S.A pivot pin slack-a handling problem!

you know this swingarm is making a mess of my frame!

i've harked on about this once before but i'm going to get into this one with a bit of help from you boys!

first the problem;
1) the '04 pin i have fitted is very loose in the hollow dowels that reside in the left and right sides of the swing arm.

2) the hollow dowels themselves are a loose fit within the needle rollers

3) the dowels are too narrow and unfortunately the tightening of the pin also crushes the walls of the frame into the swingarm creating increased friction

4) the above wears a ring in the wall of the frame and so now the pin is definately crushing the swing arm and only a little on the dowel

5) the above means the dowel isn't tight enough not to move anymore so it grinds away at the frame even more!

6) the dowels sit off centre due to the sloppy fit making the needle rollers only work on one side taking a hammering. the paint on the pin is missing at diagonally opposite points both in a horizontal axis and a vertical axis. so each end of the dowel to pin interface has two rub marks 90d around from each other (then nothing for 270d) and the 4 marks represent rubbing every 90d when noted from the end. this is for each side.

what's needed?
i'm told that some riders have checked out an early '01 or '02 pin and the pins have a bigger o/d . can anyone measure an earlier one?

2) i need to know whether it's possible to locate a hardened steel rode of the diameter i need?

3) a dowel that has a slightly larger o/d would be great but it's very doubtful if there is one. if i was really lucky you would find an imperial measurement that was say .005" larger than it's metric counterpart a bit like the old 3/4" and 19mm scenario.

4) a slightly longer dowel and then put plastic caps (ribbed on the end of the S.A.

i don't think welding a shim on the end of the dowels will work.

any thoughts? i can start measuring up tomorrow evening and post some dimensions here. then i need to know about bearing sizes etc.

to have a swingarm pivot like this just undoes everything that you're trying to do to a bike.

regards

Taffy

doh! i've gone technical again! sorry lads-let's just stick to decal sets and starting lefrog's bike shall we?

regards

Taffy

Taffy said:

what's needed?
i'm told that some riders have checked out an early '01 or '02 pin and the pins have a bigger o/d . can anyone measure an earlier one?

regards

Taffy

Click to expand...

can anyone measure an earlier pin please???? vernier/micrometer?

either on the paint or on the metal where it has no wear.

c'mon chaps!

also there is a rumour (in my head) that the hollow dowels are modified gudgeon pins!!!!!!!

regards

Taffy

helping your old mate out are we brookster?

no problems with parts. no problems with dealers?

no problem with DCR except when you keep bringing it up.

no problems with mates.

in fact brookster-what are you on about?

Taffy

can i first of all say to brookster that i called up dave clark today and asked him what was going on. dave doesn't know who 'brookster' or 'gix' are and that he doesn't want anymore agitation.

we chatted for nearly one-hour even though his mobile was going all the time. because of my years in the car trade we talked the same language and by the end were getting on very well indeed. too well infact!

i explained that i had only ever said what had happened to me and that i wanted even now to draw a line under it. he said that it was a right f... up! at that time and i didn't realise it but he had all kinds of things going off. i won't say it openly here though. also that various people felt that they couldn't say positive things about DCR without 'winding up' those of us that said we'd had bad service in our time.

we discussed the problems he's faced, values of bikes, racing in the UK and abroad. my old regular dealer has painted a poor picture of him and i began to realise just what a hard job it is for him.

i was impressed in his sincerity and the amount of time we chatted. he said he doesn't visit web sites, even SM web sites because for every 20 good customers he has to face one that doesn't like him and it puts too much conflict into the melting pot. too much angst.

apparently he has some SM slanging going on from someone somewhere at present and talked as if i'd know about it. i don't. i mentioned that brookster had brought him into the general battle lines here at UHE and he doesn't want nowt ta doo-wee it. because he was 100% pleasant i can say that that is all he said.

so perhaps gix and brookster, would you like to just tell him again who you are so he can get a handle on you? please?




