| Author | Message | ||
     Rogue_biker |
My 2008 1125R just went over 40k miles. In the last 15k miles, I've noticed the bike developed a noticeable driveline lash. Belt drive bikes aren't supposed to have this. The original belt still looks really good in my eyes. It has no tears, no missing teeth, no fraying at the edges. I just replaced the belt with a new one and now the driveline lash has been eliminated. My question is: 1) Should there be a replacement interval for the belt? Maybe every 30k miles? 2) Should I have replaced both front and rear cogs? Thanks all. | ||
| Froggy |
Officially, there is no interval. Personally I recommend replacing it occasionally, like 20k miles. The belt will fail eventually, so it is best to change it when it is convenient, and not when it is too late. I would hold onto the old belt, as they make good emergency spares. Old belts are broken in and are very flexible, you can fold it up like a saw blade and stuff it under the seat, hopefully never needing to use it.
Nope! If you saw the cost of the front sprocket, you'd likely just buy a new bike  | ||
| Stevel |
Froggy, Cost is very high, I agree, but sprocket wear is inevitable, especially with aluminum. Worn sprockets will trash a brand new drive belt in very short order. It is often difficult to detect wear on the sprockets by eye, they must be carefully measured. Rogue Biker, I doubt the belt was the cause of excess belt lash. I suspect it was the idler that needed attention. | ||
| Dannybuell |
I have 24,000 miles on my CR,105,000 miles on my S1. The S1 has been run hard, 3 top ends. S1's are torque monsters, I lost a belt on the freeway when I downshifted for the upcoming clover leaf exit. Pushed that bike about a mile to a friends house on a nice hot day. I ran a belt about 45,ooo miles on the S1, no signs of 'sharp teeth' or anything like that. I changed it anyway. The EBR race module on the CR has so little torque when downshifting... | ||
| Sprintst |
I have to wonder if it was a worn belt, or during the replacement you loosened/fixed an issue with the tensioner | ||
| Rogue_biker |
I replaced the Idler Pulley about 6k miles ago and I did notice an improvement in the lash. But the driveline lash slowly got worse since then. To the point where I had to choose a lower gear to avoid revving the engine lower, and/or "trained" my throttle hand to be REALLY gentle upon opening the throttle from closed. It delayed my corner exits because of that. I've seen a few items on Ebay for brand new rear cog and I was thinking of buying it. I agree, I can't tell if the cogs are worn. It's not like a chain and sprockets. Makes me wonder how much longer we can keep maintaining these bikes when wear items such as these need to be sourced from ebay of all places. In any case, I strongly believe now that all these components should be replaced every 30k miles to restore the smooth drive they had back when they were new. | ||
| Kruizen |
I'm switching to chain drive in a month. So all belt parts will be for sale at that time. | ||
| Reepicheep |
Chain drive makes gearing swaps easier. Have you priced the chain over it's replacement interval for a 100hp bike? Is it like $120 every 10k miles or something? | ||
| Rogue_biker |
I've always had chain driven bikes. Their chain size is dependent on their horsepower/torque. 525 being the weakest and 530 being the strongest (and heaviest). I routinely replace my chain and sprockets between 25k-30k miles. It normally will cost me $275 for parts, and I buy high quality chain and sprockets because this is an area I refuse to compromise. I do the labor but I believe they charge 2 hours of labor to install the set. It is easier to replace belts and cogs than chain and sprockets. It's also a whole lot messier with chains. | ||
| Stevel |
Chains have the advantage of quick gearing change, less parasitic power loss, easy replacement and inexpensive replacement and maintenance. Belts have much lower maintenance, more durability. Chains fail much more often, require constant cleaning and re-lubrication and essentially make a mess. Belts are more susceptible to stone damage and are expensive to replace. So, if you are a commuter, drive many miles on the road, the belt is the clear winner. If you are a sport rider, do track days and do relatively low miles or have a need for maximum rear wheel horsepower, the chain is the winner. (The belt will consume 5 horsepower more than a chain) | ||
| M1combat |
"less parasitic power loss" No. "The belt will consume 5 horsepower more than a chain" No. | ||
| Rogue_biker |
