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Trophy 250 and tire size #426434
03/26/12 10:41 pm
03/26/12 10:41 pm
Joined: Mar 2012
Posts: 7
California, USA
1970 tr25w Offline OP
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1970 tr25w  Offline OP
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Joined: Mar 2012
Posts: 7
California, USA
The bike right now has the og k70's (3.25-19 & 4.00-18) on it. I'm looking at tires online right now and wondering if i could size up or down as choices seem kinda limited. Any recommendations for tires?

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Re: Trophy 250 and tire size [Re: 1970 tr25w] #426440
03/26/12 11:15 pm
03/26/12 11:15 pm
Joined: Nov 2008
Posts: 2,712
Bishop, Calif.
D
desco Online content
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desco  Online Content
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Joined: Nov 2008
Posts: 2,712
Bishop, Calif.
Depends on whet you want. Original looks or better handling. Scroll about halfway down this page to "which tires do you like best". Maybe this will help.


1968 T120R
1972 T120RV
Any advice given is without a warranty expressed or implied.
Re: Trophy 250 and tire size [Re: 1970 tr25w] #426484
03/27/12 5:42 am
03/27/12 5:42 am
Joined: Mar 2012
Posts: 7
California, USA
1970 tr25w Offline OP
BritBike Forum member
1970 tr25w  Offline OP
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Joined: Mar 2012
Posts: 7
California, USA
Better handling. I'll look for the thread.

Re: Trophy 250 and tire size [Re: 1970 tr25w] #426485
03/27/12 5:44 am
03/27/12 5:44 am
Joined: Mar 2012
Posts: 7
California, USA
1970 tr25w Offline OP
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1970 tr25w  Offline OP
BritBike Forum member
Joined: Mar 2012
Posts: 7
California, USA
Better handling. I'll look for the thread.

Re: Trophy 250 and tire size [Re: 1970 tr25w] #426665
03/28/12 9:20 am
03/28/12 9:20 am
Joined: Jun 2002
Posts: 9,466
Scotland
S
Stuart Online content
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Stuart  Online Content
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Joined: Jun 2002
Posts: 9,466
Scotland
Hi,

Originally Posted By: 1970 tr25w
The bike right now has the og k70's (3.25-19 & 4.00-18) on it. I'm looking at tires online right now and wondering if i could size up or down as choices seem kinda limited. Any recommendations for tires?


Ime and mho, I would not "size up" - the sizes on your bike are what Triumph fitted to everything bar the triples in 1970, so your lightweight 250 has tyres that were suitable for the power and weight of a Bonneville ...

Then it depends what sort of road surfaces you intend to ride on - the specific recommendations I've made below are good on tarmac but aiui K70's will be better if you ride a lot of unpaved roads.

If you want to stay at the same size, Avon AM26 Roadriders are very good; although they're a sticky tyre, you should get good mileage on such a light bike. Otherwise, be careful selecting those sizes from any other maker - in particular, overall widths for given section widths (the "3.25" and "4.00") have increased since your bike was built and you could struggle to fit the 'same' sizes from another maker.

If you want to "size down" a little, you could consider the equivalent of what Triumph fitted to 'UK & General Export' versions (you have the 'US' version). Originally, these were 3.00x19 front and 3.50x18 rear; modern equivalents would be 90/90x19 and 100/90x18; available in Roadriders too but also plenty of other makers.

Hth.

Regards,

Re: Trophy 250 and tire size [Re: Stuart] #426740
03/28/12 6:44 pm
03/28/12 6:44 pm
Joined: Mar 2012
Posts: 7
California, USA
1970 tr25w Offline OP
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1970 tr25w  Offline OP
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Joined: Mar 2012
Posts: 7
California, USA
Thank you for the great info. I'm going to look into the 90/90x19 and 100/90x18 sizes and see what I find. Can you get a tubeless tire and use tubes with it? Since many choices in that size are tubeless.

Last edited by 1970 tr25w; 03/28/12 6:51 pm.
Re: Trophy 250 and tire size [Re: 1970 tr25w] #426796
03/29/12 12:19 am
03/29/12 12:19 am
Joined: Nov 2008
Posts: 2,712
Bishop, Calif.
D
desco Online content
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desco  Online Content
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Joined: Nov 2008
Posts: 2,712
Bishop, Calif.
Yes you can use tubes. Don't forget a new rim strap.


