crf250 Rally

[minkyhead]

you better just check theres no problems with the tri links clearance ..i cant remember but quite a few years ago i went the other way putting a longer rally shock on the 300l and replacing the 250l tri links with with a rallys i wanted the extra height and travel ..i think the rally shock is a lot longer at around 420mm ..just be mindful that 20mm is going to make a big difference to the the way the shock operates and also the clearance of the rear tyre to the chassis ??...id suggest knowing you want to go the other way you best bet would be to get some 250l trilinks to put on the rallys 250l shock ..that way you get a lower bike with the correct leverage ratio...may well be ok i really cant tell you from memory /i do remember there being a problem goin one way or the other on the big adv rider thread ,, try a serch theres 2000 pages on there but summet was amiss one way or the other as i remember ..proceeed with caution and check well befire riding id think is good advice here ?
250l and rally trilinks pictured below .250l on the left and rally on the right

[garyboy]

Thanks for the reply, Minky .. I always value your opinion.

.. and OMG .. i didn't realise the linkages would be different .. I thought it was just a shorter shock length.
Even so, I think things will turn out ok, as i have already lowered the height with a kouba-type lowering link, Plus a 20mm-lower drilled holes in the oem shock .. and although not ideal, did not feel to be obstructing or rubbing anywhere.

The new yss shock will not have the 20mm lower holes drilled (but possibly later??) so I am already starting 20mm higher on the shock, and also minus 25mm on the 420mm length shoch, as this is 395mm length shock... also the 420 shock actually Raises seat height by like 10 or 15 mm? .... So that makes it .. er.. um .. I'll get back to you lol .. (me `eds gorn).


compared to my old modded shock (which has a kouba-type lowering link) .... +20 (gained at forked base)....... -25 (lost, over the 420)...... +15 (avge gained ride height with yss) ............... = (about) 10mm longer shock ???? (a slightly higher seat height than at present??

but compared to oem shock .. o .. I give up lol

here's the shock, anyway ..

sss by gary boy, on Flickr

[Magnusson]

Do you have a part number for this one. I had some YSS part number that was supposed to fit my old bike, but it seemed to be discontinued.

Suspension is a bit of black magic, shock length, stroke length, movement resistance, spring rate, linkage leverage, ride height, suspension travel. Riding will tell, use the old tie wrap trick to check how much it travels when you ride.

[garyboy]

I looked at the printed number on the actual spring.. YSS-56-110-215
the 56 is the internal spring dia, and the 215 is the length of the actual spring.... I am wondering what the `110` is, but I know i ordered the `100` figure in that position. I don't think it will make a difference.? hopefully, as i didn't know what the 100 was anyway.

I measured the eye-to-eye [ c/c ] and it is 395 exactly. Which is the length of the shock I ordered ok. I suppose it makes sense to measure total shock length that way.
the shock number is (from memory.. its on this thread somewhere) mz456-395TR-21-85... Just checked anyway.
mz .. m is the type of shock... gas filled but no external reservoir. z is a rear fitting.
456 .. is 45mm dia and 16mm rod, i think from memory.
T is threaded preload adjustment.
R is Rebound adjustable,. ...[ but if it had an L it would be adjustable for length. But seems to be anyway, if unscrew the end eyelet.]
the instructions with the parcel were not the same as what i got.
the `21-85` is an item id number...
btw..the measured dia of spring wire is 13.. but not that figure i saw earlier in my investigation?
395 is this shock length.. [420 is a Rally length, but this shock is designed for the crf250`L`, which has a lower seat height, due to lower suspension.]

Marc of Brook Suspension had never heard of this exchange of shocks from L to Rally, but reckons it would probably work, but not recommended as it may restrict proper designed spring action. ie not using the full length of the spring. He was eager to pursue the sale though, as he sent me an invoice saying ` awaiting payment` (£394.. [388 plus vat, plus postage]). I soon cancelled that though, as ebay had the same spec and id number L shock for £60 less (£332 .. no vat, and free postage), lol.
He did say that the L shocks are stiffer than the Rally shock. but are ok as within the range. That suits me fine, as, at 90kg, I am at the top end of the range of 95kg. and i do carry a lot of weight as clothing and protection and tools.


the only reason i ordered the L shock is that it is shorter (by 25mm), .. and I am struggling to get on and off and dab now, as it is, even with a lowering link (don't know how much it lowers by, but I used the max 13mm adjustment in the adjustable lowering link) .. wish i had measured before/after. I will lose the benefit of my 20mm lower drill hole bodge, but gain the benefit of the -25mm shorter shock. but these yss shocks are known to raise the seat height by about 15mm? .... So I should end up somewhere in the correct ball park anyway .. ish.


