[HondaDad]

There's a gap in 50cc to 100cc kids bike market and can't find a bike for my boy to progress from his CRF50. He's a quick and confident trail rider but not reckless or into motocross which rules out the KTM 50's in my opinion. I believe he get another year out of the CRF50 if it had better suspension and a 12" front tire. However, all the suspension upgrades I see are aimed at adults wanting to ride minibike so the spring rates won't suit a kid rider.

What options are available for tuning the CRF50 suspension to have more height and travel for kids who are more into enduro style of riding?
( The next challenge seem to find suppliers who have any parts in stock at the moment too, particularly in Australia )

 

[jamesfl]

I think you and your son would likely be better off just upgrading to a CRF70. You will get 14/12 wheels, slight more rear suspension travel, and forks with actual dampening. You can probably sell the 50 and pick up a 70 for about the same price.

 

[HondaDad]

I think you and your son would likely be better off just upgrading to a CRF70. You will get 14/12 wheels, slight more rear suspension travel, and forks with actual dampening. You can probably sell the 50 and pick up a 70 for about the same price.

That would seem to make sense, but we already own a 2020 CRF110 which has a seat height of 25.9in and he's not big enough to ride it yet.
Unless I'm mistaken the old CRF70's actually has the same seat height at 25.8in.

 

[jamesfl]

You are correct. The 110 actually replaced the old 70 in the CRF line up.

If your son is still riding with the stock shock and you don’t want to break the bank, you might want to start with a better shock. Perhaps try the Fast Ace shock with adjustable dampening and rebound and make sure to adjust the pre-load to suit him. If I am not mistaken sag should be about 1/3 of the total length of travel so perhaps start with about 1 to 1-3/16” but that is just a estimate on my part.

If you want go all out, you could look for a MX style swinger, perhaps a +1 or +2 and some +1 forks or swap in some CRF70 forks.

 

[mr.skywalker]

I think the budget way to get it a little taller and better suspension is swap suspension parts from xr/crf70. It was common in the early days to swap forks and swingarm to lift the 50 but adults usually paired it with a better rear shock and heavy fork springs and damping rods but in your case you could just do all stock components and it may work to last another year. It does take a little fab work but nothing to terrible.

 

[stunt-ur]

CLICK HERE
Not all spring rates are the same. This shock spring is the least aggressive one I found. 30% more aggressive than stock. Fast 50s is 32%, and BBR is 40%. Fast 50's advertises their's for adults and kids, so I would imagine the T3 minis one (30%) would be perfect.

CLICK HERE
If you want to raise the rear some and stiffen it simultaneously, this Kitaco shock is a good option. 3/4" longer than stock. I have owned it, and it was not that stiff. I actually found it to be too soft for an adult. It also won't require any labor putting on the spring like above option.

The fork springs are a little confusing. These also raise the front end 1". You could also get the extended legs if you want to go 2" taller than stock in the front. Also I recommend replacing the bushings with delrin bushings to remove some of the slop. According to advertisements the Two Bros springs would be your best bet, but seems everyone except ebay sellers are out of stock currently. CLICK HERE
Fast 50's: 30% stiffer than stock (perfect for 150+ rider)
BBR: 60% stiffer than stock (perfect for adults)
T3: nothing advertised
50 stunt: nothing advertised
Two Brothers: (perfect for 125+ rider)
Factory Metals: nothing advertised

Or you could just run stock crf70/xr70 forks. Find a pair someone is taking off. They bolt right up and not much taller than stock. And much more tuneable. Can raise/lower height, change fork oil wt, damping rods, springs.

Hope this helps.

 

[mr.skywalker]

Can raise/lower height, change fork oil wt, damping rods, springs.

One thing here is they cannot be raised or lowered without aftermarket triple clamp but they are much more tunable. You will want at least a small lift in the rear to match, like the kitaco spring or other shock(I ran a klx110 shock once but it took subframe bending to fit bc its wide)

 

[stunt-ur]

One thing here is they cannot be raised or lowered without aftermarket triple clamp

Ah, forgot about that part. So you would need a BBR SP5 top clamp if you wanted to lower ride height on them.

 

[Darrie]

These bikes ride like a brick from stock, and suspension upgrades is challenging. I’ve done it twice over on both my mini’s …. Once as my kids got faster, then again when they grew to adults and still wanted to ride them !

You have to use a balanced approach improving them at both ends, if you do one end only it will ride worse (I learnt this after upgrading the rear shock, back would soak up bumps but your arms were hammered, not pleasant riding. My advice is keep it simple first .. score some reasonably cheap hydraulic forks up front that fit (Chinese) & add a slightly longer shock in the rear that gives both more travel and rebound control (like a Fastace). Save the big bucks for their next bigger bike, but keep the mini's. If in later years they like still for fun, then do the adult suspension upgrades.

 

[HondaDad]

Thanks guys, I've solved the problem by buying a new JR80 Suzuki - it's too tall but he'll grow into it.