Progressive Monotubes Review...
#1
Progressive Monotubes Review...
'13 Softail Slim.
I already installed a Shotgun Shock on it last year, and while the ride was fantastic, it also amplified how lacking the front suspension was.
If I rode with the rear lowered more than an inch or so, it seemed to throw the center of gravity off enough to make the front end feel lighter.
Even small bumps would hammer me in the shoulders.
So... time for an upgrade.
After much research I decided on the Progressive Monotubes, over their progressive springs and Ricor Intiminators.
After waiting a week for the parts (BO'd from two different vendors) they finally arrived Saturday.
I got the Progressive Monotubes model # 31-2502, which is designed to maintain stock height.
They came in two flavors for my bike, the 31-2502 (stock height) and the model # 31-2504, for those who want to lower the height either 1" or 2"...
Installation was simple, in fact the hardest most time-consuming part of the whole job was removing my auxiliary lights, headlight and shrouds.
Installation only required that I just pull out the stock guts (main spring, damper rod & top-out spring) and replace with the monotubes.
I had to re-use the stock top-out spring as per the instructions.
And thanks to the advise I got here, I decided to just go with the one pre-load spacer as opposed to two which were supplied with the kit.
I can already tell from a 100-mile ride yesterday that this was the right move, two would've probably been too much, ie; too stiff.
Also, when I went to the dealer for new damper bolts and crush washers, I decided to NOT buy their fork oil, since neither their "Type E" or "SE" oils display weight info.
I've seen posts here arguing which one to use, some saying one is 5W and the other 10W.
Other posts say the opposite, and since the guy at the dealer parts counter couldn't say for sure, I decided not to take a chance.
The installation guide for the monotubes is very specific that you need 10W oil - so instead I went to the local dirt bike shop and bought a liter of BelRay High Performance 10W fork oil for $15.
Problem solved. You only need just 5 oz. per tube, strictly for lubrication, and not for damping.
The only issue I encountered during reassembly was getting the last remaining stock piece, the "centering cup" relocated properly.
It sits all the way at the bottom of the tube and can't be removed without popping the seals and totally disassembling the tube.
It seems that when I turned them upside-down to drain for a day, they became dislodged and turned sideways.
All I had to do was to turn the tubes vertical and shake until I saw daylight, looking down from the top.
Being tapered, they fell right back into place. Easy enough.
And lastly, for reasons I don't understand, the monotube kit came with two new chrome fork tube caps and rubber washers.
I have no idea why they included such a (probably) pricey bit when the stock ones were perfectly fine - in fact they're identical.
I only mention this because I found it curious that they directed me to re-use my existing "el-cheapo" (probably $2) top-out spring, then they threw in a far more expensive precision chromed bolt that I didn't even need.
One thing I did screw up on though was forgetting to add the stock "flat washer" back under the fork caps before re-installing.
Again, an easy fix.
The ride...
The ride is noticeably improved.
Like the Shotguns it feels more firm, more planted, without as much bounce as the stockers had.
But at the same time they seemed to eat up most minor road noise a lot better.
After heading out to some of the bumpier roads around here, I only felt the largest bumps.
The biggest improvement I've noticed so far is the lack of brake-dive.
I felt like I had better control overall.
But here's the thing - I wasn't "blown away" by the difference over the stock shocks as I was with the Shotgun.
Were my expectations too high? I really don't know. Maybe. ..Probably.
While they definitley are an improvement over stock, I can't yet say that they're a HUGE improvement.
The jury's still out on that.
More seat time will tell I'm sure, since with all the rain here lately I've only gotten to take that one ride.
..and I must admit it was on mostly good quality roads, so not quite a fair test... yet.
Lastly... having the right tools makes this job easy.
Two special items that I highly recommend are a Fork Cap socket: Fork Cap Socket for HD
and a long 6MM allen socket - I found one at Lowe's of all places: Kobalt 3/8-in Drive Hex 6-in Driver Socket
..and don't even attempt this without a service manual, red & blue Loctite, anti-seize (for your axle) and two torque wrenches, one for ft.-lbs, and another for in.-lbs.
I already installed a Shotgun Shock on it last year, and while the ride was fantastic, it also amplified how lacking the front suspension was.
If I rode with the rear lowered more than an inch or so, it seemed to throw the center of gravity off enough to make the front end feel lighter.
Even small bumps would hammer me in the shoulders.
So... time for an upgrade.
After much research I decided on the Progressive Monotubes, over their progressive springs and Ricor Intiminators.
After waiting a week for the parts (BO'd from two different vendors) they finally arrived Saturday.
I got the Progressive Monotubes model # 31-2502, which is designed to maintain stock height.
They came in two flavors for my bike, the 31-2502 (stock height) and the model # 31-2504, for those who want to lower the height either 1" or 2"...
Installation was simple, in fact the hardest most time-consuming part of the whole job was removing my auxiliary lights, headlight and shrouds.
Installation only required that I just pull out the stock guts (main spring, damper rod & top-out spring) and replace with the monotubes.
I had to re-use the stock top-out spring as per the instructions.
And thanks to the advise I got here, I decided to just go with the one pre-load spacer as opposed to two which were supplied with the kit.
I can already tell from a 100-mile ride yesterday that this was the right move, two would've probably been too much, ie; too stiff.
