I have a 2020 Harley Roadster that I am planning to build into a light cruiser. I like the Roadster because of the dual front disks, a decent lean angle, and a bit more rear suspension travel. I am planning to put the larger (4.5 gallon) tank on it, along with a large enough windscreen to make it comfortable cruising at interstate speeds. My question today is about the engine. The original engine needs a rebuild, so now is the time to decide what to do going forward.

One of the possibilities that is really interesting is the Hammer Performance 90 cubic inch modification. The biggest question for me is reliability. Will a 90 incher, well-maintained, hold up for the kind of miles/years that a stock 1200 will do, or is this going to be a problem for daily use and/or road trips? Heat problems? I have looked at published dyno results, and it looks like a lot of fun, but I want something that is going to stay on the road for the next 30k miles or so.

Any thoughts are welcome, especially for anyone with first-hand experience.

Thanks,
WLW

 

Absolutely you should do it! There is no rational reason to justify it so why are you trying? It will cost too much, you will have too much power, your face will prematurely age from over smiling, you will have to buy more gas, you will go though back tires quicker, your wife won’t understand why……blah blah blah.

 

I just rebuilt my engine and looked into this but decided to go a different route. I wanted a cruiser. I can't speak to the reliability but it is a custom build and they bore the cases. The cylinders are also thinner which is why they use iron not AL. Bottom line I decided against it as it seemed to me if reliabilty and longevity was my main goal building a torque monster wasn't really in line with that. That was just my thought process, wrong or right. If I wanted a bike to haul *** around town I would have gone that route. Hammer makes good stuff and I used plenty of their parts in my build. Just not one of their kits. Your bikes only 2 years old. I would just keep the core motor intact and build from there. It should have a lot of life in it. Mine was 20 years old on the original motor and even then it wasn't having any issues. It was just tired.

 

I've built several 1250 motors with NHRS parts, previous to Hammer doing his thing. They've been bullet proof motors. With N4 or 560 cams they've been a hoot to ride. My current sporty 1250 has over 20k miles on it, other than a weepy lifter tube, perfect.

Power and economy are great. Bike will power wheelie my fat *** at most any time, and returns 50mpg with a light wrist.

That said, do your research, and build accordingly. Hammer knows his business, and a chat with him is gold.

 

Here is a video about a Sportster with an S&S 100 cubic inch (1640cc) kit, it produces 127hp at the rear wheel.

 

How much power do you need, and how much are you willing to spend? Going to 90 inch means splitting the cases and some machine work. I would imagine there is a huge "delta" from just changing cams, heads, and barrels versus taking the next step and ugrading the lower end. For what you say you need, it seems just spending money on your top end would be a reasonable upgrade. The more stuff you change and modify, the more things that can go south.

But, it's your budget, good luck!

I just did the basic Hammer 1250 upgrade, and have more than enough power for my needs. YMMV.

John

 

Looks like Jorgen Karlsson's previous motor... The later one is 124cid (151 rwhp).


T.

 

The engine needs a rebuild, so the cost consideration is the difference in cost between a stock 1200 and whatever else I might consider doing. Possibilities include a nicely built 1200, a 1250/1275, and/or a 90 incher. If I'm building this thing, I don't want to look back later saying "I shoulda . . ." With that in mind, I really don't NEED a 90 incher on the bike, but in my 70 years on Earth, I have never been disappointed to find that i had too much torque/hp.

 

Inquiring minds.... So I'm just wondering why a basically 'new' 2020 model
would already need to be rebuilt ? Did someone run it without oil or what's the story ?

Thanks!

T.

 

A two year old motor needs a rebuild? Why?

Doesn't HD offer a 2 year warranty? Have you tried to contact HD?

John