Narrow Case Rear Wheel

[Terryp]

Hi
I was wondering if anyone could help me with some measurements for the rear wheel on a 250 Narrow Case Ducati. My bike at present has a rear Grimeca hub and brake from a Benelli 2c, I think this is creating some of my handling issues as the rim may not be in the correct position relative to the hub. Could someone confirm the spacer on the sprocket side, is this 25mm dia x 15mm dia by 13.5mm thick?. Should the rim be spoked centrally about the spoke flanges on the hub? Ideally if some one could measure or advise on the spoke offset from the brake opening, the width of the rim, and the offset from the cush drive opening that would be great. Many thanks in advance, Terry

[shat]

Originally Posted by Terryp

Hi
I was wondering if anyone could help me with some measurements for the rear wheel on a 250 Narrow Case Ducati. My bike at present has a rear Grimeca hub and brake from a Benelli 2c, I think this is creating some of my handling issues as the rim may not be in the correct position relative to the hub. Could someone confirm the spacer on the sprocket side, is this 25mm dia x 15mm dia by 13.5mm thick?. Should the rim be spoked centrally about the spoke flanges on the hub? Ideally if some one could measure or advise on the spoke offset from the brake opening, the width of the rim, and the offset from the cush drive opening that would be great. Many thanks in advance, Terry

Terry,

I so happens that I have complete front and rear wheels (rims/tires/hubs/ axles and spacers) from a 1967 250 MK 3 sitting in my storage. I took it off a totally original bike to add an alloy-rimmed setup several years ago. I kept these totally intcat incase I changed my mind. I'll measure tonight.
Steve

[Terryp]

Hi Steve

That would be great, much appreciated

[shat]

Terry, The offset is one full inch toward the brake side with the spacer inserted within the dust shield on that side. Steve

[shat]

Terry, Let me be a little more specific: Using a 18" straight edge resting across the poen brake hub the distance to the edge of the rim should be a full one inch less then the same measurement on the chain side with the sprocket carrier and cush drive removed. This assumes you have a stock period steel rim WM-2 (by Radelli usually). Baruzzos are often mistakenly installed on the rear but I have found that in two instances of known factory original narrowcase sport models (a Mach One and a Mark 3) each came with WM-1 Baruzzos (CEAT 2.50 skin) on the front and WM-2 Radellis (CEAT 2.75 skin) on the rear (both chrome on steel of course - never alloy). If you are using some other width rim, the offset concept should remain about the same.

As to spacer, just a single planted in the the well on the sprocket side is all that Ducati used on the 250 N/Cs.

Hope this helps.
Steve

[Terryp]

Hi Steve, thanks for that, a great description. I do have an alloy rim 2.15 x 18 so long as there is 1 inch less offset on the brake side as opposed to the cush drive side i should be right. Thanks for your time much appreciated
Terry