o .. i forgot to say ... a very important point .................. the front fork adjustment.
when set at 30mm through the triple clamps, the handling was horrendous, but at 10mm lower.. 40mm through, it was perfect. for my rear bodges. This took me months to get right, after reading a lot and watching videos of suspension stuff, and bit by bit gleaning bits of facts. the main thing being that Rake and Trail are best left at oem ..... obvious really, but i was experimenting with unknowns (to me lol)
So I have to go through that again, but should be easier as I now know what an elevated front feels like ..... It bounces off small rocks and stones.
Should be fun..lol.

o .. just remembered ... when I read the paperwork with the shock, it said the shock was already set at the correct settings ..... I don't really know what that means .. but i shall just fit it as it is... probably. as i don't want to mess about with the settings as is. but may??

[Scott_rider]

o .. just remembered ... when I read the paperwork with the shock, it said the shock was already set at the correct settings ..... I don't really know what that means .. but i shall just fit it as it is... probably. as i don't want to mess about with the settings as is. but may??

I reckon they mean that the shock has been set up with settings for an average rider of average weight, and then the individual rider can tweak it from there.

[minkyhead]

the 110 is spring rate in nmt .. the 250l spring rate is higher than the rallys as there is a differenece in springlength and stroke on the shock ..a standard yss for the rally is somthing like 90nmt and for a average rider with no luggage it should be ok ...im 100kgms and take up to 15kgms of luggage and needed a 100nm spring on the rally shock ..otherwise the preload is wound a long long way on the threads to get any kind of stattic sag set ....
its confusing as they are different shocks i can say for certain 110 nmt spring on a RALLY shock would be a very very hard spring indeed for somone your weight id say on that shock a90nmt would be spot on for you and maby a 95 if you do luggage

that all said i dont know how the 250l 110 spring will be on the rally as its a diffrent length and stroke and the trilinks starting position wil alter too so will have a effect on the comression rate also
.in effect you will have a shorter stronger spring being asked to compress the same as a longer spring rated 25nm less ...my basic logic says that its going to feel pretty hard at that rate ?
try and set some kind of stattic sag about 2/3 cm ...what i do then is ride the same track harder each time to provoke it to bottom out ..if it wont bottom out keep softening the preload until it does ..you want maby just one bottom out on really big hit so as you know its using all its travel when worked hard ...when you have that its a case of controling the rebound ..id start with a soft rbound and then just hit that same hole repeatedly until the kick back becomes less and less ..you will feel it ..the rebound control deffo works quite well on the yss

hope it goes well ..best cae its does and worse case youll have to get some trilinks off a 250
..

[garyboy]

Thank you, Scott and Minky ... hmmmm .. much to think about.
I had a strong feeling that it is a 110nm spring.
Not sure how I feel about that ... apart from ..Sick. but open to 'positive '.

I'm tempted to slacken the spring to full open, and possibly the same with the rebound. but thinking it may be best to fit 'as is'.

It's to cold wet and windy her in Wales atm anyway.
I'll just have a cuppa for the moment lol.

[minkyhead]

your in now gary stick it on and see what happens innit

[garyboy]

Thanks, Minky,
Yeah, I'll do that.
I don't fancy sending it back. I was about to check my ebay order.. I know I chose the 100 as opposed to the other alternative of 110 .. but it is not clear, exactly, what these figures refer to.

On the box it just states the model number, which is correct to what I ordered , but there is no reference to spring rate ... so I don't see how a sorter/operative could know which is the 100 or the 110.
There is a website address, for yss, but, I can't even understand the Scottish speaker who answers on my electricity supplier, lol. I suppose I could try to contact the ebay seller, but doubt any joy.

So, I will wait for when the cold wet weather is not so likely to blow away my Bike Tent if opened, and hopefully, the arrival of a new scissor bike lift, and then have a go ... after I fit my new ebc clutch plated, lol.

Father Christmas is being good to me lately, lol, .. ie, since I stopped spending my small govt pension on other people.
Being selfish has its advantages... and necessities to mental health and wellbeing.
Perhaps that's why this spring shock is so important lol.

[minkyhead]

you cxan find the weight on the actual spring gary
this is off my road bike for example

the 56 is internal diameter 180 is spring rate in nmt the 150 is uncompressed length hope that helps