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DungeonMaster
GRiSO
GRiSO


Posts : 1163
Join date : 2013-11-26
Age : 53

PostSubject: Re: penske shock   Sat Jun 07, 2014 7:19 pm

beetle wrote:
Sorry to butt in, but I have concerns with FreshEggs problem of stability at speed. I have my forks raised so that all 6(?) rings are visible and yet I find the GRiSO not only super stable at speed across any hard surface, but also somewhat slower steering than some bikes I've ridden.

Could there be some other cause for his stability issue?

Hmmm, I'm at five.
I saw wallycycle had his at six and I am contemplating doing the same.
My stock rear spring is already tightened up close to max.

DM


Last edited by DungeonMaster on Sat Jun 07, 2014 10:00 pm; edited 1 time in total
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FreshEgg
Tanabuso
Tanabuso


Posts : 89
Join date : 2013-09-11

PostSubject: Re: penske shock   Sat Jun 07, 2014 7:33 pm

Uzidzit: I think you nailed it. For whatever reason the fork packing down badly. Bottomed out on me a couple of times today when riding to local Moto Guzzi Breakfast. Compared preload on front to Steak' bike and mine was much less, which also confrirms it as damping issue.

Weird thing is no recent setting changes on my part. Either something broken, plugged up or fork fluid turned to molasses. Going to try local outfit GP Suspension in Auburn, WA. They apparently have a fork cartrigefor Showa too. Will report back after we establish baseline and then start working on it.

Cheers!
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FreshEgg
Tanabuso
Tanabuso


Posts : 89
Join date : 2013-09-11

PostSubject: Re: penske shock   Mon Jun 09, 2014 10:29 pm

Pete Roper wrote:
I've got the number for steering head tapered rollers to replace the shitty ball and cone set-up from the factory but I'm down the beach this weekend. Nag me Tuesday and I'll dig 'em out. (Its a long weekend in Oz this weekend.)

Pete

A little tardy but, THanks Pete!
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DungeonMaster
GRiSO
GRiSO


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Age : 53

PostSubject: Re: penske shock   Tue Jun 10, 2014 6:14 am

ball bearing steering bearings????
Are you for real????

That was the first mod I always did on my old UJM's - ditch the ball bearing and tap in some tapered rollers.
I am very interested in the tapered rollers myself please.

DM
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Uzidzit
Tiradritto
Tiradritto


Posts : 325
Join date : 2013-12-01

PostSubject: Re: penske shock   Tue Jun 10, 2014 6:35 am

Just a little something to ponder...there is actually a reason that ball bearings are still used as head bearings and it has nothing to do with being cheap. There is actually a lot better feel and more precise steering from the front end...They are still used on the top end race bikes.

Tapered rollers are maybe more durable(I say maybe only because if balls type are kept adjusted I have not seen much difference in life) they do work better if generally neglected as head bearings usually are.

Also seen them produce problems, many "conversion sets" do not really have proper seal combinations and get contaminated and corroded. and have been set up wrong with too much preload and caused a jittery front end. (just like a screwed up steering damper)

just mentioning as roller head bearings are NOT always an improvement, and shitty rollers are just as bad as shitty balls
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ghezzi
Fra Cristoforo
Fra Cristoforo


Posts : 1692
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Age : 59

PostSubject: Re: penske shock   Tue Jun 10, 2014 3:46 pm

Uzidzit wrote:
 and shitty rollers are just as bad as shitty balls

Uzi, you sure you doin it right?  Shocked
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http://www.biketowbrisbane.com.au
Uzidzit
Tiradritto
Tiradritto


Posts : 325
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PostSubject: Re: penske shock   Tue Jun 10, 2014 6:38 pm

ghezzi wrote:
Uzidzit wrote:
 and shitty rollers are just as bad as shitty balls

Uzi, you sure you doin it right?  Shocked

Rollers wear and hammer the races the same as balls both are line of contact bearings, and on many necks there is not a direct replacement size when there is not a perfect match the available seals do not work well and very often the bearings get contaminated quicker than the original. or the available seals drag badly or do not work.

The fit issues are not much of a problem for me as I will just make new steering stems as needed and billet shields to use proper seals, or just make new triple trees... a bonus of being a machinist and having a a machine shop with cnc mills and lathes at my beck and call. (the last crazy one was fitting xr-650 forks to a kz-750 frame for an unlimited enduro build these were a roller conv. custom desigined neck and billet shields, etc.) You should see the monoshock conversion with the xr swing arm on this beast...I am way to nice to say no to any of my lunatic friends and their hairball ideas Suspect 

Was just mentioning this because roller bearings are not always the best bearing for neck applications. and do not always last longer than ball bearing neck bearings. My personal favorite neck bearings are NSK barrel roller, or nsk angular contact ball bearings. these take the loads of straight rollers without loosing the feel of a ball bearing neck.

