Marzocchi 35mm forks spares?

[themoudie]

So what am I to do with the Marzocchi 35mm forks on the Duke and as fitted to other 1970's-80's singles and V-twins, when the wear in the fork slider becomes excessive?      

There are no replaceable bushes in the slider or on the bottom of the stanchion! Unlike most other fork legs. Marzocchi motoX forks have bushes fitted. Machining the upper integral aluminium bush in the slider casting to take a bush doesn't help, as you need another bush at the bottom of the stanchion.

Marzocchi now specialise in making forks for the MTB fraternity and I realise that this is a far more lucrative market than the Italian small motorcycle market.

Do I have to go and buy a set of Ceriani's? LINK_TO_CERIANI_GP_FORKS

2nd hand Marzocchis could be a nightmare, with greater wear than the ones I have. 

Thank you for reading this and good health.

My regards, Bill.

[steveD]

Why not have them recoated?

Involves grinding off the old chrome, rebuilding with a powder coating of steel, grinding and then re-chroming.

There is a specialist steel powder coating specialist here nr Huddersfield that should be able to do the job.

SteveD

[Propellor]

..........Machining the upper integral aluminium bush in the slider casting to take a bush doesn't help, as you need another bush at the bottom of the stanchion..........

Ay up.

Would the upper end tend to wear more than the lower? Thinking that most heavy wear would occur under braking. Purely theoretical (read "guessing"). So maybe you could machine the top whilst the bottom end would remain "acceptable"?

Up the oil viscosity and sod it?

I can't remember any bushes in my Beemer yet my yamaha has bushes. Go figure.

Ask me one on torque

[steveD]

Can you get some pics and detail of wear. This could be an interesting engineering problem, right up my street. I was in a past life a Toolmaker and as a Specialist tooling Engineer at BEA (Military Aircraft)  this sort of problem was a daily occurance. That may have been quite a while ago but old skills are still there. Keep in touch.

Anything to help and a ride up North of the border would be good.

Steve

[Steve Lake]

My son has those forks on his Morini 3 1/2 sport... you should be able to get spares and info at North Leicester Motorcycles (NLM)... worth a try

[Furry John]

So what am I to do with the Marzocchi 35mm forks on the Duke and as fitted to other 1970's-80's singles and V-twins, when the wear in the fork slider becomes excessive?      

There are no replaceable bushes in the slider or on the bottom of the stanchion! Unlike most other fork legs. Marzocchi motoX forks have bushes fitted. Machining the upper integral aluminium bush in the slider casting to take a bush doesn't help, as you need another bush at the bottom of the stanchion.

Marzocchi now specialise in making forks for the MTB fraternity and I realise that this is a far more lucrative market than the Italian small motorcycle market.

Do I have to go and buy a set of Ceriani's? LINK_TO_CERIANI_GP_FORKS

2nd hand Marzocchis could be a nightmare, with greater wear than the ones I have. 

Thank you for reading this and good health.

My regards, Bill.

Bill, people with Ducatis, mostly Vee twins, seem to get them refurbished ok.
As a first suggestion try Tony Brancato, Then possibly Howard at Disco Volante. Both do parts and services for restorations.

I'll ask on Bevelheads and pass on any answers.

Furry

[themoudie]

Thank you all for your suggestions and the time taken to make them.

I took a single leg across to an engineer acquaintance up here and we had a ponder! I'm getting my nickers in a twist!    Yes, there is play in the bore, but not sufficient to warrant the hassle the engineering requires. Importantly, they wouldn't fail an MoT and are unlikely to give the 'walking' feeling or juddering under braking.

I have spoken with NLM already, as I knew they raced the 500 Vtwin using these forks and was informed that apart from using 'Progressive' springs, new seals and using clean oil, they were standard. However, this was not a discussion with Chris or Alex, but Bob in the stores, the others not being about. I may try and speak directly with either Chris or Alex later this month.

Also I suspect I'm being a cheapskate over the Ceriani GP replica forks made using CNC parts.

2 x stanchions alone is £250. CNC machining of the guts of the legs another £100 - £150 each. With an engineer costing at least £30 pound an hour and garage labour charges now exceeding £100 per hour at main dealers and £40 per hour at competent garages, the £675 + VAT is not far off the mark.

Needless to say, I am reverting to a good clean out, new seals, springs and playing with the idea of popping a pair of emulators between the bottom of the spring and the damper rod. 

Howard (Disco Volante) used to be in the skyline business in Wales many moons ago!    Tony Brancato, I'm sure would come up with a very nicely engineered solution.

The reality is that renovating these sorts of bits of kit costs dosh!    So will away to the workshop and do a bit more, even though we have the sun today and you appear to have the rain, for us tomorrow.

Good health, Bill.