another Hyperpro fork spring question..

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fatfreddy000
Posts: 186
Joined: Thu May 04, 2017 7:02 pm

another Hyperpro fork spring question..

Post by fatfreddy000 »

After being away in scotland for a month i got back to working on the storm again yesterday- so good to be back improving even though i arrived to both a flat front tyre and battery.
yesterday the 2nd hand Renntec rack went on (without any need for a bracket?)
the battery was charged and is just about holding but a new leoch 20ah is on its way now.
head bearing got cleaned, greased and readjusted- nasty clicking is gone and steering is a little smoother (lock washer hadn't been done up properly at some point prior to my ownership)
fork preload got maxed out and some improvement with bottoming out on speed bumps etc but still thuds if i brake hard or land after popping the front wheel.
due to having to wind in the spending on her i am not now getting them 'Rodgered' but will go with a hyperpro progressive spring and 7.5w oil kit.

I have questioned hyperpro and calsport stockists and they have both assured me that the orientation of their progressive springs is tight coil at the top (unless otherwise specified in kit instructions) and that the air gap should be 160mm (not the 140mm i thought it was)
so what gap do i go with?- I'm assuming less air gap will mean less compression potential and more damping?


the list of jobs still hasn't got any shorter with around 30 things ticked off now..
for everything i fix on her currently it seems i discover 2 other areas that are dodgy or have been bodged.
still, lucky i like the tinkering and the improvements are becoming obvious when i ride her..
“If all insects on Earth disappeared, within 50 years all life on Earth would end. If all human beings disappeared from the Earth, within 50 years all forms of life would flourish.” Biologist Jonas Salk
tony.mon
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Joined: Wed Jul 25, 2007 10:46 pm
Location: Norf Kent

Re: another Hyperpro fork spring question..

Post by tony.mon »

Tight coils top is right.
I played for a fortnight experimenting with different weight oils and air gaps and found best results with 140mm and 7.5 weight.
You could try 160 and thicker oil, say 10, and see if it worked for you but trying air gaps in10mm increments using 7.5 oil, 140 was definitely best for me using 100 steps.

135 was slightly better after refining with 5mm gaps.

But that's my riding style and usage, I weigh14 stone, adjust as necessary.

Suggest you try 140 and 7.5 oil and refine if needed.
It's not falling off, it's an upgrade opportunity.
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popkat
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Re: another Hyperpro fork spring question..

Post by popkat »

Oil level will effect the last 3rd of the fork travel, 160mm could possibly have the forks bottoming out, 140mm is regarded as the norm and works, I have this oil level on my storm.

Oil weight will effect compression and rebound damping, the forks can take 10wt but wouldn't go any heavier as the oil will not go easily through the shims. I have 10wt in mine.

Why are you going with progressive springs ? standard are progressive, I tried some aftermarket progressive springs in a storm years ago and found them to be a little firmer but the forks were still not good. Linear springs on these bikes give a nice compliant ride, are easier to set up, there's no downside really.


.
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fatfreddy000
Posts: 186
Joined: Thu May 04, 2017 7:02 pm

Re: another Hyperpro fork spring question..

Post by fatfreddy000 »

popkat wrote:Oil level will effect the last 3rd of the fork travel, 160mm could possibly have the forks bottoming out, 140mm is regarded as the norm and works, I have this oil level on my storm.

Oil weight will effect compression and rebound damping, the forks can take 10wt but wouldn't go any heavier as the oil will not go easily through the shims. I have 10wt in mine.

Why are you going with progressive springs ? standard are progressive, I tried some aftermarket progressive springs in a storm years ago and found them to be a little firmer but the forks were still not good. Linear springs on these bikes give a nice compliant ride, are easier to set up, there's no downside really.


.
I went with the hyperpro progressives in the end after reading good reviews here and elsewhere and as hyperpro where the only company who replied to my email queries.
Well, they will certainly be better than my current ons- even maxed out on preload and damping they are still bottoming out on hard braking.
Thanks for the info..
“If all insects on Earth disappeared, within 50 years all life on Earth would end. If all human beings disappeared from the Earth, within 50 years all forms of life would flourish.” Biologist Jonas Salk
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