ribbo
New Member
Posts: 21
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Post by ribbo on Dec 15, 2008 14:40:49 GMT -5
Hey guys
Can you put a set of xs 250/400 forks on an SR 500 ?
Ribbo
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Post by Just Plain Bill on Dec 16, 2008 1:14:39 GMT -5
You might be able to, with enough work, but they are not going to drop in. Seems like they're a little spindley, with 33mm fork tubes while the SR has 35mm fork tubes so you will have to swap out the complete triple clamp assembly (which might not fit). Better find out how long the fork legs are too. You don't want them much longer or shorter than the SR fork legs. Also, the springs may turn out to be soft for the SR. All manageable problems. Just takes time, patience and money. Have fun.
Bill
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ribbo
New Member
Posts: 21
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Post by ribbo on Dec 16, 2008 4:47:35 GMT -5
Many thanks Bill
How about putting XS 250/400 custom alloy wheels in SR 500 do you think that I can do this and modify the spindles/bearings and spacers and change the rear sprocket ?
Ribbo
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Post by aero on Dec 16, 2008 7:39:06 GMT -5
You definately don't want to go fitting slimmer fork stanchions to a SR. Early XS650s had 34 mm stanchions, but these have considerably thicker walls then the later 35 mm tubes. Even then 34mms are worse then 35mm for flex.
You might be surprised to find the front wheel drops in to the SR forks. From memory the XS and SR set up are very similiar. A XS650 front wheel from a 80 on model will fit in without any work as the forks are the same between the two bikes. Cast wheels tend to be cheap, even XS650 ones. The rear will fit with some work and are much better then XS250 items.
It is better to modify the wheel to fit what's there then try and modify the bike too much. You can do alot with a bearing size chart too (metric)
Have you thought about the rear sprocket. Can you get one in the right chain size and size range to fit the XS250 hub?
The other more important thing.....are you using a rear drum brake? If so be very careful. The XS250/400 rear drum was very thin and cracks and distorts, the custom 16 inch wheels were worse then the 18 inch road models, but all were pretty terrible. It would be silly to do loads of work and end up with a brake that grabs or pulses when applied.
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Post by Just Plain Bill on Dec 17, 2008 3:29:07 GMT -5
Ribbo, in the U.S. we only got the XS400 (no XS250's) in <edit - correction> 1976-83. I have no personal experience with them and am depending on the Yamaha fiche site noted below. I gather that the "Custom" XS is the one with 18" front and 16" rear wire spoke wheels, drum brakes at both ends <snip>. Aero's remarks about the weakness of the rear brake should be given considerable weight, as should his suggestion that you consider using XS650 wire wheels instead of XS400 wire wheels. That said, you asked whether the XS400 wheels could be used on the SR500. Using the Yamaha on-line parts fiche ( www.yamaha-motor.com/sport/parts/home.aspx ) it appears that the XS400 has the same diameter rear axle (17mm) as the SR500. The XS400 wheel might drop right in; assuming it isn't too wide. XS400 models use the same size chain (DID 50) as the SR500, but you might need to change the sprocket. However, the front axle is smaller at 15mm instead of 17mm as on the SR. That's a little troublesome since it will require machining the front axle to 15mm diameter and making a reducer for the right side fork leg (and any spacers that might be needed). The XS400 custom also uses a 3.00x18 front tire, which is rather skinny and will require using an XS400 speedo drive to keep the speedometer accurate. Fender to tire spacing will change with an 18" front wheel and it might not be very attractive. You haven't mentioned the year model of your SR500. If it has a drum rear brake, the rear wheel swap will be easier. If not, it gets a bit tricky with having to weld a tab for the brake stay on the underside of the swing arm (or rotating the brake plate and mounting the stay above the swing arm). At the other end, if it has a disc front and you use a drum front brake, you will have to acquire a new hand brake lever, perch and cable and fabricate a brake stay between the backing plate and fork leg. Bill |
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Post by davedunsboro on Dec 17, 2008 5:20:31 GMT -5
SR400 bits just bolt straight on!(Please kill me if I mention this again! Dave)
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