Max tyre size on rim for Triumph
DocDelete
wide as possible. I'm *thinking* that I might get away with 205/70/14 on
these...any advice please? Ta.
Application: Triumph 2.5 PI Mk2 with Stag/2500s alloys.
--
Ken Davidson
---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.512 / Virus Database: 309 - Release Date: 19/08/03
PJML
> Just about to get some new tyres for my 14" 5.5J rims - and I want to go as
> wide as possible. I'm *thinking* that I might get away with 205/70/14 on
> these...any advice please? Ta.
>
> Application: Triumph 2.5 PI Mk2 with Stag/2500s alloys.
I run 195/70-14 tyres on 6-inch rims - I wouldn't
want to go for 205s on 5.5-inch rims myself as
the sidewalls will be bowed-in a bit too much for
my tastes.
Iain Miller
"DocDelete" <docd...@removehotmail.com> wrote in message
news:q5j8b.917$0x5.1...@stones.force9.net...
> Just about to get some new tyres for my 14" 5.5J rims - and I want to go
as
> wide as possible. I'm *thinking* that I might get away with 205/70/14 on
> these...any advice please? Ta.
>
> Application: Triumph 2.5 PI Mk2 with Stag/2500s alloys.
Also beware that in changing the tyre width you will change the rolling
radius & so the gearing if you don't adjust the profile to compensate.
What's on the car now?
I
awm
> Just about to get some new tyres for my 14" 5.5J rims - and I want to go as
> wide as possible. I'm *thinking* that I might get away with 205/70/14 on
> these...any advice please? Ta.
>
> Application: Triumph 2.5 PI Mk2 with Stag/2500s alloys.
>
Physically possible (check wheel arch clearance) but definitely not
adviseable this is the extreme to end of what will fit on the rim, for
best handling the tyre size should be at the narrower end of sizes
suitable for the rim width. 185/70x14 would be a better choice or at a
pinch 195/65x14.
shazzbat
> Also beware that in changing the tyre width you will change the rolling
> radius & so the gearing if you don't adjust the profile to compensate.
Changing the width doesn't change the radius. Changing the diameter ie from
13" to 14" does. I think this is what you mean.
Steve
Lordy
> > the rolling radius & so the gearing if you don't adjust the
> > profile to compensate.
>
> Changing the width doesn't change the radius.
Erm, yes it does :)
There are three given measurements to a tyre, the inner diameter, the
width, and the profile. The profile is a percentage measurement of the
width, ergo any change to the width of a tyre (whilst retaining the same
profile) will result in a change in the rolling radius (e.g. the 70 in
205/70 R14 means 70 percent of 205mm, if he changed to those from 155/70
R14 tyres then it would have been 70 percent of 155mm.
> Changing the diameter ie from
> 13" to 14" does. I think this is what you mean.
No, it's not. The difference however is marginal and not worth worrying
about, and seeing as speedos over-read anyway it may even make it *more*
accurate than it was previously (obviously depends on the exact changes
taking place in the rolling radius).
--
Lordy
shazzbat
"Lordy" <sp...@recycle.bin> wrote in message
news:MPG.19cc3d1bc...@newscache.cable.ntlworld.com...
All right, all right, *effectively* doesn't, because it's such a miniscule
amount.
Changing the diameter affects gearing/speedo reading, Changing profile
affects it less, changing width affects it not enough to be noticeable.
*for practical purposes*
happy now?
ops
DocDelete wrote:
> Just about to get some new tyres for my 14" 5.5J rims - and I want to go as
> wide as possible. I'm *thinking* that I might get away with 205/70/14 on
> these...any advice please? Ta.
>
> Application: Triumph 2.5 PI Mk2 with Stag/2500s alloys.
>
Stick with the recommended tyre size for the prescribe rims. Triumph
should show a tyre size.
The Doggimite Sprint shows a 175/? x13 and I went to 185/? x13 this
was quite sufficient increase as the smaller size became unpopular and
harder to obtain a decent tyre. ( not sure what profile it was but still
kept the rolling radius).
I would think that 205/70/14 may cause problems and may not go under the
guards.
r
DocDelete
"awm" <thevi...@nohere.com> wrote in message
news:bjt4l0$ae0$1...@sparta.btinternet.com...
> Physically possible (check wheel arch clearance) but definitely not
> adviseable this is the extreme to end of what will fit on the rim, for
> best handling the tyre size should be at the narrower end of sizes
> suitable for the rim width. 185/70x14 would be a better choice or at a
> pinch 195/65x14.
