CB350 shock upgrade.

A place to discuss matters related to Honda Helix scooters.

CB350 shock upgrade.

Postby mikel » Thu May 16, 2019 1:00 pm

I dont recommend the CB350 shock upgrade! To summarize, your better of buying a direct fit replacement if you feel the need. Regardless, do at your own risk.

So who feels the vibration around 100kph(60mph) on their helix. I tried the plumbers rubber coupling and rubber inner tube over the shocks to dampen any possible "tuning fork" vibration in the rear shocks. I dont think it made any noticeable difference riding with them in place all last year. So I ordered a CB350 shock kit from ebay for what I thought was a reasonable price. It came with 3 different size upper rubber mounts. I choose the size that could use the original bushings. And bolts. The top was plug and play with the kit I purchased, however, the bottoms were not.

Many trips to the hardware store later...

For the drivers side(your left side as you sit on the scoot)bottom end of the shock I ended up drilling both holes out to size. I believe they were .550" and .450" but dont quote me. 1/2" Copper water lines inside diameter was a perfect match for a bushing, I was going to get washers but the copper pipe fit so nice and I had it on hand. Special ordered one lock nut m10x1.25, I think. There was not enough clearance around the housing of the shock so I ground most of it off, did the same for the other shock as well.

For the passenger side(right) bottom end of the shock, the shock holes and matching screw I special ordered were too large for the scooters bushing mount. I didn't want to drill out the bushing on the scooter end in case I wanted to put the original shocks back on. Glad I took this route. So I ended up making little metal shims by hand from a piece of steel sheet metal i had and inserted them into the shock mount holes and used a longer m8 screw and lock nut from the hardware store with a couple washers for spacing.

So why dont I recommend the CB shock upgrade, well I'm a 5'4 lightweight, say no more. The shocks raised the seat height nearly 1" and are very stiff even on the softest setting, however, riding 2 up was better than the original shocks. If I were the big and tall kind I may have been happier. But I have never been happier being short then when I got on my helix for the first time! I could explain it to you but you wouldn't understand unless you were short your whole life. and no I ain't buying thick soled shoes and cutting the foam out. ..again. .. maybe.

So I got my first ride in last night putting 150km on my helix after the CB350 upgrade. The shocks are better riding 2 up, but too stiff otherwise for me. Used cb350 shocks that may be more worn may prove softer. Also the vibration was still felt at the same speed up around 100km. I went through a lot of head scratching and failed trips to the hardware store, so if I had it to do again, I would have just bought a set that was a direct fit. Good luck.

Not going to try and figure out how to post my pictures if someone wants to post them, let me know and I'll send you them. Thank you.

Oshawa, Ontario
Posts: 5
Joined: Fri Jun 15, 2018 9:05 am

Re: CB350 shock upgrade.

Postby zozman » Thu May 16, 2019 3:55 pm

The CB350 shock upgrade was never intended for the CN 250 Helix as the Helix has one clevis and one eye type shock. It was written specifically for the 1985-88 Honda Elite CH 250 which has two clevis shocks. Stick with the OEM Honda shocks.

87 & 98 Helix
Posts: 626
Joined: Sat Aug 01, 2009 10:59 am

Re: CB350 shock upgrade.

Postby mikel » Wed May 22, 2019 3:13 pm

Update: Ok, I'm a believer in the tuning fork effect on the shocks at speed causing that vibration noise. After I installed the cb350 shocks the vibration was still there around 60mph. However i am now hearing it on deceleration just before the clutch disengages. And i sometimes hear the noise on takeoff around that same speed. I was able to reproduce the noise at a stand still with the brake in and some gentle throttle. Placing my hand on the drivers side shock spring would make it stop. I am a believer. I will never doubt again. If I have some time this weekend I will try playing around with the shocks. I still have the plumbers rubber coupling. Interestingly, that side shock doesn't have the rubber mount between the shock and the crankcase. I'll see what happens.
Posts: 5
Joined: Fri Jun 15, 2018 9:05 am

Return to Honda Helix

Who is online

Users browsing this forum: No registered users and 4 guests