What Does An “S” Stamp on a Transmission Mean.

[72r60/7]

I’ve heard that the “S” Stamped on the Transmission Filler Area stands for Sport Gearing. Is that True ? When were they used ? I have a ‘57 R60 Transmission with the Stamp on it.

Does anyone know the Transmission Gear Ratio’s for the “S” and the “Non S” ?

Charlie

[20774]

Typically "S" stamped on the transmission indicates "solo" or in other words non-sidecar. Duane has an additional note for some '57 models...he says that the "S" was for sport gearing.

https://w6rec.com/restorers-details/

I've not seen printed what the gear ratios were for the "sport" transmissions.

[72r60/7]

Thanks Kurt. I did find what ratios that seem to be standard (w/o sidecar). Still looking for “S” Gearing ratios.
I can’t remember where I got this from, but I apparently did save.

From an old riders manual, gear ratios are:
Solo - 4.171 -- 2.275 -- 1.938 -- 1.54
S/C - 5.330 -- 3.020 -- 2.040 -- 1.54

This is the “S”

08ED5892-E576-4056-A0A4-5F0D64697B58.jpeg

If I have the Sport Transmission (which is probably Taller), a 2.91 Rear End and the wrong size rear tire (4.00 x 18) for the Rear End, then I have the Tallest combinations I could possibly have.
Time to put a new Rear Tire on this new to me bike. I may have found a good 3.18 Rear End, which matched up to a 3.5” Tire, and i think it will be immensely more rideable to me.

Charlie

[20774]

Update...I posed this question to Duane and we had a discussion about it. He admits that he might not be that clear regarding the names given to the transmission. There were only two types of transmissions - solo and sidecar. He said that early on, people referred to the solo transmission as a sport transmission. So, in this instance, solo is the same as sport. On the above link, he mentions that right out of the gate, the default transmission was a sidecar one and the solo version was an option. In mid '57, that was reversed such that the solo transmission was the standard installed.

Below the three pictures on that page is a paragraph which describes how to determine which transmission you have. Just by checking the output in 1st gear, you'll know which transmission you have.

Duane said he'd update the website when he had a chance.

[69zeff65]

Hi Kurt

I have had a tough time finding time to complete my 13 year '55 R 50, it seems I've fallen down with photos also. I can share what unique items I have for the bike and hopefully get a few pictures of it post this weekend.

I have early flattened / squared off air filter, the correct head light shell & lens, none Solo transmission, Viegel black face KPH speedometer, correct final drive, acorn tail light, 14 mm bolts, correctly placed original chrome & black bolts, correct carbs X 2 sets, correct cylinders, heads, valve covers and as an extra treat I have a NOS early seat cushion as well as an early small coffee can tail light housing that bolts up to the rear fender in the same spot as the acorn tail light.

I have made a set of early rounded front shock covers and I,m working on replicating a set of the smaller head light brackets as I have not had much luck in finding a pair.

I am pushing to have it complete and running for the MOA National, its been a challenge lately with family issues and a work schedule change but its about 65% finished. Did I mention its wearing Holt Police Green with matching correct 1X rims.

I'll try to some pictures posted by the weekend

[jagarra]

Here is a link to a R50S that used to belong to Duane, seller even has old registration with Duane's name on it. Thought you might enjoy checking it out.

https://sacramento.craigslist.org/mc...898770675.html