2 STROKE WORLD .net

The 2-Stroke Garage => Turning Wrenches => Topic started by: Scooterror on February 20, 2019, 05:40:51 PM

Title: Rear Suspension Recommendation
Post by: Scooterror on February 20, 2019, 05:40:51 PM
Anyone have a recommendation for non oem uprated rear suspension for a 74 Rd? I have installed bronze swingarm bushes. Not a track bike but for aggressive street riding. I'm sure this was covered in excess on the old site. Sorry for the repeat
Thanks
Title: Re: Rear Suspension Recommendation
Post by: Eric P on February 21, 2019, 10:39:38 AM
When it comes to suspension, the sky is the limit and your budgets and performance requirements will pretty much determine the best option for you.

I've had really good luck with those really cheap "RFY" adjustable shocks. They can be had for about $50-60/set and are a major upgrade over stock shocks. A lot of people rebuild them with fresh seals and a known weight oil to improve the damping. There are a few tutorials kicking around on how to do it. They're pretty much a bottom of the barrel budget option but seems to be working well for the street riding I do. They held up well on my cross country trip and my bike was loaded down pretty heavily with tools/parts/supplies. Well worth it for the money, but not necessarily the best quality out of the box.

I don't have any pictures of my cross country bike at the moment, but here is a photo of my R5 with the RFY shocks:
(https://i.postimg.cc/HLdRxK7Y/00000-i-Diu-Nxgyd-EV-600x450.jpg)

If you're looking to spend a bit more for quality and retain more of a stock appearance, Hagon would probably be my choice for name brand shocks. And if you want to spend big money and get a custom made shock with your specified spring rate, there's always Ohlins... though I've never been able to justify over $700 on a pair of motorcycle shocks!

Note that stock shock length is 325mm, so you'll probably want to stick to that or you'll be changing your suspension geometry. Also make sure that you get shocks with the correct ends as there are a few different types.

There's also suspension swaps from other bikes (notably the ninja 250), but I assume that that topic is a bit out of the scope of your question.
Title: Re: Rear Suspension Recommendation
Post by: m in sc on February 21, 2019, 11:52:52 AM
rfys are 'ok', i have a set on 2 bikes, one being an R5. icon is good, as is hagon as well. .02

also, occasionally redwing nos rd shocks come up on ebay, ive run those as well. stock looking slimlines, but good performance.
Title: Re: Rear Suspension Recommendation
Post by: ~JM~ on February 21, 2019, 01:16:28 PM
Tag along...

I've used Hagons & like them. Seem to recall a problem or price increase possibly due to new imported steel tariffs. Could be wrong on that. Had either Koni or Boges on my XR when I was a kid.

What about improving the swing arm rigidity?
Title: Re: Rear Suspension Recommendation
Post by: Organicjedi on February 21, 2019, 01:21:59 PM
Progressive 12s are a very nice shock too.
Title: Re: Rear Suspension Recommendation
Post by: bizzcb1100f on February 21, 2019, 01:38:55 PM
I also have a set of the RFY shocks on my 77 RD400. had Chris Livengood (CL Mototech) go through them, change oil and properly charge them. They have worked out pretty well so far.
Title: Re: Rear Suspension Recommendation
Post by: Hawaii-Mike on February 21, 2019, 03:13:06 PM
I really like Koni's and their modern day versions, Ikon shocks.  They cost more but the ride is very nice. 
Title: Re: Rear Suspension Recommendation
Post by: Dvsrd on February 21, 2019, 03:22:17 PM
If I was to buy a set of new shocks today, Falcon would be my choice. https://www.falconshockabsorbers.co.uk
They build any length and stroke you want, and offer both alloy and steel bodies, in 3 and 4" stroke. For a performance oriented RD, I would have considered around 13.5" length with a 4" stroke. However that would require careful checking of tyre clearance and chain tension at full compression, and maybe some frame mods, depending on tyre width and section. 13.9" length with 4" stroke would eliminate those issues, but may create other problems.

What about longer swing arms for the early RDs? The 400s have 25 mm longer, and some aftermarket swing arms are even 51 mm/2" longer than stock. That must surely improve comfort and stability a bit, and tame the wheelie tendencies as well..... The last part may not be desirable for everyone  ;D

I actually had Danny at 29Cycles build me a 50 mm longer custom swing arm from slightly larger tubing. I still haven't fitted it, as I have to make a new loop (where the indicators are mounted), to be able to move the rear fender. One change leads to another...Also, longer swing arms OR longer shocks create clearance issues with stock mufflers. The advantages may or may not be worth it, depending on your priorities.
Title: Re: Rear Suspension Recommendation
Post by: e30 gangsta on February 27, 2019, 09:41:56 PM
I got a set of new Hagons valved and with the correct spring for my weight. I love them.
Title: Re: Rear Suspension Recommendation
Post by: SoCal250 on March 01, 2019, 01:45:23 AM
Quote from: e30 gangsta on February 27, 2019, 09:41:56 PM
I got a set of new Hagons valved and with the correct spring for my weight. I love them.

