Bike broke completely in half while riding!

[TWalker]

I got real busy and hadnt told this story yet but its a couple weeks old, I supplied a kit to a friend of mine we/she installed in on a Trek mountain bike, drilled the front mount, nothing too unusual but of course not ideal. (I built my first one 3 years ago so I know about happytimes).

Bought the kit from Revolution and the last 2-3 have been ****, old style clutch levers, a a muffler painted black with non hi temp paint! First time I rode it i practically had to use a fire extinguisher to put it out!

Any way this kit vibrated like there was no tomorrow and we never could solve the vibration, it sheared engine mount bolts, the carb fell off, the insides of the carb shook loose....you name it it had it.

Well after a while we decided to take a ride and I rode hers she rode mine. About a mile out I notice its wobbling a bit and I thought oh **** another sheared engine mount. i pulled over and the frame had broken in half where both engine mounts are!

It literally was supporting me by just the top tube, I have pics but they are on my phone and I need to transfer them onto the PC so I can show ya.

It truly could have been a disaster and I must say i am ready to move away from happytimes altogether. Ive built enough to know unless the quaslity imprioves drastically these are not something I want to offer the consumer and the support for.

 

[Snax]

I've thought about the mounting system of these things with some suspiscion. It looks to me like this could be an issue eventually for any long ridden HT bike even without drilling.

I'm working on a better solution which should reduce allot of this worry and limit much of the vibration that is transmitted into the frame. It's fairly simple, but I've not seen anybody with anything quite like it yet.

 

[TWalker]

I think a major part of it is this:

They are a few factories making them and quality control is **** depending on which factory. Number one some engines particulalry 80/70/66cc are being made extremely unbalanced, the piston is too light? and does not balance the crank out. I got a 50cc at the same time I got a 70 and the vibration on the thing was no problem, ran like a clock and I used little if any rubber to mount it. This 50 is the first 50 I ever bought and smoothest engine I ever bought.

QC sucks and I was told by one of Grubees suppliers who shall remain nameless that QC is a problem right now and Don is working on it.

But how long and where have these kits been sitting to have old style levers and HEAVY rust on the inside of the mufflers? And who the heck is spray painting mufflers with regular spray paint and passin em off as EPA approved?

Now I know who revo has a deal with to drop ship, but that doesn't necessarily mean thats his only source, in fact I had a talk with the guy before all this happened.

I'm tired of this. Now I did order a "special edition black kit" form PowerKing at the same this revo **** came in and the difference was night and day. Powerking sent a sweetly packed kit with brochure etc. didnt care for glossy black paint job but at least the muffler was legitmate EPA and it had an alloy lever etc.

 

[Esteban]

"" QC sucks and I was told by one of Grubees suppliers who shall remain nameless that QC is a problem right now """

This has ALWAYS been a problem, & I doubt it will ever be solved. Go with a true Japanese motor, & be done with it. I have a Robin/Subaru engine on my 25 year old weedeater, & it runs like a champ !!
You get what you pay for !

 

[ihatemybike]

I haven't liked the drill through the frame mount option on the HT engines since the moment I laid eyes on it. If you drilled through your frame, inspect that area for cracking before every ride. If you are planning to mount a HT engine, don't drill through the frame. Figure out a way to mount it using U-bolts, pipe clamps, or something else.

 

[JemmaUK]

...And this is why the expense of something like a GEBE or Staton kit is worth the extra money...

If you have to drill the bike frame you are putting further strain on something that wasnt designed for the 25-35+mph speeds that MBs can reach - and this even if the engines were clockwork smooth. I havent ever ridden a HT machine but the most vibration I get on my bike is 3/4 up a hill when shes revving her guts out trying to keep in the torque band - other than that there is nothing through the bike at all! The impression I have gotten so far from people on here is that a HT in comparison is like your own personal earthquake on wheels.

It used to be back in the day that you would get airframe failures and such, which often couldnt be predicted or explained from design specifications and details, failures which shouldnt have happened. It tended to happen that these failures later were attributed to metal fatigue due to sympathetic vibrations (which is why you *always* balance the engines on an old multiprop before you taxi out). This seems to be something of the same situation.

What worries me most for the rider is safety - but there is also another consideration here.. with the poor quality of the kits and the questionable methods used in some cases to mount them.. how long is it going to be before someone gets sued by a deceased family simply because they did a friend a favour and built them a bike.

And worse still - lets say we have a nice photogenic teenage girl with her whole life ahead of her (delete cliches as applicable) who gets killed or worse paralysed as a result of this sort of failure... It will be all over the national and international news and Govt's will slap controls on MB's faster than you can blink...

As of now this is effectively a backroom industry - so we cant afford this sort of issue. Manufacturers or even talented tinkerers need to have a look at this problem and solve it in a safe and effective manner.

Jemma xx

 

[ihatemybike]

Put the GEBE and Staton in the frame and I might buy one. I plan on commuting to work during the week and being a little goofy with mine in designated ORV areas on the weekends. I want a centrally mounted engine.

 

[Snax]

The frame mount is the ONLY reason I went with a HT motor. When a good viable 4-stroke kit becomes available, I'll be on it.

 

[Pablo]

Make your own engine mounts or buy some of the homespun ones available now. NEVER ever drill a hole in your frame. I could care less if someone tries to convince me this is OK, even if they provide the structural analysis....

 

[boltupright]

Yes, I agree, when I saw the extra hardware that was sent with my kit to drill in case my frame had the larger radius front tube, I thought "WTF"?
It's a good thing I could file the radius big enough on the mount to fit my front tube, as my front tube is only slightly larger than the rear.
I didn't think it was a good idea at all to drill a hole in the frame & then torque a bolt through it.