ST1100 Fork Differences?

Joined
Nov 16, 2013
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ST1100Y and ST1300-2
OK I have a 1994 non abs bike.
I was struggling with a handling issue so from ebay I purchased what was advertised as pair of 1994 non abs fork legs.
I had them professionally serviced new seals etc, Newish springs and a re paint.
When I fitted them on the bike they are totally different.
The fork tube width is the same, and they fit in the top and bottom yoke ( triple tree ) ok, but the fittings in the fork leg bottom for the mudguard were a smaller diameter, so I had to change the mudguard bracket and bolts, then the new bracket didn't fit the old mudguard ( drilled hole in plastic was bigger than the mudguard bracket fastenings ) so bought a new mudguard.

and when I put the wheel in, ( Mine is a 3" width ), there was an obvious gap between the wheel and the forks. Even swapping the off side brake calliper brackets I couldn't get the brake discs in line with the brake callipers.

What have I re furbished ?
Could I fit a 3.5" front wheel in and solve all my problems?
or would that worsen the already worrying handling issues ?
 
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Joined
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Re: Fork Differences?

Just a guess, but I suspect what you bought were '94 ABS model forks, since the brakes seem to be the problem. Not much help, but, if so, you would be better to go back to square one with the correct forks.
 
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Re: Fork Differences?

I have two st1100's a 1991 and a 2000 in the garage, both non-ABS. From the outward physical appearance they are identical. The are easily swapped between the two bikes.
 
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Tommo
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Re: Fork Differences?

Thanks for your response. It must be that they are for an ABS, I had assumed the gap for the bigger wheel was provided by a slightly different sized steering stem ( triple street ) and top. Didn't realise it was the fork bottoms. :mad:
 
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8470
Re: Fork Differences?

I would measure the fork tubes with a caliper. Your originals should be 41 mm in diameter. You may have a set of 43 mm fork tubes off a 96-99 ABS model. I bet with only 2 mm difference, you could get them to slip into your triple tree, but that would cause the mis-alignment, maybe .......
The 92-95 ABS are 41 mm in diameter. These diameters are according to the info. on the RaceTech website.
 

Uncle Phil

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Re: Fork Differences?

ABSI forks (Pre 96) are the same size as the standard - 41mm. ABSII forks are 43mm and the caliper mountings are totally different. Also the anti-dive is on the right fork for ABSII and the left fork for standard. All years rims will fit on all years forks (have done that to verify), but the ABSII discs are smaller than the standard/ABSI discs. If the caliper mounts and fender mounts are different, you probably have a set of ABSII forks - which require a totally different front fender from the standard fender. I currently run a ABSII rim on the front of my 97 standard with the standard discs and the original forks and it all bolts up fine.
 
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Re: Fork Differences?

ABSII forks won't fit the
standard bike triple trees, they are fatter. Possible your "new" forks are not off an ST?
 
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Tommo
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Re: Fork Differences?

Had a vernier caliper on the fork leg tubes and all sets are 41mm, so I can rule out ABSII 1996 onwards. It could be an ABSI 92-95 is there an easy way to work it out? The only markings I can see are MT3-R ( right leg) MT3-L ( Left leg ) with SA-1 below and both stamped 14 on the bottom of the lower forks.

Looking around the net, there are loads of variations ABSI/II 41mm/43mm fork tubes and even differing fork tube lengths 633mm and 614mm.
Does anyone know of a site that lists the various changes in Fork Specs and Wheel dimensions?

Edit: Should think in reverse. I've looked at the parts fiche for my St1100PP and the spring is 51401-MY3-781, which when I look to buy new, tells me its off ST1100A. So its me that's got it wrong, I should have bought a 1993 ABS fork leg.

Still does anyone know where it lists the specs for each development of ST1100?
 
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soCal
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687
Re: Fork Differences?

The service manual shows the front fork/wheel removal with std/ABSI on one page, ABSII on another page. The parts microfiche shows the std and ABSI forks for a 1994 as looking similar, but the parts numbers are not the same. I'd get the part numbers off of a Honda microfiche online and do a web search and see if you can get any more info on dimensions, or I'd try to call a Honda tech and see if they can give you any answers.
 
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Tommo
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ST1100Y and ST1300-2
Re: Fork Differences?

I do appreciate all answers so thank you for taking the time to think about it and respond.

I now realise I have OCD and have become a ST1100 Klemtomaniac. I only have one engine and one frame but own all sorts of wheels / forks, brake callipers,calliper brackets and more. Trawling through old threads and manuals I sort of have this ( below ), any thoughts ?
It needs a knowledgeable eye to review it. I also now know the right brake calliper and bracket changed through the years as there are at least two ( the 2 potted variety ) of each. "Yes I have bought some".


