is 1.8lb lighter. The GSXR wheel itself is slightly lighter (0.8lb) despite its width, and most of the difference is in the sprocket carriers with the SV unit a full 1lb heavier. So it might be fair to assume we don't save a great deal in terms of rotational/gyroscopic mass, we do save a notable amount in terms of unsprung weight, and gain a wider contact patch as well as (I think) a wider range of tire choices. Plus it just looks damn cool :cool:

[Red Herring]

I've got a GSXR 600 K4 swingarm to go with my wheel.....I wonder if it's easier to fit the swingarm to the SV than to machine the wheel? I suspect I may have trouble getting the rear exhaust routed.

[CheGuevara]

Well the wheel conversion alone will be 2 new spacers, 2mm off the inner sprocket-carrier spacer, and 2mm skimmed off of the caliper carrier. Maybe a little skimmed off the sprocket-mount face of the sprocket carrier, or might be able to get away with spacing the front sprocket out a few mm with a 520 conversion. Not too complex really.

A GSXR swingarm I suspect might be fairly wide at the pivot in comparison, but if you're able to trim enough off the ends it might be worth a go. Exhaust might be an issue (not insurmountable) as you noted though. You'll still have issues with sprocket alignment though - an extra 2mm you'd have to take up that yu wouldn't otherwise be gaining by turning down the inner sprocket carrier spacer.

[zadar]

when I measured this wheel I came up with complete wheel to be moved to right by 5mm and sprocket by 7mm to align wheel and sprockets.

[CheGuevara]

Did you base that on a centred wheel? I believe that finding rim centre (not hub centre) is critical, and then all measurements taken from that point on both wheels:

-Centre to outside of RHS spacer
-Centre to outside of LHS spacer
-Centre to sprocket mount face

Comparing these 3 measurements between the 2 wheels shows how much each of those components of the GSXR wheel need to move inboard, while keeping the wheel on centre.

I've definitely got no more than 2mm to the right (via the brake caliper carrier) to centre the wheel -and confirmed this with someone who has completed the conversion.

I do have 6-7mm to the right to align the sprockets, less the 2mm taken from the right leaves 5mm max. 2mm more gained by mving the sprocket carrier inboard (machined inner spacer -again measurment confirmed), leaves 3mm remaining which can either be machined from the sprocket carrier mounting face or the the front sprocket spaced out slightly, or some combination.

I've got 6mm more to come off the LHS spacer so that it all fits in the swingarm, and that's easily obtainable.

I'll update the posts above once I've confirmed (by making it all fit), or if I need to make any changes.

Still waiting for my friend's lathe to be set up before any of this happens however :s If it looks like it's going to be a while I might start shopping around to see where I can get it done reasonably cheaply.

[zadar]

I did it on curvy.
did you measure if rotors falls in center of caliper?
there is also some info here http://twfracing.com/forums/viewtopic.php?f=3&t=522

[TheStudent]

Inpressive stuff, very intrigued to see how it comes off.

Zadar: You have done this on a curvy? Was it worth it?

[zadar]

no, I did not actually do this, I was measuring.

[CheGuevara]

I did it on curvy.
did you measure if rotors falls in center of caliper?
there is also some info here http://twfracing.com/forums/viewtopic.php?f=3&t=522

That's a good thread. Luis has not been quite that forthcoming with figures when I asked him :) Not to say he hasn't been helpful, but as he's hoping to at least recover some of his costs...


It's interesting the different approaches taken. I hadn't actually considered measuring from the swingarm -but I'm convinced that relative distances from the centre of both wheels is valid as well. As my old PL/SQL instructor used to say, "There's more than one way to code a cat."

My rotor falls in the centre of the caliper- I haven't changed that relationship at all (RHS spacer and LHS of the caliper carrier remain untouched). I physically confirmed this by placing the GSXR wheel on the axle with the roter and SV carrier and caliper in place.

I think I've spotted a flaw in my logic now about how much I need to move the sprocket inboard: I've subtracted the 2mm I've removed from the RHS (to centre the wheel), which doesn't work because the centre-line does not move.

Still, working with 7mm difference, subtract 2mm from the inner carrier spacer, then 3mm from the sprocket mounting face of the carrier, and space a 520 front sprocket out by 2mm... and that just echoes what Zoran has posted on the other thread :)

Out of curiosity, what stopped you from moving forward with the swap?

[zadar]

Out of curiosity, what stopped you from moving forward with the swap?
not enough time to play with it and fact I already have aftermarket wheel :)

[zadar]

this is 01-05 gsxr wheel. note new caliper bracket moving caliper out.

