Widest tyre on 3 inch rear rim

**DODO``** · 3rd March 2018, 23:28

Hi all!
Time for another silly question of the day that I haven't been able to get a straight answer from the dealer.. or anyone..
I am looking into modding rear end of my bike and wanted to first establish what size would be the widest tyre my 3 inch rear rim will take.

Currently it has factory 150 tyre installed.

Thank you look forward to your experience and knowledge.

**Akzle** · 4th March 2018, 05:15

420 BLAZE it YO!

**F5 Dave** · 4th March 2018, 07:01

For a normal tyre on a 3" rim 110 is the go. A 120 will go on but will be misshapen and handle worse. There are some exception tyres with stepped beads to allow wider but these aren't common at least on tyres for proper motorbikes.
Size of rim will be on the rim somewhere.

**AllanB** · 4th March 2018, 08:06

What's the bike?

A 180 tyre generally uses a 5.5 inch rim, front 3.5 rim a 120.

So your 150 on a 3 inch strikes me as oversize.

As above the actual rim size will be stamped on the wheel.

**DODO``** · 5th March 2018, 15:43

Originally Posted by AllanB

What's the bike?

A 180 tyre generally uses a 5.5 inch rim, front 3.5 rim a 120.

So your 150 on a 3 inch strikes me as oversize.

As above the actual rim size will be stamped on the wheel.

the bike is 2018 HD street bob.
yeah.. 150 on 3 .. both factory stock.

**F5 Dave** · 5th March 2018, 17:04

Ahh ok so special tyre type.
If you lace on a bigger rim, if spoked, or mag wheel you can fit a bigger tyre. If you have clearance, both to chain to outer of tyre and tyre to other components. The tyre may grow bigger in all directions but weirdo tyre on now will likely be high profile.
Be prepared to spend. It's easy to make something dangerous if you don' know what you're doing.

And you can really screw up the handling but that's probably not a design criteria.

Edit googled, read belt not chain, and spoked. But that rim looks bigger than a 3".

**F5 Dave** · 5th March 2018, 17:14

Good grief, just googled rim sizes. It' a 4.5". I wouldn't recommend you proceed further if you can't get a grip on the basics. This shit can be dangerous.

**DODO``** · 5th March 2018, 17:52

Originally Posted by F5 Dave

Ahh ok so special tyre type.
If you lace on a bigger rim, if spoked, or mag wheel you can fit a bigger tyre. If you have clearance, both to chain to outer of tyre and tyre to other components. The tyre may grow bigger in all directions but weirdo tyre on now will likely be high profile.
Be prepared to spend. It's easy to make something dangerous if you don' know what you're doing.

And you can really screw up the handling but that's probably not a design criteria.

Edit googled, read belt not chain, and spoked. But that rim looks bigger than a 3".

Originally Posted by F5 Dave

Good grief, just googled rim sizes. It' a 4.5". I wouldn't recommend you proceed further if you can't get a grip on the basics. This shit can be dangerous.

Thanks for the reply, yeah. I am consulting Harley themselves too. I am sure the stock rim is 3" according to HD booklet.. Have you googled pre-2017 streetbob? 2018 streetbob is completely new bike. Clearance to belt, rear fender etc seem ok, guess I will find out once the tyre is fitted.

**Akzle** · 5th March 2018, 18:09

Originally Posted by F5 Dave

Good grief, just googled rim sizes. It' a 4.5". I wouldn't recommend you proceed further if you can't get a grip on the basics. This shit can be dangerous.

it's only a strayan... and a hardley...

**AllanB** · 5th March 2018, 20:13

If it's the same bike it says a 3 incher here.

http://www.syshd.com.au/motorcycles-...il/street-bob/

And the photo looks like that rear tyre is on the rim tight.

Here's a thought - take a ruler and run it through the spokes and measure it with ya eyeball. The width is actually to the inside of the tyre beads so it should be a bit larger from outer edge to edge.

If it's 3 inch (which should be stamped on the rim as 3.00 x 16 ) then I'd be sticking to the stock tyre size unless you lace up a larger rim.

**DODO``** · 6th March 2018, 00:46

Rim has a stamp 16x 3.00 ......

I just had a brain fart though.
Ran a vernier caliper and measured a section end to end.. and it measures 4inch..
I'm confused.

**Grumph** · 6th March 2018, 06:18

Originally Posted by DODO``

Rim has a stamp 16x 3.00 ......

I just had a brain fart though.
Ran a vernier caliper and measured a section end to end.. and it measures 4inch..
I'm confused.

So am I - where are the ends on a rim ?

Believe the stamping.