HAS ANYBODY HAD ANY PROBLEMS WITH 17 INCH ALLOYS ON A BRAVO ie. IVE BEEN TOLD THEY CAUSE GEARBOX PROBLEMS IS THIS TRUE?
General Bravo Problems 17 Alloy
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General Bravo Problems 17 Alloy
no probs on mine :slayer:
ChristieCruiser
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how can it cause gearbox probs???
speedo probs yea... becasue the larger diameter can cause the car to think the wheels are spinning at a speed when they are infact spinning faster...
but not much on a 17" to be honest.
geerbox??? well if there was a prob have alittle search it would have been reported on here somewhere.
check that your geerbox has fresh fluids etc and i cant see their being any problems full stop
speedo probs yea... becasue the larger diameter can cause the car to think the wheels are spinning at a speed when they are infact spinning faster...
but not much on a 17" to be honest.
geerbox??? well if there was a prob have alittle search it would have been reported on here somewhere.
check that your geerbox has fresh fluids etc and i cant see their being any problems full stop
how can it cause gearbox probs???
speedo probs yea... becasue the larger diameter can cause the car to think the wheels are spinning at a speed when they are infact spinning faster...
but not much on a 17" to be honest.
geerbox??? well if there was a prob have alittle search it would have been reported on here somewhere.
check that your geerbox has fresh fluids etc and i cant see their being any problems full stop
cheers for that
i can carry on with the mods, i must admit i thought it was a little bit strange for it to cause such a problem, but i thought i would see if anybody else had sufered anything like it.
If you have a 205 45 17 profile tyre you should be ok.
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that seems rather bif to me Bunny, surely 205/40/17? i know mine were this on the Marea, and i know the bravo (less the HGT) ride on smaller wheels
yeah. just realised i but 45 and not 40.
every now and then you'll hear the good old big wheel gearbox damage claim. its not completely unfounded because a bigger wheel is harder to turn, so that should put excess strain on the gearbox internals. however this claim fails to consider the fact that an engine's torque output will be constant regardless of wheel size, so the forces will not change significantly. instead the engine will struggle to turn the wheel as quickly, causing a loss of acceleration. this will not cause gearbox damage, however the strain put on the gearbox internals during hard acceleration will be slightly higher than with a smaller wheel. the difference will not be enough to cause damage, but it will increase the rate of wear slightly. its nothing to worry about.
RickyF430
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i had a friend buy a second hand bravo with 17'' alloys on it, the wheels had messed the gearbox up because i think it changes all the gear rations with bigger wheels. He sold the 17's and with the money bought a scrap gearbox and 14'' alloys, nice!
the overall ratio (final drive) is effectively altered (made longer) because the distance travelled in one rotation is further on a bigger wheel. thats why acceleration suffers, because the gears become longer, and a longer gear is harder to turn. however gearbox damage will not occur unless the car is driver by an abusive driver, and tbh the gearbox will die either way in that situation, i should know i've destroyed my fair share of gearboxes over the years regardless of wheel size.
ChristieCruiser
Member
i stand corrected then.
Sowwie
Sowwie
Although sometimes the actual difference in circumference is much smaller than people realise. For instance the original 195 60 15 tyres that came with my factor alloys actualy have a larger circumference than the 205 40 17 tyres I have on my other alloys. So that in theory my 17"s are better for acceleration than my 15"s.
thats true, you can only compare the overall tyre circumference, not alloy size.
most people fit 40 profile tyres to 17s, which gives a circumferecne of 74.68"
if you had 60 profile tyres on 15" alloys the circumference is 74.58"
so there is only an increase of 0.1", which could not affect the gearbox at all.
however most bravo's come with a standard size of 175/60/14 on steelies, which is only 69.96". percentage wise a 17" alloy with 40 profile tyre is going to be 6.75% bigger. thats still not enough of a change to damage your gearbox, but it is enough to suddenly notice that your engine lacks torque.
you also need to consider weight. a heavier wheel will be harder to accelerate, and alloys are often lighter than steel wheels, which helps to reduce the extra strain even if the circumference increases.
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