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Author Topic: Ton up SR250 - a cafe racer by the numbers: 100mph, 100kg, 30hp  (Read 45767 times)

Offline pidjones

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Re: Ton up SR250 - a cafe racer by the numbers: 100mph, 100kg, 30hp
« Reply #370 on: Aug 09, 2019, 08:00:51 »
A hint for loosening and removing that bottom bolt - do it vefore you remove the top plug and spring - the spring will help hold the inside from spining. And, use an air impact. I've had to fight those seals out of GoldWing lowers - even made a seal puller that reaches behind them, but still ended up getting them real hot with a propane torch to get them to let go.
"Love 'em all.... Let God sort 'em out!"

Offline JadusMotorcycleParts

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Re: Ton up SR250 - a cafe racer by the numbers: 100mph, 100kg, 30hp
« Reply #371 on: Aug 09, 2019, 09:06:11 »
Thanks for the tip pid, but I tried that!  I am yet to encounter a fork that you can undo that bolt without holding the damper rod in some positive way.  Maybe I just work on f*cked bikes  ;D  I went to extreme lengths to open up some SR250 Classic forks, absolute nightmare haha

Online goldy

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Re: Ton up SR250 - a cafe racer by the numbers: 100mph, 100kg, 30hp
« Reply #372 on: Aug 09, 2019, 09:13:44 »
An electric impact driver works extremely well...spins that stubborn little bolt right out in a matter of seconds. Probably the best Christmas gift I've had in a long time; in the past 10 years I only had one set of forks where I had to hold the damper.
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Offline pidjones

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Re: Ton up SR250 - a cafe racer by the numbers: 100mph, 100kg, 30hp
« Reply #373 on: Aug 09, 2019, 14:07:01 »
I've learned to pull that bolt before even loosening the tripple clamps. Drain first, though (unless you like stink oil baths).
"Love 'em all.... Let God sort 'em out!"

Offline teazer

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Re: Ton up SR250 - a cafe racer by the numbers: 100mph, 100kg, 30hp
« Reply #374 on: Aug 09, 2019, 14:57:15 »
You are all right.  If possible, loosen that lower damper rod bolt while the top cap is still in place and the spring is pressing down on the damper rod.

If the bolt turn turns and will not loosen, try an impact driver - or if you don't have one, smack teh wrench with a large mallet and sometimes that will crack it free.

If/when that still doesn't come loose, or the forks were partially dismantled already, that's when you need to use a tool to hold the damper rod still.  Some forks need a special tool to match the odd damper rod top, but most work with a bolt.  I use a length of steel tube with a Tee handle on top 0 drill a hole through the tube and use a screwdriver or weld a cross tube in place.  Then weld a suitable hex nut to the bottom of teh tube to lock the damper rod. 

I had to make one the other day for a buddy who had partly stripped his GS1000E forks and it took all of about 15 minutes to make.  But I was lucky that I had a spare set of dismantled identical forks to measure what size nut I needed.

Other time you have get away with a long extension and a couple of nuts on a bolt in the socket.

I have even seen a broom handle whittled down at the end and rammed into the top of the damper rod.

Offline pidjones

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Re: Ton up SR250 - a cafe racer by the numbers: 100mph, 100kg, 30hp
« Reply #375 on: Aug 09, 2019, 16:00:12 »
I've heard of the broom handle trick, too. Hope I never need it, but it's an option.
"Love 'em all.... Let God sort 'em out!"

Offline crazypj

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Re: Ton up SR250 - a cafe racer by the numbers: 100mph, 100kg, 30hp
« Reply #376 on: Aug 10, 2019, 16:09:41 »
I've used broom handle, still connected to shop broom. Had one of the boys hold fork slider down as tight as her could then used 'burp' gun on it. Always a good idea to smack the Allen down, if only to make sure it's fully seated
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Offline JadusMotorcycleParts

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Re: Ton up SR250 - a cafe racer by the numbers: 100mph, 100kg, 30hp
« Reply #377 on: Aug 16, 2019, 07:52:10 »
Haha, yepp, tried the broom stick trick and a few other home made tools!  Mostly because the stupid design of the SR250 Classic forks rip the top of the damper rod and they used an insane amount of Loctite on the form bolt upon install at the factory.

I did a blog post about that nightmare process here:  https://www.jadusmotorcycleparts.com/single-post/2017/08/17/SR250-Classic-Fork-RebuildSeal-Replacement

Offline JadusMotorcycleParts

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Re: Ton up SR250 - a cafe racer by the numbers: 100mph, 100kg, 30hp
« Reply #378 on: Aug 16, 2019, 08:22:55 »
As mentioned much earlier in this thread while planning the rebuild of the forks I thought I would try something mentioned in the Minton mods...  To use a looser fitting fork seal to reduce fork stiction.

The only option for the SR was this seal I found for a 33mm stanchion (as apposed the SR's 32mm) which has the correct outer dimension (44mm) but is a little shorter.  But they are press fit so I think the height difference (9mm as opposed to 10.5mm) will not be a problem. 

I am not 100% sure the seal will be enough to contain oil in the fork but there is certainly (obviously) much less stiction and the seal still engages a decent amount.

I am also tossing up not installing the fork seals - because even they contribute a lot to stiction.  Still undecided here! 

Offline Sav0r

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Re: Ton up SR250 - a cafe racer by the numbers: 100mph, 100kg, 30hp
« Reply #379 on: Aug 16, 2019, 16:32:34 »
All those tools of destruction scare me.

On a light bike really low friction suspension is imperative. Not sure about going seal-less, but fork oil is cheap so it might be worth a shot.
Sav0r the adventure.

Visit www.chrislivengood.net to get more information on my RD350 dubbed Mia Wallace as well as my other projects and snafus.

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