[Pillows]

CB300F and CBR300R stiff jolting bumpy uncomfortable ride on rough-ish streets. What to do?

Hello. First off I understand that the suspension is limited by its price point but am wondering whether this can be fixed at all?

BACKGROUND- CB300F, 130 pound rider, stock suspension. Rear Preload set to 5, (softest, or I think) 10,000 miles on bike.

Issue is that I ride 40 miles a day at least, easy, and the streets are a mess. by the time I get off the bike I have a headache and back ache from the jolting zero give I get from the back suspension. I've no problem riding this bike on a track or smooth road.

I really feel that it is the rear suspension that is the problem. It is as if it has NO flex or give.

OPTIONS- I can replace the rear shock with an Ohlins HO426 meant for CBR250R but it will fit. Or a YSS MZ366-295TR-14.

OR Is it just not a problem I can fix on this bike and should I spend the money otherwise spent on a very expensive shock on a new bike. Say a CB500X or the likes?

Any advice on the specific shocks and overall experience advice is A+++.

 

[Gromit]

I;m 150 pounds and have the rear suspension at 1 click up. Front fork springs replaced with Hyperpro progressives. Normally have a back ache due to dislocation 50 years ago but I can ride my CBR for 3 - 5 hours without getting off and no back trouble. I'm 81 and have arthritis so your roads must be dreadful.

 

[JimShortz]

Are you sure you haven't got the rear preload on the highest setting? If you look at it I think it is pretty obvious which direction pre-loads the spring and which direction doesn't - take a look. If you can't work it out for sure, just move to the other end of the spectrum and try it. It's a 5 minute job (tool needed is under the seat) to do it and then go see.

At the softest setting the rear should work just fine for you. Also, unless you are really heavy, go for no more than 33 or 34 pounds in the rear tyre, so that that provides some "give" too.

The only other thing to consider (other than swapping out the front fork springs and/or changing fork oil weight) is the actual tyres. Half decent radials such as Pirelli Rosso 3 have much softer sidewalls than the hard walled crossplys that come as standard. Radials make for a much more confortable ride, but cost a bit more - not too bad at this size though...

 

[Pillows]

I;m 150 pounds and have the rear suspension at 1 click up. Front fork springs replaced with Hyperpro progressives. Normally have a back ache due to dislocation 50 years ago but I can ride my CBR for 3 - 5 hours without getting off and no back trouble. I'm 81 and have arthritis so your roads must be dreadful.

Are you sure you haven't got the rear preload on the highest setting? If you look at it I think it is pretty obvious which direction pre-loads the spring and which direction doesn't - take a look. If you can't work it out for sure, just move to the other end of the spectrum and try it. It's a 5 minute job (tool needed is under the seat) to do it and then go see.

At the softest setting the rear should work just fine for you. Also, unless you are really heavy, go for no more than 33 or 34 pounds in the rear tyre, so that that provides some "give" too.

The only other thing to consider (other than swapping out the front fork springs and/or changing fork oil weight) is the actual tyres. Half decent radials such as Pirelli Rosso 3 have much softer sidewalls than the hard walled crossplys that come as standard. Radials make for a much more confortable ride, but cost a bit more - not too bad at this size though...

First of all. Yes the roads in LA suck. I have no idea where my high tax dollars are going. I've hit a pothole so big my phone flew off its mount. It looks like there was a missile attack on some of these streets I kid you not.

Also my rear preload is turned all the way clockwise when lying on the chain side with your nostrils facing the rear wheel. I'll link a photo. I have heard that the rear shock is bad though.

 

[kiwi rider]

Yes, it looks like you have it set to the softest setting. As much as I'm a fan of aftermarket suspension, I cant help but feel that you would be dissappointed with the results for your application. Given the type of riding your doing I would be looking at changing bikes to something with longer suspension like the bike you mentioned or a BMW310GS or a Kawasaki Versys X-300. Short travel sports bikes will never soak up rough potholes well. I've upgraded the rear shock on my Ninja 400 from stock to K-tech at considerable expense and while it has improved it's handling on smooth to medium roads it still kicks me in the arse on rough bumps.
The front fork springs on the CB/CBR300 are already very soft stock so there's not much you can do there.

