| Author | Message | ||
     Dustyjacket |
I have a stock Blast with a Corbin seat. I weight 230 lbs. I took a longer ride than normal, and felt every bump in the road. 2 days later, my rear end is starting to hurt from the ride. Is there a way to get a smoother ride and have the shock absorb the bumps? | ||
| Ezblast |
The Corbin's new right? - they take about 600 miles to break in - break it in then let us know - lol GT - JBOTDS! EZ  | ||
| Dustyjacket |
Actually, I have about 800 miles on the Corbin.Normally it is good, but the bike was transmitting every bump in the road, either through the sear or bars, depending how I sat. | ||
| Ezblast |
There are suspension shops that will rework your suspension or you could buy upgraded parts from Works Suspension - the former actually less expensive in parts though you pay for labor. GT - JBOTDS! EZ | ||
| Mmelvis |
penskeshocks.com has a rear shock and piston kits for the blast. The rear shock will run you about $775. Piston kits vary but you would be looking at around $200 installed depending on the shop. | ||
| Dustyjacket |
Thanks, guys. I'll try one more longish ride Thursday to be sure I want to do this. (My wife will take the Blast from me later this year, so I need to consider her in what I am doing. I was hoping the stock shock was adjustable.) My other option is to stop for a rest every 75 miles or so. | ||
| Ezblast |
LOL | ||
| Ezblast |
Here is an example of a great local shop that will upgrade the Blast suspension with different springs fr and rr and valving - http://www.aftershocks-suspension.com/pages/home.htm - pricing for this starts - front $350.00 (includes valve kits and springs & labor) & rear (shock & labor) $679.00 (or if your going to dedicate it to pure track they will work the stock shock, but it won't be fit for the street - lol)- to start - they also have group rates for those groups of folks doing racing series - thought I'd let you know - this is an example of many fine shops out there that do suspension work, there are others - ask around. GT - JBOTDS! EZ | ||
| Dustyjacket |
Thanks again. | ||
| Gearheaderiko |
Pirelli tires! Nice ride. Sit closer to the tank and the Corbin is softer and a better ride. | ||
| Naustin |
I've been reading about increasing the rear ride height on a GSXR. If you shim the rear shock 3mm, you get 12mm of increased ride height - and that translates into different geometry, quicker turn-in, and more ground clearance. The Blast has a different shock mount design, so it would be impossible to merely shim it, however, it wouldn't be too difficult to fabricate and weld on a new lower shock mount... What does anyone think?? Obviously, you wouldn't be changing the shock itself, or the amount of travel or the dampening characteristics, but it might keep the hard bits, especially aftermarket exhausts off the pavement.  (Message edited by naustin on January 12, 2006) | ||
| Gearheaderiko |
You can shim the spring which will give the added height. You can jack up the shock mount as described very easily. About 1/4 inch shim = 1 inch ride height. Remember that whatever you do to the rear will affect the front and that should be adjusted accordingly. Upping the rear will make the front that more soft. I'm not sure if most street riders will benefit from more turn in, especially at the expense of highway stability. If you ride 2 up, shimming the spring would be ideal. The one thing I've learned is that what seems like a simple adjustment or change can have a different outcome than expected. | ||
| Naustin |
So you're suggesting that I can simply shim the spring without re-mounting the shock? Which would be better. Move the whole mount, or shim just the spring?? nick | ||
| Bobbyhead |
Naustin, just shimming the spring is basically the same as adding preload. It's no big deal on most shocks, as they are adjustable, but the blast shock isn't. So you just need to compress and remove the spring, then add the spacer and reinstall the spring. Voilą, instant preload. The ride height will be increased, but it can never be increased past the fully extended length of the shock. But if you started changing the lower shock mount and moving it forward, you increase the ride height past what you could have with mere spring preload/shimming. But like Gearhead said, what you do at the back affects the front, as well as maybe other areas of handling. Bobby (Message edited by bobbyhead on January 12, 2006) | ||
| Jprovo |
What Erik and I found was that 1/4" of pre-load for the rear shock too about 1" (25mm) of sag out of the suspension. That's for me, and I weigh ~195. We also shimmed the front end for more pre-load too. The stock suspension on the Blast seems to work well for spirited street riding, even if it is a bit soft. | ||
| Jprovo |
Naustin, I might try lowing the front fork tubes in the front clamps to get the same effect that you think will happen if you changed the rear shock mount. This would allow you to quickly preview what the suspension change is going to do to the handling. Personally, I wouldn't change the shock mount, I'd just make some pre-load shims for the shock. If you need help with a shock dis-assembly tool or anything, let me know. James | ||
| Bobbyhead |
James, won't sliding the fork tubes up in the triple tree reduce the wheelbase, and also effect the trail. I'm not sure that would have the same effect as raising the rear ? | ||
| Jprovo |
