Tyre Pressures (Does size matter?)

highwayman

New Member
Well I've recovered from the trip and have started to sort out a few problems. I notice that I have 14" wheels and tyres not the 15" I expected! Olive is a 73 registered Highwayman. Anybody know if this is correct and what tyre pressures to use. Ta!

ITS JUST COMMERN SENSE TO HAVE ONE
 

Jostein

Well-Known Member
Tyre pressure for 15 and 14 inch wheels attached.

These are standard specs - so the rather heavy Highwayman body may require higher pressure, I don't know.

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Chamba

Member
Stick a set of 15's on the back and you'll be able to raise your gearing so your Commer screams at 55 rather than 50!
 

Enigma

Active Member
quote:
Originally posted by Chamba

Stick a set of 15's on the back and you'll be able to raise your gearing so your Commer screams at 55 rather than 50!



Is that right? have I got it wrong? but surely if you put bigger wheels on the back it will be screaming at 45?

Just thinking back to when I was sweeeeet 16 amd had a 50cc bike,,,we used to put a bigger sprocket at the front and a smaller one at the back to get 50 out of a 30mph restricted bike!:D

or am I now elderly and confused[?]:D


''COMMER'EnSayThat''
 

bazzateer

Well-Known Member
The larger tyres at the back means that you'll be going faster than the speedo thinks you are, therefore if it screamed at 50 before (say 5,000 revs) with the larger tyres at 5,000 revs you'll be going faster (although the speedo will read the same). Interestingly, with the Imp the speedo reads off the front wheel so fitting larger tyres on the rear will keep the speedo reading correctly.

BAZROCKS.jpg
If I told you I was a pathological liar, would you believe me?
I've got a Highwayman!!!
 

renaultvation

Well-Known Member
quote:
Is that right? have I got it wrong? but surely if you put bigger wheels on the back it will be screaming at 45?

Just thinking back to when I was sweeeeet 16 amd had a 50cc bike,,,we used to put a bigger sprocket at the front and a smaller one at the back to get 50 out of a 30mph restricted bike!

or am I now elderly and confused



When you changed to a smaller sprocket on your rear wheel, you were changing the gear ratio, not the size of your wheel. With a big sprocket at the front and small at the back, for every rotation of the front sprocket you would get more rotations of the rear sprocket. Increasing the size of your rear wheels without changing the gear ratios has a similar effect in that for every rotation of the larger wheel, the further it travels relative to a smaller wheel. If you turn the larger wheel at the same speed as the smaller wheel, that further distance travelled equals greater speed on the road.

Does that help with the confusion? Sorry, I can't do anything about the elderly bit! [}:)] :D

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'I'm the same age as a Forward Control Commer'
 

Panky

Administrator
Staff member
Yeah - but if you put smaller wheels on the back you'll get blistering acceleration:)

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eldiablo

Member
with bigger wheels (tyres) you get higher end speed ,but you loose pulling power ..it will even be harder to go uphill ;)
 

S0updragon

Well-Known Member
Not sure how much 1in will affect speed etc but commercial tyres over domestic is important. And check they put the hubcaps back on properly as i lost one and never found it
 
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