BritBike Forum logo
BritBike Sponsor BritBike Sponsor BritBike Sponsor
BritBike Sponsor

BritBike Sponsor

BritBike Sponsor
BritBike Sponsor BritBike Sponsor BritBike Sponsor
JRC Engineering dealers
Home | Sponsors, Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons, "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Member Spotlight
Mike, in Idaho
Mike, in Idaho
orofino Idaho
Posts: 71
Joined: November 2007
Show All Member Profiles 
Shout Box
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Random Gallery photo
Who's Online Now
43 registered members (Alan_nc), 265 guests, and 230 spiders.
Key: Admin, Global Mod, Mod
Newest Members
JoeBrown, Bart223, Duckster, IDG1, pemdoc65
10173 Registered Users
Top Posters(30 Days)
Lannis 94
reverb 86
Stuart 72
koan58 66
NickL 66
Popular Topics(Views)
551,558 mail-order LSR
Forum Statistics
Forums34
Topics66,576
Posts645,450
Members10,173
Most Online3,995
Feb 13th, 2017
Like BritBike.com on Facebook

Previous Thread
Next Thread
Print Thread
Rate Thread
T120 - a wider tyre, pros and cons? #104837
11/05/06 9:21 pm
11/05/06 9:21 pm
Joined: Sep 2006
Posts: 26
UK
J
Johann T Offline OP
BritBike Forum member
Johann T  Offline OP
BritBike Forum member
J
Joined: Sep 2006
Posts: 26
UK
I'm just about to order new rims for the 1969 T120 Triumph Bonneville I'm restoring. (see http://bonneville.typepad.com for more about the bike).

Standard rims are WM2-18 for the front, and WM2-19 for the rear. However, the wheel-building company has suggested I go for the standard WM2-18 on the front but a wider WM3-19 on the back.

I can see that a wider rear tyre makes sense in terms of increased road grip, but are there any other pros and cons I should be aware of in terms of handling etc before I make a final decision?

Any words of wisdom gratefully received,

Johann T
http://bonneville.typepad.com

Support Your #1 BritBike Forum!

Check out British motorcycles for sale:
British Motorcycles on e-Bay UK, British motorcycles on e-Bay North America
Check out British motorcycles for sale:
British Motorcycles on e-Bay UK, British motorcycles on e-Bay North America
Re: T120 - a wider tyre, pros and cons? #104838
11/05/06 9:27 pm
11/05/06 9:27 pm
Joined: May 2005
Posts: 3,804
ohio
shel Offline
BritBike Forum member
shel  Offline
BritBike Forum member
Joined: May 2005
Posts: 3,804
ohio
if I were your wheel builder I would suggest you put the 18" on the rear and the 19" up front laughing


When given the choice between two evils I picked the one I haven't tried before
Re: T120 - a wider tyre, pros and cons? #104839
11/05/06 9:33 pm
11/05/06 9:33 pm
Joined: Sep 2006
Posts: 26
UK
J
Johann T Offline OP
BritBike Forum member
Johann T  Offline OP
BritBike Forum member
J
Joined: Sep 2006
Posts: 26
UK
My mistake - it's been a long weekend. I should of course have referred to an 18" on the rear and 19" up front. My fault, not the wheel-builders.

All the same, does anyone have any experience (good or bad) of a WM2-19 on the front and a WM3-18 on the back?

JT

Re: T120 - a wider tyre, pros and cons? #104840
11/05/06 9:41 pm
11/05/06 9:41 pm
Joined: May 2005
Posts: 3,804
ohio
shel Offline
BritBike Forum member
shel  Offline
BritBike Forum member
Joined: May 2005
Posts: 3,804
ohio
i was just having a little fun with you.
my parts catalogue list a wm3-18 as standard for 1969. was this different for home market models?


When given the choice between two evils I picked the one I haven't tried before
Re: T120 - a wider tyre, pros and cons? #104841
11/05/06 9:57 pm
11/05/06 9:57 pm
Joined: Sep 2006
Posts: 26
UK
J
Johann T Offline OP
BritBike Forum member
Johann T  Offline OP
BritBike Forum member
J
Joined: Sep 2006
Posts: 26
UK
Hi Shel -

I've just re-examined my parts book and although the WM2-18 appears to be standard for the UK bike, it DOES list at the foot of the page a WM3-18 as an alternative rim for a 4 inch tyre. I hadn't noticed this before. Thanks for causing me to take a closer look! :-)

Re: T120 - a wider tyre, pros and cons? #104842
11/05/06 10:04 pm
11/05/06 10:04 pm
Joined: Aug 2001
Posts: 1,853
The Northwoods... Michigan
Steve Erickson Online content
BritBike Forum member
Steve Erickson  Online Content
BritBike Forum member
Joined: Aug 2001
Posts: 1,853
The Northwoods... Michigan
I think that the "home" models came stock with a 3.50X18 on the rear on a WM2-18, whereas the export models, at least those to the US, had a 4.00x18 on a WM3-18 rear as standard. Some models even had different side stands because of the tire size, I believe.

