Front Wheel Shimmy

Thanks for all of the suggestions chaps, this is what makes forums great.

Yes they are the cast wheels and not spoked.

Embarrassingly I don't actually know what tyres are on there but they were put on in May/June last year by Mr Nairn and have only done a couple/three thousand miles since then.

Some of you guys are recommending higher pressures and seen as I started off lower than what I am now and the shimmy was worse, I might try higher than F33R36 and see what happens. The bike was thoroughly gone-over by Keith when it was up there so I don't expect any major problems. One of the rear shocks does weap a little oil after riding to the point where it does form a drip at the bottom. Maybe the next thing to do is have them overhauled.

Thanks for the advice!
 
It's BT45s that need the higher pressures, other brands may or may not need such high pressures.
Check the specs on the brand owners website.

A couple or 3 thousand miles may be enough to square off a rear tyre.

 
A couple or 3 thousand miles may be enough to square off a rear tyre.
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Did that on Metzeler's on a new 750 SF0 back when.

Metzeler's Buttered.

Put Phantoms on her and could not wear them out until they rotted off.

Where did the Pirelli Rayon Belted Radial Phantoms GO ?

My Favourite Breganzie Motorcycle tire ;o(
 
Back in the day we used to run Phantoms at 34 front 38 rear for the longest of times due to weight of bikes.. Pirelli recommendation..

Now I run Pilot Actives on al the fleetl and run 36 psi front 40 psi on rear just got back from 1280 mile round trip on the old Jota no issues.. hands off bars no shimmy, hi speed chasing Tom no issue... though one of two slides in greasy peasy stuff but then again rear tyre is well worn.

Find that under 36 psi on the front of the RGS gives the dreaded shimmy bad...you can feel it right away... 

Pilot Actives dont seem to scallop any where near as bad as Pirelli or Bridgestones.

Also as per Piet check your steering head bearings... a lot replace the top with a taper then have issues with preload etc.. I run taper lower, roller top even in the RGS now seems to be more better.... but what would an old dumb arse mechanic know  8)

 
I run taper lower, roller top even in the RGS now seems to be more better.
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G'day Brett,
My RGS came with tapered bearings top and bottom. If I change to a roller top bearing do I have to change anything else as a tapered inner race sits proud of the outer race whereas a roller bearing inner and outer races are flush.
Cheers
 
Legs said:
G'day Brett,
My RGS came with tapered bearings top and bottom. If I change to a roller top bearing do I have to change anything else as a tapered inner race sits proud of the outer race whereas a roller bearing inner and outer races are flush.
Cheers
Click to expand...

As long as nothing is binding on the tip top of the steering head tube it'll be OK. If it is, all you need is a spacer to sit on the inner race of the top bearing to lift the top triple clamp (or bearing dust cover plate) clear of the steering head tube.

If you find that a spacer is required, let me know how thick you need it to be and I'll turn one up for you.

Taper bottom and roller top is my preference too. Makes more sense that tapers both ends for that application.
 
Thanks for that, reckon that if the roller bearing is sealed, the dust cover could be dispensed with, easy enough to ensure that the top triple clamp doesn?t foul the bearing outer race or tube.
Added to the ever growing jobs to be done to keep the Yellow Peril on the road ::)
 
Brett said:
Back in the day we used to run Phantoms at 34 front 38 rear for the longest of times due to weight of bikes.. Pirelli recommendation..

Now I run Pilot Actives on al the fleetl and run 36 psi front 40 psi on rear just got back from 1280 mile round trip on the old Jota no issues.. hands off bars no shimmy, hi speed chasing Tom no issue... though one of two slides in greasy peasy stuff but then again rear tyre is well worn.

Find that under 36 psi on the front of the RGS gives the dreaded shimmy bad...you can feel it right away... 

Pilot Actives dont seem to scallop any where near as bad as Pirelli or Bridgestones.

Also as per Piet check your steering head bearings... a lot replace the top with a taper then have issues with preload etc.. I run taper lower, roller top even in the RGS now seems to be more better.... but what would an old dumb arse mechanic know  8)
Click to expand...

Roller top bearing?

The factory fitted sealed ball bearings to the top of the steering head.

RGS frames had tapered top and bottom, ex-factory.

piet
 
Ralph at Motalia in Norfolk (UK) does stainless top bearing covers, very useful if you are converting a 180 in order to have taper rollers top and bottom.

I have the bearings and the stainless top cover in stock and can be used by locals on a take mine and replace later basis, if that helps anyone.
CLEM
20 miles South of London (UK)
 
If you fit taper roller bearings top and bottom on a 180 don't be surprised to find your chrome headlamp tubes rattle up and down as you have just introduced a few extra mm between top and bottom yoke.
 
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