Me too. I ordered some a few years ago with custom length and spring rate. They're great, especially for the price.
Title: Re: Rear Suspension Recommendation
Post by: 71R5JPAR on March 08, 2025, 10:40:42 AM
Anyone give the Vintco air shocks a try? Cannot find any reviews on them for RD bikes.

https://hvccycle.net/air-shocks-vintco-13-5-inch-to-17-5-inch/
Title: Re: Rear Suspension Recommendation
Post by: automan on March 08, 2025, 11:11:05 AM
Ain't nobody wants air shox

esp. at 800
Title: Re: Rear Suspension Recommendation
Post by: axldk6 on March 19, 2025, 06:25:57 AM
suspension is next on my list. so what model or part # is the RFY ( 74 350) ? looked on the site but 325 mm shows a ninja 250 with remote reservoir? tia.
Title: Re: Rear Suspension Recommendation
Post by: sav0r (CL MotoTech) on March 19, 2025, 11:13:39 AM
The correct, or at least most correct RFY is the 320mm base shock with the 7mm spring. Ideally, if you can find it, the conical wound 7mm spring, but the square wound one is more common. Keep in mind even that spring is slightly stiff. I landed on 80lbs per inch on my fairly light RD350, I weight around 150lbs. RFY 7mm springs are like 96lbs per inch. Some people like it, some people want the mushy stock ride. It's all preference.
Title: Re: Rear Suspension Recommendation
Post by: The Red Scourge on March 20, 2025, 09:12:47 AM
Quote from: sav0r on March 19, 2025, 11:13:39 AMThe correct, or at least most correct RFY is the 320mm base shock with the 7mm spring. Ideally, if you can find it, the conical wound 7mm spring, but the square wound one is more common. Keep in mind even that spring is slightly stiff. I landed on 80lbs per inch on my fairly light RD350, I weight around 150lbs. RFY 7mm springs are like 96lbs per inch. Some people like it, some people want the mushy stock ride. It's all preference.
Aha!  I was waiting for the RFY expert to weigh in!
Title: Re: Rear Suspension Recommendation
Post by: LMS on March 26, 2025, 03:21:12 PM
I run the RFY 320 with the conical 7mm springs. I sent them to some guy on the interweb that had a good rep on rebuilding them. I have older konis, but like these better. I was the last person to have them upgraded, took forever to get them back, thought he ghosted me. But it was worth it.
Title: Re: Rear Suspension Recommendation
Post by: IR8D8R on April 04, 2025, 02:57:10 PM
These are supposed to be Girling type derivative.
https://njbshocks.co.uk/
$135 the pair.

 I have RFY on on my RD350. A little stiff for most people but I'm ~240 lbs. I don't really like the reservoir type so I may try the NJB. They are available in 320mm.

IR8D8R
Title: Re: Rear Suspension Recommendation
Post by: m in sc on April 04, 2025, 03:05:07 PM
that's a great find 👍
Title: Re: Rear Suspension Recommendation
Post by: 2t Fan on April 06, 2025, 04:25:28 AM
Quote from: IR8D8R on April 04, 2025, 02:57:10 PMThese are supposed to be Girling type derivative.
https://njbshocks.co.uk/
$135 the pair.

 I have RFY on on my RD350. A little stiff for most people but I'm ~240 lbs. I don't really like the reservoir type so I may try the NJB. They are available in 320mm.

IR8D8R

Any pics of it mounted on the bike

cost £115when I checked. He will ship also
Title: Re: Rear Suspension Recommendation
Post by: IR8D8R on April 08, 2025, 03:26:22 PM
I also found them on an Italian site for 130 Euro ($142.63). Motorcicliveloce.it.

They only had a photo of their Cerianis mounted. 570 Euro the pair.

This is not a 2-stroke but it's still bike porn.
Title: Re: Rear Suspension Recommendation
Post by: quocle603 on August 20, 2025, 09:41:58 AM
Video was made 6 months ago but very informative for those who want to rebuild the RFY shocks.

Title: Re: Rear Suspension Recommendation
Post by: Brad-Man on August 20, 2025, 10:13:26 AM
Savor custom built RFY reservoir shocks for me - I gave him my weight and he got the correct springs and worked his magic.
Title: Re: Rear Suspension Recommendation
Post by: chuck norris on August 24, 2025, 01:50:51 AM
I have no advice on the subject but I might offer a point of interest. I was listening to the cycle world podcast and they were discussing how the Kawasaki triples handled like they were hinged in the middle. Kevin Cameron said that it was common to find no oil in one or both of the shocks right from the factory and simply upgrading the rear shocks would solve a lot of the issues. I can't imagine Yamaha and Suzuki used better quality shocks.
Title: Re: Rear Suspension Recommendation
Post by: sav0r (CL MotoTech) on August 24, 2025, 09:53:53 AM
The RFY's got me quite frustrated in the post Covid world as they were coming in numerous varieties. Some good and some not so good.

