| Author | Message | ||
     Jim_h |
I have a '05 XB12S and have always thought the bike was geared too low. I would like to gear it up (lower engine speed) for a lot of reasons - better mpg, easier cruising, less fan, etc. The stock primary gearing is 38t engine and 57t clutch. My question is: Does Harly have sprockets set/chain (possibly from a sportster) that would do this - larger engine sprocket and/or smaller clutch sprocket. Any help would be appreciate. Jim H | ||
| Bombardier |
At least one person on this site has geared their XB12 with XB9 gears ( search in the Knowledge Vault). This makes for higher revs at cruising speed(10%) and they report better fuel economy. One of the sponsors on this site(Buellerparts) has been experimenting with larger primary drive gears and has had some success with top speed etc. You will find him to be a hell of a nice guy. | ||
| Petebueller |
Thanks Bomba We are playing around with a bigger front pulley. The results are encouraging and we think we are close. We started with 41 teeth. The bike is smooth, gets better fuel which we didn't expect to be significant. The bike is an XB12R with a Micron and Open airbox. It is still pulling to the rev limiter on the track but now it is at 240 kph instead of 225, It still monos in first and second with ease. The guy who is testing it says he would not go back to the stock gearing after testing this one. Everyone is different in the way they like their gearing. The only issue is that there is a "Ducati" noise at idle, and it seems that the chain with an extra two links is creating too much slack for the tensioner. I've had 42 and 43 tooth versions made and they are ready to test. There is a chance that 40 teeth may go on with the stock chain. I'll try one of those next. (Message edited by Petebueller on June 14, 2008) | ||
| Jim_h |
Thanks Bomba, Petebueller, I use my bike mostly for commuting to work. If I keep my speed down a little, I get over 60 mpg. But still at 60 mph the engine is at 3,000 rpm - higher than it needs to be. I'm not concerned about acceleration, it's fast enough, but I would like to cruise fast without over working the engine. Petebueller, where are you getting the larger engine sprockets? Are they Harley parts? Making them from common parts? How do you re-size the chain? Do they have links that can be added? I definitely think the bike is geared too low. If I'm not in a hurry I often shift 1-3-5 and it moves out nicely. I'd like to gear it up to a 40 - 42 tooth engine sprocket. Is it not possible to make the clutch sprocket smaller? Are there any Harley parts (1200 Sportster new or old) that would accomplish what I want to do? Thanks again, Jim h | ||
| Petebueller |
Hi Jim There are lots of smaller sprockets but I didn't find any bigger. My interest in this is pretty much the same as yours. I find the first up-change is too early, and I would be happy at 100kph (60 mph) at about 2,800 rpm. This is even more so since I fitted a Micron and I find I have a lot of low torque. The teaming with someone who races his Buell gave me a test rider. I paid for the first cog and he paid to have it fitted and did the test riding. We are sharing the costs of the next round of pulleys. I can't find the chain in Australia. In the end I bought an extra stock chain and used links out of it to create an extended chain. I am a sponsor here, and I have put up a bit about it on the XB forum. If I get something that works I'll sell them. Selling isn't about income, it is about financing projects that interest me. I have been given a quantity rate that will allow me to sell them for less than I paid for the first one off and if I sell enough I may pay off the attempts that don't work. If all goes well I'll also get a gear that suits me. This is a picture of the 41 tooth next to the stock.  The gear cutter is top notch and very helpful. I think he is interested in this one as well. I'll let you know if I find one that works well. Peter | ||
| Jim_h |
Peter, Please let me know if you go into production with the engine sprocket. I would be interested. I haven't given up hope that there isn't a larger Harley engine sprocket out there - their cruisers couldn't be geared that tall. I'm also thinking about a slightly taller rear tire. It probably wount make much difference and will throw off the speedometer, but worth a try. There is alway a conversion to chain drive and different final ratios, but the belt drive is one of the best features. gooday, Jim | ||
| Petebueller |
My friend forgot to tell me that the noise stopped after a couple of rides. The pins on the primary chains are tight through all links, not just the outer plates. It seems it just needed to wear in. (Basically the 41 tooth works and the gearing seems good.) He also sold his XB to buy another race bike, so I have lost my test rider. My bike gets services in a couple of weeks. I get the fit of both the 42 and 43 tooth cogs tested on my bike. All going well I'll keep the 42 on mine and look for someone to test the 43 on a track. Once I know what works, I'll check a 40 tooth with a stock chain. I'll keep you posted Jim | ||
| Petebueller |
Hi Jim I have posted a bit on the BuellerParts sponsor's forum. Basically 42 teeth is the most viable option. I would have liked 40 teeth with the stock chain, but it is too tight for the tensioner. 43 teeth fits on, but it is like a bow string, too tight and too dangerous to try to tension. I took a long ride tonight with the 42 tooth and it is perfect for me. 4th gear is about the same as 5th (60mph at 3000rpm). First is still fine. I don't need to rev it to take off or anything it just feels normal, but it winds out a lot further before I need to change up. This gearing suits me. I have ordered the first batch and I'll put them on the site in 2 to 3 weeks. Peter | ||
