I have an 06 650L with 14/45 sprockets on it. First gear is just about right and 5th is enough. The stock 15/45 was better for street riding but not worth the sacrifice off road. My question is, has anybody really done anything
about the gap between 1st and 2nd? I hear the 600r tranny will fit and this fixes it. Also somebody in a previous thread said installing the 2nd gear from an NX500(?) does the trick. Has anybody actually done either of these mods? And if so could I get more detailed info about it as far as cost, technical ability required, year of bikes that are compatible etc.? I've searched the XR650 forum and all I see is these mods mentioned, no real first hand knowledge.
By the way, this is an excellent forum. I've read a lot, learned a lot and laughed a lot. The BRP is the first bike I've had in 20 years and it has been like a fountain of youth. And TT has been a wealth of information. How did people learn tips and tricks about their machines before the internet? This forum has added a lot to my enjoyment of the bike.

As they come, the 15/45 gearing is IMHO too high but was necessary for low RPM/noise emissions testing.

I have 14/48 gearing on mine, the original idea was so I could let the clutch out in 1st and it run at a quick 'walking' pace. I normally use 2nd to start in with just a hair of clutch slip, I rarely use 1st on the street anymore. Being the old truck driver I am, I call my setup a 4-speed with a 'Low-Range.' The only place I find a problem is on the highway, it'll go 65mph but I don't like to take it much beyond that for very long; that's the price I pay for trail gearing. Oh, well.

As far as changing the gearing on the transmission... I don't know. That's waaay beyond my expertiese and I wonder if it would be worth the bother and potential problems you may face. I think you would be better off adjusting your gearing accordingly... but I'm sure someone here will give you a good answer on the transmission gear swap.

Good luck!

"How did people learn tips and tricks about their machines before the internet? This forum has added a lot to my enjoyment of the bike."

I don't know... those were the Dark Ages of information!

I own an '88 NX650 and have owned a number of XR650Ls. I haven't swapped a tranny, but I have worked with them enought to know they are interchagable.

The '88 NX650 has a lower second gear which is much nicer for the trails. The '89 NX650 has the same gearing as the XR650L.

pablo83 said:

is it difficult to swap out just one gear?

I can honestly say that the gap between 1st and 2nd really is the biggest down fall of this bike. Recently I've been running singletrack, 1st is too low 2nd is too high with my 13/48 gearing. However, with that gearing super slow moving is pretty good.

Soo.. here is my thought... change 2nd gear to the nx650 gear... AND add the kick starter, part hunting begins now!

since both mods require case spliting, might as well do them at the same time... Probably a new piston too. salvage title with 13500miles

sassage said:

splitting the cases is always a big job. the biggest issue is keeping track of parts. particularly with the tranny. take lots of pics as you disassable everything. then lay them out in the order they go back on and take a couple more pics.

as far as I remember, there are two special tools required to get to the tranny. one is a holder for the cam chain tensioner, I made one out of a piece of welding filler rod. the other is the alternator rotor puller. IIRC it takes three 6mm bolts on a steering-wheel type puller that you can get at an auto parts store, someone correct me if I'm thinking of a different bike.

also you'll want a manual. it will come in handy many times.

sassage said:

In doing a bit more research on this, it looks like the nx650 second gear would fit, but it then creates a larger gap between second and third. It seems that the answer is to swap in an XR600R tranny as the ratios in the 600 gearbox are equally spaced throughout (the 600 first gear is a bit taller than the 650's first gear). If you were to swap in the 600 trans and then lower the ratio on the final drive, I think you'd have it right. I am in the middle of a countershaft replacement, so I may end up with a 600R tranny (if it works)

pablo83 said:

The flywheel puller is just a large bolt that threads into the flywheel and bottoms against the crank.

If the clutch cover is off I just hold the chain tensioner with my fingers, no tool required. It's still a pain to get the cam chain just right with the sprockets. The biggest issue I always have is the chain wants to come off the bottom sprocket. You always have to check that the chain is actually on the sprocket. Then be sure to enable the tensioner before tightening the cam sprocket bolts. Without the tensioner the torque will cause the chain to slip a few teeth on the bottom sprocket.

I think I would rather have the gap be between 2nd and 3rd rather than 1st and second.

kpatrick said:

I agree! No doubt it will increase the gap between 2nd and 3rd.. but I am hopeful it won't be much of an issue. currently 2nd and third seem relatively close anyway

ThumpNRed said:

Do you happen to have the gear ratios (or even better, the number of teeth) for the trannies on these bikes? That would be useful information for some of us.

pablo83 said:

Sure thing:









XR650L:
1=12:32 (.37)
2=17:28 (.60)
3=20:25 (.8)
4=23:23 (1)
5=25:21 (1.19)
NX650:
1=12:32(.37)
2=16:28 (.57)
3=20:25 (.8)
4=23:23 (1)
5=25:21 (1.19)
XR600R
1=13:33 (.39)
2=17:28 (.60)
3=20:25 (.8)
4=23:23 (1)
5=25:21 (1.19)

Notice how the XR600R jumps approximately the same amount at each gear. The others have larger gaps either between first and second or second and third. If you use the 600R's ratios and lower your final drive (14:48) you would have a well spaced trans with a useable first gear.

I am going to give the NX650 second gear setup a try. Has anyone else given this a shot?

The NX 2nd gear just moves the gap to 2/3 shift. Is it really that much better? Thanx ThumpNRed. Good numbers to have.

valvesrule said:

Yes, yes it is. 3rd gear you are starting to gain momentum/speed, which means the terrain will probably a bit more open than tight single track. I'm going for the NX gear too, and kick starter.

it's obvious that sum of u have convenced urselves that "regearing" is better than sliced bread :smirk:

but short of maybe an overdrive and/or the elusive 6th gear...why not set ur sprockets for 2nd thru 5th and be done w/ it? :excuseme:

gear ratios being fix'd will always be a compromise and there will never be a perfect gearing for all applications...especially on a bike that is the definition of compromise.


:cheers:


P.S. if u r just doing this for a fun off season project great but i just don't think that u'll be achieving nirvana.

Do your bikes also shift hard from 1st to 2nd because mine does, sometimes I have to pull pretty hard and it clunks so When I let people ride my bike I always tell them dont wind out first gear just use it to pull out otherwize its is hard to shift and clunks, The rest of the gears shift perfect anyone have this.

I hate to say, the best way for me to deal with the 1-2 gap was to focus on riding faster.

At 14-48 I'm only in 1st for the really tight stuff, and can get pretty slow in 2nd without chugging it by giving it juuuust enough throttle.



Dave

ThumpNRed said:

Thanks. Excellent info :thumbsup: Where do you find these stats? I could use them on a few more bikes.

My opinion on the whole tranny thing: YES, the NX second gear is clearly better than the XR's on the trails. On the street it is not very noticable. Yes, you can gear the bike down for better overall trail performance. A 13T front will make the bike great on the trails, but then you lose a lot of top end speed for the highways.

I'm realize that a second gear swap may not be perfect...

But in various conditions, with various gearing (tighter woods stuff to rougher fire road sections) and with how I ride (Pace etc.) That gap always seems to be an issue. 1st to slow 2nd a bit too fast...

On the road (and faster trails) I tend to be in 3rd or higher 95% of the time anyway.

Nirvana for all... No, but it sounds like the right mod for me.
And yes, it's my off season project. Gear, kick start, Rings (maybe piston too).