There are many tricks to getting then to work the best they can, assuming they have the good internals, which is on par with most dampers on the market. At least for street use. Spring rate being one, proper fill being a close second. Those two things will get you working great. Beyond that, One of the most common issues was that the piston is simply loose on the shaft in many cases. That means the shims aren't sealed to the piston and results in very poor performance. Of course you don't want the piston but too tight either as it will cause deflection of the shim and again cause a poor seal. I didn't watch that video very closely, I will later but I'm visiting family currently. In the comments somebody asked about the large cup seal trapping air. That's a problem solved by real damper heads seals, but since that's not an option one easy trick is to drill a small hole in the side of the large cup seal at about the mid point and this will vent the majority of the trapped air during assembly. It reduces the sealing surface and can damage the seal making it unusable if you aren't careful, it's a sort of risky upgrade. Better is to use a standard depth cup seal but I've not found any that didn't like to leak fairly quickly. The shaft sizes are odd. In between 1/2" and 12mm as I recall. I machined some real head seals for them and they work great, but it's not something worth selling. Beyond that, checking for leaks as leaks from the reservoir to the body happen and occasionally the shock tube to the body leaks. Most don't leak but some do. Some of them don't have the proper bushings in the linear bushing. They are just the pot metal bearing housing, sans a real linear bearing. These usually are too loose on the shaft or are not concentric and that causes many additional issues.

Checking these items and correcting them will get you to through about 95% of all the RFY concerns and produce very good working dampers. With some additional mods you can make them better than the vast majority of even mid grade dampers. Spherical bearings for example take them to another level. But it's best to do the other stuff first.
Title: Re: Rear Suspension Recommendation
Post by: m in sc on August 24, 2025, 01:35:24 PM
in regards to the triples.. yup. and the swingarm bushings and the period tires were not good eaither TBH. ive had plenty of triples that handled just fine with bronze swingarm bushings, fairly modern tires and decent shocks. the myth on them is so over hyped its ridiculous.
Title: Re: Rear Suspension Recommendation
Post by: busa1300 on August 24, 2025, 06:38:30 PM
I got some aluminum body Ikons for my last twin shock project.
Not cheap, but the quality is worth it.

IMG_8451.jpeg
Title: Re: Rear Suspension Recommendation
Post by: Vintagewannabe on August 26, 2025, 07:52:49 AM
I love my IKON shocks. My RD is the second bike I have ran a set on.
Title: Re: Rear Suspension Recommendation
Post by: m in sc on August 26, 2025, 08:24:22 AM
i have a set on the CB1100, really good units for the money. i didnt find them overpriced TBH, especially compared to other options.
Title: Re: Rear Suspension Recommendation
Post by: quocle603 on September 01, 2025, 01:20:24 PM
Throwing this into the mix.

Stumbled upon these shocks, they look like ohlins clones. Not sure if anyone has any experience or dare to try them out. They seem like you would need to get the adapter for the o style as well

"http://ebay.com/itm/285926580743?_trkparms=itmf%3D1%26aid%3D111001%26rkt%3D8%26mech%3D2%26algv%3D%26pmt%3D1%26amclksrc%3DITM%26sid%3DAQAKAAAAEHdHs9MrGT58JaWsg9RVvnc%3D%26itm%3D285926580743%26noa%3D1%26plcampt%3D0%3A12373977019%26algo%3DREC.SEED%26brand%3DUnbranded%26asc%3D20160811114145%26ao%3D1%26rk%3D3%26pid%3D100667%26b%3D1%26mehot%3Dnone%26lsid%3D100%26meid%3D71eb6a45835f442a8b7264642c11ed41%26pg%3D2334524&_trksid=p2334524.c100667.m2042&pfm=0"
Title: Re: Rear Suspension Recommendation
Post by: sav0r (CL MotoTech) on September 02, 2025, 11:20:47 AM
Those ones look nice but the standard RFY is a better option. For starters, the knobs are fake on those clones.
Title: Re: Rear Suspension Recommendation
Post by: m in sc on September 02, 2025, 11:53:59 AM
are they really? thats funny
Title: Re: Rear Suspension Recommendation
Post by: sav0r (CL MotoTech) on September 02, 2025, 01:56:03 PM
It's been a while since I have seen a set, but the knobs were indeed just for show. They went as far as adding detents with a spring and ball setup, but the knobs turned indefinitely and had zero bearing on internal function.

There are RFY's that have a shaft adjustable setup that actually works and they come with a really good modern piston. They are hens teeth though. 

(https://chrislivengood.net/wp-content/uploads/2014/01/Model-2.jpg)
Title: Re: Rear Suspension Recommendation
Post by: quocle603 on September 03, 2025, 07:00:15 AM
Quote from: sav0r on September 02, 2025, 11:20:47 AMThose ones look nice but the standard RFY is a better option. For starters, the knobs are fake on those clones.

Thats hilarious that they would add the extra material and hardware to make a buck. Very strange indeed.
Title: Re: Rear Suspension Recommendation
Post by: sav0r (CL MotoTech) on September 03, 2025, 09:20:45 AM
Welcome to the world of subsidized manufacturing. It's much easier to get government subsidies in China to produce items. So the products don't always make sense, or even need to, since it's much easier to turn a profit with even sub par products. The lack of meaningful knobs being case and point.