Cold tear - can a worn shock linkage make it worse?

[TonyB]

Thanks Robert, that will come in very handy.

So looking at the numbers, in theory the bike probably still has slightly too much rear sag. Or at the very least the amounts of sag I have front and rear aren't well matched. I'll see how it feels this weekend and try changing them to see what effect it has.

[sinfull]

Enjoyed that read ! Very informative, thanks guys !

[TonyB]

Enjoyed that read ! Very informative, thanks guys !

Really? Because after last weekend I was completely confused! However I have now learnt the value of doing EVERYTHING on the setup sheet, rather than cutting corners....

I believe I have found at least part of the cause of the Monsters poor handling- I am now sure that the spring rate is too low. I had only measured the rider on board sag and had ignored the static sag. I had managed to achieve a rider sag of 32mm, but after talking to Linton from Dirt Action Services today, I measured the static sag and found it to be 0 to 2mm. I believe in order to achieve the required rider sag, I have had to compress the spring way to far. I also think that the shock has too much rebound damping for the spring rate.

The symptoms are:
- The shock feels VERY hard initially
- It bottoms out quite easily
- If I hit a number of bumps while braking the rear end bounces around
- It can cope with a single bump, but not multiple bumps
- It feels fine on a smooth track, but very unsettled on bumps
- The bike is tending to run wide on entry and exit
- The bike is still spinning the rear while lent over (it only has 62hp at the wheel)

I emailed the above to Robert Taylor and he confirmed my theory. I'm trying to work it so that I can get a second hand spring from him on Friday....which is the same day as the B family are heading off on holiday.....GAH!!! Why does everything always happen at once?

So basically I have been riding a bike that alternates between topping out and bottoming out because of a spring with too low a spring rate which has been pre-loaded all to hell to achieve the rider sag, and excessive rebound damping. If I had just measured the static sag like the instructions suggest, I would have figured this out a long time ago

I'm REALLY looking forward to trying it out with the correct spring rate. I know that the shock itself is still going to be very much "budget" in terms of performance, but its going to be MILES better than what it is now! I'll do an update once I've tried it (wont be till the end of Feb though)

My advice to anyone who is considering taking the "economy" route, and modifying their bikes stock shock....DON'T DO IT!!! Its a false economy. Unless there is a tried and tested kit available to modify the shock, you are basically going to be paying for R&D. You may end up spending nearly as much as you would have on a good shock, but still have "budget" performance.

[sinfull]

My advice to anyone who is considering taking the "economy" route, and modifying their bikes stock shock....DON'T DO IT!!! Its a false economy. Unless there is a tried and tested kit available to modify the shock, you are basically going to be paying for R&D. You may end up spending nearly as much as you would have on a good shock, but still have "budget" performance.

Yep, think most who have gone down that road will be nodding in agreement with ya !
Spend as much if not more and then find you go to the experts in the end and spend it again !
Take me today for example, it's only paint i can do it with a spray bomb bwahahaha only two cans of bourbon left though and two coats to go ! I swear if that can of gloss spits as much as the primer and undercoat did i'll have me a guy fawkes in the incinerator ! (Move the bike a safe distance first though)
Cost me near a hundy in shit and prolly could have got it done by a mate for less !

On a side note : You doing the bears down there at the end of feb ?
Keen as cat shit but that bloody ferry crossing is an expensive bastard in a van !

[TonyB]

On a side note : You doing the bears down there at the end of feb ?
Keen as cat shit but that bloody ferry crossing is an expensive bastard in a van !

You betcha I'm doing it. I've got another thread under Events with the entry forms. Get ye down here, you wont regret it!

[sinfull]

You betcha I'm doing it. I've got another thread under Events with the entry forms. Get ye down here, you wont regret it!

You know your bloody right, i wouldn't regret it ! But 5 days, a couple of k in expences later, mmmm the mrs might regret it lol, but what does she know, food and a roof over ya head are highly over rated aye !
Damn it i have always lived by JFDI ! See ya there !

Beware of the white tails !!!!

[DVS 69]

Yeah really good read, i had exactly the same problem with a K1 on the rear, without warmers ....... Altho ive always felt that my stock shocks do what they should, i agree tho once a tire has "cold tear" it just seems to get worse, the tire i used had only done 16 laps at cemitry curcuit on a buell (without warmers) and looked abit worse than that in your photo. I put it down to the tire maybe rooted before i had even put it on the bike. Im gunna run K2 rear with K1 front next and use my tire warmers and see how that goes, its trial and error but i think id rather spend on a new tire 1st and if it does it again then look at suspention. Its just the cost is huge .... I know that ohlins are the bees knees but dam soooooooo expensive. Heres hoping the K2 dont turn to shit like the K1 did.