Does the W have a first that is as high as a Bonny? The 18 on the front of my Bonny makes first just a little high for running around town, but improves the rpm at highway speeds. Also, the Triumphs have a 1.07 fifth, Kawasaki may have an overdrive or 1:1. Actually, the lower the ratio number is, you are going higher is gearing (decreases engine speed at a given mph). You are changing two link lengths, probably would be able to adjust that much. I put the 17 back on for a snow trip because I wanted a lower first, now need to change back for highway running. If the T100 already has an 18, you are going really high. The other thing is that front sprockets cost less than rears.

[ This message was edited by: kdrake on 2006-03-28 06:00 ]

 

Bob,are you talking about your Bonnie or the 650? Many of us have changed the front sprocket.No chain change with the common choices.[16,17,18,19] It is an easy mod that with the right tools,can be done in 1/2 hour. The rear is a more involved job,but since your taking the tire off anyway,shouldn`t be any harder to complete. I`m not sure if the chain would have to be shortened or not though.However,if you dont like the gearing afterward,dismounting the rear will be a pain to have to do again.And I`m guessing the rear cogs cost more too. :???:

 

On 2006-03-28 05:45, ohiorider wrote:
...I'm thinking about dropping from a stock 43 tooth to a 41 tooth rear sprocket, which would place me somewhere between stock (2.53:1) and using 18 tooth front (2.38:1). The 41 tooth would result in a final drive ratio of (2.41:1), just a bit lower gear ratio than using the 18 tooth front sprocket.

I would have to determine if I could retain the same chain length taking this approach.

Bob

I can't imagine you would run into any chain problems with that setup. Would the ratio difference you mention be noticeable, that's the question. I'd try just swapping to an 18t front sprocket and see if you like the results, that alone is a whole lot less work! When I picked up my 18t, and mentioned I'd save my 17t in case I didn't like the results he replied, "don't store it somewhere handy, I've never known a customer to have any desire to switch back".
He was right by my experience. (on my America)

 

i have a 02 790 america , if i put a 18 tooth front sprocket on and leave the rear stock , will the chain fit?

 

Thanks guys - I probably confused my initial post by mentioning the W650. My Bonneville is the bike in question.

I guess I was a little concerned that going from the stock 17 tooth to the 18 tooth was going to make the lower gears, especially first, somewhat high, and I was shooting for a happy medium by switching the rear sprocket instead. (Do you guys using the 18 tooth feel like you have to slip the clutch too much around town when starting off in first?)

You both make a good point ... it is easier and less expensive to test out the 18 tooth countershaft sprocket than to change out the rear sprocket.

Just needed a sounding board before I did anything.

Thanks
Bob

 

I like your idea Bob. I took it one step farther on a previous bike. Purchase the 41 tooth rear as you described and also buy a front sprocket one tooth smaller than stock. Then you are both higher and lower than the original gearing by changing the front sprocket only. As far changing only the rear for a taller overall gear. The front is cheaper, easier to return to stock and you may not need to shorten the chain. Have fun!

Mike

 

Do you guys using the 18 tooth feel like you have to slip the clutch too much around town when starting off in first?

I'm on a Bonnie with a 18t front . I live in the heart of Los Angeles Ca. and use the bike as a daily hack when I don't have to take tools or materials to a job site. My comute consists of 1/3 street- 1/3 freeway--1/3 street. I have no problem on the street and it really helps on the freeway. In very heavy stop-and-go traffic it can be a little tedious as it does take off a little fast. I just try and time time flow and balance to get around that.
I drove the thing bone stock for the first 1K miles (about 4 weeks) just to get use to it and break it in. I put on the 18t and what a difference. The change was nothing dramatic but just made the the bike much more functional. As stock, it really is Euro-geared.
I consider an 18t front sprocket almost manatory for the American roads.
Put on the 18t front and ride it for a month. If you still think it is tall in 1st then you can play with your rear sprocket.
I have a 19t front that I have never used. I plan on taking a few long Hiways trips this summer and will put it on for those trips. I'll bring the 17t-18t fronts with me and change then out when I get to where I'm going (Coeur D'Alene, Idaho. just east of Spokane, Wa.).

 

O-Rider,
I noticed that you mentioned the aluminum rear sprockets. There is a performance benefit to this piece, beside the customization of gearing. There is a big difference in weight between aluminum and steel sprockets that is realized on an unsprung part of your bike. Because your suspension has less weight to control, it becomes more capable of controlling your rear wheel. However, the down side is less durability. Just the same, you can maximize the life of the aluminum sprocket by purchasing one that is hard anodized. This process of hardening the surface of the metal can also earn you style points, as anodizing is available in colors.

On the other hand, you can realize a great deal more of an unsprung weight savings with aluminum rims, but that is off the subject. Like nearly everyone else who has responded, I installed an 18T front sprocket and have been very happy with the change. As stock, it does require a bit more clutch slipping. However, this represents a very small difference that is soon forgotten. In fact, now that I've done some breathing and jetting mods, I'm considering the 19T!

 

On 2006-03-28 17:03, Sheepdog wrote:
....In fact, now that I've done some breathing and jetting mods, I'm considering the 19T!

Good point, I swapped my front sprocket just after rejetting and adding a new exhaust. I think those mods more than made up for any lost "uumph" off the line.

 

Bob,
I'm taking my bike into the dealer on Thursday for the sprocket change to an 18 tooth and the jetting fix. I'll let you know how the sprocket change works, should have it by the first of next week, weather permitting.

Bob

 

I have an 18t front sprocket on my bonnie. I do about 3/4 highway travel. Hardly notice the difference on take off, but heaps better on the open road. Still look for another gear occasionally though, I reckon it would cope with the 19t depending on the load :wink:

 

Go with the 18t. You won't regret it.