Also, when I went to the dealer for new damper bolts and crush washers, I decided to NOT buy their fork oil, since neither their "Type E" or "SE" oils display weight info.
I've seen posts here arguing which one to use, some saying one is 5W and the other 10W.
Other posts say the opposite, and since the guy at the dealer parts counter couldn't say for sure, I decided not to take a chance.
The installation guide for the monotubes is very specific that you need 10W oil - so instead I went to the local dirt bike shop and bought a liter of BelRay High Performance 10W fork oil for $15.
Problem solved. You only need just 5 oz. per tube, strictly for lubrication, and not for damping.
The only issue I encountered during reassembly was getting the last remaining stock piece, the "centering cup" relocated properly.
It sits all the way at the bottom of the tube and can't be removed without popping the seals and totally disassembling the tube.
It seems that when I turned them upside-down to drain for a day, they became dislodged and turned sideways.
All I had to do was to turn the tubes vertical and shake until I saw daylight, looking down from the top.
Being tapered, they fell right back into place. Easy enough.
And lastly, for reasons I don't understand, the monotube kit came with two new chrome fork tube caps and rubber washers.
I have no idea why they included such a (probably) pricey bit when the stock ones were perfectly fine - in fact they're identical.
I only mention this because I found it curious that they directed me to re-use my existing "el-cheapo" (probably $2) top-out spring, then they threw in a far more expensive precision chromed bolt that I didn't even need.
One thing I did screw up on though was forgetting to add the stock "flat washer" back under the fork caps before re-installing.
Again, an easy fix.
The ride...
The ride is noticeably improved.
Like the Shotguns it feels more firm, more planted, without as much bounce as the stockers had.
But at the same time they seemed to eat up most minor road noise a lot better.
After heading out to some of the bumpier roads around here, I only felt the largest bumps.
The biggest improvement I've noticed so far is the lack of brake-dive.
I felt like I had better control overall.
But here's the thing - I wasn't "blown away" by the difference over the stock shocks as I was with the Shotgun.
Were my expectations too high? I really don't know. Maybe. ..Probably.
While they definitley are an improvement over stock, I can't yet say that they're a HUGE improvement.
The jury's still out on that.
More seat time will tell I'm sure, since with all the rain here lately I've only gotten to take that one ride.
..and I must admit it was on mostly good quality roads, so not quite a fair test... yet.
Lastly... having the right tools makes this job easy.
Two special items that I highly recommend are a Fork Cap socket: Fork Cap Socket for HD
and a long 6MM allen socket - I found one at Lowe's of all places: Kobalt 3/8-in Drive Hex 6-in Driver Socket
..and don't even attempt this without a service manual, red & blue Loctite, anti-seize (for your axle) and two torque wrenches, one for ft.-lbs, and another for in.-lbs.
Last edited by jam436; 07-01-2017 at 06:17 PM. Reason: added links
The following users liked this post:
betho61 (02-18-2023)
#3
I was surprised to see just how soft the stock shocks were.
They would compress and travel 3-4" or more just accelerating and braking.
EDIT: Here's a short GoPro video clip showing just how soft the stock suspension was.
It's only about a minute and half but fairly revealing...
I guess I should get one now of the "after"...?
Last edited by jam436; 05-12-2014 at 06:33 PM.
#5
#6
Great stuff, JAM. Appreciate your thoughts and your great write-ups.
Of particular interest was the GoPro vid. It showed me what I was kind of sensing - the brake dive in particular. Was surprised at the travel at other spots, too - shifting, accelerating. Would be great to have a repeat with the new system - but, knowing you, you've probably either already planned on it, or have already done it.
I'm hoping to be able to upgrade at the same time I PC the forks... Scored a nice PC system from a guy who's shutting down, so hopefully I'll be able to do my own work here in the next couple of months, or, at least, next winter.
Of particular interest was the GoPro vid. It showed me what I was kind of sensing - the brake dive in particular. Was surprised at the travel at other spots, too - shifting, accelerating. Would be great to have a repeat with the new system - but, knowing you, you've probably either already planned on it, or have already done it.
I'm hoping to be able to upgrade at the same time I PC the forks... Scored a nice PC system from a guy who's shutting down, so hopefully I'll be able to do my own work here in the next couple of months, or, at least, next winter.
#7
A surprisingly easy upgrade - this is the second time I tore my front end down, 1st time was for powercoat...
You wouldn't even need to remove the headlight.
Just unbolt the shrouds and the headlight and do what I did, bungie it up onto your handlebars.
Drop your wheel off and once you have access to the pinchbolts (from the front on the bottom tree) the forks slide right out.
Last edited by jam436; 05-12-2014 at 06:06 PM.
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#10
Here's the after video (after the Progressives) on the same road...
Fork bounce, travel and brake dive have been greatly reduced.
Where I was getting upwards of 4" of travel with the stock shocks (just accelerating and braking), they'e now firmed up to where it's more like only 2"...
Quite a difference.
Fork bounce, travel and brake dive have been greatly reduced.
Where I was getting upwards of 4" of travel with the stock shocks (just accelerating and braking), they'e now firmed up to where it's more like only 2"...
Quite a difference.
The following users liked this post:
betho61 (02-18-2023)