Since I'm well above the "average" 180 lb rider that Harley sets their bikes up for, I've always had to upgrade suspension. Since most of the weight sits on the rear shocks, its usually an easy rear shock install. Did that already on my '19 Low Rider, with a 13" Ohlins monoshock set up with springs for my weight. Awesome improvement. The extra half inch length from the stock 12.5 raised the rear of the bike about an inch and a half. Next was forks. As I always understood it, it was rear for comfort, front for handling. I've had Ohlins fork cartridges in my past two HD's, and RaceTech springs and emulators in my FXR. Since i'm actually happy with the dampening of the new Showa DBV forks, I decided to try just swapping out the stock springs our for higher rate RaceTech springs for my weight.

Racetech has a calculator which said I should be using 1.3 kg/mm springs. My friend Howard Messner from motorcyclemetal.com recommended I go with 1.1 kg springs. Since he's been making suspensions for me for several years now, I trusted his opinion. So I got the springs today. Cut the spacer tube they included in the kit based on their preload calculations, and used a pair of preload adjustable fork caps I had from a Dyna, that I never installed. The whole job took less then an hour. Simply lifted the front end, loosened the top pinch bolt, removed the cap, fished out the stock spacer, washer and spring, and measured the length needed for the new spacer, taking into account the length of the preload caps. The RaceTech springs are shorter then the stock springs, so I couldn't reuse the stock spacer. Wrestled the new springs, washers, spacers and caps down onto the forks and got everything back together. Getting those caps back on wasn't easy, but its manageable. Torqued the caps and pinch bolts down and went for a ride.

Howard was spot on with the rate. I'm pretty damn happy. For the $140 the springs cost me, this is one of the best improvement to cost ratio mods I've done. Front end brake dive is cut in half or more. Bike feels more planted, stable around turns, and amazingly not any harsher over bad roads then the oem springs. I would dare say it actually feels better over crap roads.

I haven't measured sag or messed with the preload adjustments yet, I want to let the springs break in a bit first, but hell, this is a big win.

If you're weight is more (or less) then the "average" rider, this $140 mod is definitely worth considering.

And as is usual for me, I didn't take a single damn photo of the job... Sorry.

 

Chadly Sir the stock front spring rate is 1.1 as well ,so you're saying the Race Tech spring feels a higher quality set with a better action than the stocker. Did you add any pre-load that was not added to the stock spring length.Quality equipment always has a good feel to it I believe and usually tends to last longer.

Cheers Chad.

Peace.

 

Where did you get that info? HD doesn’t publish that anywhere. Also, stock springs are progressive, so they should have a lower rate for a certain travel and a higher rate for the rest I believe. Perhaps the race tech being linear is the difference?

I set the preload for initial specs, didn’t add anything yet. The front end doesn’t dive anywhere near what it did stock, so I can’t accept there’s no change on spring rate, actual or perceived due to the linear nature.

It just doesn’t make sense to me based on the ride ride/performance.

 

Looking further RT lists the Dyna street bob 49mm fork (the bike they had that I figured was closest weight and characteristics to the softail low rider) as using .5 kg/mm stock shocks.

 

I'd think progressively wound springs would in general be superior, but would indeed suffer more fork dive on stopping. The softer section of the progressive spring lets the fork respond more quickly to small variations in the pavement surface without transmitting so much shock to the rider.

The fork dive with the stock spring should be small, but every rider is different and it sounds like you've found the combo you like. Part of this may just be how our brains process things. Some of us would accept the fork dive for the smoother performance all around; some would rather not have the brake dive.

But throw in the effects of your stiffer and longer rear shock and your higher body weight, and now you've actually transferred some weight forward onto the fork. I'm guessing for you, the stiffer front spring helped even things out. Glad you found a combo you like!

 

I agree, generally progressive springs will give a more compliant ride, but a lot also has to do with dampening. I was always told by an expert that springs sole job is to compensate for gravity and keep the suspension at the right level. Dampening is what impacts ride comfort/control.

I can turn my Road King into a rolling brick by adding too much compression dampening, and contrarily change it into a floating boat with too little. All with the same springs.

Fact is as you said, I weigh more then the average Rider HD sets them up for, and while if your 40lbs more it may not be impactful, but when you’re 100lbs more it becomes much more noticeable. Front end still gets some of that weight no matter how you figure it.

Anyway, that said I’m going to get some real miles tomorrow, and be able to judge better then last nights post-install (and sadly, post happy hour) ride.

But I still want to hear where Agoober heard the stock springs are 1.1kg.

 

Yes, that would be a good data point to have.

 

Resolved.

I sent AGoober a PM asking where he got that data. He explained that:

In a previous thread where I was asking about what spring dimensions I might need for this project, Howard Messner from MotorcycleMetal.com, (who I bought two sets of Ohlins fork carts and a half a dozen rear shocks from) chimed in with that 1.10kg/mm rate. I also was a bit confused at the way Howard wrote it, and was unclear if those were the specs from the stock springs or if that's what I needed for my project. So I gave him a call and he cleared up that those specs were for the springs I would need. I never posted that phone conversation on the other thread. So it was easily interpreted that he posted the stock spring specs.

Thanks.