Wednesday, July 7, 2010

1972 R5C AMA Homologation Special?

Bob writes in with a rather intriguing story:

i have a 1972 R5-C that was delivered new from Yamaha with a six speed transmission instead of the standard 5 speed. the dealer told me Yamaha made 200 of these with a six speed to qualify for AMA racing rules at the time. i have tried for years to get some kind of info or documentation about these 200 bikes but have not had any luck. I have been told by some that Yamaha never such a bike and the dealer probably just installed a TR3 six speed transmission in the bike at his shop. I suppose that is possible but i was there when he unloaded the bike new still in the crate from Yamaha and he told me then about the six speed transmission. He owned the bike for a short time then sold it to my best friend and I eventually ended up with the bike and have had it in my possession ever since. I was just wondering if you have ever heard of these 200 bikes with a six speed or know where i might be able to get some info on them... serial number is R5-111013 manufactured 12/71.

Very interesting. When asked about any distinguishing features, Bob sent the following:

i will get some pics but it looks identical to a standard RB-C except for the rubber rings around tach and speedo... here are photos of the tach rubber on the standard bike and the "six speed" bike. notice the tall front on the rubber on the "six speed" bike [above] compared to the standard bike [below]. Maybe some other Yamaha model has that shaped rubber? Oddly enough there is absolutely no difference in the rest of the bike.

I've seen other bikes that have been homologation specials of this era, and it does seem that 200 is the magic number in order to qualify for AMA racing. Anyone have any ideas, leads, or information about this particular run of homologated specials?

Tuesday, July 6, 2010

Fork Lock on a 1970 R5?

Laura writes in to say hello and ask this question about fork locks:

For one your web site is awesome!! I'm trying to figure out if all 70's have a steering lock key.. I keep looking but do not see one on my bike. And I guess I'm trying to find some shows to go to or put my bike in. 1970 yr5 1200 original miles immaculate condition.

I have an R5C, which is the 1972 model year, and unfortunately all of my manuals are 1972 or later (see links at right), so I'm not sure about the lock on the 1970 year. If your manual says you have one, then you just might... try looking here, on the fork under the left-hand end of the handlebar:

This comes from my original R5C rider's manual - download the whole thing here (26MB PDF). The instructions are confusing. Gotta love the typos, too...

Anyone know if these locks are found on 1970 models?

Thursday, July 1, 2010

Questions about Bars, Mirrors, and Leaky Pipes

Alex wrote is with some questions:

Awesome R5 you got! Where did you get your cafe racer handlebars and mirrors? Also, does your bike seep oil from it's pipes? If so, any tips on how to correct that?

Alex -

Thanks! I replaced the stock bars for lower, somewhat uncomfortable (until I added rearsets) but much better looking cafe bars. The bars are clubman-style, non-adjustable, similar to this. You can find them just about everywhere, in a few different styles and finishes. Just make sure you get the right diameter for the Yamaha.

Note: In order to get the clutch lever off the stock bar, I had to cut off the stock hand grip. I tried not to, but the sucker wouldn't budge. Once the one was cut, well, I went ahead and replaced them both with ProGrip 699 Superbike grips. They have a good vintage look to them, and are pretty cushy to soften vibrations. I simply took an Xacto to the grip ends and trimmed myself a hole on both sides to make way for the mirrors.

Now about those bar-end mirrors... while looking great, no matter how much tightening and adjusting, they just never stayed put. The one thing I could count on was a good view of the ground behind me or my armpit - not good when you actually need to check your background for a quick lane change. They may have just been the brand I ordered (Napoleon), so your mileage may vary.

Anyways, I decided to remove the bar-ends, replace the stock endcaps in their stead, and remount the original stock dental mirror. I managed, after quite some searching, to find a NOS right-side mirror. It didn't quite fit, but with a little Loctite and some swearing I made it work.

The stock left mirror that came with my bike is convex, so it gives me a greater viewing area on my passing side, while the right mirror is flat and just gives me a direct view of what's behind me. The way they're mounted (into the threads on each lever) they are high enough to be useful but not look like antennae, in keeping with the whole cafe racer aesthetic.

As for oil seeping from pipes, I do get a drip or two now and again, same from the case bottom. Nothing too serious. If you're having more than that, I would look into it... anyone here have any suggestions?