Re: T120 - a wider tyre, pros and cons? #104843
11/05/06 11:07 pm
11/05/06 11:07 pm
Joined: May 2005
Posts: 3,804
ohio
shel Offline
BritBike Forum member
shel  Offline
BritBike Forum member
Joined: May 2005
Posts: 3,804
ohio
i wish they would have gave us the big tank as well laughing


When given the choice between two evils I picked the one I haven't tried before
Re: T120 - a wider tyre, pros and cons? #104844
11/06/06 10:48 am
11/06/06 10:48 am
Joined: Oct 2004
Posts: 4,429
Melbourne Australia
Tiger Offline
BritBike Forum member
Tiger  Offline
BritBike Forum member
Joined: Oct 2004
Posts: 4,429
Melbourne Australia
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by shel:
<strong> i wish they would have gave us the big tank as well bigt

Johann, you could easily end up with tyre/chainguard clearance problems if you go too wide with a rear tyre and std chainguard.
A 110 Avon is very close on my '69 Tiger.


1969 TR6R
7.62 x 51 is not a maths puzzle.
Re: T120 - a wider tyre, pros and cons? #104845
11/06/06 11:57 am
11/06/06 11:57 am
Joined: Sep 2006
Posts: 26
UK
J
Johann T Offline OP
BritBike Forum member
Johann T  Offline OP
BritBike Forum member
J
Joined: Sep 2006
Posts: 26
UK
Thanks for the clearance advice. The bike definitely has a WM2-18 on the rear. Do you think I will have clearance problems if I go for a WM3-18?

Re: T120 - a wider tyre, pros and cons? #104846
11/06/06 12:20 pm
11/06/06 12:20 pm
Joined: Aug 2001
Posts: 3,913
Houston Texas
Britbodger R.I.P. Offline
In Remembrance
Britbodger R.I.P.  Offline
In Remembrance
Joined: Aug 2001
Posts: 3,913
Houston Texas
Johann,

I can verify that models exported to the US have a 18" WM3 rim on the rear so should be OK on your bike. Actually, I have a WM4 rim on my Triumph that I use for Proddie racing and it works fine.

As Tiger has pointed-out its more the tire width that you need to be concerned about. In this regard there is no clearance problem with the original 4" K70's that were fitted stock. However you have to be carefull when selecting a more modern tire. In the case of Avon Road Runners/Super Venoms that are very popular the widest you can get away with without the tire rubbing the chainguard is 90/110 (4.33") as Tiger has already stated. However, if you are prepared to run without the chainguard or alternatively cut a slot in it a 90/120 (4.72") will fit OK. That is what I have done with my T120 and BSA Rocket Three.

HTH

Re: T120 - a wider tyre, pros and cons? #104847
11/06/06 5:35 pm
11/06/06 5:35 pm
Joined: Feb 2006
Posts: 111
Peasmarsh, East Sussex
M
Micknal Offline
BritBike Forum member
Micknal  Offline
BritBike Forum member
M
Joined: Feb 2006
Posts: 111
Peasmarsh, East Sussex
Johann

I had exactly the same decision to make when rebuilding my 69 TR6 over the last few years.
It was only when I spoke to the very reputable Tony Miller at the then Miller Motorcyles,Hastings ,that I made my mind up and went for the stock WM3-18. I was able to source a new old Avon Roadrunner R2 100/90 that was a bit difficult to fit to the rim but didn't give me any clearance problems with the chainguard.
On the original WM2-19 front I have fitted an Avon Roadrunner AM20 which has performed fine this summer.
BTW Tony also advised against drilling the rim and fitting the security bolt as all I was using the bike for was pleasure riding as against speed trials or other high performance riding.
HTH.


Mick
1969 TR6
Re: T120 - a wider tyre, pros and cons? #104848
11/07/06 6:40 am
11/07/06 6:40 am
Joined: Jun 2002
Posts: 9,689
Scotland
S
Stuart Offline
BritBike Forum member
Stuart  Offline
BritBike Forum member
S
Joined: Jun 2002
Posts: 9,689
Scotland
Hi Johann,

Quote:
Originally posted by Johann T:
the WM2-18 appears to be standard for the UK bike,
I believe it's actually a typo - if you look in other Triumph publications for the model, and in other years, you'll find WM3-18 for the rear rim on a UK & GE bike; also, if you look at the other bikes in the range, they were all specified for WM2-19 front and WM3-18 rear.

Hth.

Regards,


Moderated by  John Healy 


Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Powered by UBB.threads™ PHP Forum Software 7.6.1.1
(Release build 20180111)
Page Time: 0.366s Queries: 14 (0.022s) Memory: 1.0739 MB (Peak: 1.2709 MB) Zlib disabled. Server Time: 2018-04-23 22:59:29 UTC