I want to taller Gearing! on XR650R

Hey All, I have stock 14/48 gearing on my recently street legal XR650R, I like the pep and punch for city driving but I do have some buddies on the outskirts I want to ride to at ~25-30 miles of highway driving and at 65-70 its too buzzy for me!

I have edelbrock QS w/ 21 Needle, Airbox mod, and stage 1 Cam, Big-gun Race exhaust/header as well as the standard uncorking.

I certainly want 15/ but how small on the rear sprocket is my concern, 46 or even 45...

What do you think of what you run?

Thanks

J_T

Timely - I just replaced the stock 14 with a 15 tooth sprocket this afternoon - seems to have made a big difference. Used to have that feel that I needed one more gear. This may have resolved it, in fact it may be too tall in lower gears. Only went a couple of miles, but 1st seemed like it may be to high now, won't know until I get out on the trail. Regardless it sure ran well in the 45 to 55 range, didn't get to open it up. RPM seemed to be down noticeably.

I would change the front sprocket and check it out before I changed the rear. It is really a quick mod.

Timely - I just replaced the stock 14 with a 15 tooth sprocket this afternoon - seems to have made a big difference.

I would change the front sprocket and check it out before I changed the rear. It is really a quick mod.

What he said :thumbsup:

I've been running 15/48 for some time, it's better, but not good enough for extended highway speeds, 65mph+. Euro/Aussie 650R's come with 15/45 stock, that's what I'll be trying next.

15/45 is fine. It makes the bike feel a heck of a lot smoother too.

I have run 15/48 15/46 15/45 15/44 all are okay.

the 44 is too tall to enjoy the bike off road, but it's really great on the

highway.

The profile of the tire you're using will determine how tall you can / should go.

If I run DS tires 6.40 rear the 15/45 is great.

If I run stock 110/100 rear I like 15/46 it'll still pop up the front in 4th with a

bit of a bounce and tug :thumbsup:

15/45 is a good trade off for on and off road, any taller and first gear would be to high in the tight stuff off road.

I have a 15-45 setup and it's great for the paved stuff. Sometimes you'd wish it was even a little taller for that.

My next question to all of you riding 15/45 and 15/46 gearing. ARe you running the stock length, 110 link, chain as well?

The gearing calculator shows that it ought to work but I thought I'd make sure!

Thanks

JT

Mines stock length with 15/45.

my chain has been shortened by the previous owner - rear wheel is totally at the beginning of the adjuster block range, with the rear tire nicely rubbing on the plastic shroud. I would have gone back to the 14-48 a few times for dirt rides if my chain had been longer. No idea how many links are missing, but if I want back to 14-48, I will definitely need a longer chain.

My next question to all of you riding 15/45 and 15/46 gearing. ARe you running the stock length, 110 link, chain as well?

The gearing calculator shows that it ought to work but I thought I'd make sure!

Thanks

JT

You have to knock out a link to get to 15/44.

15/45 has the wheel set almost all the way back with the 110 links (stock)

The Honda team runs 15/45 at Baja. they say that keeping the rear wheel

as close to the front as possible is the best for steering geometry so they

run with a shortened chain.

I guess they don't have to worry about the tire eating a hole in the shock

guard since they get replacements for free :thumbsup:

I ran mine on a shortened chain for over 2000 miles and it never wore through.

I've been running 15/47 and really like it.

good enough to run 80 down the highway at 1/4-1/2 throttle, tops out at around 100+ and has plenty of grunt for the tight technical rocky stuff .

Yeah I run 15/47 its a good offroad/road compromise, if I was doing a big road trip I would go with 15/45. Mine came stock with 15/41 thats way too high geared, the motor was lugging all the time at 100km/hr so I would ride everywhere in fourth! fifth was like an overdrive.

somewhat related question - has anyone ever tried 13-45? My chain has been shortened to fit on the 15-45 and I want to make the gearing as short as possibe for a weekend of tight single track riding without buying a new chain for this one time ride. There's a 13 sprocket in my parts bin, but I never used it. Came with the bike. Anything I should be worried about with a 13 front sprocket?

Peter

If you have the Excel Gearing Worksheet it gives you an idea of links needed for particular combination and Speeds, It can be found at http://www.xr650r.borynack.com/GearingcalcXR650R.xls .

But its showing that it should fit with <110 Links > 108, But check out the file and plug in your sprocket ratios for a guesstimate.

JT

didn't know about the spreadsheet. Too cool. I may even be able to put a 13-48 on the bike based on those chain numbers. The chain may just be a hair too short for the 13-48, but it should definitely work with the 13-45, which is almost identical to stock ratio.

thanks

Peter

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