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1Back to top Go down   41mm Showa forks in 41.3mm yokes Empty 41mm Showa forks in 41.3mm yokes Sun Jan 08, 2017 9:37 am

Snod Blatter

Snod Blatter
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Life time member
Hi all, the "S" Brembo forks on my '89 SE are, well, let's be kind and say they're simply beyond help. They leak so much that the oil seeps out the bottom of the gaiters and wets the top half of the legs..

I've lusted after some K75 Showa forks for a while and am pleased to see there's a pair on ebay and that they even have the fork brace mounts so they should be a simple drop-in replacement, though I don't know if that extra ABS sensor bracket will get in the way. Or if I can use it, perhaps? Anyway, the big problem people talk about is that the Showa stanchions are slightly smaller in diameter - has anyone clamped them up with the older yokes successfully?

I'm not too concerned if it's a big no-no and the later yokes are absolutely required as the steering head bearings are a bit notchy so I could possibly replace the whole lot but I'd rather just drop the forks in and carry on, at least for now.

Oh and if someone has a pair of Showas and would take less money, do let me know Cool


__________________________________________________
1989 K100RS SE ABS 8v  VIN: 0149214
Others: 1.5 x CBX250RS-E, '94 CB250, '95 TRX850, '16 Z250SL, '01 R1100GS
http://justbikethings.blogspot.co.uk/
    

2Back to top Go down   41mm Showa forks in 41.3mm yokes Empty Re: 41mm Showa forks in 41.3mm yokes Sun Jan 08, 2017 10:22 am

Rick G

Rick G
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They are K100 16V 0r K1100 and will be 41.7mm


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1999 K1100 LT with a Big Block 1200
    

3Back to top Go down   41mm Showa forks in 41.3mm yokes Empty Re: 41mm Showa forks in 41.3mm yokes Sun Jan 08, 2017 10:23 am

BobT

BobT
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Would it not be much better and cheaper to just change the fork seals? Most of them last a short while apart from the ones that you buy from BMW. A few have found that they are the only ones that last.

    

4Back to top Go down   41mm Showa forks in 41.3mm yokes Empty Re: 41mm Showa forks in 41.3mm yokes Sun Jan 08, 2017 10:37 am

Snod Blatter

Snod Blatter
Life time member
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RicK G wrote:They are K100 16V 0r K1100 and will be 41.7mm
Ah, haha. Thanks!

BobT - it's beyond seals. The stanchions have huge scores in the area of travel and the inside of the leg will be just as bad. It has been this way since I bought it, and the lack of oil means the front is really quite soggy. I wonder if it also contributes to the head shake I can get on worn tyres when coasting on overrun between 60 and 50mph.


__________________________________________________
1989 K100RS SE ABS 8v  VIN: 0149214
Others: 1.5 x CBX250RS-E, '94 CB250, '95 TRX850, '16 Z250SL, '01 R1100GS
http://justbikethings.blogspot.co.uk/
    

5Back to top Go down   41mm Showa forks in 41.3mm yokes Empty Re: 41mm Showa forks in 41.3mm yokes Sun Jan 08, 2017 10:45 am

Born Again Eccentric

Born Again Eccentric
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Snod Blatter wrote:
... and the lack of oil means the front is really quite soggy. I wonder if it also contributes to the head shake I can get on worn tyres when coasting on overrun between 60 and 50mph.
The head shake is more likely to be due to your worn head bearings - but soggy forks won't improve the situation and will affect cornering stability - especially if there are different levels of oil left in each fork!


__________________________________________________
41mm Showa forks in 41.3mm yokes Uk-log10 41mm Showa forks in 41.3mm yokes Sco-lo15
                              Paul  41mm Showa forks in 41.3mm yokes 905546712

"Heidi" K100LT 1991 (Grey) (VIN 0190172 Engine No. 104EB 2590 2213) - 5th owner. January 2014 (34,000 - 82,818 miles and counting....)
"Gretel" K100LT 1989 (Silver Grey) (VIN 0177324 Engine No. 104EA 2789 2211) - 4th+ owner. September 2015 (82,684 miles and counting....). Cat C Insurance write-off rebuild Feb 17
"Donor" K100LT 1990 (Red)  (VIN 0178091 Engine gone to Dai) - 6th & final owner (crash write-off now donor bike).   June 2012 (73,000 miles) to November 2013 (89,500 miles)
    

