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General Category => Modifications => Topic started by: aj52 on November 22, 2018, 11:04:32 AM

Title: Fork inner tubes
Post by: aj52 on November 22, 2018, 11:04:32 AM
Hi guys

A friend of mine had an mishap with a pavement.
Since I have done a USD modification on my ABS, I have OEM forks available for him. He has a 1998 model.
The old inner tubes of mine are pitted.
What I want to know is, is the inner tubes interchangeable between the ABS and the CV models?
His tubes has no pitting.
I offered him the ABS front wheel, but won't fit, because on the right hand site, it needs to have a keeper "pin" for one of the wheel covers where the sensor fits.
I want to swap inner tubes between the 2 models so that he can use the ABS front wheel.

Hannes

Title: Re: Fork inner tubes
Post by: Pat Conlon on November 22, 2018, 12:05:25 PM
Hello Hannes, a quick check on the Yamaha parts shows that the '91-'93 FJ's have the same part # for the fork inner tubes (aka stanchion tubes)
https://www.partzilla.com/product/yamaha/3XW-23110-01-00?ref=b1808c6ef0f19bfb53765254b6c84b7810b3c0a2 (https://www.partzilla.com/product/yamaha/3XW-23110-01-00?ref=b1808c6ef0f19bfb53765254b6c84b7810b3c0a2)

The '84-'90 FJ's share the same tube:
https://www.partzilla.com/product/yamaha/3CV-23110-00-00?ref=3e055b382968a0580aa40f1d8bf45bfcb54b728c (https://www.partzilla.com/product/yamaha/3CV-23110-00-00?ref=3e055b382968a0580aa40f1d8bf45bfcb54b728c)

That said, I recall the difference in the fork caps but don't recall any difference on the lower side of the tubes.
Therefore, *I think* if you use the correct caps, the tubes should interchange.

I don't know if the fork caps interchange between the Gen 4 ('91-95) and the earlier Gen 1,2 and 3 FJ's
The early fork caps have a nice 3 step preload feature the later caps don't have.

Others will advise.

Pat

Title: Re: Fork inner tubes
Post by: racerrad8 on November 22, 2018, 01:25:48 PM
I'm working from memory and can research early next week.

But there are three different length fork tube for the models offered in the US.

I believe the 84-90 were shortest and the 93 ABS being the longest.

But since you are working on a 98, I am not sure if I will have any info on the fork tube length.

Randy - RPM


Title: Re: Fork inner tubes
Post by: aj52 on November 22, 2018, 03:57:21 PM
Quote from: racerrad8 on November 22, 2018, 01:25:48 PM
I'm working from memory and can research early next week.

But there are three different length fork tube for the models offered in the US.

I believe the 84-90 were shortest and the 93 ABS being the longest.

But since you are working on a 98, I am not sure if I will have any info on the fork tube length.

Randy - RPM


Sorry Randy

It is an 1988

Hannes
Title: Re: Fork inner tubes
Post by: racerrad8 on November 22, 2018, 06:09:48 PM
Quote from: aj52 on November 22, 2018, 03:57:21 PM
Quote from: racerrad8 on November 22, 2018, 01:25:48 PM
I'm working from memory and can research early next week.

But there are three different length fork tube for the models offered in the US.

I believe the 84-90 were shortest and the 93 ABS being the longest.

But since you are working on a 98, I am not sure if I will have any info on the fork tube length.

Randy - RPM


Sorry Randy

It is an 1988

Hannes


So what year are your forks?

I'll be able to get the length difference at something this weekend.

Randy - RPM
Title: Re: Fork inner tubes
Post by: aj52 on November 22, 2018, 06:38:27 PM
Quote from: racerrad8 on November 22, 2018, 06:09:48 PM
Quote from: aj52 on November 22, 2018, 03:57:21 PM
Quote from: racerrad8 on November 22, 2018, 01:25:48 PM
I'm working from memory and can research early next week.

But there are three different length fork tube for the models offered in the US.

I believe the 84-90 were shortest and the 93 ABS being the longest.

But since you are working on a 98, I am not sure if I will have any info on the fork tube length.

Randy - RPM


Sorry Randy

It is an 1988

Hannes


So what year are your forks?

I'll be able to get the length difference at something this weekend.

Randy -
Hi Randy

Mine is an 91ABS,my friends are an '88.
I want to use his inner tubes with mines outher tubes if it is possible.
The ABS right leg has an keeper pin to prevent the sensor' plate' from spinning.

Hannes
Title: Re: Fork inner tubes
Post by: aj52 on November 22, 2018, 06:46:07 PM
He wasted his front wheel on a pavement, it is bent behound  repair.
I offered him the ABS front wheel.
Only to realize when want to fit, that the right outer tube is not the same on non ABS.
I want to know if the inner tubes are interchangeably between the 91 ABS and 88 CV models.
What I seen was that with the disks there is a difference.
I don't want to wast my time trying to match it, if it is not possible

Hannes
Title: Re: Fork inner tubes
Post by: ZOA NOM on November 23, 2018, 09:25:34 AM
Quote from: racerrad8 on November 22, 2018, 01:25:48 PM

I believe the 84-90 were shortest and the 93 ABS being the longest.

