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General Category => Modifications => Topic started by: grannyknot on November 04, 2011, 10:39:52 AM

Title: 17" front wheel
Post by: grannyknot on November 04, 2011, 10:39:52 AM
Is there any reason I can't put a 17" front wheel on  stock 84 forks? At the moment I have the the stock 16" wheel on it and there is a little more than 1" between the top of the tire and the bottom of the mud guard.
A 17" wheel and tire would only take 1/2-3/4" of that room.
I would probably have to come up with an adapter for the brake calipers to match up with the the new rotors though.
Title: Re: 17" front wheel
Post by: SlowOldGuy on November 04, 2011, 12:57:16 PM
The lower profile of the 120/70-17 makes it practically identical in overall diameter to the stock 160/80-16 tire.  The problem is your old brake rotors will NOT fit on a newer 17" wheel and the new rotors on a 17" wheel are a larger diameter and with not fit with your stock calipers.

You will need the lower fork sliders off of an 88+ FJ, axle, calipers, and rotors.  Look up additional details on this stie.  It's an easy mod and well worth the effort/cost.

DavidR.
Title: Re: 17" front wheel
Post by: grannyknot on November 04, 2011, 05:07:30 PM
David, I found that "Easy fork & front wheel upgrade" file and have been scouring ebay, craiglist and local wreckers for those parts without much luck. There is one set of forks on ebay at the moment but they want top dollar for them and nothing extra comes with them, I will keep looking.

Is it the lower profile of the 120/70-17 tire that makes the huge difference in handling on this conversion?
Title: Re: 17" front wheel
Post by: Pat Conlon on November 04, 2011, 06:34:37 PM
Hey Chris, it's a combination of factors which improve the front end stability.
1) Lower sidewall height of a 70 series vs oem 80 series tire
2) Radial tire construction vs. bias ply construction. Lighter tire carcass with less heat buildup and less tread deformation with lateral loads.
3) A lighter rim, lighter rotors, lighter tire = considerably less unsprung weight. The narrow oem 16" rims and double vented rotors are pig heavy.

Keep a eye out for the '87/'88 FZR front rim which is 3.5" wide and still uses the 15mm dia. front axle. The '89+ FZR used a larger 17mm dia. axle, no good.

If you do this wheel mod along with the '89+ lower sliders with cartridge emulators and springs, you now have the ability to add in the R-1 brake caliper upgrade, which is the cat's meeeow.

Cheers
Title: Re: 17" front wheel
Post by: fj11.5 on November 05, 2011, 02:00:59 AM
+50 on the r1 calipers,
Title: Re: 17" front wheel
Post by: Alf on November 06, 2011, 04:11:05 AM
Apart for better tyre choice, I can´t see any reason to change to the 17" rim: I ride habitually my friend Mingo´s 87 1200 and in thigh curves is really exceptional, with no vices on fast roads. The OE callipers combined with Fazer master and metallic hoses are near as good like my R1 callipers
He is limited at Avon Azaro ST radial tyres, but these are very good
Title: Re: 17" front wheel
Post by: SlowOldGuy on November 06, 2011, 04:22:25 PM
Wow, differences in perception is funny. With the 16" front on my '85, I had to really countersteer to hold it down in a lean. If I touched the brakes, it wanted to stand right up and run wide.

I didnt know how bad it was until I got my '93.  That bike would float thru the curves with no drama at all.  It was so much better that I parked my '85 because it just wasn't fun. 

Since the only difference between them was the front wheel size, I decided to try a 17" on the '85.  Still the amazing transformation in handling I've ever experienced.

What say you, ChrisP?

DavidR.
Title: Re: 17" front wheel
Post by: Pat Conlon on November 06, 2011, 11:00:12 PM
The lighter 17" front end is really noticeable in side to side transitions.

Alf, I'm sorry but there is no comparison between the oem brakes and the R-1's.
Title: Re: 17" front wheel
Post by: 1tinindian on November 06, 2011, 11:24:48 PM
Quote from: Pat Conlon on November 06, 2011, 11:00:12 PM
The lighter 17" front end is really noticeable in side to side transitions.

Alf, I'm sorry but there is no comparison between the oem brakes and the R-1's.

I'll second that.

All anyone would have to do, is go back and read about how much I hated my stock front brakes on my 91.
It took some time, but the good folks here finally got through to me that the newer calipers were the way to better braking, and boy were they right.
If I were ever to buy another FJ, the R1/R6 calipers would be first on my list to swap.

Leon
Title: Re: 17" front wheel
Post by: Alf on November 07, 2011, 02:28:00 AM
Pat
Really, with Fazer master cylinder, good lines and OE pads the OE 84-87 callipers and discs are excellent!!!!, not the post 88, Leon. These are SH**
And I insist: not only my friend Mingo´s FJ with 16" go fantastic. Mi ex-FJ 1100 was amazing. When I trade it for a new FJ 1200 I was never completely happy with the 17" front. There were no way to brake and entry into thigh curves and near impossible to change fast from side to side. Only with the new dogbones and raising the front legs I´ve got a similar feeling to my ex-FJ 1100 and my friend´s FJ and it is possible again braking hard and with the brake applied take the bike to the side in a smooth transition, and go side to side with only a hint of gas and sweet imput from my feet pushing the peg