Sprockets - Does new bike have the wrong ones?

[Lou Ranger]

I ordered a 17T front (JTF-571.17) to lower my rpm count - hopefully to around 5600 at 100 kph - if it fits.

Will I be able to get the old one out and insert the new one without disturbing the chain around the rear sprocket?
I figure one extra tooth equals "shortening" the chain by one link = 5/8". So that would mean moving the rear wheel 5/16" closer to the front?

The adjusting bolts are currently set about half way between tight and loose.

 

[bentwrench]

Lou, I would think you'll need to loosen the back to get the needed slack...

 

[Lou Ranger]

...loosen the back to get the needed slack...

I figured I'd have to loosen the the back wheel and slide it forward but was hoping I would only have to wrestle with the chain at the front and not have to detach it from the rear sprocket.
I will report on how easy/difficult it turns out to be - and if I have to have a mechanic make a house call.

 

[jayel]

don't remove a link Lou it will adjust for the added tooth, it's not a linear change it's a change in circumference 16 x .625 = 10, 17 x .625 = 10.625 but it's divided by 2, top and bottom runs of the chain .312 (5/16ths) but that's not the whole story... circumference divided by pi 10/3.14 = 3.185 10.625/3.14 = 3.384 3.384 - 3.185 = .199 this is the difference the chain is going to see, slightly more than a 3/16ths

 

[Lou Ranger]

don't remove a link ... circumference divided by pi 10/3.14 = 3.185 10.625/3.14 = 3.384 3.384 - 3.185 = .199 this is the difference the chain is going to see, slightly more than a 3/16ths

Out of curiosity, I will be marking and measuring the change along the swingarms. If I remember, I'll take pics too.
Today I cleaned some gunk for Fubar and took this pic to show the guy at the bike shop. He thinks the 17T will have the same 2 holes for the 2 bolt retainer. I hope he is right.

 

[Lou Ranger]

Better late than never, the new 17T sprocket arrived this afternoon.
May have to wait until after the holiday weekend to install it as I promised SWMBO we would leave tomorrow before the traffic starts up.
Does it look like it will fit and replace the (different brand) 16T pictured above?
Thanks .....

 

[DanMach]

Late to the party.. but the gearing you described was identical to mine. 60mph = 6000rpm.

 

[Lou Ranger]

60mph = 6000rpm.

Thanks Dan, I will let you know how I like 17-35 if the new one fits - you might welcome a few less revs on some of those beautiful desert roads out there.
We were in AZ in Feb. Is it too hot to ride at noon yet?

 

[DanMach]

Ya I was looking at the sprocket and gearing calculator just a few minutes ago. Its never too hot to ride here! I'll be riding home in the 100+ weather here in about 2.5 hours though.

 

[jayel]

think I see what's going on with that sprocket Lou, are the two small holes tapped to accept bolts? if not that raised center section makes me think it uses a nut to hold to the output shaft (like the 650's) and you may have to have it machined down to get proper front/rear sprocket line-up and the holes tapped to use the lock plate if they otherwise line up with your lock plate, (or drill and tap new ones that do)

 

[bentwrench]

I'm interested to see - looks like the bolt holes may not be wide enough... but it's tough to tell.

 

[lhaolpa]

You can get a #3 philips and grind about1/32-1/16th" off of the tip and use an impact driver[Harbor Freight has them cheap]and make sure that you're putting the pressure in a counterclockwise direction when you hit it. I've got an impact driver that I bought when I was about 14 years,about 46 years ago. lha

 

[Lou Ranger]

are the two small holes tapped to accept bolts? if not that raised center section makes me think it uses a nut to hold to the output shaft (like the 650's) and you may have to have it machined down to get proper front/rear sprocket line-up and the holes tapped to use the lock plate if they otherwise line up with your lock plate, (or drill and tap new ones that do)

The holes have threading inside to take bolts and I think they are the same distance apart as on the 16T. I guess it will depend on whether the old 16T has a raised centre section hidden under that lock plate.
I have the DOHC engine (like the Seca) and the part is listed for the Seca - however, unlike the Seca, the Maxim has a 5-spd. With my luck, because of the tranny difference, the output shafts will be different somehow and the raised section is there to line up the chain properly on the 6 spd.

 

[DanMach]

I think you're gonna be fine. Bikebandit lists the 17T as a possible front sprocket replacement. I've used them for a lot of random small parts on the maxim and they always send the right part.

 

[Lou Ranger]

I think you're gonna be fine. Bikebandit lists the 17T as a possible front sprocket replacement. I've used them for a lot of random small parts on the maxim and they always send the right part.

Thanks, I hope this isn't the exception (like I said - with my luck .....).
Have you ever had a look under the lock plate at your Maxim's front sprocket? I'm hoping there's a raised centre.

 

[DanMach]

No I haven't, I can do it when I get home tonight though.

 

[Lou Ranger]

No I haven't, I can do it when I get home tonight though.

Thanks, but don't go to any trouble now. If I find a difference between the 16 that's on there now and the 17 I got yesterday, I may ask.
Went to BikeBandit, got their part number and entered it into the JT Sprockets site. Not available.
The part number I received (JTF571.17) is listed on the JT site - but as applying only to the XJ600.
Yet part #JTF571.16 (whose dimensions and side profile are all identical to the .17) are listed as available for 20 Yamaha models (400s, 550s and 600s).
I'm hoping you can't believe everything you read on the Internet.

 

[bentwrench]

Lou, I like you, which is why I do things like this.

I checked my front sprocket, and it looks just like the 17t - there's a raised centre section.

No worries - you'll be riding and enjoying your new sprocket on this beautiful long weekend.

 

[Lou Ranger]

Lou, I like you, which is why I do things like this.
I checked my front sprocket, and it looks just like the 17t - there's a raised centre section.
No worries - you'll be riding and enjoying your new sprocket on this beautiful long weekend.

I wish, not until Wed though - upon returning from black-fly country after May Two-Four. Awfully nice of you B-W, you shouldn't have. I can't wait until fall when your newborn is big enough to ride in the tank bag so I can buy you a coffee in Belfountain at the Forks.

 

[DanMach]