| Jim_h |
Peter, The 42 tooth sprocket sound great. But I don't understand about the chain/tensioner. I'm pretty sure the stock chain will not work. Do you have to add links? How many (is it easy to do)? Does the stock tensioner work with this arrangement? I have no doubts that the Buell (especially the 1200) can handle the lower engine speed. In fact it probably accelerates faster and is easier to ride. Thanks for the info. Jim H | ||
| Petebueller |
Hi Jim The kit will include the sprocket an chain, I could do just links as well as the chain for those that want to save cost. I'd recommend adding into a new chain rather than the old chain. A new chain may be cheaper to buy locally. I used one new stock chain for links. The link pattern is paired son they can only be added in multiples of 2. For my bike I had the links inserted into a new chain. On Paulo's bike we just added them into his chain. Hi bike was near new anyway. The links are hard to fit. The pins are tight through all plates. Several motorcycle shops made a mess trying to fit the links to Paulo's bike. I took it to a chain specialist and he made it look easy. He did mine in 5 minutes. My thoughts are that it is safer to get them from me with the chain made unless you know a good chain maker. With the 42 teeth and two links extra the tensioner is set with exactly the same adjustment as the stock set up. | ||
| Redbuell1203 |
What was the final rpm at 60? When is the conversion available to be bought? What is the cost buy a kit with the chain already made? | ||
| Petebueller |
At 60mph it is turning at 2750 rpm. About 10% taller. The final drive ratios are about Gear | Stock | 42 tooth -----+---------+--------- 1 | 10.688 | 9.8 2 | 7.635 | 7.0 3 | 5.687 | 5.2 4 | 4.706 | 4.3 5 | 4.036 | 3.7 Forth is now about half way between the old 4th and 5th which works well. Those that have ridden my bike say that first just feels like a "normal" first. It goes further out before you change up. There is still lots of pull in 5th, but obviously it is less than the old fifth. The item is the pulley and the chain. I decided not to sell the pulley separately because the chain can be a hassle to modify by anyone but a chain maker. This is the link to it on my site http://www.buellerparts.com.au/index.php?act=viewP rod&productId=118 . They are normally AUD $445 plus postage. BadWeb discount goes to $425, and I am capping postage to $50 to the US for BadWeb. It will be more than this. With BadWeb discount they are AUD $475 delivered to the US by registered mail. Today's paper doesn't have the rate, but last time I looked it was around $455 US. Delivery seems to take about 10 days to the US. If you do want to order one please put that you are BadWeb in the comments at the checkout, and I will amend the invoice and charge you the discounted amount. Send me a PM as well in case the comment get lost on the order. The guy who tested the 41 tooth pulley thought that he got better fuel consumption. I haven't noticed any better on my mine with 42 teeth, not around town anyway, and I haven't used a full tank on a highway trip yet. It hasn't got worse  Speedo works fine and I keep the belt which is what I wanted. You need a puller to remove the pulley and a locking bar to hold the gears while you do it. The new torque on the nut is 250 ft lbs which is massive. The pulley does up to 07. For 08 and later let me know if you want me to make them. 08+ Ulysses have the alternator cover and the pulley as a single part, so they may not be possible. Peter | ||
| Petebueller |
The Aussie Dollar has dropped almost 30% in the last few weeks so todays price of AU$475 delivered to BadWeb members in the USA is only US$310. This is about US$270 + delivery which competes very strongly against other ways of gearing the bike up.  | ||
| Gjwinaus |
And on a related note about engine sprocket changes, I was always looking for 6th gear on the highway on my XB9R, I changed the 35 tooth engine sprocket for a 38 tooth -12 front engine sprocket and I think I'm happy with it, on the road the new ratio is like having a 5 1/2 gear not a 6th gear, at 100 kph (62 MPH) the revs were 3300, now they are down to 3000 rpm but to overtake I need to drop down to 4th. 4th gear is 3600 rpm at 100 KPH. At the traffic lights the starts are no problem, although I think I will have to ride it a bit like a Japanese bike in the corners | ||
| Gjwinaus |
an update, The 38 teeth sprocket is just a little to tall for dribbling along in stop start traffic, I have to slip the clutch more than I like | ||
| Petebueller |
Going up to the 42 tooth on my XB12 would be like you going to the 38 on your XB9. A friend is going to up his XB9 like you have so I let him ride mine last weekend just to show what taller gearing is like. A bit hard to compare still because mine is geared nearly 25% higher than a stock XB9, and the XB9 is a revvy motor compared to the torquier XB12. He said he went to change from first to first only once and that was on a round-a-about. He found that the bike pulled it like a normal first. The first gear ratio feels more Ducati-like. If I use the clutch a but more it's not much. And I prefer that to up-changing early. |