Well if belts do NOT consume more horsepower, then Buell overstates their crank horsepower figures. Japanese sportbikes with chain drives always end up with 10 bhp LESS at the rear wheels. The Buells always end up with 15+ bhp LESS at the rear wheel. Someone explain this to me. | ||
| Luc1f3r |
@rogue_biker parasitic loss is measured as a percentage, not a hard number. So 15hp loss on a 146hp bike is 10% loss...a 100hp sport bike with same loss is 10hp. There is negligible difference in rolling friction between a belt and chain | ||
| Stevel |
I'm not going into a pissing contest on this loss thing. My statement is true. Do your own research. The additional loss is due to rubber friction within the pulley grooves and air pumping losses at the belt pulley interface. The latter was a major fault found during the development of the British hovercraft, as those skirt pressurizing air pumps are tooth belt driven The pulleys had to modified to provide a bleed air path. Please also note, that these pulleys wear.....well, that's caused by friction. None of this friction or air pumping is present with chain drive. | ||
| Sprintst |
What we need is someone that dyno'ed an 1125 stock, then did a chain conversion and dyno'ed it | ||
| Rogue_biker |
Luc, if what you say is true, and I'm not contesting it, then it only makes sense that my statement is true regarding published horsepower. For example, my VFR800 has a claimed crank hp of 109. And it consistently produces 98-99 rwhp from a variety of sources. The 1125R has a claimed crank hp of 146. Yet it consistently shows somewhere around 125 rwhp am I right? So how does one explain this? | ||
| Luc1f3r |
Synchronous belts are 98-99% efficient, chains are also 98-99% efficient. Here is a white paper published by Gates: http://www.gates.com/~/media/Files/Gates/Industria l/Power%20Transmission/White%20Papers/WP%20Cost%20 SavingsEnergy%20Efficient%20PT%20Systems.pdf Any loss do to pumping in efficiencies in a 1inch wide belt is negligible, and im sure that the reduced inertia would make up for it anyway. The differences you see in rear wheel power aren't from the belt...they're from any one of the hundreds of factors that will show the same vehicle dyno differently on different days. | ||
| Rogue_biker |
I looked it up. 2008 Ducati 1098: Claimed HP - 160 RWHP - 139 2008 Honda CBR1000RR: Claimed HP - 171 RWHP - 154 2008 Yamaha YZF-R1: Claimed HP - 177 RWHP - 150 Buell 1125R: Claimed HP - 146 RWHP - 120 So with the exception of the Yamaha R1, which lost 27 hp from crank to rear wheel, the rest consistently lost around 17-20 hp. The Buell lost 26 hp from crank to rear wheel. (Message edited by rogue_biker on March 04, 2015) (Message edited by rogue_biker on March 04, 2015) (Message edited by rogue_biker on March 04, 2015) | ||
| Fdl3 |
I think there are a *few* more bits besides a belt/chain between the engine crank and final drive! I bet *claimed* power figures are about as reliable as *wet weight* figures. | ||
| Reepicheep |
This was hashed out in the old days... One consensus then was that a brand new chain with brand new sprockets had the potential to be slightly more efficient in transferring power than a belt. But a worn chain and sprocket system drops off efficiency much faster than a belt. So if you took an average random belt drive bike out of a parking lot somewhere, and a random chain drive bike, and compared them, the belt drive bike would probably be a little better in general (because nobody has new chains for long). But not enough to really make a difference... | ||
| Rogue_biker |
Based on my very limited experience on my belt driven 1125R, I think this bike should have its belt, cogs (front & rear), and idler pulley replaced every 30k miles. My XB12R had 30k miles on it and I don't remember it having driveline lash issues. Of course that bike was not as powerful. | ||
| Nobuell |
I have a slightly used 1125R drive belt for sale in the parts listing. Only has less than 200 miles. | ||
| Coastrambler |
Have 45,000 miles on my 1125, no sign of needing to replace belt. Belt life varies directly with wrist bend action, and clutch technique. Popping wheelies will take it's toll. Slow is smooth, smooth is fast. | ||
| M1combat |
And a number of other things ... Hopping curbs and jumping the bike doesn't make them last any longer for sure. They'll also break much more readily below 20 degrees Fahrenheit. | ||
| Cutty72 |
My belt blew out at ~18k accelerating from a stop light. That year I had done a lot of commuting on gravel roads, probably hard on it, but looked good overall. I am now sticking to a 15k change, because I don't like pushing. | ||
| Sprintst |
I'm guessing our belt drive has additional loss, it's due to the idler, not because it's a belt |