Fork tube diameter

Fork tube length 633mm or 614mm / hex cap

Spring length / width



Front Wheel Width

Front Wheel bearing size

Right brake calliper

Right brake calliper bracket

Rear Wheel
width diameter change when? bearings

Non ABS
1991-1996

41mm

??mm / 17mm fork cap hex key

415.6mm / 35mm



3” 18” 110/80

42mm

Careful there are differences

Careful there are differences

??” 17” 47mm

Non ABS
1997-2002

41mm

??mm / 17mm fork cap hex key


??mm


3” 18”

47mm

Careful there are differences

Careful there are differences

??” 17” 47mm

ABSI
1992-1995

41mm

??mm / 17mm fork cap hex key

474.2mm / 35mm



??” 18”

42mm

Careful there are differences

Careful there are differences

??” 17” 47mm

ABSII
1996-1999

43mm

??mm / 24mm fork cap


??mm


3.5” 18”

47mm

Careful there are differences

Careful there are differences

??” 17” 47mm

My
Police Non ABS PP 1994

41mm / inner takes a 34.2mm spring only



??mm / 17mm fork cap hex key

Fitted with ABSI spring
475mm /34.2mm



3” 18” 110/80

42mm

Careful there are differences

Abs with a ring

??” 17” 47mm

Police Non ABS PY



41mm

633mm / 17mm fork cap hex key

415.6mm / 35mm



??” 18”

??mm

Careful there are differences

Careful there are differences

??” 17” 47mm

TCS/LBS/
ABSII 1996-2002

43mm

??mm / 24mm fork cap

483.1mm



3.5” 18”
120/70

47mm

Careful there are differences

Careful there are differences

??” 17” 47mm




















 
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ST1100Y

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Re: Fork Differences?

I now realise I have OCD and have become a ST1100 Klemtomaniac.
So, why can I relate to this... ;-)

Any chance that the forks obtained at eBay were fitted with some after-market fork tubes, possible not designed for the ST1100?

I've 3 sets of OEM fork springs for the non-ABS model here, all are 35mm OD...

So out of interest:
'92 ABS-I/TCS, spring, fork: 2x 51401-MY3-781 (L & R)
'92 non ABS, spring, fork: 2x 51401-MT3-003 (L & R)
'95 non ABS, P-spec: spring, fork: 2x 51401-MY3-781 (L & R)
 
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Tommo
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Wigan, Lancashire
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ST1100Y and ST1300-2
Re: Fork Differences?

I have been checking and if you have a 1993 or 1995 ( police ) spec bike made by Honda, you will have ABSI forks fitted with non ABS brakes.
Having checked Part Fiche they both use the ABSI fork springs - 51401-my3-781 springs.

Now here is the funny.....

If you've read the above you know my 1993pp had pipes that are 41mm external diameter but won't take the 35mm springs, because the inside is slightly narrower. Well I got a set of fork legs for a 1995 police spec bike, and guess what. Exactly the same springs and forks as mine. The ABSI used on the police spec bikes ( it could be all ABSI's ) has a thicker metal wall, and the spring is slightly narrower to fit in.

Watch out if buying off ebay, you could end up like me with 3 sets of fork legs, and 4 sets of springs !!
 

ST1100Y

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Re: Fork Differences?

The ABSI used on the police spec bikes ( it could be all ABSI's ) has a thicker metal wall, and the spring is slightly narrower to fit in.
Does make kinda sense though...
The P-spec bikes also have a different rear spring installed; figuring they might see more abuse during duty, Honda seems seeing a need to "beef up" the suspension on squad bikes...
 
Joined
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ST1100AN
Re: Fork Differences?

Did I get this right, ABS II forks (43 mm) are completely different than ABS I and std forks (41 mm). But are standard and ABS I forks similar?
 
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Re: Fork Differences?

Did I get this right, ABS II forks (43 mm) are completely different than ABS I and std forks (41 mm). But are standard and ABS I forks similar?
...and the most imprtant part, are the slide tubes similar in ABS I and standard versions? I crashed with a car and now I have to replace bent slide tubes. It is cheaper to buy a complete fork, used of course, than two slide tubes. But looks that ABS I parts are rare to find as used.
 

Uncle Phil

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Yes, ABSII forks are 43mm, standard and ABSI are 41mm. The forks are constructed differently between the ABSII and the others - different mounts for the calipers and the damping rod/anti-dive is in the right fork for ABSII, left fork for the standard (and the ABSI I presume).
 
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Yes, ABSII forks are 43mm, standard and ABSI are 41mm. The forks are constructed differently between the ABSII and the others - different mounts for the calipers and the damping rod/anti-dive is in the right fork for ABSII, left fork for the standard (and the ABSI I presume).
Yes, true, but I'm still thinking about installing pre-96 standard fork legs to an ABS I. Would that work...?
 
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If I remember this right I have calipers originally from standard model. I changed only right caliper mounting bracket because of ABS sensor. Anyway, that won't help, mountings could still be different. I have to wait till I can take some measurements from a standard model.
 
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