hard ride problem solved

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David Richard
Posts: 273
Joined: 04 Sep 2017, 20:21

hard ride problem solved

Post by David Richard »

i have a 750 d1 i got late october 2019 with low miles ,never got to use it much through lock down,but used it last year and was pleased with it ,i always thought the front end was very harsh and over damped .when i changed the fork oil i measured the fork springs they were 460 mm long with a 50 mm spacer which was the reason for the rough ride .even progresive springs are only 405 mm long the standard spring length is 391mm i cant see why they were changed would any one know what the spacer length should be i have to cut them to size thanks
David Richard
Posts: 273
Joined: 04 Sep 2017, 20:21

Re: hard ride problem solved

Post by David Richard »

just to post this the length of the spacer is 130 mm long for the d1 d2
andye
Posts: 71
Joined: 11 Sep 2017, 10:03
Location: Merseyside

Re: hard ride problem solved

Post by andye »

Hi Dave

Does your second post mean you have sorted it by using 130mm spacers or that the standard spacers are 130mm.

If it is still too stiff Thinner oil may help. The stiffer Hagon springs I have fitted to my D1 are supposed to be used with 7.5 weight oil. The air gap can also makes a difference.

Andy
David Richard
Posts: 273
Joined: 04 Sep 2017, 20:21

Re: hard ride problem solved

Post by David Richard »

thanks yes the standard length is 130 ,can you remember the length of your hagon springs were ,
andye
Posts: 71
Joined: 11 Sep 2017, 10:03
Location: Merseyside

Re: hard ride problem solved

Post by andye »

Can't remember the length but they went in with the standard spacer. I've got the original springs in the Hagon box somewhere, i'll dig it out and see if there's any info.
Freddy
Posts: 695
Joined: 06 Sep 2017, 11:06
Location: Sydney Australia

Re: hard ride problem solved

Post by Freddy »

The length of the original spacer is actually not important, other than as perhaps a starting point. The correct length spacer is that which gives the correct amount of 'rider sag' for whatever springs have been installed. If I understand it correctly, it seems clear the springs have been changed. I assume to linear rather than the original dual rate springs that were standard in a D1. I think they are dual rate rather than progressive, too lazy to go down the shed and look for them.

On a more modern bike you'd be in effect altering the 'spacer' length when you screw in/out the external preload adjuster (to set rider sag). Exactly the same thing is achieved by altering the spacer length in an older style (no external preload adjuster) set of forks.

A comfortable ride will be a combination of tire quality, tire pressure, spring weight, spring preload, fork oil weight, fork oil height.

P.S. I don't believe it possible to get a decent suspension on a D1 with its standard antiquated damper rod type suspension. You either end up with a bouncing ball ride because you have to put in such light fork oil to try and stop the suspension locking up under a hard bump which is really dangerous. People think the suspension 'bottomed' but really it just hydraulically locked. OR, you put in heavy enough oil (needs about a 30W) to get a decent rebound damping which massively exacerbates the previous problem. Can all be rectified for about $200.
David Richard
Posts: 273
Joined: 04 Sep 2017, 20:21

Re: hard ride problem solved

Post by David Richard »

hi freddie i remember reading your post a couple of years ago about fitting emulators and how much it improved the ride and i get it about how basic these are i think that might be a project for next year i think its just what you get use to and settle for what you got thanks
Freddy
Posts: 695
Joined: 06 Sep 2017, 11:06
Location: Sydney Australia

Re: hard ride problem solved

Post by Freddy »

David Richard wrote:hi freddie i remember reading your post a couple of years ago about fitting emulators and how much it improved the ride and i get it about how basic these are i think that might be a project for next year i think its just what you get use to and settle for what you got thanks
My thoughts, don't settle for how the bike is standard. Not only can it be made to handle comparable with a modern bike, but I honestly believe the stock design is truly dangerous. There are a couple of events etched permanently in my mind of the bike being barely kept in control due to the front suspension hydraulically locking up. One was hitting a rural train line crossing at straight line open road speed, the other big dips and bumps in a fast sweeping corner.

The biggest problem with emulators is getting them set correctly, as they have to be pulled out to adjust. So the trial and error process becomes quite tedious (and messy). However, I'm confident I've now got them good and more than happy to share the settings and necessary modifications if you decide to go this way.
David Richard
Posts: 273
Joined: 04 Sep 2017, 20:21

Re: hard ride problem solved

Post by David Richard »

hi thanks for all of that info i have all mine away now for the winter but next year i will look into it ,i will do lots of reading and book a test ride on a modern bike to compare the ride thanks
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