Author Topic: harsh std suspension  (Read 4164 times)

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Offline phattanglo

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Re: harsh std suspension
Reply #30 on: November 27, 2020, 03:16:39 PM
Actually based on UK prices the YSS would only be 20 more so based on your advice I think that would be the way forward.

Offline phattanglo

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Re: harsh std suspension
Reply #31 on: November 27, 2020, 04:04:41 PM
Just as a Matter of interest is the 2019 part that partzilla describe as the pipe seat?

Offline Oyabun

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Re: harsh std suspension
Reply #32 on: November 27, 2020, 05:24:17 PM
*Originally Posted by phattanglo [+]
Just as a Matter of interest is the 2019 part that partzilla describe as the pipe seat?
I've put here the part number and description in this thread earlier, I can't remember exactly, but yes I think so.

Offline Oyabun

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Re: harsh std suspension
Reply #33 on: November 27, 2020, 05:27:04 PM
*Originally Posted by phattanglo [+]
Actually based on UK prices the YSS would only be 20 more so based on your advice I think that would be the way forward.
220 was including the damper rods. As you can buy the pd valves for 75gbp including shipping from Italy, the patchwork set comes to 190. That's 50 gbp difference.
You have just explained many times that cost is a major issue, so I've explained the cheapest option to you. I support that you buy the complete set.
Rgerds machining. The inside diameter on the top of the damper rod is slightly smaller in diameter than the matching part on the PD valve. The YSS kit uses an assimetrical spacer (the shiny ally part in the kit) to overcome this. The machining to be done is to increase the inside diameter of the top on the Damper rod by roughly 1mm. It is about 5 minutes work per side with a small flap wheel in a dremel.
Last Edit: November 27, 2020, 05:32:56 PM by Oyabun

Offline phattanglo

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Re: harsh std suspension
Reply #34 on: November 28, 2020, 08:29:25 AM
That is much clearer now oyabun many thanks.
I understand the k-tech springs come in different rates so I'll ask Brooks the most suitable rate for a 100kg rider.
I'll also look at the new damper rods.
Could you please recommend an oil viscosity and airspace for basic road riding with the new components.
Kev.
Last Edit: November 28, 2020, 08:30:30 AM by phattanglo

Offline Oyabun

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Re: harsh std suspension
Reply #35 on: November 28, 2020, 02:53:09 PM
*Originally Posted by phattanglo [+]
That is much clearer now oyabun many thanks.
I understand the k-tech springs come in different rates so I'll ask Brooks the most suitable rate for a 100kg rider.
I'll also look at the new damper rods.
Could you please recommend an oil viscosity and airspace for basic road riding with the new components.
Kev.
I'd suggest to go for a 7.5 or 8 N/mm linear spring (Ohlins offers 8 for the 150mm travel 19-20 models) and 15w fluid.
I'd start with 170 mm air gap and depending on your experience add or remove 5mm to help avoiding bottoming if needed.

Offline phattanglo

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Re: harsh std suspension
Reply #36 on: November 28, 2020, 10:50:41 PM
I'm just about to order the springs and it occurred to me that as I have lost 10 kg in the last few months and hope to get to 95kg I wondered if I will have sufficient adjustability with an 8 N/mm spring or should I go straight for the 7.5..
Santa is bringing the preload adjusters and  I'll fit the pd valves later funds permitting.
My main priority is to get away from the terrible ride quality and I'm sure the springs will help.
I work in a hospital but by the time I've ridden to work I feel like I should be an inpatient with all my rattled bones😁

Offline timur

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Re: harsh std suspension
Reply #37 on: December 01, 2020, 02:14:16 PM
*Originally Posted by Oyabun [+]
Absolutely. 5.5N/mm is enduro/off road bike territory, but those have 260-300mm travel to soak up bumps, compared with the officially 140mm of the 500x. Funny is, that RR uses the same spring rate for the 140mm stock, and 170mm L2 travel. I understand the financial and logistics realities of it, but after trying it, not my piece of cake.
I though a lot about his problem months ago and my conclusion was - combination of shim stack with stiffer springs won't work on this fork because of the need for higher viscosity oil in order to get more rebound damping. As I understand shim stack + thicker oil is a bad idea (unlike Valve Emulators that can run with thick oil with zero fuss). But Matris has the same configuration - shim stack, stiffer springs and I suppose its rebound damping is OK so something is wrong in my conclusions :027:

This point is a thorn in my side - would do more to improve my fork and finally sticked with RRP springs due to a mix of laziness and being ran out of ideas. I won't modify my CB fork anymore but I'm curious - how Matris FSE kit achieves correct rebound damping with stiffer springs and lower viscosity oil? Do you know by any chance what oil it uses? Seems like they have shim stack for rebound (RRP kit have only check valve for rebound) but AFAIK shim stack for rebound damping in this configurations would only produce cavitation. I'm missing something but don't know what :084:

Regards

Offline phattanglo

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Re: harsh std suspension
Reply #38 on: December 01, 2020, 02:40:54 PM
Hmm, is that a spanner in the works or are the YSS valves the same as emulators in which case won't they be ok with thicker oil?
Last Edit: December 01, 2020, 02:41:25 PM by phattanglo

Offline Oyabun

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Re: harsh std suspension
Reply #39 on: December 01, 2020, 09:07:16 PM
*Originally Posted by phattanglo [+]
Hmm, is that a spanner in the works or are the YSS valves the same as emulators in which case won't they be ok with thicker oil?
No issues on your side. The YSS PD valves are only different from Racetech emulators in a few points not to be penalised for patent infringement - practically the Y are the same - what equals no problems with stiffer springs and thicker oil.