[CheGuevara]

this is 01-05 gsxr wheel. note new caliper bracket moving caliper out.

That must be unique to that wheel - I think it's quite a lot wider at the hub? Luis managed to get the k6/k7 wheel into a curvy I think using the same "kit" he sells with only a little bit of tweaking the dimensions.

[zadar]

That must be unique to that wheel - I think it's quite a lot wider at the hub?
center to sprocket is same on both, center to rotor is more on older and reason for caliper been moved out. I had to machine left side 7mm to move sprocket to center, same as needed on 06/07. instead of machining carrier I did wheel itself so carrier stayed stock while wheel was 7mm narrower on left side.
here is wheel surface machined

[Kuku]

Guys, i'm wondering about the sprocket carrier interchangeability, because i'll need a sprocket carrier for my rear wheel conversion, but don't know which one (except the original) fits to a GSXR-600 K4/K5 rear wheel.

I think that the sprocket carrier of these models is interchangeable:
GSXR-600 - 2001-2005
GSXR-750 - 2000-2005
GSXR-1000 - 2001-2004
SV1000/S - 2003-2007

Is that correct?
And if it's correct, that means i can't use the SV650 sprocket carrier for a GSXR rear wheel?!

[CheGuevara]

All I can say is it definitely won't work with the K6/K7 600/750 wheel as the design is quite a bit different. Not the mention the SV carrier is a lot wider which would compound the problems...

Probably doesn't help you much with an earlier wheel, but maybe useful to someone else reading this.

[Varun1794]

So I've decided to aproach this from a slightly different perspective. I figured that the critical primary measurement was from the centre of the rim to the outside of the RHS outer spacer. With that I can get the wheel centred, and then determine how much the LHS needs to move.

With that in mind, I figured my best method to find the rim centre was to remove the tire from the wheel (on both wheels), mark the edges of the rim on a piece of paper on the floor, and then use a straight edge as a plumb line to mark relative reference points (spacers, sprocket etc) down to the paper. And this is without the need to remove bearings, possibly destroying them in the process.

I've done this once now, and I'm happy with the results, but will start again from scratch to verify my measurments:

1) I get 8mm total difference between the SV & GSXR, from the outside of the LHS spacer to the outside of the RHS spacer.

2) From rim centre to the outer edge of the RHS spacer there is just 2mm difference between the SV & GSXR - so mill this amount from the outside of the brake caliper carrier (and the locating bar on the swingarm as well if necessary to alllow the carrier to sit flush against the swingarm).

3) The wheel will now be centred, but we need to remove 6mm total from the LHS to fit it into the swingarm.

4) Remove 2mm from the inside edge of the inner sprocket carrier spacer. If you also remove the little bridges and nodules from the cush rubbers this will allow the entire sprocket carrier to move inboard 2mm.

5) Remove 4mm from the outer LHS spacer. The wheel should now fit in the swingarm (we've narrowed it by the 8mm difference).

6) We still need to make sure the rear sprocket is in line with the front. The difference between the measurements of the rim centres to the centreline of the SV's 525 sprocket, and a 520 sprocket on the GSXR, is 2.7mm. We've already moved the carrier inboard by 2mm, so we're dealing with just 0.7mm. I think I can live with that, but if you can't it's possible to mill this much(or more -up to about as much 3mm if you decide to stick with a 525 sprocket) from the sprocket mounting face of the GSXR sprocket carrier.

Now just to be clear, when I'm suggesting "remove 4mm from the outer LHS spacer" what I mean is that a new sleeved spacer must be machined 4mm amount narrower than the stock LHS spacer, that will also take up the difference between the diamer of the SV axle, and the GSXR bearings & centre spacer etc. A sleeved spacer is also machined for the RHS, and both spacers should (I believe) overlap the centre spacer so that the entire assembly is stable.

I'll get some diagrams off to my machinist (that'd be a friend with a lathe and a bit of skill) and see how it goes. I'l post up my results of course.

IMPORTANT NOTE: As mentioned above I've measured this just once, and need to do it again to confirm my measurments and calculations. Even then, please make sure you confirm these figures for yourself before you start butchering your parts.



Hey guys I followed these steps on my 07 sv with a 06 gsxr rear wheel and everything worked out pretty well except that my brake rotor only just touches the outside of my calliper bracket, anyone have this problem? I could just take another 2mm off the bracket and add 2mm to the rhs spacer but I want to make sure i haven't screwed up somewhere else to start with.