Bridgestone Motorcycle Parts Discussion Board

Bridgestone Tech Talk => 50, 60, 90 & 100 Talk => Topic started by: reed on November 19, 2010, 10:42:06 PM

Title: DUAL REAR SPROCKETS ON A BRIDGESTONE 100TMX.
Post by: reed on November 19, 2010, 10:42:06 PM
DUAL REAR SPROCKETS ON A BRIDGESTONE 100TMX.
What a inventive idea from Bridgestone to put a dual rear sprockets on there 100TMX.
I have this model TMX and you easily changed over from one sprocket to the other.
They say you can do this in 10 minutes so you ride to where you want to go off road
Changed over to a bigger sprocket and off you go there is one thing i would like to do
To the Bridgestone put in twin spark plug so you would stop the motorcycle and swap
The plug cap onto the other plug in the Cly head and that plug would be a cooler plug.
Then when you are done swap back to the road plug etc and you are on your way!
Thanks.
Reed.

Title: Re: DUAL REAR SPROCKETS ON A BRIDGESTONE 100TMX.
Post by: BS Mechanic on November 19, 2010, 10:55:53 PM
Reed, your second plug is a really interesting idea, It would be really fun to try! 
Title: Re: DUAL REAR SPROCKETS ON A BRIDGESTONE 100TMX.
Post by: reed on November 19, 2010, 10:59:19 PM
BS Mechanic
When i get the 350 out of the way its on my list of things to do!
Thanks.
Reed.
Title: Re: DUAL REAR SPROCKETS ON A BRIDGESTONE 100TMX.
Post by: disc_valve on December 02, 2010, 07:40:16 AM

I like the concept of the TMX dual sprocket arrangement, but I'm not so sure about it in practice. It seems a fine idea if you leave the chain on one sprocket for most of the time, but if you intend to change over "on the road" then you have to carry the greasy extension chain around in your pocket and something to clen your hands after messing with the chain. Sods law states also that when you get to the trail and go to change to the larger sprocket you find that the extension chain is in your jacket pocket alright - the pocket of your other jacket that's still hanging up in the garage at home!

I also wonder what happens if you do most of your riding on the road sprocket. The main chain will wear after a while, but the little-used extension chain will be relatively new. Sounds like a recipe for one gigantic tight spot when you st off olong the trail.

Seriously, though, does anyone out there regularly use the changeover facility on a TMX or a  90Trail/Mountain? The dual sprocket arrangement is certainly a conversation piece - "What's the other sprocket for" is the second most popular question after "Nice bike - What is it?" - but the Suzuki Trailcat or the "Go-Matic" bolt-on accessory seems a more practical idea.

I have tried my own TMX with on both sprockets at different times, but I admit that these days I leave it on the smll sprocket as I do 99% of my riding on the road.

Graham   
Title: Re: DUAL REAR SPROCKETS ON A BRIDGESTONE 100TMX.
Post by: Toystoretom on December 02, 2010, 10:45:25 PM
If there are dual sprockets on the rear hub, how do you keep the chain in alignment when switching to the other sprocket? Are there dual sprockets on the front also? Is this just the forerunner of the dual range transmission?

There was a 90 Mountain for sale here locally not too long ago, I could never get the kid to send me any pictures so I never saw it. I have no idea what happened to it.
Title: Re: DUAL REAR SPROCKETS ON A BRIDGESTONE 100TMX.
Post by: scrambler on December 03, 2010, 12:41:27 AM
The larger sprocket actually fits around the smaller sprocket so they are in the same alignment. A few other cycles used this as well, I know Hodaka did and think Bultaco did also.

(http://img.photobucket.com/albums/v199/Hahnda/Bridgestone/90TrailBack.jpg)
Title: Re: DUAL REAR SPROCKETS ON A BRIDGESTONE 100TMX.
Post by: BS Mechanic on December 03, 2010, 12:33:07 PM
For a poor student in about 1971, this was a really great feature.  The inconvenience of the oily length of chain was well worth the ability to change the gearing.  I remember riding 10 miles with the road sprocket to compete in the ISU cycle club's hill climb, then changing to the big sprocket for the event, then back home again with the road sprocket.  Didn't have or need any transportation but the TMX!
Title: Re: DUAL REAR SPROCKETS ON A BRIDGESTONE 100TMX.
Post by: ColoStone on December 03, 2010, 06:43:15 PM
Being such a Newbie with all this bike tech , That is just WAY COOL !
        Thanks
            Randy
              P.S now I am beginning to understand why folks want to buy as many Stones as they can get there hands on.
Title: Re: DUAL REAR SPROCKETS ON A BRIDGESTONE 100TMX.
Post by: reed on December 03, 2010, 08:21:50 PM
BS Mechanic
That takes me down memory lane remembering the Suzuki TC90 TRAIL CAT with high and low range.
You had a lever you would move and it would shift between high and low range.That was one of my
only form of transport in them days and it run 65 70 MPH the good old days when you road your bike
To work and to the pub after a hard days work in the workshop!
Many thanks.
Steve.
Title: Re: DUAL REAR SPROCKETS ON A BRIDGESTONE 100TMX.
Post by: reed on December 03, 2010, 08:27:28 PM
Randy
You are right the more Bridgestones you see the more you will want!
Its a great hobby.
Thanks.
Steve.