Hyper pro R1 shock for RC390

[psych0hans]

Got a really good deal on a Hyper Pro shock for an 07-08 R1. Having it rebuilt and then will install as soon as I get my hands on it. It comes with high speed and low speed compression damping and rebound damping. Unfortunately no height adjustment, which I would have loved, but beggars can't be choosers. I paid about 350$ for the shock and another 100$ or so to have it rebuilt. Hopefully i'll have it in 2 weeks time.

 

[Formula390]

? How are you planning on fitting it? The length isn't correct either if I recall correctly. What's it's eye to eye length? You are looking for something in the 305mm range, +- 5mm.

Sent from my A0001 using Tapatalk

 

[psych0hans]

Hi Matt, the Eye to Eye length is about 300mm, so I don't think that should be an issue. Also, I was planning on fabricating a bracket to maybe increase it by a bit. Not entirely sure how I'm going to do it right now, but I'll definitely keep you posted.

 

[psych0hans]

Took some measurements today and it's looking positive.

Top Bushing Hole - ~10mm


Top Bushing Width - ~30mm


Bottom Bushing Hole - ~ 10mm


Bottom Bushing Width - ~25mm


Overall Length - ~298mm (I actually measured this with a vernier caliper later and it came to be 298mm. It is supposed to be about 300mm on paper)


The kind of bracket I might land up making to compensate for the length.

 

[psych0hans]

So, based on the above post, should I just drop it in or should I make the bracket for increasing the height? Also, is there a way to tell the rate of my current spring? It just says "HYPERPRO" and "620" on the spring...

 

[Formula390]

So, based on the above post, should I just drop it in or should I make the bracket for increasing the height? Also, is there a way to tell the rate of my current spring? It just says "HYPERPRO" and "620" on the spring...

You want your total length to be somewhere between 305 and 310mm. Any spacer you make to lengthen even if it was RIGHT against the shock is going to add too much length as you'll end up somewhere in the 320-325mm realm it looks like... so you'll be well beyond the 310mm length and will start running into interference with the swingarm. So really, your option here is "run it" as is. With a 298mm length you are going to be short. If you're spring is correctly rated you can take SOME of that up a bit by preloading enough to just loose some of the extra length to static sag, but that's problematic too. It's basically not ideal either way you go really. An alternative might be to possible mill off the bottom busing entirely, then drill and tap the hole, to put in an adjustable ride height adjuster. For that, you're taking a bit of a risk because you don't know how much material you have in there. It's also not without risk, because you don't know the quality of the metal... you could easily machine away too much, and risk a shock failure. I've also had serious concerns about how to intent to get that reservoir to clear... with the way it's mounted on the shock jutting straight out like that, I have serious doubts it's gonna fit without having to modify the exhaust quite a bit. Now, you have access to a full exhaust fabrication shop, so that's not as big a deal for you as others, so that may not be as big an issue... but I'm not sure if even with that you'll get it to fit. Have you actually verified you can get it in there yet?

If it were ME, I'd scrap the idea of using that particular shock, sell it, and find something the correct length. It's just the wrong size of shock. I went through a LOT of shocks finding a swap candidate, and the only real one that's viable, for those who are really that concerned about cost, is to go with a used Gen1 99-02 R6 shock. It's 304mm and mounts right up with the addition of a small bushing for the bottom and some bushings for side play at the top. That's WAY easier to fabricate and zero risk. You can put any spring on there you need. For your weight, you are going to want either a 600# or 650# spring. I would probably recommend going with the 650, considering the roads ya'll have there in India. You can get springs the correct size, and threaded preload adjusters that'll replace the stock stepped adjuster. Sorry man, but it's just not a good swap candidate.

Edit: I'm saying this because I'm genuinely concerned about what modifying the shock will result in. You do NOT want to risk having a catastrophic failure of the rear shock. Folks die from that sorta thing. Finding a used Gen1 shock is easy, and cheap. You can drop a spring on it, and just run it. If you pop the seal, just buy another. Or put the money towards a "real" shock like the JRi... but I wouldn't risk it with that R1 shock.

