Another 120/70 thread

[Guerrero]

I talked to the WC Bridgestone distributor and he recommend to run a Type 3 003 race tire 120/70 for the front and a 090 150/60 18 for the back. I used to run 003 race tires on my other bikes and for the price I loved them.

I read couple threads about the 120/70 and I found mix feelings about it... On the VFR do I need to drop the front? And how much? Now I have the forks flush with the triple (maybe drop them 5mm). On my K7 I drop the front 7mm and it made a huge difference. Also I read that to fit 120/70 you have to modify the rad bracket ??? What modifications I have to do to fit the taller tire?

I'm only going to ride the VFR on the track, and if I like it I may start racing... I just need to set her up first and take it from there... suspension is next

[Cammo]

Why not just get them to order in the proper tyre size? 003's come in 120/60. I used a 120/70 and it fouled the v-piece (not an issue on a track bike), and if you set the forks up to be flush with the top yoke then it compromises the handling IMO.

Personally I wouldn't mix tyres. Since 090's have been discontinued and 003's don't come in an 18" rear - get hold of a 17" rear wheel.

Tyre size issues for nc30's will only get worse in the future, you may as well bite the bullet, get a 17" and then set the suspension up to suit.

[999Gomerz]

I have a question please:

Is the idea to have the front as low as possible without having the tyre contact the rad, head etc at full compression?

[amorti]

I have a question please:

Is the idea to have the front as low as possible without having the tyre contact the rad, head etc at full compression?

On tiny bikes like nc's, yes.

I didn't realise 090's have been discontinued. That sucks if you've still got an 18" rear.

[Variablevalves suck]

You will be fine with a 003 F and 090 R, Bridgestone will happily recommend these. They even do a more race R10 front that they told me to use with a 003 rear on the 17"'s.

[999Gomerz]

I have a question please:

Is the idea to have the front as low as possible without having the tyre contact the rad, head etc at full compression?

On tiny bikes like nc's, yes.

I didn't realise 090's have been discontinued. That sucks if you've still got an 18" rear.

I wouldn't have thought the tiny factor was a point.

Just had a look and with a 25 degree 20 min steering head angle the NC30 is somewhat of a chopper.

It appears that the concensus is to drop the front and raise the rear, to I assume steepen up the steering angle.

This will reduce the trail from 96mm which you wouldn't want to do too much of. Pity the forks weren't 20mm longer and you could raise both front and rear to get the weight to transfer a little more and keep a shed load of trail too.

Oh well.

[Cammo]

Just had a look and with a 25 degree 20 min steering head angle the NC30 is somewhat of a chopper.

True. It's preferable to raise the rear (longer shock, modified linkage etc) than drop the forks in the yokes (potential tyre clearance issues, less cornering clearance etc). I have a bit of both, but can only use a 120/60.

Raising the shock 10mm will give the nc30 geometry similar to most current sportsbikes. I prefer the quicker turn in and less stability with this setup, takes a lot less muscle to turn in.

[999Gomerz]

Just had a look and with a 25 degree 20 min steering head angle the NC30 is somewhat of a chopper.

True. It's preferable to raise the rear (longer shock, modified linkage etc) than drop the forks in the yokes (potential tyre clearance issues, less cornering clearance etc). I have a bit of both, but can only use a 120/60.

Raising the shock 10mm will give the nc30 geometry similar to most current sportsbikes. I prefer the quicker turn in and less stability with this setup, takes a lot less muscle to turn in.

Bugger, I like the Dunlop front. Will have to rip out the fork springs and see where the clearance isses are and see if a work around can be managed. Will advise results.

[Cammo]

Bugger, I like the Dunlop front. Will have to rip out the fork springs and see where the clearance isses are and see if a work around can be managed. Will advise results.

You can run a 120/70 no problems, but It WILL hit the v-piece (fairing in front of radiators) under heavy braking on a road bike with standard fork springs.

On a track bike with no v-piece and harder fork springs it won't hit anything if the forks aren't protruding too far above the top yoke.

[Guerrero]

I love the 120/70, with a 8mm drop on the front... I have stock farings and stock suspension so it was hitting the upper part of the v-piece. I cut it just enought to clear it and it was good to go after.