Bridgestone Motorcycle Parts Discussion Board
Bridgestone Tech Talk => 350 Talk => Topic started by: ridered on October 04, 2010, 06:59:03 PM
-
After my Bridgestone resto is complete my next project will be an old school cafe racer. The bike I will be using is a Honda GB500 parts bike I have. I really like the GTR 350's gage setup and was wondering if they would work for my project. I don't know how all that works, are gages are set up to work with any wheel or engine? This is probally an ignorant question but need to know.
Thanks
Mike
-
Hi Mike I am sure Reed or someone will give you the exact skinny on the 350 spec on the gauges , but I do know that mechanical tacks and speedo`s operate off a worm gear/like with a specific ratio that will match a specific gauge accurately, how a Mod to another bike with the 350`s gauges can be done ? the ones in the know here will come through if its possible.
good Luck :D
Randy
-
Mike
I would start with the cables to see if they would fit first from the Honda.
And then you could check ratio on the speedo or check it with another motor
Cycle at say 40 mph and see how far it is off and go from there!
It will be a trial and error job.
Thanks.
Reed.
-
Mike, It would probably be best to get a speedo and the matching wheel/tire size assembly. This way everything is calibrated for correct (or near correct) mph. If you just have a speedo, you will need to know what bike it came from and find out the wheel/tire size. You wouldn't want a speedo from a 21" front working with an 18" or 19" front wheel. I hope that makes sense. Just my .02 cents worth.
-
Poppaweelee
I agree with you but i think he want to use the speedo and rev counter from a Bridgestone gtr 350!
Thanks.
Reed.
-
As noted in previous posts, start with the fit of cables, although those can be made special if needed. Next is the combination of wheel size and drive gear ratio for the speedo, and the tach drive ratio in the engine. As reed says, it's all trial and error. However, since the tachs and speedos on early Japanese bikes are all similar mechanical devices, they may turn out to be pretty close, especially if you're just mostly interested in the look of these particular items. You can do mental corrections as you ride even if they aren't accurate. In the case of the speedo, both the original on my GTR and a new replacement from Richard are 15% - 20% optimistic, so all the calculations in the world may not mean much. I really don't know how accurate the tach is, but the engine response curve and the red line numbers seem to correspond pretty closely with what I would expect.
-
Your right Steve about what gages I'm trying to use. I think The GTR gage setup is the best I've seen, small,easy to read and look great. I have an idea that may work, put a mark on the wheel and rotate it one full turn and count how many turns the output shaft on the speedo drive turns. I will do this on each bike and see how close they are. I have 2 of the GB500's and one runs so I can do a speed to rpm check on that one. Then I will swap the stock GB tack out with the bridgestone tack and see how close they are.
Will be a little work but if they turn out to be close it will be worth the trouble.
Mike