Thanks - any reason you didn't suggest 195/**70** x 14? I've seen this
option available on all the internet traders I've looked at.
--
Ken Davidson
---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.515 / Virus Database: 313 - Release Date: 08/09/03
DocDelete
"ops" <martin@w'gong.apana.org.au> wrote in message
news:3f62a5a1$0$95046$c30e...@lon-reader.news.telstra.net...
> Stick with the recommended tyre size for the prescribe rims. Triumph
> should show a tyre size.
> I would think that 205/70/14 may cause problems and may not go under the
> guards.
:-)) Heh, s'funny - the resource available at www.kvaleberg.com/t-tune.html
cites a range of 5.5J to 7J for 205/65 x 14!!
Looking at the arches myself, and given the standard offset I'm pretty sure
205 is possible without fouling (agree it could well be /very/ close) but
I'm surprised no-one apart from PJML has mentioned sidewall bowing as a
major consideration.
It's looking like I'll go for 195 on as higher a profile ratio as I can
find - maybe 70. I know certain sources (eg. Mr G Robson) view fitting wider
tyres as anathema, but for a car this weight and size 195 would be okay,
given that contemporary GTs were shod with similar (things like Opel Mantas
without PAS et al).
--
Ken Davidson
---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Lordy
> >
> > Erm, yes it does :)
> >
> > There are three given measurements to a tyre, the inner diameter, the
> > width, and the profile. The profile is a percentage measurement of the
> > width, ergo any change to the width of a tyre (whilst retaining the same
> > profile) will result in a change in the rolling radius (e.g. the 70 in
> > 205/70 R14 means 70 percent of 205mm, if he changed to those from 155/70
> > R14 tyres then it would have been 70 percent of 155mm.
>
> amount.
Hehe, that's not what you said before :)
> Changing the diameter affects gearing/speedo reading, Changing profile
> affects it less, changing width affects it not enough to be noticeable.
When people change to larger wheels they generally go for a lower
profile, so the difference on either type of change normally isn't
particularly great. 70 profiles are huge things, the difference between
155/70 R14[1]and 205/70 R14 is probably about 3cm, which is more than
enough to equal the change caused by going up an inch in wheel size. To
be honest, it sounds like *more* than the change caused by going up an
inch in wheel size and having a lower profile to compensate.
> *for practical purposes*
>
> happy now?
Me ? Nah, not until we've taken it to the limit and started calling
each other cnuts, heh. We can always cut the idle chit chat and get
straight onto the swearing if you want :))
--
Lordy
[1] Just a random example, I can't see any reference from the OP
as to the original tyres he's talking about are.
DocDelete
> > > > Changing the width doesn't change the radius.
> Lordy
> [1] Just a random example, I can't see any reference from the OP
> as to the original tyres he's talking about are.
The original "on spec" tyres are 185 x 13 - yep, you read correctly - *no*
profile percentage, full 100% old fashioned huge 'uns. I've got some 14"
alloys to bung on - spec for these according to the book was 185 x 14 so I'm
guessing that the factory was okay with the small increment in rolling
diameter.
--
Ken Davidson
---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Dave Baker
>From: "DocDelete" DocD...@nospamhotmail.com
>Date: 13/09/03 22:13 GMT Daylight Time
>Message-id: <IML8b.975$0x5.1...@stones.force9.net>
>
>"Lordy" <sp...@recycle.bin> wrote in message
>news:MPG.19cd8072c...@newscache.cable.ntlworld.com...
>> > > > Changing the width doesn't change the radius.
>
>> Lordy
>> [1] Just a random example, I can't see any reference from the OP
>> as to the original tyres he's talking about are.
>
>The original "on spec" tyres are 185 x 13 - yep, you read correctly - *no*
>profile percentage, full 100% old fashioned huge 'uns. I've got some 14"
>alloys to bung on - spec for these according to the book was 185 x 14 so I'm
>guessing that the factory was okay with the small increment in rolling
>diameter.
The aspect ratio of a tyre with no marked profile % is not 100%. It is 82%.
The highest aspect ratio that is normally indicted on the tyre is 80%. These
are fairly rare though as are 75% aspect ratio tyres. The highest marked ratio
in common use is the 70 series.