 

[psych0hans]

How come you're always right... hahaha I'm not TOO worried about the height right now, as I'm not running anywhere near race or even a fast pace for that matter. But I do have an idea of what exactly I'm going to do about it. It will involve two brackets on either side of the swingarm mounting brackets to increase the height by as little as possible, just need to work out the dimensions and then make a 3d print to test the fitment. Do you know the width of the stock shock bushing? I don't have a vernier caliper at home, or I'd measure it myself.

 

[Formula390]

How come you're always right...

Clearly you haven't been talking with my Wife!!!

I'm not TOO worried about the height right now, as I'm not running anywhere near race or even a fast pace for that matter. But I do have an idea of what exactly I'm going to do about it. It will involve two brackets on either side of the swingarm mounting brackets to increase the height by as little as possible, just need to work out the dimensions and then make a 3d print to test the fitment. Do you know the width of the stock shock bushing? I don't have a vernier caliper at home, or I'd measure it myself.

The height at 300mm vs 298mm isn't terrible. That's assuming it's really 298. I thought I remember it being 295 from my research but that's fuzzy memory. You need to remember tho that the shock length is magnified at the end of the swingarm a great deal tho! Pythagorean Theorem aside tho, you don't want to deliberately shorten your suspension travel. I think you're going to be spending a lot of time and effort on this shock for ultimately not being happy with it. You could spend the same time on a suspension setup that will work great and require FAR less customization if you go with a shock others have already proven to work. If you are just buzzing around on city streets on it and "not racing or fast pace" then stick with the stock shock and put a decent straight rate spring on it with correct sag. After that you can look at the Gen 1 R6 shock, or upgrade to the JRi (or the recently introduced Ohlins). JRi also just came out with a single adjustable 35Pro which has an integrated reservoir that's very competitively priced! It's more targeted to the Duke but it would work on the RC too.

 

[psych0hans]

Hi Matt, this is what I found online regarding the lengths.

Year 04-06 Shock length 300 mm
Year 07-08 Shock length 302 mm
Year 09-11 Shock length 297 mm

This is what I bought, it fits 07-08, so I doubt it will be smaller than that. Was going to fit it this week, but the guy who was going to do it for me was too busy, so it's shifted to next week. I'm also reworking my forks at the same time. I'll either go in for a .85kg/mm spring + heavier oil, or, if they fit, RC8 Internals. Not sure about the latter.

 

[psych0hans]

? How are you planning on fitting it? The length isn't correct either if I recall correctly. What's it's eye to eye length? You are looking for something in the 305mm range, +- 5mm.

Sent from my A0001 using Tapatalk

Hi Matt, I finally got to trying to fit it today and it just wouldn't fit... Only way it will fit is if I get rid of the rear fender and mount it upside down. This is actually not a problem, as confirmed by hyperpro, but then I'll be flinging mud all over the shock... So, it's up for sale and I'll finally be buying a shock actually made for my bike... lol. Thank you for your patience and support

 

[Formula390]

Yeah, pretty much figured. The stock gen1 R6 shock will work, but other manufacturer shocks are a total wild card! When I saw the arrangement of that shock you were wanting to use I just though... "No Way is that going to work!"

I've got the JRi shocks in stock, as well as R6 shocks built for the RC390. Let me know if I can help with that...

 

[psych0hans]

THE DEED HAS BEEN DONE!!! I have finally managed to achieve what I intended. It shouldn't have taken nearly as long, but I was just dilly dallying on it. Still haven't ridden the bike after the install, but will do so tomorrow.

 

[GOJO]

Surely theres room for a duke hugger as that is what i have done

 

[psych0hans]

View attachment 4048Surely theres room for a duke hugger as that is what i have done

I actually bought a duke hugger and then promptly lost it... lol I'll fit a new one asap.