I never said do not do the conversion, just said do not always assume it is a magic conversion, there is a trade off...are they better than the old style loose ball 70s vintage neck bearings 99% of the time yes, are they better than a bronze cage nsk angular contact ball bearing not in the feel dept.

do I use rollers, yep in almost all my old bikes, do I just go out and replace a perfectly good set of ball neck bearings just to do it Hell no. when they need to be replaced I will use rollers on most bikes if there is not an alternative, but I know I am giving up something. (rollers are a hell of a lot easier to maintain than loose balls.

Keeping headstock bearings in good shape is maint. that nobody wants to do or pay to have done...or does have done.. till it is too late and there is a problem with handling in my experience.

Just wanting to point out they aint magic, and their is a down side that rarely gets mentioned but it completely real...did not want to highjack the thd tho
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ghezzi
Fra Cristoforo
Fra Cristoforo


Posts : 1692
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PostSubject: Re: penske shock   Tue Jun 10, 2014 7:03 pm

Ah. My comment was tongue in cheek. Shitty balls could mean you're sticking it in the wrong hole. bounce if you know what I mean.

Anyhow, I am most impressed with your machining abilities / engineering skills.
Bella would be greatly enhanced visually, with a set of billet triple trees.

I'm supposed to be finishing a long term 2 stroke project but.

Bella has revalved cartridges & resprung front end with monobloc 999R calipers and radial m/c.
Yokes dropped 13mm. I have a 120/70 x 18" tyre. I would like to convert to a 17" front wheel. (= drop of another 13mm & 1 degree less rake)

Rear end has height adjustable Matris R shock. Eventually raising this with above may net me a rake of less than 26 degrees.
Offset of yokes could be reduced to increase trail to maintain stability, but also shorten wheelbase and add more weight bias to the front. mmmmmmmmmmm?
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Uzidzit
Tiradritto
Tiradritto


Posts : 325
Join date : 2013-12-01

PostSubject: Re: penske shock   Wed Jun 11, 2014 5:32 pm

25.5 should still be fine, I am at 25.8 on my GRiSO without issue.

Offset triples, are a bit of a pain (I have to set up on a sine plate, I do not have a live trunion), The last set I did was for a guy with a cali t-3 that needed a zero trail fork for a outfit. they were 4 degree as I recall...I think you could get a degree or two with a new eccentric stem in the standard trees. I have done this a few times in the past. it involves plugging the the upper and lower clamps and boring at a slight angle and facing the bearing surfaces. the fitting a new stem, it can be a cost effective way to alter the head angle if you do not need much.

The Rats ass is to fit sphericals on eccentrics and make the stem adjustable for angle but that is a LOT of work to get right, and some bikes just have too much crap around the neck to make it work .
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Pete Roper
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PostSubject: Re: penske shock   Wed Jun 11, 2014 9:03 pm

The tapered rollers that are dimensionally identical to the original ball and cone type steering stem bearings are #32907X or XU

Should work with all the stock seals etc.

Pete


Last edited by Pete Roper on Thu Jun 12, 2014 12:06 am; edited 1 time in total
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FreshEgg
Tanabuso
Tanabuso


Posts : 89
Join date : 2013-09-11

PostSubject: Re: penske shock   Wed Jun 11, 2014 10:00 pm

Pete Roper wrote:
The tapered rollers that are dimensionally identical to the original ball and cone type steering stem bearings are #32907X or XU

Should work with all the stock seals ECU.

Pete

Thanks, Pete!
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BCGriso
Squinternotto
Squinternotto


Posts : 2
Join date : 2016-11-16

PostSubject: Re: penske shock   Wed Nov 16, 2016 2:30 pm

I'm late to this thread, but I'm looking to spec a Penske shock. Uzidzit - do you have the specifics of your Penske build sheet?
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Pete Roper
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PostSubject: Re: penske shock   Wed Nov 16, 2016 3:24 pm

Uzidzit flew the coop a while back.

pete
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BCGriso
Squinternotto
Squinternotto


Posts : 2
Join date : 2016-11-16

PostSubject: Re: penske shock   Wed Nov 16, 2016 3:27 pm

Thanks Pete!
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guzziownr
Biondino
Biondino


Posts : 216
Join date : 2013-12-23

PostSubject: Re: penske shock   Wed Nov 16, 2016 3:45 pm

Pete Roper wrote:
Uzidzit flew the coop a while back.

pete

He might still be on Wildguzzi, same username.
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PostSubject: Re: penske shock   Today at 8:37 pm

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