Dave Baker - Puma Race Engines (www.pumaracing.co.uk)
I'm not at all sure why women like men. We're argumentative, childish,
unsociable and extremely unappealing naked. I'm quite grateful they do though.
shazzbat
"Lordy" <sp...@recycle.bin> wrote in message
> > > > Changing the width doesn't change the radius.
> > >
> > > Erm, yes it does :)
> > >
> > > There are three given measurements to a tyre, the inner diameter, the
> > > width, and the profile. The profile is a percentage measurement of the
> > > width, ergo any change to the width of a tyre (whilst retaining the
same
> > > profile) will result in a change in the rolling radius (e.g. the 70 in
> > > 205/70 R14 means 70 percent of 205mm, if he changed to those from
155/70
> > > R14 tyres then it would have been 70 percent of 155mm.
> >
> > All right, all right, *effectively* doesn't, because it's such a
miniscule
> > amount.
>
> Hehe, that's not what you said before :)
I know. I added *effectively* and *for practical purposes* because my
original belief that its meaning would be understood was sadly not the case.
Lordy
> > > miniscule amount.
> >
> > Hehe, that's not what you said before :)
>
> I know. I added *effectively* and *for practical purposes* because my
> original belief that its meaning would be understood was sadly not the
> case.
Hehe, quick thinking :)
--
Lordy
Iain Miller
"DocDelete" <DocD...@nospamhotmail.com> wrote in message
news:IML8b.975$0x5.1...@stones.force9.net...
> "Lordy" <sp...@recycle.bin> wrote in message
> news:MPG.19cd8072c...@newscache.cable.ntlworld.com...
> > > > > Changing the width doesn't change the radius.
>
> > Lordy
> > [1] Just a random example, I can't see any reference from the OP
> > as to the original tyres he's talking about are.
>
> The original "on spec" tyres are 185 x 13 - yep, you read correctly - *no*
> profile percentage, full 100% old fashioned huge 'uns. I've got some 14"
> alloys to bung on - spec for these according to the book was 185 x 14 so
I'm
> guessing that the factory was okay with the small increment in rolling
> diameter.
The "standard" profile is 82 IIRC so your original tyres are 185 x 13 x 82.
If I read what you are saying correctly they also fitted 185x14x82 - that'd
be quite a big jump in gearing - are you sure they didn't change the diff
ratio when they did that? If you were staying on 13s I'd say your options
would be something like 195x70s or 205x65 or 205x60 if you could get them on
the rims. Going up to 14s I'd say you'd need a much lower profile tyre to
compensate - maybe a 185x60 or a 195x55
I.
awm
Don't confuse section size and tyre width
awm
> "awm" <thevi...@nohere.com> wrote in message
> news:bjt4l0$ae0$1...@sparta.btinternet.com...
>
>
>>Physically possible (check wheel arch clearance) but definitely not
>>adviseable this is the extreme to end of what will fit on the rim, for
>>best handling the tyre size should be at the narrower end of sizes
>>suitable for the rim width. 185/70x14 would be a better choice or at a
>>pinch 195/65x14.
>
>
> Thanks - any reason you didn't suggest 195/**70** x 14? I've seen this
> option available on all the internet traders I've looked at.
>
>
> --
> Ken Davidson
It would just bee too big a 195/65x14 is more likely to clear the wheel
arches and because of the slightly lower profile is less likely to
affect the handling. 175/65x14 is also worth considering as its cheap
and easily available and would give better handling.
When the tyre is wider than the rim the tyre wall is cantilevered
outwards and as result tends to roll about and gives poor imprecise
handling. This is why Lotus cars tend to come from the factory with wide
rims but tyres that are quite narrow, the Elan when fitted with 5.5jx13
rims used 165x13 or even 155x13 tyres.
With tyres it is always better to invest in a quality tyre rather than
squeezing extra width on an existing rim.
TimM
too far!
DocDelete
"Dave Baker" <pumar...@aol.comma> wrote in message
news:20030913172412...@mb-m07.aol.com...
> The aspect ratio of a tyre with no marked profile % is not 100%. It is
82%.
>
> The highest aspect ratio that is normally indicted on the tyre is 80%.
These
> are fairly rare though as are 75% aspect ratio tyres. The highest marked
ratio
> in common use is the 70 series.
Thanks for that - however, I've just noted a figure on the tyre wall that
says 88R(atio)? Maybe 88% on the current Pacific Rim import rims?
--
Ken Davidson
---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).