little cafe racer - Ducati.ms

187 speed · Jul 31st, 2011, 10:00 am

So awhile back I sold my 750ss and have been "itching" for another ducati. I enjoy building things since that is my profesional background so I figured a vintage cafe racer would fit the bill perfect. So after just snooping around alittle and keeping my eye out I found a donor bike on ebay, a 160 monza junior. Other than the motor the bike seems very complete and really in decent shape. I already know i want to switch to some 17" alloy wheels and strip it down to almost full racebike attire but my main debate right now is what to do for a motor? I dont mind saving for a bit and searching for a something really cool or just building the 160 I just dont know what all motors will fit and what would be best suited for this project since this is my first vintage ducati? I am not worried about being a direct bolt in since I have access to lots of cnc equipment and have the skills to build anything i need to adapt so its just a matter of choosing a motor, finding one and stuffing it in!! I am not worried about originality or correctness since this will be something for my enjoyment which i plan on keeping and enjoying for a very long time. Any advice or sources any one can reccomend would be greatly appreciated!!

gregwils · Jul 31st, 2011, 1:35 pm

Funny. I bought a 160 about six weeks ago - very low miles, engine spins freely, bike is mostly complete except for some rusty wheels. Make that seriously rusty wheels. I did buy a replacement set of 16's from another junior as a temporary replacement, but 17's are the way to go. It's my understanding 18's won't fit.

You might want to consider buying Tom Bailey's buyers guide. He gives good perspective on singles. He talks a little about swapping motors. The downside of the 160 frame is the forks are from the Bronco, and are inferior than the 125's which most of the bike and motor are based. Also, the rear swing arm is shorter than the 250's, so the bike is more nimble around town at low speed, but less stable at high speed.

Tom talked about people putting 160 motors in 250 frames. IRRC, he said they just needed some spacers at the front mount, so you would probably need to machine the larger case or adapt the frame to accept the wider (20 mm).

There was a 160 in Indiana on eBay a few days ago, is that the bike? Please share your progress, I hope to learn from you.

187 speed · Jul 31st, 2011, 3:01 pm

Yeah the one on ebay was the one i bought. The guy who i bought it from was awsome, worth the two hour drive just to meet him. He is a vintage road racer who races old kaw tripples. I have two 125 motors but really dont want to use one in this because it is my understanding they are way down on power!! I think you could put 18's on it with alittle modification but not sure, I will investigate that for sure!! I can see this thing being allittle (or alot) twitchy at high speeds but really not planning on opening it up on any long straights, just mainly to cruise around town on and ride to some local things. I will continue to post updates and info as I go but just a warning it will probably be a very long term project because I have a couple other non ducati projects already going. Got it stripped down and cleaned up this morning and it now resides in my living room, yeah my wife is the best!! oh yeah I also stuck one of the 125 jugs and head on it so it looked alittle better!!

187 speed · Jul 31st, 2011, 3:16 pm

And also thanks for the suggestion on the book, just ordered it!!

DesmoDog · Aug 1st, 2011, 10:51 am

You can put any of the narrowcase engines in it. I'm going to use the 250 as an example since they are the most common in the US but a 350 would also work.

Spacers for the front engine mount are trivial. You can, and probably should, put the better front end from a 250 in the 160 also. You can either make another spacer (the 250 steering stem is longer) and/or you can convert over to roller bearings. IIRC most of the conversions for roller bearings are taller than stock.

The swingarm on a 160 is shorter, as mentioned. You can get an 18" wheel to fit, but you can't use a rear fender if you do. You can put a 250 swingarm on it. You're probably going to go with longer shocks so the slight difference in the rear section of the frame won't interfere with the larger wheel and maybe even fender? (The 160 has a flat rear loop, the 250 sweeps up a bit at the end)

Any of the narrowcase tanks will fit it though some may need minor mods. Note that a 350 is taller than a 250 which is taller than a 160 so when fitting a tank use the engine you plan on going with. Likely not an issue for you, but the 350 will hit the bottom of some tanks. Some Benelli tanks will fit too.

187 speed · Aug 1st, 2011, 10:13 pm

Thanks for the wonderful info!! I am learning soo much about these singles on here, I am soo excited about this project I think it might be getting bumped up on the priority list!! So the real question, in everyones opinion what do I do for a motor?? This will mainly be in town cruising and short blasts of maybe 20 or 30 miles, no real long rides anticipated. I am clueless of how much power any of these motors make or what performance mods are possible, availability needs to be taken into account aswell. The bike currently has the bottom end of the 160 but no piston, jug, head or any of the bevel drive stuff. Thanks everyone!!!

