CBX front sprocket for rear wheel upgrade

[SILVERGOAT]

Let me start by thanking EVERYONE for this website. TO ALL THE SENIOR MEMBERS, thanks for your diligence to keep this site as pleasurable as it has been to use. Welcome to 2010 everyone, hope you all get to enjoy your respective rides as much as possible. I am looking forward to a week in Texas at the end of this month for a fly and ride reprieve from the horrible Northeast weather we are currently having(my '03 FZ1 is on a truck on it's way as I write this thanks much to Don at JC Motors). Anyway, I have just finished modifying my left spacer and rear caliper arm for fitting a YZF600 rear wheel to my '89 FJ. I am trying to do as much of this myself, so I am contemplating what to do about the rear sprocket carrier. So being that it is cold as h*@l outside and snowing, I searched on line for a new front sprocket. On JT Sprockets website, they have all the specifications and pictures for just about every make and model. I think a Honda CBX front sprocket( http://www.jtsprockets.com/52.0.html?&L=0&sel_uid=4305&p=)is exactly what is needed to match the rear offset of the YZF rear wheel plus I am thinking it will gain a bit of needed chain/tire clearance. Here is the kicker, it only comes in a 15 or 18 tooth size! Will the 18 fit inside the front cover, or should I go with the 15 and go to a 35 tooth rear sprocket to get me to a 2.33 vs. a 2.35 stock ratio. Let me know. Thanks.

[Arnie]

The diameter of the sprocket (and chain) will fit inside the cover.  I'm using an 18t sprocket now.   I don't know if the offset will cause it to rub the cover.

Cheers,
Arnie

[rktmanfj]

I'm running 18/40 with the 170/60/17, with no problems, and like it a lot.   

Randy T
Indy

[Harvy]

I'm running 18T offset '86 Honda VF1000R sprocket thru to 38T rear 5.5x17 rear wheel in FZ1 swingarm.......have now used Michelin Pilot Road, Power and currently Conti Attack and I have NO clearance issues on '91 FJ.

Harvy

PS the Conti Attack is wider than the Michelins........2-3mm chain to tyre edge clearance........all good.

[andyb]

If you go to a 15/35 set, I'd be concerned that the chain will 1) wear out more quickly due to the tiny front sprocket and 2) probably rub at the front of the swingarm.

With an 18, you may have to make a little extra room inside the front cover, but you could then go from a 38-49 in the back and have a load more choice in ratios, plus it'll help the chain life a bit. 

If you were able to machine down the brake caliper mount, why can't you do the same to the sprocket carrier?  Knock 3mm off all the way around and be done?

[SILVERGOAT]

I have done all the metal work using a drill press and a file set and a set of calipers. Working on the rear sprocket carrier, there are six very small places (where the studs mount)where material has to be removed perfectly level and exactly the same amount so the sprocket does not wobble. I do not have the right tools for this kind of work. I figure the factory got it right, so don't mess with it if at all possible. Other members have asked about doing a "bolt on kit" for this mod, so if I can source some parts that will work with minimal money output, we all will gain.

[SILVERGOAT]

    Thanks for the info on choosing the correct front sprocket size. I have decided to try a CBX and VF1000R front sprocket  in a 18T and I will let you all know how it works out.
     I also have decided to break from the norm and go with a Bridgestone BT021 160/70R17R and a  120/70R17F on a YZF 3.5" wheel. I currently have this particular tire on all my current daily ridden bikes(98 VTR(stock), 03 FZ1(not stock), 01 Bandit S (now my girls and back to stock, but not always so), 01 SV650S(my girls since new and still stock, w/ only aesthetic mods). I have found this tire to have excellent grip, wear characteristics and very neutral handling.
     

[SlowOldGuy]

     I also have decided to break from the norm and go with a Bridgestone BT021 160/70R17R and a  120/70R17F on a YZF 3.5" wheel. I currently have this particular tire on all my current daily ridden bikes. I have found this tire to have excellent grip, wear characteristics and very neutral handling.

Sorry for the thread jack, but it's funny how much opinions/experiences vary with tires.  I absolutely hated the BT021s that were on my '02 FZ1.  They wore quickly (3rd rear tire by 8000 miles, and I'm no stuntah), and were more than a little squirrely when leaned over.  The front tire also wore significantly more on the right side than the left side.

I'd like to say the Pilot Roads I have on it now are bettter, but I'm not too impressed with their overall performance either.  For wear, they are definitely better, but they appear to be wider than the BTs and thus make the FZ handle like a truck.  It feels a lot like my '85 FJ before the 17 inch front wheel mod; wants to stand up in turns unless a LOT of countersteering is applied.

DavidR.

[andyb]

Depends on the bike's setup, pressures, and how you like to ride.  The BT021's that I'm using I've been pretty happy with, they seem like a good compromise between a racier tire and a commuter.  I hated the BT020 that I ran for awhile though, on another machine, so go figure?

You can dial out things a bit with fiddling the geometry, but it's really best to just find tires you like and stick with them.

[flyingbanana]

I am planning on running a fazer 1000 swingarm, and caliper, with a Thunderace wheel, I have just had the sprocket carrier machined 5mm, planning on a 18/40, which should lessen sprocket wear 

[the fan]

Still off topic, but I trashed a set of BT-021's in a single rally.

I believe it was Henry that pointed out how worn my front tire was mid way through the weekend. By the time I loaded up and headed home the now 5 day old tires were worn well past the wear bars and cupped badly enough to be felt through the bars. No too impressive considering I got the spring and fall rallies plus my usual ammount of street riding in between out of a set of Pirelli Diablo Stradas the year before.

They handled OK for a ST tire, but turn in was muted compared to what I prefer and the front felt like it was flat under hard braking and aggressive cornering. Not really all that confidence inspiring by my book. I went back to Pirelli, but plan to try a set of Michelins at some point.

[andyb]

I hear the pirelli angels are the current winners in the ST arena.  Probably will be my next set.  

Though if I get tired of the lack of stick from the harder tires, it'll be back to tires that last as long as an oil change.  I think my current FJ tire has 500 miles on it and is nearly dead  Drag racing is hard on them...


Also (more on topic), different tires measure different widths.  I know that the BT56 series was wider than their spec said they should have been, the Shinko that I've run also was decidedly wider than a normal tire in the same size.  If you can, the best way to figure out how much clearance you're going to have is go to a big-ish dealer and start putting the tape measure on some rubber that you're considering.  Plus this way you get to drool over bikes without the SO complaining as much

[SlowOldGuy]

The BT021's that I'm using I've been pretty happy with, they seem like a good compromise between a racier tire and a commuter.  I hated the BT020 that I ran for awhile though, on another machine, so go figure?

Oops, my brain may have been in neutral.  I think the stock tires for the FZ were BT020s rather than BT021s.  If that's the case then I have no experience with 021s so feel free to ignore anything I may have said.

DavidR.

[Harvy]

I hear the pirelli angels are the current winners in the ST arena.  Probably will be my next set.  

Andy, I see there is a second 180/55/17 listed that is "2 ply carcass for heavier bikes".......I would assume a stiffer side wall for this one......well worth considering for those of us running a 5.5 rear IMO. Sorry for the thread highjack.....blame Andy 


Harvy

[andyb]

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