It would be similar. Raising the rear is going to affect the trail, and the steering head angle by making the bike stand more on it's nose. Lowering the front by sliding the forks up into the triple tree will do the same thing, make the bike stand more on it's nose. Lowering the front end only will also make the bike slightly shorter in wheelbase. Raising the rear will also affect the wheelbase. Depending on where the swingarm sits with Naustin sitting on it, it could make the bike longer or shorter. If the Swingarm pivot is lower to the ground than the rear axle, raising rear ride height should make the bike longer. If the swingarm pivot point is higher or the same height as the rear axle, then raising the ride height will make the bike shorter. The numbers that we're talking about here are small. Some people will notice them, some people won't. I've known guys that could tell that their bike handled differently after they adjusted the chain, and had to take out a chain link to make themselves happy. I'm not one of those people, but shimming the rear shock 1/4" made a HUGE change in the bike. James | ||
| Naustin |
Thanks guys. Sounds like adding some preload is a better option than changing the shock mount. Another obvious question - has anyone found a bike with an adjustable rear shock assembly that could be adapted to the blast? It would be way cheaper to salvage one off a wrecked bike than the Works unit. nick | ||
| Jprovo |
Not yet. I'm working on a lower $ alternate. Everything is WAY too long. The only options that we have right now is Stock, Works Performance, and Penske. | ||
| Naustin |
I've seen some 11" units, but it was for a Suzuki intruder... What would the maximum length be? | ||
| Jprovo |
The Blast shock is 10 3/8" long. I wouldn't go over 10 1/2", and even that might make the bike too unstable. 11" is a 5/8" change, that seems too long to me. 5/8" at the shock is a lot more at the rear wheel. | ||
| Gearheaderiko |
My opinion is that the body length is most important,first. If the body is the same size (or shorter) as the Blast, the suspension will bottom out at the same point. A dirt bike shock might be 12" but may compress down to 10.5 or less when loaded. The shorter Sportster & FXR shocks would fit, but there isnt enough dampning or spring rate in a single shock. More than likely only shocks from a monoshock bike would be worth researching unless the bike is really heavy. There's not much room on the Blast for a longer shock, but I think 11" is passable or longer if it doesnt change the (loaded) ride height. Theres's a whole bunch you can do to modify a shock, but some will be more adaptable than others. Its true though that most are too long and the ones that arent are dual shocks or off a 'cruiser'. The Work Performance website gives a listing of stock shock lengths, but they dont list any other specs (spring rate,travel,diameter,body length, etc). I'm sure a shocks out there that will fit, but it wont do us much good if its off something exotic. | ||
| Spooky |
The stock spring rate is 900lb. No other street or dirt bike runs a spring rate that high. Most of them run a spring rate around 200lb - 350lb. By the time you get done finding a shock, having it re-valved for the high spring rate that is needed for the blast, and the chance of needing a new spring with the correct inside diameter you'll be better off buying an aftermarket shock that is made for the Blast. | ||
| Naustin |
The closest I've found if a 11.25" (unloaded) unit off a 98 CBR600F3. As the CBR is really only slightly heavier than a blast, and the shock is adjustable for preload and dampning, I figured it would be pretty close as far as its dynamic characteristics. But another think to consider is that the CBR shock makes use of a linkage system, and therefore it may have jacked-up spring rates. But, by your calculations, it would raise the rear way too much anyway.  | ||
| Gearheaderiko |
I dont really think finding a spring that fits or re-valving is much of an issue. I do find it hard to believe that there is a 600lb difference in spring rates (for mono shocked bikes) between most others and the Blast. I would like to know for reference where there is a listing of spring rates. And it is certainly true that custom building a shock could run up the price to that of a Works unit. Naustin: 11 1/2 is only too long if the body is too long or it changes the loaded ride height. I do think this topic is worth researching as would be finding a set of fork tubes that are adjustable and 'bolt right on'.  | ||
| Spooky |
Call Works and talk with them. They test the stock springs to find the spring rate before they even begin to build a shock or even re-valve one. Most sport bikes can get away with the low spring rate due to shock placement and the linkage system helps manipulate the spring rate ( or boost the spring rate ). | ||
| Gearheaderiko |
Yeah, I thought about the linkage too. The Blast uses 1/2" of shock travel to absorb a 2" bump and through the linkage system a sportbike can use 2" of shock travel to absorb the same bump. Makes fine tuning a lot easier (the sportbike). I just cant believe the Blast shock is that unique but it still might be like finding a needle in a hay stack! Even if research yields nothing, it still gives a greater understanding of suspension workings and thats why I love badweb. More of how stuff works and why, than just swapping out parts. | ||
| Naustin |
Hold on... The Honda 919 has a 11.25 inch unit that attaches directly to the swingarm with the right style connections, and has NO linkage... The VLX600 used a 10.35" unit, that also did not use a linkage. (Message edited by naustin on January 15, 2006) | ||
| Matty |
Spooky, where on Earth did you get that spring rate and are you referring to the XL shock or the Blast shock? |
