JCosta on Tmax 530

[bikerdezzie]

Tell them but I don think it will make any difference on ya insurance, its a gearing change your not adding power per se like a pipe or something, my bike I have now is double the value new with mods and cost me 25 quid after declaring it all.

[rjc1944]

I was just asking really has anyone made the change in variator/pulleys and had an alternative quote? I refuse to believe that everyone who does this hides it from their insurance!

[michaelphillips]

when doing an insurance quote, they ask whether any modifications or additions to your scoot, which is then always in writing in your documents, i always tell them and tell them if made changes afterwards, i did this on the J300 at buying the docs came back with screen and givi rack and box, then phoned them regarding exhaus, again with dr pulley hit clutch and rollers, and did not cost me anymore, its if you dont declare then involved in a claim, and find you are not covered, well thats up to you. as your ride does get inspected by the insurers, generally if you mention its not performance related its no difference to policy, yet if written off the value of the claim differs

[tmaxrob]

Just to recap, when I bought my bike mid Jan it came with the jcosta fitted. Having ridden the 530 for 6 weeks now, I had my local mtorcycle shop remove the Jcosta and put back in the standard variator. Took them 2 hours however they said most of that was spent removing all the bodywork
What a difference its made! I sooooo much prefer the std part. To contrast, the jcosta made the bike very revvy. Engaugement didn't start until 3k and pulling away off the line for a quick get-away would see easily 5-6 during the launch. Steady state 30 - 40mph would see 4-4.25 K. The acceleration is very impressive, easily comparible with some 500/600cc geared bikes, but for me and my useage / riding style, it just wasn't working. It's a 530cc engine not a 125/250 screamer. You shouldn't be needing to work the motor so hard.
Back now on the stock part, the bike is smoother, quieter and less silly revs off the line. It uses the plentiful amount of torque the engine has instead of the high revs. The bike will still rev but you'll have to open the throttle further to do so. Engaugement is much lower and smoother. I've heard people mention that the jcosta improved fuel economy. I can't see how that can be the case having ridden both - time will tell. Without a doubt the sharp very punchy edge of the bike has gone now but I took the bike out for a good ride on Sunday and can honestly say I prefer the bike as Mr Yam intended. It's road manners are far better now. So anybody interested in 2-3K mile Jcosta for a 530? It'll be on ebay very soon.
In my opinion, the bike is capable enough as std. The jcosta, while a lot of fun detracts from other areas of the riding experience.

[MrGrumpy]

What a difference its made! I sooooo much prefer the std part. To contrast, the jcosta made the bike very revvy. Engaugement didn't start until 3k and pulling away off the line for a quick get-away would see easily 5-6 during the launch. Steady state 30 - 40mph would see 4-4.25 K. The acceleration is very impressive, easily comparible with some 500/600cc geared bikes, but for me and my useage / riding style, it just wasn't working. It's a 530cc engine not a 125/250 screamer. You shouldn't be needing to work the motor so hard.

Interesting. As I've said before, the mk4 feels like a diesel when it accelerates (especially when overtaking). Yamaha improved the variator for the mk4 (as well as the extra 30cc), so I was expecting it to rev more than the mk3, but it didn't at all. I did try the Malossi variator on the mk3 which did make it rev a bit more and go better, but the mk3 was stodgy. So given your experience, it seems that Yamaha did something quite clever to the transmission when they designed the mk4. If only it had a bit more top end!

[tmaxrob]

I think all thats needed is a very slight decrease in the roller weights. But it really would be a minimal reduction. Annoyingly I didn't weigh the standard ones before it was refitted.

[Funkycowie]

I am quite happy with the standard variator on the MK3 even on standard rollers and nearly new belt, adding in Dr Pulley sliding rollers would give me that little extra take off torque at a fraction of the price of a JCosta.

Tried the JCosta on my Nexus 500 and basically had the same experience you had on the MK4 TMax, a 500 really does not need to sound like it lost a 0

[michaelphillips]

according to dr pulley the standard roller weights for the 500 are the same weight for the 530 yet the 530 uses different sliders to the 500

size 25x15 weight 19gms x 8 so 10 to 15% reduction, i always went to 10%
so 17gm dr pulleys here http://www.drpulley.info/shop/product_i ... cts_id=636
if you want the sliders as well
sliders for 530 http://www.drpulley.info/shop/product_i ... cts_id=744
sliders for the 500 http://www.drpulley.info/shop/product_i ... cts_id=907


dr pulley even do round rollers, but i cant see the point for the mininal cost over dr pullers weights, using their compound http://www.drpulley.info/shop/product_i ... cts_id=952

[SkuTorr]

There are 4 sliding pieces in the 500's. The variator was changed in the 530, it rides on a larger shaft and has 8 sliding pieces, like a Mallossi and Polini do.

The 530 pulls like a diesel because they lowered the peak torque point to 5,250 RPM, right where it runs at full-throttle. That's why it's almost 3 seconds faster 0-100km/hr. than the 500. The 500's torque peak is at 6,500 rpm, but at full throttle it runs at about the same 5,200 rpm as the 530. STUPID! That's why it's so slow, the engine and gearing are not even close to being matched.

A set of 16.5gm Dr. Pulley sliders raised my full-throttle rpm from 5,200 to 6,200rpm, and it then was exactly the same speed as my (lighter!) brother's 530, from 20-80mph. Off the line the 530 is quicker initially, due to less lag in the belt drive and a more aggressive, larger clutch.

It's all about usable torque...

[MrGrumpy]

There are 4 sliding pieces in the 500's. The variator was changed in the 530, it rides on a larger shaft and has 8 sliding pieces, like a Mallossi and Polini do.

The 530 pulls like a diesel because they lowered the peak torque point to 5,250 RPM, right where it runs at full-throttle. That's why it's almost 3 seconds faster 0-100km/hr. than the 500. The 500's torque peak is at 6,500 rpm, but at full throttle it runs at about the same 5,200 rpm as the 530. STUPID! That's why it's so slow, the engine and gearing are not even close to being matched.

Interesting. The Malossi variator on the 500 mk4 did let it rev more, so this explains why it helped acceleration (especially mid range). This also suggests why fitting a J Costa or something to a 530 that lets it rev more may not produce a lot of benefit.