9" Diameter Wheels

[dmorewood]

We had originally designed our drive chassis to be fit with the Andy pneumatic wheels. We're now looking at these wheels on a drive train compared to the defenses and thinking that they're rather small. We have 6 8" diameter wheels from earlier this wheel, but would prefer to find even bigger wheels. Our design constraints dictate that the biggest we can go as of now if 9.75" diameter with a 2 inch width. Does anyone know where to buy wheels between 8.5-9.75" in diameter and that have a 2" width? We need 12 if that's possible.

[Anupam Goli]

First off, have you tested the wheels? I assure you that if you designed to use 8" wheels, you should try them out. Our team is able to get over the defenses with 6" wheels. Secondly, if you swap wheels, you'll need to modify your Gearbox so you can keep a reasonable speed, so keep that in mind.

[dmorewood]

Our wheels our enclosed within the chassis so we're pretty sure were going to hit the rock wall and stop with the Andymark wheels. The gearbox can be fixed rather painlessly if need be.

[Boe]

You could look into a system like Wildstang in 2012 to raise the front end and get the wheels on the defenses if space and weight allow.

[dmorewood]

Unfortunately our sheet metal chassis is set in stone at this point. We also only have three inches of clearance currently between our bumpers and the floor.

[Jarren Harkema]

Originally Posted by dmorewood

Unfortunately our sheet metal chassis is set in stone at this point. We also only have three inches of clearance currently between our bumpers and the floor.

Bumper or chassis? Read the bumper rules carefully, they must be within the bumper zone.

[dmorewood]

Sorry I meant Chassis, the bumpers will be 4 inches above the floor. Thought's on doing something like 1114's 2012 chassis design?

[jamesmcip]

Our team has run into a similar issue, as the 8" wheels are surprisingly small. Once our chassis was done, we realized we couldn't get over the rock wall and moat, but by simply using flexible plastic "skid plates" on the front to reduce the angle of attack we were able to do everything as planned.

[dmorewood]

Originally Posted by jamesmcip

Our team has run into a similar issue, as the 8" wheels are surprisingly small. Once our chassis was done, we realized we couldn't get over the rock wall and moat, but by simply using flexible plastic "skid plates" on the front to reduce the angle of attack we were able to do everything as planned.

Soooo like 1/8th lexan? And you can get over the rock wall with this?

[page2067]

Originally Posted by dmorewood

We had originally designed our drive chassis to be fit with the Andy pneumatic wheels. We're now looking at these wheels on a drive train compared to the defenses and thinking that they're rather small. We have 6 8" diameter wheels from earlier this wheel, but would prefer to find even bigger wheels. Our design constraints dictate that the biggest we can go as of now if 9.75" diameter with a 2 inch width. Does anyone know where to buy wheels between 8.5-9.75" in diameter and that have a 2" width? We need 12 if that's possible.

Mountain Board Systems has a 9" x 2" tire (9" is really about 8.5")
Unfortunately they have been wiped clean of their inventory it appears - and won't have them until end of February per the website.

But we used them in 2012 and they provide nice customer service, suggest giving a call to them.

[jamesmcip]

Originally Posted by dmorewood

Soooo like 1/8th lexan? And you can get over the rock wall with this?

Yeah Lexan would work fine, we just used some random ABS I think and yes we could get over the rock wall with only 3" of clearance.

[Lil' Lavery]

Assuming you guys are comfortable making/modifying hubs, Harbor Freight has an option:
http://www.harborfreight.com/8-inch-...ire-47638.html

They are listed at 8", but are closer to 8.5" IIRC. There's a few Harbor Freight locations around Philadelphia (Sharon Hill, Norristown, Northeast Philly) if you want to inspect them in person.

[Max Boord]

+1 for the the Harbor Freight tires. They have similar grip to colsons and are between 8.5 and 8.75 inches in diameter depending on inflation. They also have the + of only being 8 dollars each. For hubs we grinded out the center bearing housings and laser cut some plates with a hex in the middle that bolted on with the pre existing hole patern. They are quite heavy however, so they may or may not be an option.

Harbor freight also sells the same size wheel as a castor with a black wheel. It is not nearly as grippy as the one linked above.

[dmorewood]

Originally Posted by Lil' Lavery

Assuming you guys are comfortable making/modifying hubs, Harbor Freight has an option:
http://www.harborfreight.com/8-inch-...ire-47638.html

They are listed at 8", but are closer to 8.5" IIRC. There's a few Harbor Freight locations around Philadelphia (Sharon Hill, Norristown, Northeast Philly) if you want to inspect them in person.

These are great if their actually 8.5". The color is an added plus. Would we be able to use the vexpro hex hub kit? We already own and were planning on using these. What is the width of those wheels?

[Lil' Lavery]

Originally Posted by dmorewood

These are great if their actually 8.5". The color is an added plus. Would we be able to use the vexpro hex hub kit? We already own and were planning on using these. What is the width of those wheels?

Don't know the width off-hand.

The Vex hubs won't fit the wheel natively, but it could be adapted if you're careful to ensure it's centered.