I was about to place an order for a set of Performance Machine direct bolton 6 piston calipers for my 08 model Street Bob. Luckily, I've asked the quesiton whether their would fit without any modifications. Unfortunately - they will not! The caliper only fits 11 1/2" disc. Indeed, every model SB up to 2008 had the 11 1/2" disc.

However, in their "infinite wisdom" for 2008 HD had changed the disc diameter for 2008 model Street Bob and some other 08 model softails to 11.8". Obviously, a larger disc diameter means better braking performance but once again the aftermarket accessories will no longer fit. This was also the case with risers being "built-in" to top tripple tree which prevents 08 model SB owners from utilising "pull back" handle bars similar to Burleigh.

Is anyone aware of any other slight modifications that factory has introduced on 2008 model Street Bob and that are not widely publicised?

Are there any other 6 piston calipers that will fit 08 Street Bob without modifications?

The obvious solution is to use PM 11.2" disc. However IMHO it would constitute a step back since PM discs are smaller in diameter and semi-floating. While HD discs are fully floating.

So any ideas guys/gals?

ta
Vlad

 

why dont u get a 07 front rotar???

 

Well, I could potentially get an 07 front rotor but it is smaller in diameter. The idea here is to improve braking by changing over to 6 piston calipers. It makes no sense to utilise larger calipers with smaller disc. The resultant braking performance might not improve.

 

11.5 and 11.8 is hardly a diffrence man the six piston over a 07 disk would produce better stopping over a 11.8 with a stock caliper

 

If you are really after vetter braking, go to the V-Rod twin...Unbelieveable difference.

 

i had no idea that the 15 thousanths of an inch difference was so large. if the pm 6 piston calipers don't fit i would be surprised.

 

tomato - love your v-rod setup! Would you care to provide a detail description of what is required to upgrade to v-rod setup.
I'd imagine that you need at least the following:

1. V-rod front forks
2. V-rod front discs
3. V-rod front calipers

What model V-rod did you use as a donor bike? What modifications do you need in order to fit the above? I would appreciate any detailed info?

Have you considered the Fat Bob twin setup?

 

First of all the internal valving is different on the V-Rod than your bike. The V-rod is also 2" shorter. Once you completely set up your bike you also need to buy a 2" (approximate) shock. I have all of the parts needed to do this job at HD. Will pick them up tomorrow & get to work. Once we figure it out, we will put one on Jay Risk's bike for testing. Might even do Mudd's bike also. Jay wants Brembo's. tomato, good job and rims looks nice. Always been a sucker for the red ones.

Ps the rotors are 300 millimeter = 11.811 023 622 inch or 0.15551" (Radis) (Around 5/32") larger than your stock rotors. I do not think it would work as I have a set of 6/differential PM's and they are very tight against the top of the 11.5" rotor. $499 X 2 = alot of investment to sell on e-Bay

 

FastHarley - Please keep us posted on your progress. Would love to know the exact details/problems of the conversion.
Have you considered the Fab Bob twin setup?

 

Monday update

Others have tried it and the only way that works is if you use new trees off of a FB. The calipers do not line up with the rotors, understandability. Do a search or "talk" with the member who posted photos on this forum. This approach is not the one I wanted to take.

My goal is to use your mid-glide (stock) trees, a 2X hub like the one found on your spoked wheel, add a 300 mm rotor and add caliper(s). Of course you need lowers w/2X caliper mounting points. When/if we come up with a viable solution, I shall post only after it has been extensively road tested for reliability and safety. This must be a cost effective modification only.

I do not own a 06 & above bike to personally test it on. I have tried to buy a complete 49mm front end to put on my 05 Dyna for testing only. The member here who had the complete front end has not contacted be back yet with repleted attempts on my side. I will pick up the brand new stuff from HD today or tomorrow. Our first step.

Jay Risk has been working with me and has professed to give a truthful and honest evaluation for you guys. He owns this type of bike.