Sprocket truth

[GMP]

So what is the real story here, Honda sprockets the same or not? Like Steve I find it hard to believe that two companies would mfg and sell under a different part# if the Honda part was equal. I had a Honda CR sprocket for years I finally got rid of with all my GG stuff. If someone has one please measure the inner dia.,thanks.

[mtdirtbag]

Glenn there is a thread on TT in the Beta section on sprockets and one fellow posted a pic of his 13 300rr with a Honda sprocket, I think that will answer the question for you. Here it is: http://www.thumpertalk.com/topic/104610 ... ry11065511

Tom

[GMP]

Yes I know, that is Hammer's bike and what prompted this post. Steve and I have talked about this and it was strange that Dirttricks and Supersprocks have beta specific parts. If you look at it from an AM Beta marketing perspective though it makes sense.

[Hubert Carpet]

I have Supersprox KTM sprockets front and rear on my 2014 300 RR 2T. I sold a 250 EXC 2T to get the Beta and had a load of KTM bits left over. I have a trade discount with Supersprox

The front sprocket shaft is identical, even down to the fixing circlip, but looks and feels better made than the KTM, especially on the spline tolerances. Much less play between sprocket and shaft.

The rear OEM sprocket was marked as "by Supersprox" and the spare road homologation sprocket was identical in fixing points and thickness to a KTM one I had in stock.

Apart from the larger rear brake disc, the Beta wheel looks very similar to a KTM. I have a set of KTM wheels left over and will try them for size soon. I have heard that the back wheel fits but the front has different spacers and offsets and is too much hassle to bother trying to adapt.

[Beta Steve]

If you have a look on the JD Jetting site you will see my bike, with a 2013 KTM wheel and street tire, on his dyno. It will fit, but as you noted, the disc will not. No info on the front.

[Hammer]

690 has a 240mm rotor

[Hubert Carpet]

If you have a look on the JD Jetting site you will see my bike, with a 2013 KTM wheel and street tire, on his dyno. It will fit, but as you noted, the disc will not. No info on the front.

That's great info, thanks. If you have used a 2013 wheel then my 2011 wheel my not fit due to rear axle diameter and I shall need to swap the rear spacer bushes as I believe that the bearings are the same. That sounds like a winter project.

From what I picked up on the UK KTM forum, trying to fit a KTM front wheel is a world of pain. The front disk is very similar, the only main difference is the position on the speedo trigger magnet. It is about 10mm further away from the centre on the Beta and may be too far out to trigger the pickup. Another project, I think.

[GMP]

So if this is true, then that means KTM and Honda are the same? Please don't take this the wrong way but I would like to see this, or the measurements of the ID of each sprocket. The front I can see being the same. I have a suspecion a fair amount of KTM parts come out of that Beta factory, more than most might think.

Rear hub sprocket to rotor offset is approx 16mm wider on the Beta than the KTM or GG. Its the same as a newer Husky. Believe me I had a two sets of GG spare wheels I would have kept if it were possible. This is what gasgastrials means, see the pic of his bike on the dyno with the caliper tied back?

[Hubert Carpet]

Beta actually make a number of the KTM engines for them, especially the smaller MX engines. It should be no surprise that they have exploited that experience when they have gone to target KTM's core market.

I have taken some photos today to show the similarity between Beta and KTM rear sprockets and will upload them later.

Does anyone know which Honda sprocket is on the bike in the photo? According to my Supersprox catalogue, there are about 8 different patterns depending on model.

[Hubert Carpet]

P1010762.jpg (120.7 KiB) Viewed 16963 times

P1010763.jpg (130.59 KiB) Viewed 16963 times

As promised, photos of the KTM and Beta sprockets side by side and together. The silver Beta sprocket is a 45 tooth EU homologation number that comes with a 15T front in the crate. Not a high tolerance item as they normally get thrown to the back of the garage and never used.

Shot 1 shows side by side and then shot 2 together, with a set of KTM sprocket bolts through them. Not a 100% perfect fit in that the bolt heads don't drop cleanly into the counter sinks. I am putting than down to the thick paint cover on the Beta sprocket.

The Supersprox pattern number is a 49T alloy 990.