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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: pdg on March 02, 2013, 04:47:36 PM

Title: Tyres again
Post by: pdg on March 02, 2013, 04:47:36 PM
I'm sure it's been covered before, but I've searched (apparently badly) and can't find it...

Is there any issue putting radials on the original k75 'Y' spoke rims? Rim profile, width etc.?

Cheers
Title: Re: Tyres again
Post by: frankenduck on March 02, 2013, 04:56:46 PM
I haven't looked too hard but if you can find something in a 130/80-17 that would probably work on a .2.75x18 wheel.
Title: Re: Tyres again
Post by: pdg on March 02, 2013, 05:25:17 PM
I've not tried putting a 17" tyre on an 18" rim before, I'll probably need longer levers :giggles I can source loads of different 130/80-17s though so that's not a problem - is there clearance for something like a 110/80-18 on the front?

I've currently got Hi-Max 130/90-17 rear and 100/90-18 front, but they seem a little skittish in the wet.

The thing that I was mainly thinking of was the rim bead profile and whether there's any known problems with that...
Title: Re: Tyres again
Post by: frankenduck on March 02, 2013, 05:32:25 PM
I've not tried putting a 17" tyre on an 18" rim before, I'll probably need longer levers :giggles I can source loads of different 130/80-17s though so that's not a problem - is there clearance for something like a 110/80-18 on the front?

Kind of hard to guess what size rear wheel you have unless you include it in your post or put your year and model in your signature. (Hint, hint.)

Quote
The thing that I was mainly thinking of was the rim bead profile and whether there's any known problems with that...

Shouldn't be.
Title: Re: Tyres again
Post by: pdg on March 02, 2013, 05:55:15 PM
To be honest, I forgot the drum brake rears on the 75 were 18"...

I was considering going to later 3 spoke rims, but I heard/read the Y spokes were stronger - the roads here are terrible and the front already has a small dent from a pothole so I'm probably going to replace it with another the same. (Unless a pair of wire spoke wheels turn up :loopy: )

Oh, I'll put something in my sig area too.
Title: Re: Tyres again
Post by: frankenduck on March 02, 2013, 06:43:24 PM
Yes, the 3-spokes are a softer alloy.

The 130/80-17 is for the rear.
Title: Re: Tyres again
Post by: frogy on March 02, 2013, 07:12:36 PM
Is the 85 K100 diff. from the 87 K75.
I have viewed threads that showed riders exchanging their 100/90-18 fronts for 110/80-18 radials.And the rears which were 13/90-18 go to the larger 140/80-17 radials.
With the Naked project I am working on I have already put the radial front on as you can see in my avitar.Next I will be replacing the back with a Bridgestone Battleax 45v 140/80-17,I hope Im not wrong on this...am looking forward to putting radials on this K.
Title: Re: Tyres again
Post by: pdg on March 02, 2013, 07:36:01 PM
As far as I know the K75 and K100 rear ends (in the 'early' years) are the same apart from the gearing - the wheels are a direct swap (probably the same part?) Front end is the same too if I'm not mistaken...

I can't do one end at a time - it's illegal here to mix bias/cross/radial ply tyres and the bike is 'in use'. It's all or nothing so I don't want to get it wrong.

The only thing putting me off slightly is longevity - the current front hi-max is just nearing the 'need to replace' stage after (I'm informed) 15,000 miles. The rear hi-max is barely scrubbed so far and it's over 2,000 miles old.
Title: Re: Tyres again
Post by: frogy on March 03, 2013, 08:30:30 AM
Agreed,I would never mix bias and radial.Its like mixing bear and wine,somethings going to get upset.
Title: Re: Tyres again
Post by: Niemand on March 03, 2013, 02:02:23 PM
...like mixing bear and wine...

Agreed.  Bears tend to be mean drunks.
Title: Re: Tyres again
Post by: K75RT Keith on March 04, 2013, 01:11:21 AM
No need to reinvent the wheel or the tire.  There is a thread on using radials on the K's  I think you need a 140 on the rear and he claims it will fit on the 2.75 rim with no problems. 

The link is below for the thread.  Search for radial in the Lieberry    http://www.motobrick.com/index.php/topic,2927.msg21014.html#msg21014 (http://www.motobrick.com/index.php/topic,2927.msg21014.html#msg21014)
Title: Re: Tyres again
Post by: frogy on March 06, 2013, 05:11:48 PM
...like mixing bear and wine...

Agreed.  Bears tend to be mean drunks.
  Well you can tell I dont drink BEER,I cant even spell it :neener:
Title: Re: Tyres again
Post by: frankenduck on March 06, 2013, 05:38:08 PM
No need to reinvent the wheel or the tire.  There is a thread on using radials on the K's  I think you need a 140 on the rear and he claims it will fit on the 2.75 rim with no problems. 

The link is below for the thread.  Search for radial in the Lieberry    http://www.motobrick.com/index.php/topic,2927.msg21014.html#msg21014 (http://www.motobrick.com/index.php/topic,2927.msg21014.html#msg21014)

That's on a 3-spoke 3x17 rear wheel. I don't know if/what radial works on a 2.75x17 Y-spoke rear.
Title: Re: Tyres again
Post by: K75RT Keith on March 06, 2013, 11:28:40 PM
I stand corrected.  I read it a while ago and didn't remember the different rim size.
Title: Re: Tyres again
Post by: TIV on March 11, 2013, 07:50:09 AM
I got new Bridgestone´s, last summer. 110/80-18 BT45F Front and 140/80 B17. When I asked the British and German riders what they used, they all recommended these tyres, and they really have improved riding and handling.