Randy - RPM


They're the thickest too.  :hi:
Title: Re: Fork inner tubes
Post by: racerrad8 on November 26, 2018, 11:49:33 AM
Here are the fork tube lengths:

YAMAHA   FJ 1100   1984-1985   41x612
YAMAHA   FJ 1200   1986-1990   41x612
YAMAHA   FJ 1200   1991-1992   41x625
YAMAHA   FJ 1200 A   1991-1996   41x625
YAMAHA   FJ 1200 ABS   1992         41x629


As you can see the ABS are the longest at 629mm and the 84-90 the shortest at 612mm.

Quote from: aj52 on November 22, 2018, 06:46:07 PM
Only to realize when want to fit, that the right outer tube is not the same on non ABS.

Hannes

Hannes, what is different on the right lower fork leg that will not allow the fitment of the ABS wheel?

I am not aware of any difference between the non-ABS & ABS forks/wheel that will not allow them to interchange. The only difference I can see between any of the fork legs is the early model anti-dive and the later model forks.

Randy - RPM
Title: Re: Fork inner tubes
Post by: Paul.1478 on November 27, 2018, 06:23:43 AM
I just swapped my forks on my ABS with a 1990 set I got with RMP valves and springs.
there is a difference on the fork legs. On the left side there are 2 small tabs that hold the speedo cable from turning. On the ABS there is the same tabs on the right side to hold the ABS sensor.
Title: Re: Fork inner tubes
Post by: RPM - Robert on November 27, 2018, 10:31:54 AM
Quote from: Paul.1478 on November 27, 2018, 06:23:43 AM
I just swapped my forks on my ABS with a 1990 set I got with RMP valves and springs.
there is a difference on the fork legs. On the left side there are 2 small tabs that hold the speedo cable from turning. On the ABS there is the same tabs on the right side to hold the ABS sensor.

My 1991 also has the tab on the right fork leg but it does not interfere with the original spacer that is on the wheel (See picture). Other than the anti dive and the dampening adjustment the only other difference in the lower legs should be the brake caliper mount spacing. I just put a FZR wheel on the front and rear of my dad's ABS bike with no problems, I had to rob a spacer out of the bone yard in the back but other than that it is a direct bolt on. FZR wheel is a direct bolt on the the 89-+ non ABS models, and since I just put one on a ABS bike I don't see why there would be any problems, unless missing parts or incorrect parts (maybe wrong year)?
Title: Re: Fork inner tubes
Post by: aj52 on November 27, 2018, 10:48:53 AM
What I want to know is if the non abs inner tube will fit the ABS lower. Reason for that is, I sponsered an ABS wheel to a friend. Because of the piece where the sonsor fit, will rotate without the tabs on right lower leg.
With all of the ABS parts that goes with wheel, there will be no problems to fit it to a non ABS bike.
It is just that tab that is missing that will cause a problem.

Hannes
Title: Re: Fork inner tubes
Post by: RPM - Robert on November 27, 2018, 11:09:00 AM
Yes the tubes will fit. The non ABS fork tube is shorter than the ABS (see earlier response). Also the internals are different so you should not mix and match parts if possible. The earlier forks have preload and dampening adjusters; whereas, the ABS will only have preload.

If you are using the ABS wheel on earlier fork lowers you will have the problem of the sensor spinning as there is no key to hold it. Possibly remove the ABS disc and make or have someone make a spacer from the fork leg to the wheel bearing. However, I don't have an ABS wheel in front of me to see if it is possible.
Title: Re: Fork inner tubes
Post by: aj52 on November 27, 2018, 05:51:57 PM
Another difference between the two wheels are the disks.
The ABS disks has an larger inside diameter than non ABS.
The ABS rim nr are a 54,while non abs are 45 if I remember correctly.
Title: Re: Fork inner tubes
Post by: aj52 on November 27, 2018, 05:58:16 PM
The 2 different wheels
Title: Re: Fork inner tubes
Post by: RPM - Robert on November 27, 2018, 06:00:47 PM
Yes, the mounting point is different to accommodate the ABS sensor. However the OD is still 300mm and the spacing is correct for the forks. You will need ABS rotors to use the ABS wheel but the caliper mounting brackets are the same for all of the non anti dive FJ forks.
Title: Re: Fork inner tubes
Post by: aj52 on November 27, 2018, 06:07:49 PM
The wheel is complete with all the necessary parts and spacers.
Those measurements that Randy gave, is that for the inner tubes?

Hannes
Title: Re: Fork inner tubes
Post by: RPM - Robert on November 28, 2018, 10:21:47 AM
That is correct. Those are the length measurements by year for the fork tubes.