Fasted 250 Big Red needs tall gearing.

[Mickey Dunlap]

I admit I have no idea of what gearing I need to gear my 250 es Big Red as tall as I can. What rear end gears do I need and what Engine gears do I need and who has them for sale?

Project "Sleeper" is in the making!

[onformula1]

I don't know what that engine will actually pull, but I use these guys-

http://sprocketspecialists.com/sproc...-catalog-home/

Excellent product, tons of options, steel or aluminum & if you check out their website they obviously support 3 wheelers, so many places don't!

They have counter shafts sprocket from- 10-15 in one tooth increments.

They have rear sprockets from- 34-74 in one tooth increments.

I don't think that trike will pull 15/34 though....unless Mickey Dunlap built it!...LOL

[Flyingw]

By taller gears, can I assume that you want higher gearing for more top end?

[Mickey Dunlap]

Yes I need gears not sprockets with the shaft drive. I didn't pay attention to what gears and what rear end diffs they used.

[onformula1]

By taller gears, can I assume that you want higher gearing for more top end?

I assumed that's what he meant-
Old school hot rod guys would say taller gears for higher gearing & short gears for lower gearing.

[Louis Mielke]

I'm pretty sure he's talking about a bigred 250es, shaft drive, and thus he's looking for rear end gears. I think the trx300 rear end swaps and is taller?

[onformula1]

Missed that, sorry I can't help. Never heard of different gears being made by anyone. Custom built?

How about some 36" tires?

[Flyingw]

What I can offer is this, the SX tranny is geared higher. Each gear is one tooth smaller. The same for the rear end. The SX has a unique gear set whereas the ES and TRX all use the larger ring gear. I once tried to stick an SX gear set in to an ES case. It was then I realized the ES main shaft has a very slight machining difference and when I tightened down the cases, the main shaft wouldn't turn. I then tried an ES gear set in SX cases and the gear set just didn't stack up right so I ended up putting an ES motor in my SX. If you want taller gearing in your ES, put an SX motor and differential in your BR.

[NeverLift]

http://www.yukongear.com

I've never had it done but one of my instructors at MMI said these guys built him custom gears for his CR250. Give them a call i'm sure they can build you whatever you need.

[Mickey Dunlap]

I'll buy a SX motor then to see what I can do, but I already have a extra ES motor. I'll get the gears for the 300 rear end and maybe that will be enough gearing so I don't hit the rev limiter so quick. I remember our SX at Powroll hit the limiter too quick, so I know it's going to be a problem, unless the ES doesn't have one. Anyone hit the rev limiter on their Big Reds?

[Mickey Dunlap]

So this is all I need out of the TRX 300?

[Flyingw]

Mickey, I have an 86 ES diff already rebuilt if you want to go that route. I tooled up to rebuild differentials so it is completely rebuilt and not just the ring gear bearings and seals. 325.00 shipped. If not, keep in mind the ring and pinion gears are match ground when they were manufactured.

[Mickey Dunlap]

Mickey, I have an 86 ES diff already rebuilt if you want to go that route. I tooled up to rebuild differentials so it is completely rebuilt and not just the ring gear bearings and seals. 325.00 shipped. If not, keep in mind the ring and pinion gears are match ground when they were manufactured.

I think I'm getting a 85, is there a diff with the diffs? lol I have never been in one so I have no idea what goes bad, but I want it rebuilt right but with taller gears.

[Flyingw]

In 86, Honda made a casting change in that the sealing lip on the axle tube was lengthened. The corresponding sealing surface in the diff was deepened to accommodate the extending sealing lip on the axle tube. Their attempt failed!!! Water intrusion was still a problem using their OEM configuration utilizing an oring for the seal. Throw away the oring and seal each joint with silicone. The 86/87 diffs can be used on any year swingarm but you can't use an 85 diff on an 86/87 without doing some grinding on the axle tubes. The one I have is an 86/87 diff.

The main point of failure in the diff is the needle bearing on the end of the pinion shaft. When the needle bearings fails, the ring and pinion gears destroy themselves in short order. Special tools are required to get the pinion shaft out of the case and other off the shelf tools are needed to get the needle bearings out. I have all the tools to rebuild the diffs. If you want to see what's involved with the diff and see the inside of the diff, checkout my tutorial on rebuilding the diff.

http://www.3wheelerworld.com/showthr...54#post1282554

[Mickey Dunlap]

OK I can handle all that our Brute Force front diff is like that. My big question is have you ever geared one up?