1968 T120R
1972 T120RV
Any advice given is without a warranty expressed or implied.
Re: Trophy 250 and tire size [Re: desco] #426939
03/29/12 10:54 pm
03/29/12 10:54 pm
Joined: Mar 2012
Posts: 7
California, USA
1970 tr25w Offline OP
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1970 tr25w  Offline OP
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Joined: Mar 2012
Posts: 7
California, USA
100/90x19 should fit the front? I'm looking at Shinko 712's.

Last edited by 1970 tr25w; 03/29/12 10:59 pm.
Re: Trophy 250 and tire size [Re: 1970 tr25w] #426988
03/30/12 7:58 am
03/30/12 7:58 am
Joined: Dec 2004
Posts: 9,071
Scotland
kommando Online content
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kommando  Online Content
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Posts: 9,071
Scotland
According to this review Shinko;s are great for upright but less grip if you lean over, I suggest you go with the Roadriders for grip and handling. Avon also support rear tyres at 19" so good second reason as these are getting more difficult to find.

RIDER NOTES:

“Predicable but somewhat heavy steering. You have to be really, really smooth during acceleration out of a corner. Anytime you’d put any immediate load on the rear tire it would break traction. Rear side grip was a bit sketchy and got worse as more heat got into the tire. Drive-grip on the fat part of the tire was really good. The Honda wanted to wheelie everywhere and you had to stand on the rear brake to keep the front end down. Tires were on the stiff side and the front tire was especially vague feeling.”

Re: Trophy 250 and tire size [Re: 1970 tr25w] #427056
03/30/12 7:10 pm
03/30/12 7:10 pm
Joined: Jun 2002
Posts: 9,466
Scotland
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Stuart Online content
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Stuart  Online Content
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Joined: Jun 2002
Posts: 9,466
Scotland
Hi,

Originally Posted By: 1970 tr25w
100/90x19 should fit the front?

I would advise against it for two reasons:-

. 100/90 is very wide overall, wider even than the 3.25 fitted originally (that I pointed out was also fitted to everything Triumph made, including the 650 twins and, at one time, the triples). Only the triples were fitted originally with something as wide as 100/90 on the front, and they were/are 450lb.+ bikes.

. To fit a 100/90 between the '70 forks, you either have to remove the mudguard/fender and its brackets, install the wheel then refit the mudguard/fender and its brackets; or fit the wheel with the tyre deflated then pump the tyre up again.

Do you want that amount of faff for poor steering? frown

Originally Posted By: kommando
Avon also support rear tyres at 19"

Errrmmm ... as he's said already, his TR25W has an 18" rear wheel and a 19" front wheel. whistle

Hth.

Regards,

Re: Trophy 250 and tire size [Re: Stuart] #427080
03/30/12 10:12 pm
03/30/12 10:12 pm
Joined: Dec 2004
Posts: 9,071
Scotland
kommando Online content
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kommando  Online Content
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Posts: 9,071
Scotland
Yes I know a TR25W has a 18 rear but for those of us with 19 rears buying Avons keeps them in production. From TR25W's bigger bikes grow wink .

Re: Trophy 250 and tire size [Re: kommando] #428111
04/05/12 6:12 pm
04/05/12 6:12 pm
Joined: Feb 2012
Posts: 40
Virginia
sparks Offline
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sparks  Offline
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Posts: 40
Virginia
I just bought a TR25W and I'm confused on the wheel sizes. It has an 18" rear and a 19" front. The specs in the Parts Catalog state 18" for both front and rear. I'm wondering if the US export version shipped with the 19" front. Anyone know?


1968 TR25W
1973 T100R Daytona
Re: Trophy 250 and tire size [Re: 1970 tr25w] #428112
04/05/12 6:16 pm
04/05/12 6:16 pm
Joined: Dec 2004
Posts: 9,071
Scotland
kommando Online content
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kommando  Online Content
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Joined: Dec 2004
Posts: 9,071
Scotland
The TR25W did come with the 19" front wheel, there are some which came with the 18" front but these may have been non US.

Re: Trophy 250 and tire size [Re: 1970 tr25w] #428457
04/07/12 3:01 pm
04/07/12 3:01 pm
Joined: Oct 2003
Posts: 11,140
North Georgia, USA
RF Whatley Online content
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RF Whatley  Online Content
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Joined: Oct 2003
Posts: 11,140
North Georgia, USA
You think you have issues. Try getting a 1971 model T25 with a 20" front wheel !!

eek


Don't hide 'em, Ride 'em !!

RF Whatley
Cornelia, GA

"Shop Boy" at Rodi British Bikes

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