Triumphrat

Travster · 04-02-2009, 06:38 PM

Well, my TBS has just over 12,000 and the chain is to the end of it's adjustment (yea, I need to check the valves too..)

So, new chain time. I was thinking RK or DID or something good.. if I'm gonna spend the money I want it to last awhile.

I've been looking at sprockets, and I have found that Renthal lists some specifically for the model. I have found the mfor sale on kneedragger.com, but they only have 40t, 43t (stock) and 46t rears. They do have 17t (stock) 18t, and 19t fronts.

I was thinking of going with an 18t up front, to get the chain up off the rubber guide (which, of course is trashed and will be replaced) however I want to lower the gearing if anything, not raise it. Just to keep the gearing near stock, I would have to run the 46t. That's actaully a 2.56 ratio vs the 2.53 (43t/17t) stock so it's 0.03 larger, but I don't think that's much.

Also, I've read about how it's best to use odd toothed sprockets, or at least one. Worst of all being two even number of teeth on each as it dramatically lowers the number of full chain rotations it takes before the same link and tooth contact one another, which is what causes the most wear, in theory at least. So, in conclusion, I was thinking of keeping the 17t for gearing (probably the triumph stock part for fitment) and going with a 45t rear.

I was wondering if there were any other manufactures you folks are aware of, and/or places to get sprockets? Also, any awareness of interchangability of sprockets that might only be listed for other bikes, but work perfectly fine? Say, bonnie, thruxton? I know there are 520 conversions out there for them as well, so that would be cool. Maybe ZRX sprockets? I know they share some similarities of design, and other parts are simple bolt-on swaps..

I have read the webbikeworld.com TBS article on chain replacement, and actaully the author steps up to a 45t sprocket on the rear, and gets it from JT. However, I have been having trouble finding them on the web, besides their homepage, which is about as informative as smoke signals.

Ksound · 05-13-2010, 05:42 PM

Can anyone chime in on this post? I have the same questions.

Where does everyone shop online for sprockets, and are there any other bike models that fit up to a thunderbird sport?

I just bought a new chain and need to buy new sprockets asap.

thanks

KD5QOQ · 05-14-2010, 05:04 AM

My first thought is that going to a 520 will probably have the chain laying on the road prematurely. they're 530 for a reason.

denny · 05-14-2010, 05:09 AM

Triumph used the same Countershaft sprocket on all of the T3's and many of the 955's.

I read somewhere that some models of the Honda 750 Magna use the same dimension rear sprocket, but I can't verify that one,
maybe that was the rear rotor?

Go to the JT sprockets website and download their complete catalog. There are cross reference tables in that book.

JT Sprockets and Renthal make sprockets that fit. I am sure there are other manufacturers that do too.

jwolf · 05-14-2010, 10:58 PM

Here's a llink that may prove helpful to TBS owners:
http://www.webbikeworld.com/t2/motor...hain-sprocket/

I am also ready to replace sprockets and chain on my Legend. I will stay with the 18/43 sprockets and use an RK XSO 530 chain.
My independent shop offers 15% off items they order from Parts Unlimited, which makes them competitive with the internet sites, and helps keep them in business for the things I'm unable to tackle by myself.

Ksound · 05-16-2010, 02:07 AM

Thanks for the replies.

I just bought a gold 530 chain and am trying to source a black 46T sprocket. I think I'm going to try out 18/46.