Cup suspension vs Street suspension

Bagwell

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I guess one of the biggest discrepancies is the difference in suspension between the Cup RC390 and the Street RC390. I dont hear differentiation between the two when referring to suspension problems/adjustments/upgrades/tuning etc. I have a street RC and am looking at a CUP 390 for racing but wondered about the spring availability and all the actual differences between springs for both bikes as well as any differences. It would be great to see more differentiation here on the forum when referring to different bikes/suspension etc. I see it as a possible mix up situation. Specifically I wonder about spring sizes and types (linear or progressive) between the two bikes as well as the actual damping and design differences between both. Does anyone know if front spring specifications ID/OD/free length/rate are the same or different than the Street version and if so what are the specifications of the CUP bike springs?

Thanks,
 
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cjwell

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The street and cup are different dimensions, cup is linear. I can provide you with cup WP front and rear data if needed. First what do you weigh? The range for proper springs for them is very limited and for "small" people lol. I have found ways around though for better selection of springs. I use Ohlins common springs up front with adapters and a Hyperco out back. This is only for the WP cup suspension. Turns out real slick. PM if needed.
 

ArkansasDave

New Member
From everyone I've talked to the WP suspension on the cup bike isn't the best. There are plenty of good options to upgrade the street bikes suspension. I've seen a couple good cup bikes come up for sale that were used in the motoamerica series for really good prices.

edit: just realized you're in Houston. Check out the cmra forums and there is a cup bike for sale at a good price on there.
 
The Cup bike suspension is very good in my opinion. I have raced lightweight bikes and am very impressed with the front end and the adjustability. The cup suspension is the only bike you can purchase springs for directly through WP and I have had no problem getting information from them.
 
I guess if you weigh like 100 lbs you could get the available from WP cup bike springs to work optimally for you in a race environment. All the MotoAmerica cup riders I know are not happy with the limited WP supplied spring options available in 2015.
 

Bagwell

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From everyone I've talked to the WP suspension on the cup bike isn't the best. There are plenty of good options to upgrade the street bikes suspension. I've seen a couple good cup bikes come up for sale that were used in the motoamerica series for really good prices.

edit: just realized you're in Houston. Check out the cmra forums and there is a cup bike for sale at a good price on there.
Yeah, I know someone selling his Cup bike and thats what im looking into. Nicks and Braedons bikes were both for sale.
 

Bagwell

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I guess if you weigh like 100 lbs you could get the available from WP cup bike springs to work optimally for you in a race environment. All the MotoAmerica cup riders I know are not happy with the limited WP supplied spring options available in 2015.
Yeah, they are required to use ONLY the PowerParts stuff aren't they? No outside aftermarket springs or something?
 

ArkansasDave

New Member
Yeah, I know someone selling his Cup bike and thats what im looking into. Nicks and Braedons bikes were both for sale.

It's probably better to get the cup bike. It's already setup for the track and has decent suspension. You will need stiffer springs but like other people have mentioned that is possible.

Side note I believe braedons bike is already sold, unless they are selling another one.
 
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