Jump to content
IGNORED

120/60-R17 Front Tire


Selden

Recommended Posts

Based on many positive industry reviews, I decided to try a new Pirelli Angel GT on my 1999 R1100RT. Unfortunately, I wasn't paying attention when I ordered from Amazon, and didn't discover until after it shipped that I had ordered a 120/60-R17 instead of the recommended 120/70-R17.

 

I read a bunch of size comparison articles, decided there would be no harm with the lower profile, which might lower the seat a smidge — always an important consideration for someone with a 29" inseam. The 120/60-R17 measures ~10 mm smaller in diameter than the old (very worn) Michelin PR3, which translates at most to ~2-3mm difference in height at the front of the seat, which is barely noticeable, but it's definitely slightly easier to get both feet on the ground. The bike stands up very slightly more on the sidestand, with no noticeable difference in hoisting it on to the center stand. The main difference will probably be that it makes an already optimistic speedometer even more so, but that could help reduce the risk of speeding tickets. If you are inseam-challenged, it might be worth looking into a lower profile front tire.

 

The Amazing Randy mounted the new tire yesterday, and I went out for a ride today. Like any new tire, it turns in far easier than the worn tire it replaces. Other than that, it's far too soon to tell anything about handling. I hope that when it gets some miles on, it won't start howling the way all my PR3s did.

Edited by Selden
Link to comment

The smaller diameter will also effectively decrease rake and trail slightly which would tend to make the steering slightly more responsive. And to the degree that it does this on a R1100RT that is a good thing as I always felt the steering on my R1100RT was too slow requiring a lot of input force to get the bike to be flickable. When you get the tire scrubbed in and some miles come on back and share if it did make your RT more flickable...inquiring minds want to know :java:

Link to comment
LittleBriar

I would expect you couldn't do this on a newer bike with ABS, traction control due to the difference is wheel speed?

Link to comment
I would expect you couldn't do this on a newer bike with ABS, traction control due to the difference is wheel speed?

 

Afternoon LittleBriar

 

I would be very surprised if a 120/60-R17 vs a 120/70-R17 made either the ABS or the traction control default.

 

The usual difference between the two tire sizes is around 20mm difference in diameter (Selden says he only has 10mm?).

 

That is only around a 4% difference & probably well within the variation window built into the ABS & traction control systems to account for tire pressure, tire manufacturing differences, as well as cornering (tire lean) diameter changes.

 

 

 

Link to comment

I was comparing diameter of a totally shagged PR3 with a brand new Angel GT, so 15-20mm is probably about right when comparing two new tires. Different brands of the same nominal size may not measure the exactly the same.

Link to comment
Very easy to ding the front wheel with a 60 series tire. DAMHIK

 

Frank

 

Good point as I had to replace my rim after a hard square edge hit with the stock 70 series Metzler. So I maybe more prudence on speed when the road is really bad..

 

Not sure that Seldon would see the journey to the center of the earth deep potholes like we get in freeze/thaw country through!

Link to comment
Very easy to ding the front wheel with a 60 series tire. DAMHIK

 

Frank

 

Good point as I had to replace my rim after a hard square edge hit with the stock 70 series Metzler. So I maybe more prudence on speed when the road is really bad..

 

Not sure that Seldon would see the journey to the center of the earth deep potholes like we get in freeze/thaw country through!

 

 

Paul de, we have our own reasons for potholes down here in the Sunny South. Meteor Crater is one of our medium-size potholes. You may have heard of it.

Edited by Lowndes
Link to comment
I would expect you couldn't do this on a newer bike with ABS, traction control due to the difference is wheel speed?

 

Afternoon LittleBriar

 

I would be very surprised if a 120/60-R17 vs a 120/70-R17 made either the ABS or the traction control default.

 

The usual difference between the two tire sizes is around 20mm difference in diameter (Selden says he only has 10mm?).

 

That is only around a 4% difference & probably well within the variation window built into the ABS & traction control systems to account for tire pressure, tire manufacturing differences, as well as cornering (tire lean) diameter changes.

 

 

 

 

I think he meant 20mm diameter difference would only lower the bike 10mm.

 

It should change the handling a bit.

 

I have no idea how it would affect the ABS.

 

Link to comment
I would expect you couldn't do this on a newer bike with ABS, traction control due to the difference is wheel speed?

 

Afternoon LittleBriar

 

I would be very surprised if a 120/60-R17 vs a 120/70-R17 made either the ABS or the traction control default.

 

The usual difference between the two tire sizes is around 20mm difference in diameter (Selden says he only has 10mm?).

 

That is only around a 4% difference & probably well within the variation window built into the ABS & traction control systems to account for tire pressure, tire manufacturing differences, as well as cornering (tire lean) diameter changes.

 

 

 

 

I think he meant 20mm diameter difference would only lower the bike 10mm.

 

It should change the handling a bit.

 

I have no idea how it would affect the ABS.

 

 

Morning Whip

 

It wasn't stated that way & in fact was a measurement not a lowering statement ( The 120/60-R17 measures ~10 mm smaller in diameter than the old (very worn) Michelin PR3.

 

Selden did post later that it was comparing a worn tire to a new tire.

 

Link to comment

Here is a 300-mile update, more on the Pirelli than on the tire size. It's a tire. Compared to some new tires I have used, it doesn't fall in to a turn; very neutral. Other than that, I can't tell the difference from any other front tire I have used on the RT. I will probably put another Angel GT on the rear wheel @~130,000 miles, which is coming up fast, as we're trying to do a lot of 2-up riding this month to get ready for a big trip.

Link to comment

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...