Bike frames

GoldenMotor.com

gphil

Member
Jan 9, 2011
274
4
18
USA Georgia
I see some frames advertised on this site that I like but have also read not so good reports on Aluminum. Saw one with a built in tank and is real nice but how strong is it and will it withstand vibration? etc. Give a clue if you like before I get one. Just like to know the facts on things I guess. gphil
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
4,484
22
0
memphis Tn
I dislike aluminum for motorbikes, but the GT you refer to has very good reviews and is designed for a motor to mount. I'd say go for it if you like the frame.
The only issue I see using it is securing the chain idler to keep it from rotating into the spokes. You can always use one of the spring tensioners or one of the designs that spans two framerails.
 

wheelbender6

Well-Known Member
Sep 4, 2008
4,059
221
63
TX
For frame mounted engines, pre-2000 steel frames work best. Good quality alum frames work good. Discount store alum frames sometime crack at the rear dropouts.
Friction mount motors rarely cause frame cracks.
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
Because I like to weld on custom engine mounts and other do-dads, and because I've never mastered welding aluminum, I prefer steel frames. I've never owned an aluminum framed bike so my opinions are personal preference and not based on experience.

Those who have them seem to be satisfied with the aluminum frames. I suppose it will depend on how you ride and what options you want to add. There is a lot of discussion here on the comparisons between steel and aluminum. You might want to research a little and see what others have to say.

Tom
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
4,484
22
0
memphis Tn
My issue with aluminum for motorbikes is vibration causing work-hardening and failure as well as the difficulty modding or repairing.
Work-hardening causes failures with little or no warning and the level of vibration from a typical HT motor is enough to make me stay away from aluminum.
I've seen too many catastrophic failures even under human power to ever trust a aluminum bicycle frame.
I ride steel. No carbon, no aluminum. Steel.
But I would ride a GT frame if you gave me one...
Just my opinion.
 

gphil

Member
Jan 9, 2011
274
4
18
USA Georgia
You guys are sort of echoing my thoughts . I can also weld steel not Al. Just sort of was drawn to the built in tank, really neat. I for one cannot imagine a rear dropout failure at 25. I am too old for asphalt rash. I will study more. gphil
 

knightscape

Member
Jul 29, 2013
340
1
16
Maine
After buying a Skyhawk GT2A-S frame I regret not buying a Phantom frame instead.
http://phantom-bikes.com/shop/parts/
3rd item down on the list.
I'm in the middle of a GT2A-S build now you can find in the Cruisers topic, and I wished I'd gone with the Phantom frame as well. I thought incorrectly that they were the same before I ordered. There's more room for a 4 stroke motor in the phantom, nicer tank filler, better rear dropouts etc. I'm going to end up happy with my GT I'm sure, but the Phantom has some nice details.
 

gphil

Member
Jan 9, 2011
274
4
18
USA Georgia
GearNut, That was the one I was looking at. I just wonder if it will crack later on down the road. The guys are correct about the differences. I do like that frame however. gphil
 

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
Aluminum is great for our motorized builds, especially for small bore 4-strokes. You need not worry if you use a felt aluminum beach cruiser frame with an engine......cracking won't be an issue.