Bandit Alley

MODEL SPECIFIC => SUZUKI BANDIT 250 & 400 => Topic started by: matt_400bandit on February 16, 2007, 09:17:06 PM

Title: tyre size
Post by: matt_400bandit on February 16, 2007, 09:17:06 PM

would a 120/60 front tyre make my speedo severly out or just a couple of mph can anyone work this out for me because i dont no how also what effect would this have at 100mph ?????? cheers

Title: Re: tyre size
Post by: yuckhil on June 21, 2009, 06:15:49 AM

http://mc.bridgestone.co.jp/en/products/battlax/bt92.html (http://mc.bridgestone.co.jp/en/products/battlax/bt92.html)

Bridgestone lists overall diameter of 110/70R17 and 120/60R17 as 592 mm and 576 mm respectively, for the BT-92 model.
The 120/60 tyre is 2.7% smaller than the 110/70 tyre.
The circumference (pi * d = 1809.6 mm) is also 2.7% smaller
The 120/60 tyre completes a rotation in 2.7% less distance (1.8096 m).
At 100 mph (= 160.93 kph = 2682.24 m/min), the 120/60 tyre rotates @ 1482.26 RPM, which is 2.7% faster.
This causes 2.7% more turns /unit time through the speedo cable, which should increase the speedo reading by 2.7%, to ~103 mph.

Yay for high school math!

Title: Re: tyre size
Post by: gsxr400 racer on June 25, 2009, 04:13:36 PM

:yikes: my head hurts now

Title: Re: tyre size
Post by: dhcolesj on June 25, 2009, 07:39:46 PM

But the front tire has no affect on the speedo, does it?  I didn't think the front tire was were the speed came from.  Maybe I have it wrong for the B400's.

I just thought I'd help gsxr400 out a little.  hehe.

Title: Re: tyre size
Post by: Red01 on June 29, 2009, 03:54:03 PM

I'm pretty sure the B4 is like the 1G B6 & B12 and has a cable driven speedo - that read front wheel speed.  :poopfan:

Title: Re: tyre size
Post by: PitterB4 on July 01, 2009, 09:40:59 AM

Quote from: Red01 on June 29, 2009, 03:54:03 PM

I'm pretty sure the B4 is like the 1G B6 & B12 and has a cable driven speedo - that read front wheel speed.  :poopfan:

Yup!

Title: Re: tyre size
Post by: dhcolesj on July 02, 2009, 03:25:38 AM

Hmm, well I stand (or sit while I'm typing) corrected.  Thanks!