6Back to top Go down   41mm Showa forks in 41.3mm yokes Empty Re: 41mm Showa forks in 41.3mm yokes Sun Jan 08, 2017 10:56 am

Snod Blatter

Snod Blatter
Life time member
Life time member
Ha, I have no idea how much oil is in each one. All I know is the oil level is low enough that they've stopped leaking Laughing 

It's just a little centre notch, very pronounced with the forks and wheel removed but hard to find if all the weight is bolted on. No MOT tester has mentioned it yet. Is the chassis really so marginal? As an aside, if anyone else has head shakes like this then fit a Michelin Pilot Activ to the front - I've not had a shake since. Marvellous.


__________________________________________________
1989 K100RS SE ABS 8v  VIN: 0149214
Others: 1.5 x CBX250RS-E, '94 CB250, '95 TRX850, '16 Z250SL, '01 R1100GS
http://justbikethings.blogspot.co.uk/
    

7Back to top Go down   41mm Showa forks in 41.3mm yokes Empty Re: 41mm Showa forks in 41.3mm yokes Sun Jan 08, 2017 11:30 am

BobT

BobT
Life time member
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My 16v has a steering damper as standard, but I would not change a tyre to control a head shake when the steering bearings are shot, I would change them first.

    

8Back to top Go down   41mm Showa forks in 41.3mm yokes Empty Re: 41mm Showa forks in 41.3mm yokes Sun Jan 08, 2017 7:11 pm

Rick G

Rick G
admin
admin
If you can feel the notch then it's time to renew the bearings.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1999 K1100 LT with a Big Block 1200
    

9Back to top Go down   41mm Showa forks in 41.3mm yokes Empty 41 mm Showa forks in 41.3 mm yokes Wed Jan 11, 2017 3:51 am

audibob

audibob
Life time member
Life time member
Like you Snod, 

my last two Mot testers failed to notice a very slight notch on my head bearings with the bars centralised.

I do not get any shake on the bars, buy I do get a feel that the front is not as tight as it should be, whether this is how the bike is, or the bearings need changing sooner rather than later.

My head bearings are next on my list anyway.

I would like some fancy forks and twin pot brembos , but money needs spending elsewhere and I do not ride that fast around the bends to justify it.

The K1100 throttle bodies I have , ( yet to be fitted ) plus a timing tweak will give me a bit more occasional grunt without having to spend more money on the steering department..

Bob


__________________________________________________
Yamaha 90
Honda CD 175
Honda CB 360 
Triumph T 140V Bonneville
Triumph T150 Trident
Honda CB750 F1
Cz 175
Yamaha XS 750
R 100/7
R 80
K100 LT
K100 LT current bike
    

10Back to top Go down   41mm Showa forks in 41.3mm yokes Empty Re: 41mm Showa forks in 41.3mm yokes Mon May 28, 2018 7:15 pm

Snod Blatter

Snod Blatter
Life time member
Life time member
Finally I can answer this question - 41.3mm yokes will indeed grip 41mm forks, here's the proof:
41mm Showa forks in 41.3mm yokes HE0VVvn
You have to tighten the poor yoke pinch bolts up quite a lot (probably getting on for spec!) but they will do it. The Showas are a whole new world, the front is sagged by probably 10cm less (feels like it's several feet higher..) and compared to my old S forks (which I think have the wrong springs fitted, plus not a lot of oil) they are really quite taut and firm. A little crashy perhaps when the going gets harsh but they are exactly as you would expect a basic damper rod design from Showa to be, not terrible but not the greatest. I rate them over the leaky Sachs design though.

One thing to note is make sure the ABS sensor is not rubbing on the ring, mine made a noise.. Thankfully it still seems to work! I just undid the caliper bolts, shoved the caliper away from the wheel and tightened it all back up but it's something to be aware of - I don't ever remember having the bits touch with the old forks no matter how I put it back together.

Oh, and the head bearings are still notched Laughing


__________________________________________________
1989 K100RS SE ABS 8v  VIN: 0149214
Others: 1.5 x CBX250RS-E, '94 CB250, '95 TRX850, '16 Z250SL, '01 R1100GS
http://justbikethings.blogspot.co.uk/
    

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