 

[JimShortz]

I have to agree with Kiwi rider - if you are so unhappy on the softest stock suspension setting you will be needing a bike with longer suspension travel... I'm with you on the CB500X (with upgraded YSS or Ohlins suspension), the bikes Kiwi suggested, or even a CRF250 or something else with more of an an off-road bent... Yamaha Tenere?

 

[Gromit]

I would have said it is set to the hardest suspension, not the softest. It has been turned to maximum ANTI-clockwise (left to right as you are looking at it). Why not try turning as far as you can the other way?

 

[kiwi rider]

I would have said it is set to the hardest suspension, not the softest. It has been turned to maximum ANTI-clockwise (left to right as you are looking at it). Why not try turning as far as you can the other way?

Yes it's hard to see but if you look to the immediate left of the tang you can see the end of the ramp that increases the preload tension. So the only way it can be turned is anticlockwise which should be the 'harder' direction, but it's hard to see the ramp clearly.

 

[Pillows]

Yes, it looks like you have it set to the softest setting. As much as I'm a fan of aftermarket suspension, I cant help but feel that you would be dissappointed with the results for your application. Given the type of riding your doing I would be looking at changing bikes to something with longer suspension like the bike you mentioned or a BMW310GS or a Kawasaki Versys X-300. Short travel sports bikes will never soak up rough potholes well. I've upgraded the rear shock on my Ninja 400 from stock to K-tech at considerable expense and while it has improved it's handling on smooth to medium roads it still kicks me in the arse on rough bumps.
The front fork springs on the CB/CBR300 are already very soft stock so there's not much you can do there.

I have to agree with Kiwi rider - if you are so unhappy on the softest stock suspension setting you will be needing a bike with longer suspension travel... I'm with you on the CB500X (with upgraded YSS or Ohlins suspension), the bikes Kiwi suggested, or even a CRF250 or something else with more of an an off-road bent... Yamaha Tenere?

I would have said it is set to the hardest suspension, not the softest. It has been turned to maximum ANTI-clockwise (left to right as you are looking at it). Why not try turning as far as you can the other way?

My research led me to the exact same conclusion. If I'm gonna invest in shocks I gotta do it on the right bike. Well you guys rock!

 

[Gromit]

I would have said it is set to the hardest suspension, not the softest. It has been turned to maximum ANTI-clockwise (left to right as you are looking at it). Why not try turning as far as you can the other way?

Just had a proper look and yes, it is at softest. You would have to turn clockwise (right to left) to go stiffer.

 

[Tier1]

Just because you change the preload of your shock doesn't mean that you're changing the spring rate. Just though I would mention that.

I'm not 100% sure exactly where you want the sag to be (I generally say ~25-30% of the travel when you're sitting on it) but that only accounts for where the suspension sits when you're static. It still needs to be able to compress and rebound when you're on chuddery stuff on the road but the speed at which it bounces back is controlled by the spring.

Take a look at the R6 shock. You can find them on eBay as takeoffs for fairly cheap. Way cheaper than Penske,Ohlins, Racetech, etc. and they fit pretty much almost perfectly other than you will need to do a little bit of shaving off some metal due to the "piggyback cartridge". Result is that you'll get high and low speed compression and rebound as well as more fine tuning on the sag.

 

[kiwi rider]

... I'm not 100% sure exactly where you want the sag to be (I generally say ~25-30% of the travel when you're sitting on it) but that only accounts for where the suspension sits when you're static. It still needs to be able to compress and rebound when you're on chuddery stuff on the road but the speed at which it bounces back is controlled by the spring.

Equally important in this area is the internal rebound damping system which as you know is non adjustable on the cheap OEM shock. Another reason to upgrade to an aftermarket shock.

 

[Jppatrick]

I have got the yss, comfort a little bit improved with the hydraulic setting at the minimum.
Good for the back, the OEM is a piece of wood
for light driver.

 

[2dtimecb'r]

I'm a big shock swapper and have bought a number of used E-Bay shocks for use on my 2016 FZ07. My best change was to a 2000 GSF1200 Suzuki shock. Second best was a lighter rate Eibach spring(expensive) in place of the oem spring on the stock FZ07 shock. These oem suspensions are compromises and a little fine tuning will give you a nice ride. I have had Nitron and Ktec shocks on my bikes in the past and an old cheap($25 to $50) shock is an economical way to go. I'll be doing some swapping with this bike(2021 CB300R) as time goes on and will keep the community informed as to what I've found.