anon.
hi Joe.
i didn't think i could give my identical twin brother anymore publicity. he now has his own TV sketch show so it's not like he needs the publicity! i trust you yanks will let me know if the show "little britian" ever hits your shores. the comedy is very cutting and not for the C & W types though!

i think you were on this ride of bob's weren't you?

joe, it would be nice if i knew what they changed from '04. i understood that it was just the design of the pivot pin. it's now prettier! however others are telling me that the old shaft may have been slightly larger.

i doubt it. they will have been made to the same basic spec IMHO.

perhaps the needle rollers have been changed as well? nah!!!!

i hope when husabutt pulls apart the assembly he'll get the vernier going and take the codes off the end of the NRs. OR anyone else!

perhaps we should check whether the SM gets something stronger first. after all, if we're on about 'beefing up' then the SMs MUST surely come first!

i've been told by a dealer that the factory is aware of the problem and do a little kit for the top SM teams.

for us though i have had a little luck. i looked at the dowel and thought that it couldn't be so different to a little end gudgeon pin. our present dowels have an od of 22mm and 16.3 id and are 50mm long. the GP that ben from JHS racing has found is an absolutely perfect 50.8mm with 22mm od. the id is 14mm and i have ordered two and will try and machine out to 15.9mm.

i'm toying with the idea of a star shaped plastic washer on the end that's about .5mm. the shape of the neuclear triple triangle?

if it pivots it cleans dry mud away and if it doesn't and only the SA moves then it still rubs dry dirt away. no L to R thrust either.

cheers wildbill!
i agree and think there is slack between the dowels and the needle rollers and the pin through the dowels. finally, you're right the dowels aren't long enough and do graunch the frame. one thing leads to another and...

i'll keep you all posted.

here is some maths for you.
22mm (our dowel) = 880 thou
1" = 25.4mm = 1016 thou so;
a 7/8" dowel = 889 thou.

that means if we could get hardened steel that's 7/8" it will be 9 thou (.25mm) larger.

two inches in length = 50.8mm = .8mm or 32 thou longer.

these two dimensions alone are nearly perfect!

if the id of the 'dowel' was 5/8" it would be 635 thou and the pivot pin at 15.85mm od is = to 634 thou so we have a one thou gap!

all we need now is someone to find a gudgeon pin that is the following:
7/8" od
5/8" id (straight bore not tapered!)
2" long and we're there!

a good automotive book from a piston company would sort this out!

anybody get their hands on the AP hepolite catalogue out there?
what about these industrial bearing and steel companies?

i think that the gap twixt dowel and through pin on paper is too small. but i think that to get them in the hand first would be important!

regards

Taffy

joe

many years ago we had an awesome road racer over here named phil mellor. thil weighed at the most 8 stones. but of course like valentino he was awesomne!

but i learnt something one day when he said in a quote in MCN that: in the case of the handling problems of the GSXR1100R, blame can be apportioned to the rear wheel spindle which is .004" (four thou) undersize.

that shook me ridgid because i had NEVER questioned things like that. it opened a whole new world to me. i now started to 'suss' that everything on a bike could be measured with a vernier.

20 years later and i'm still trying to measure everything!

fact is-manufacturers make things over and undersize...

i will check the diameter of a pivot pin when i can.

in the meantime, on monday i will phone a bearing supplier requesting an industrial hardened dowel with the above mentioned dimensions.

if i have any luck this will be a major succes i feel.

regards

Taffy

well i sit here with two little end (wrist pins to you lot!) pins that are 51mm long (1mm longer). 22mm od (the same) and i can machine out the inside to suit the pin!

this i will do next week. i'll get it to my engineers.

the other thing i found out from the bearing specialists is that they do a hardened steel sure enough. it comes as a solid bar that is surface hardened. you can get it in 7/8" which i have stated above may be the perfect answer to handling problems.

apparently they hold the bar as stock and they'll cut it for you to length. when i'm next in cambridge i'll go see him and see if i can't get some cut and manufactured.

regards

taffy