DesmoDog · Aug 2nd, 2011, 12:58 pm

Read the book when you get it and you will likely be able to make your own choice on the engine. It really comes down to what you want to end up with. If you are going to the trouble of adding larger wheels and a better front end I'd get a 250. If you want to keep the stock front end and swingarm, I'd stick with the 160. There are advantages to either engine choice. FWIW I'm currently building both a 160 and a 250-turned-350 so I have seen the appeal of either choice.

Here's a link to my single cylinder projects: Ugly Ducs Squared

If you do decide to go with the 160 I'd probably look for an entire engine rather than the parts you need for yours... the parts you need are out there but they might end up costing more than a complete engine would. Also keep in mind that you want the cam gear and tower shaft gear to be a matching set.

In general it's easier to find parts for the 250 family of engines. It is certainly easier to find go-fast parts/info for the larger engines if that's your aim. Again, read the book and you'll have a better idea of what I'm talking about. For pure style points, some people think the 160 engine is better looking if that sort of thing matters to you.

All in all... if I were planning on spending a lot of time and/or money on a Ducati single, and didn't have any specific goal in mind, I'd start with a 250. That was my original plan but my 160 was included in a package deal. It was only my desire for a 125 Sport replica that made me consider building it. (Though the bike I ended up building isn't a Sport replica!) For the basis of a generic cafe bike the 250 wins hands down in my book. The 160 was built to be a cheap bike. The 250 has racing history, good parts support, a huge base of knowledge for tuning, and 250 Monzas are relatively common as far as Ducati singles go. 250 Scramblers are out there too but IMHO if you find a complete Scrambler you should keep it a Scrambler and not cut it up for yet another cafe bike.

187 speed · Aug 2nd, 2011, 8:28 pm

Well i recieved an email today from the gentleman I bought the 160 from, he has another 160 with a complete motor that kicks over and has compresion and this one has a title so that saves me some work on that end aswell. The best part is the price is only $50 more than I paid for the first one!! So I think this has probably made up my mind to build a 160. So the past two days my wife and I have been spending some time in the living room looking at and discussing this bike, she has a good eye for neat vintage stuff so i listen to her opinion pretty seriously. Well she wanted me to see what it looked like with the stock light and side covers back on, i put them on and she said "yeah thats the look". Our (her) idea is to use alot of the stock parts but ad little "cafe" touches to it. lose the rear fender and add some beter looking shocks on the back, larger black wheels with chrome spokes and polished hubs, some clubmans or custom cafe bars and a real trick but understated cafe seat that looks like it might have came stock on the bike. The rest of the bike could retain its factory appearance, of course knowing I change my mind every other day this is just an idea but one i really like and think would be happiest with on this bike!! Progress will start alot sooner than anticipated because of the aquisition of the second bike and i will post as many pics as i can so stay tuned!!!

gregwils · Aug 3rd, 2011, 12:12 pm

Quote:

Originally Posted by DesmoDog

You can, and probably should, put the better front end from a 250 in the 160 also. You can either make another spacer (the 250 steering stem is longer) and/or you can convert over to roller bearings. IIRC most of the conversions for roller bearings are taller than stock.

This is excellent information. I will definitely head down this path. I don't even like the appearance of the stock (Bronco) forks.

Quote:

Originally Posted by DesmoDog

You can put a 250 swingarm on it.

I was wondering about this as well. Thanks.

187 speed · Aug 7th, 2011, 11:13 am

So I went and picked up my second 160 the other day, I was pleasantly surprised at the condition of the motor and a few other parts but the frame is not soo nice. Yesturday I degreased and preasure washed the motor and just had to put it in the bike. After seing it in the bike I got the itch to do some fab work so i decided to build a seat pan. Started by raking the tail section up a bit then built a frame work out of 1/2" tubing to match it. Then I bent a hoop, tail and two downtubes to give it some shape and something for me to fasten my sheetmetal to. Once I had the sape I liked and it flowed good with the tank i welded it all up and started to shape the sheetmetal on the english wheel. Then went on and covered the seating area with a peice of sheetmetal that i ran through the bead roller to add some strength to. So now everything is tacked up and just needs final welding and cleanup then i can cut my tacks off and make tabs to bolt it on the frame, this is my first attempt at a seat with a cowl on it but i think it will be nice once its painted. Now on to build some handlebars!!!