begging new mod, need input

[pggg]

Gotta say in defence of all those pics of scavanged bits and peices of junk, you can't compare my conglomeration of nuts and bolts to a bike like Mathhs, the grinded teeth on the spline and some sprockets was the only machining I had done, the rest I did with handtools - tell a lie, also had two axle holders milled from a chunk of 100mm thick angle iron too, the trusty hacksaw got a break on that one

[xschop]

arm length

I have a couple swingarm options. VFR has 22.5" length, Triumph 955 has a 20" length. the stock xs11 length is 17.5 IIRC. I really like the vfr 5-spoke wheel compared to the 3-spoke triumph. But my question is, would stretching the S/A 5 inches mess up the handling. If I go with the vfr S/A I will later put on an 04-06 R1 front fork/wheel combo to match the rear Vfr wheel.I like what DennyZ is doing. Any ideas?

[Dennyz]

The XS has a long wheel base, short swing arm, and high steering angle compared to modern sport touring bikes.

I am considering reducing the steering angle, moving the swing arm pivots forward, and stretching the swing arm to address these differences.

Obviously this is a very extensive bunch of modification. It is all part of getting on radials, without loosing the essence of XS'ness.

[pggg]

Don't know about 5 inches(it'd work for straight line drags) I stretched an el-cheapo taiwanese non-Oring 520 chain within days on the XS11 and had the axle fully back a further 2 inches and didn't really notice any difference. With the axle 1 inch closer than normal - still no real difference, but it's possible to imagine anything. 520 sprockets and chains are way lighter than 530 and work good performance with the extra 10 or so horses stomping at the wheel. Shorten the long swingarms 5 inches at the axle point maybe.

[50gary]

If you add the stretch at the rear of the swingarm it would handle like a semi-truck. Turn in would be very slowand turn radius would be large IMHO. I would de-rake and lower the steering tube first to evaluate the handling. I believe each degree off the 29.5 caster angle equates to .5" off the wheelbase. Therefore if you reduce the rake by 4 degrees that would be approx. 2" shorter in the front and have much quicker steering inputs and more front weighted. There will be plenty of room as the 17" R1 is 2" smaller diameter with a 60 or 70 series section already, also the tire travel is then more vertical so it won't move rearward nearly as much. I have a set of R1 nearly ready to go forthe XS11 I spray welded the XS stem and had it ground to fit the R! triple clamps now I have to put the forks together and mount them on the bike. I'm dragging my feet trying to find some heavier used R1 springs to better match the weight of the XS. I think .9 would be about right?
Cheers, 50gary

[TopCatGr58]

Hey Gary and DennyZ and others,

I can attest to the increased ease of steering from Deraking the front end! Even though I have 4" over length upper tubes, due to my front ender in '86, I reduced the angle so much that I have only 2" of TRAIL!! I don't know how many degrees that makes it, but the front end is very light in the steering. This is one of the explanations that Bruce Gerkin provides for why I can run the twisties with him and Gary(66) and not fall too far behind!

The stock Trail as I was told was about 6", mine might have been a little more with the longer upper tubes, but with it being 4" shorter, that would equate to about 8 degrees reduction according to Gary's formula, so mine might have as little as 21.5 degrees??

I'm just providing this info for your consideration, several folks had a chance to ride my bike, but not thru any tight turns, Genepig was the one that pointed out to me that my frame had gotten bent...I had not known that, thought the Dealer would have noticed and informed me when they did the repair, but I guess they didn't check, or didn't tell!
T.C.

[pggg]

Well I've got an 18 inch front wheel on mine(with a 17 inch lowish profile rear) along with 1 inch 'drop-down' spacers inside the forks, the steering feels lighter and more responsive when riding, even bordering on 'slightly twitchy' but the wider than stock front tyre keeps it all nice and steady, still stable and solid at higher speeds. I'm picking a 17 incher may need a bit of tweaking to the rake/trail to keep the XS from becoming too 'loose' up front.

[Dennyz]

I don't have the FJR numbers in front of me, but I seem to remember it has several degrees less rake. I think the R1 is even less. I would like to take 2" off the front and add 2" to the rear. It would be nice to shorten the wheel base, but I think I will be lucky to end up stock. I though about making new triple clamps to pull the forks back a bit, but tank clearence is a problem.

[50gary]

I have R6 front end (2000) complete on my XS650 set at the R6 24 degrees with 98mm trail. I believe the R1 is the same? The offset of the R1/R6 triple clamps is also much less (about12mm)that alone will reduce the wheelbase and quicken the steering input. Denny, your goal is realistic to my way of thinking. That is what I did to my XS650, shortened the front lengthened the rear it has the effect of moving the engine mass forward in the wheelbase. The R1 forks are alot shorter which will also make the rake a bit steeper and increase the wheel rate of the spirngs. I would like my XS11 to be 25.5 degree of rake, I don't want a heavy touring based bike to be too quick. I bought this one to relax a bit I just want it to be more responsive. I don't know if I'll make the change or not this winter it's a ton of work?
Cheers, 50gary

[xschop]

thinking ahead

I posted earlier info about forks.I figure one of these bikes has the rake/triple tree I may be able to use?http://www.xs11.com/forum/showthread...highlight=37mm

[xschop]

one for pggg

So.... I need to make a decision on swingarm....the triumph has a 42 tooth rear sprocket and the vfr has a 43 tooth. Question is will the 13 or even 14 tooth sprocket be too low and would I do whelies in 4th gear or what? IIRC you said a 14T front sprocket will clear the xs case?

[TopCatGr58]

Hey Chop,

42/13= 3.23 ratio
42/14= 3.00 ratio

43/13= 3.31 ratio
43/14= 3.07 ratio

These are close to the stock XS11 FD ration of 3.10:1, but depending on what size tire, 16", 17", or 15" would also affect your final leverage and wheelie ability.

IIRC, the 14 tooth sprocket needs to have the case ground down a few mm to allow the clearance of the chain, that's why I ordered the 13 from him when he was having some made by the shop that he used. I didn't want to go cutting on the cases, or thinning it out too much.

I'm looking to get my 79SF basket case done mostly stock for my nephew, but I have an 81H box-o-parts that I can "PLAY" with, and will be trying to the chain drive convert on that in the distant future! I'm not looking to go with a very wide rear tire, I also want to keep the stock rim look, but I may change my mind as I get into it!?
T.C.

[pggg]

Chop most sprockets have a few different sizes available, TC's ratio formulas were bang-on right from the start, a 13T fits straight in with no dramas, 14T front fits easily enough too, I've got on a 14 X 45 now, it does around 3700 - 3750 revs at 100 kph(62 mph) checked with a GPS as well as digital Sigma speedo. Discovered the Sigma digital pushbike speedo reads exactly the same as the GPS up to around 140 kph or so, then progressively starts reading a few kph lower once the speeds start getting higher, assume its because the tyres are bulging out further and giving the digital speedo a slight error.

[50gary]

PGGG, pushbike, is that a bicycle? I use a "Topeak" bicycle speedometer on my xs650. BTW, 'Sprocket Specialists' will make virtually any sprocket for a very reasonable price I use 520 DID X-ring chain and 17/33 on my 650. Standard is 17/34.
Cheers, 50gary

[xschop]

thanks

thanks for the info.So the middle drive ratio is negligable, since I will be getting rid of it on the chain drive? I pretty much have made up my mind on the VFR swingarm/wheel....this would put the ratio back to stock 3.3/1 which is what I want for around town, light to light....chop