Whats wrong with this picture

[johnsteve]

Can someone please explain to me how to install a tophat sprocket adapter on a GTA-2 frame? Id like to see some pictures also.



What is a disc drive offset and how is it measured?



The problem I am having is that, to me, it looks like my tophat is too big for the disc to fit inside the caliper, and even if it could fit, it looks like the caliper would touch the sprocket.

Would I have to buy a larger disc in order for the caliper to clear the sprocket?

Can someone please through some advise my way?

 

[5-7HEAVEN]

I was under the impression that one type of top hat adaptor
was primarily to securely mount a rear wheel sprocket.

Orrr, another type of top hat adaptor could be used to
mount a rear brake disc AND a rear wheel sprocket.

Like so:
https://motorbicycling.com/threads/top-hat-sprocket-adapter.2131/
and:
https://motorbicycling.com/threads/installed-top-hat-adapter-on-wheel.2846/

Which type of top hat adaptor do you have?

More pictures, please.

 

[KCvale]

Would I have to buy a larger disc in order for the caliper to clear the sprocket?

The GT2A-DB gas tank frames use a 160mm disc with the frames caliper mount.

That's all the help I have for you as I've never used the top hat, if a bike has a rear disc brake, it gets jackshafted ;-}

 

[johnsteve]

I have tried the Jakeshaft and it was a PITA. Constant adjusting and I got tired of it. I decided to go with the tophat. I have learned that is about trial and error.

I did find out a nice video someone made and I wish I would have seen it before I ordered the parts.

 

[FurryOnTheInside]

Although I don't have this frame, I wonder if the sprocket is the correct distance from the bike's centreline (calculated by dividing the rear mount width by two and subtracting the distance between the left side dropout and the sprocket), compared with the front or drive sprocket on the engine.
Can the sprocket fit inside of the top hat?

Also I think the bb7 actually looks quite chunky so perhaps a thinner caliper could be used with the rest of your current setup, or maybe just a larger diameter rotor as you mentioned.

 

[Frankenstein]

Although I don't have this frame, I wonder if the sprocket is the correct distance from the bike's centreline (calculated by dividing the rear mount width by two and subtracting the distance between the left side dropout and the sprocket), compared with the front or drive sprocket on the engine.
Can the sprocket fit inside of the top hat?

Also I think the bb7 actually looks quite chunky so perhaps a thinner caliper could be used with the rest of your current setup, or maybe just a larger diameter rotor as you mentioned.

I didn't notice a difference between the rotor zone between the 2, I do know that the bb5 was so big I had to space the rotor away from the spokes because otherwise the brake would hit them with the stock mongoose terrex front wheel, those things sit pretty far out though in general. I didn't check the fit on the bb7 on the front wheel yet but it looks about the same, it's bulkier on the outboard side though, they added a rotory to the actuating side so you don't have to adjust the cable on the pull arm, just twist the indexer to move the pad closer so the brake lever hits it sooner. I dreaded adjusting it just so I can have the brake hit really early in the pull, that 6 inch lever really makes it a comfy squeeze. Now it's a flick of the wrist as the showman said.

I don't think that would affect anything you'll try to add to a bike, not many things end up in the brake caliper and rotor zone other than trees.