Best sprocket size for trail bike

[Andrew1234]

Im all for you trying to make a DIY “trail bike” and dirt jumps are always fun but…. If you’re really going to go try that stuff then be aware that

1) a mountain bike was not designed to support an engine inside it’s frame while doing extreme off-road things ( I don’t know what kind of bike you have, a high end bike or a cheap Walmart bike) either way that’s going to be a lot of stress on the frame especially if it’s the latter. ( you may get away with small jumps and light off-roading but don’t go to big).

2) depending on how fast/ big the jumps you’re hitting are and how rough the trails your planning to ride on may be, even with a front “suspension” you will be putting a lot of force and vibration into the engine mounts/ mounting points. It’s possible to break a stud or completely crack the mounts on the engine case or the thin metal strap thats holding it to the bike. You can even crack or dent the frame.

(the best thing to do would be to mount the engine to a flat welded on plate with high grade bolts, I’ll try and find pictures if you don’t know what I’m talking about)
** take into account your weight plus the weight of the engine is now going to be coming down on this bike.

3) These engine kits were not designed to build a “dirt bike” nothing that is part of your bike being motorized was meant for what you want to do. I’m not saying it’s not possible or that you shouldn’t do it, just be aware you’ll probably break stuff.

(maybe I’m getting the wrong impression, but it sounds like you want to do “dirt bike” activities like your buddy with the Surron…I’m sure you want to one up him as you already challenged him to/ won a race on your mini bike and now you probably want to hit bigger jumps than them and try to whoop em on the trails too).

Putting a cheap chinese engine on even the best dirt jumper wouldn’t make it a dirt bike or even close to a Segway.
Just don’t do anything too stupid…

I just got a 125 dirt bike so im not building the trail bike anymore but i am building a reliable commuter instead

 

[Mc2Stroke]

That’s great, shouldn’t be too hard to make that happen. Are you planning to modify it at all?
BTW If you need any help or have questions feel free to ask me.

What kind of dirt bike did you get? I hope a 2 stroke whatever it is haha
I miss my 90 yz125 it was older but the guy I got it from used to race and had some big sponsors so it had a full pro circuit suspension, pipe, and a few extra performance goodies, it was an amazing bike and with the upgrades it ran as good/ if not better than newer bikes I had the chance to ride. I really wish I didn’t sell it, I’d love to get another bike, preferably a cr250… too bad im always broke.

 

[Andrew1234]

That’s great, shouldn’t be too hard to make that happen. Are you planning to modify it at all?
BTW If you need any help or have questions feel free to ask me.

What kind of dirt bike did you get? I hope a 2 stroke whatever it is haha
I miss my 90 yz125 it was older but the guy I got it from used to race and had some big sponsors so it had a full pro circuit suspension, pipe, and a few extra performance goodies, it was an amazing bike and with the upgrades it ran as good/ if not better than newer bikes I had the chance to ride. I really wish I didn’t sell it, I’d love to get another bike, preferably a cr250… too bad im always broke.

Nice I plan on doing the exhaust and carb but sadly I only got a Apollo dbx18 it’s a 125 Chinese 4 I had to buy it myself so that’s what I could afford I plan on getting a kx85 though

 

[Whitewill1412]

Nice I plan on doing the exhaust and carb but sadly I only got a Apollo dbx18 it’s a 125 Chinese 4 I had to buy it myself so that’s what I could afford I plan on getting a kx85 though

Where did you buy it? I just looked at it on Amazon and it is $400 shipping

 

[Andrew1234]

Where did you buy it? I just looked at it on Amazon and it is $400 shipping

I got it from a dealer for 900 I had to negotiate a lot

 

[Whitewill1412]

I got it from a dealer for 900 I had to negotiate a lot

That's a good deal then compared to Amazon

 

[ImpulseRocket]

Nice I plan on doing the exhaust and carb but sadly I only got a Apollo dbx18 it’s a 125 Chinese 4 I had to buy it myself so that’s what I could afford I plan on getting a kx85 though

If you need any help or information on tuning and parts for that Apollo, check out chinariders.net. I am on that site for my own Chinese Dual sport. No better place for info.

 

[Mc2Stroke]

Nice I plan on doing the exhaust and carb but sadly I only got a Apollo dbx18 it’s a 125 Chinese 4 I had to buy it myself so that’s what I could afford I plan on getting a kx85 though

Yeah I miss riding dirt bikes, street bikes too, one day I’ll get more.
That’s cool, 4 strokes aren’t bad. I love those cheap Chinese Honda clones, they’re a lot of fun.
Judging by the size bike you’ve got/ the one you want, I’m assuming you’re a younger teen. It’s actually refreshing to hear you got the bike yourself. As a teen I had to pay for mine myself too. It’s good to learn young the importance of work and saving money for wants/ needs, too many people get things handed to them.

 

[Andrew1234]

Yeah I miss riding dirt bikes, street bikes too, one day I’ll get more.
That’s cool, 4 strokes aren’t bad. I love those cheap Chinese Honda clones, they’re a lot of fun.
Judging by the size bike you’ve got/ the one you want, I’m assuming you’re a younger teen. It’s actually refreshing to hear you got the bike yourself. As a teen I had to pay for mine myself too. It’s good to learn young the importance of work and saving money for wants/ needs, too many people get things handed to them.

Yeah I’m a freshman in high school so I work really hard for the stuff I got

 

[Mc2Stroke]

Yeah I’m a freshman in high school so I work really hard for the stuff I got

That’s great, it may seem like it takes a long time to save for something like a dirt bike and it can be a lot of work but the reward at the end is worth it.
I’m sure you’re parents are proud of you, I hope you’re proud of yourself too.