Let me start off by saying we like product testing. Well, OK: I like product testing. There are just so many different ways to design and differentiate products that it’s hard to know what works well until you put it through the paces over enough time and without any interference from handlers. That’s the best way to get a true consumer experience since most tandem consumers are truly on their own once they have a new product in their hot little hands and/or installed on their tandem.
The Bengal MB700T disc brake isn’t exactly a “new” product for us, given that we had the opportunity to do a prolonged test ride on a Santana Beyond last May, where I observed the following as part of my 2011 Santana Beyond review:
Bengal Disc Caliper & 250mm Rotor:
Our 2011 Santana Beyond was fitted with what appears to be a Bengal MB700T single piston caliper sporting Santana’s 250mm rotor. This is a new brake caliper for Santana that replaces the WinZip. While still not as easy to adjust as the Avid BB7, it’s not all that hard either: a 5mm & 2mm allen key support all of the adjustments.
Stopping power for the caliper and 250mm rotor was as you’d expect: very good and with pretty good lever modulation. However, I made the mistake of mentioning my notice that the WinZip brake had been replaced with what appeared to be a new brake while Bill had an allen key in his hand and he immediately set about to adjust the brake, even though I didn’t ask and it didn’t feel like it needed it. God love ‘em, it’s fun being around Bill! After that, there was almost zero brake lever travel so I had to stop and make a little adjustment: hey, I’ve got small hands and it makes a difference.
Anyway, my only real complaint with the Beyond’s rear disc is that the very large and thin rotor was incredibly noisy. Hit a bump, cha-ching. Riding on a rugged road, lots of ca-chings and sometimes a bit of ching-ching-ching-chingas we rolled along. I really don’t like noises coming from my bikes and tandems, so this was a bit of an annoyance to me as I’ve not had any similar noise issues with our Avid’s 203mm rotors on two different tandems that couldn’t be dialed-out in about 5 minutes and stay that way until you messed with the brake again. When I asked Bill about it, he immediately acknowledged that it does make some noise, but also said it didn’t bother him. Meh. Perhaps I’m a bit too sensitive, as there are a lot of the larger, 250mm rotors on the road and I don’t think I’ve seen any owners gritting their teeth. Cest la vie. But, aside from that, it’s a really good brake with lots of stopping power.
I should also note that this past September we received some feedback on how well various different disc brakes fared on an epic descent off Mt. Ventoux from Bill McCready as well as one of the tandem teams on Santana’s France trip last summer: you can read the entire entry and their comments HERE. The biggest take-away was that in head-to-head, real world performance the Bengal mechanical disc clearly out-performed the Avid BB7 which was plagued by the same problem it’s had for over a decade: plastic parts that melt under extreme brake heating.
Anyway, our long-time good friend Mark Johnson from Precision Tandems out in Kansas shot me an Email about a week ago to fill us in on their winter happenings and closed with a note to let us know that he was sending out a Bengal brake and rotor for us to “thrash about”: cool beans! So, a few days later a Bengal MB700T, a Bengal 203mm rear rotor adapter & a Bengal-provided 203mm rotor showed up on our front porch.
At first blush, and as best as I can tell the Bengal is a direct replacement for the Avid and fully I.S. compatible. Nothing “special” is needed to bolt-it up so long as you have the right mounting adapter for the size rotor you’ll be using, i.e., a 203mm rotor. Just to be clear, this is a dead-stock Bengal MB700T that Mark is sourcing from Bengal. The only difference I can see or detect between the one Santana is sourcing from Bengal and that was on the Santana Beyond we rode at Santana’s Chattanooga Rally is the color (this one is black, not white) and the lack of the word “Tandem” on the caliper body. Sitting alongside the Avid, the Bengal is a bit smaller and when checked on a scale is about 12 grams lighter: basically a wash. Same for the adapters and rotors; so close that weight isn’t a discriminator. I’ll go into some other differences below.
Installation was not all that much different from the Avid: Bolt the caliper to the adapter with two machine screws, then bolt the adapter to the frame’s I.S. disc mount on the back of the rear drop-out. Bengal’s instructions while not fancy are just about spot-on if you look past some of the translation / grammar disconnects that you’ll likely find: I sometimes wonder why Taiwan firms don’t find better proofreaders. While the Bengal lacks Avid’s Tri-Align™ Caliper Positioning System™, so long as the I.S. disc caliper mount is properly aligned with the frame the Bengal is also a no-brainer to set-up. The inboard adjuster is manipulated using a 5mm Allen drive and has a small 2mm Allen head-driven set screw that holds it in place once you have it adjusted. There’s also a knurled cable stop / adjuster where the brake cable housing attaches to the caliper which is a bit more intuitive to use than the outboard adjuster knob on the Avid.
Performance out of the box on our first ride was excellent. No rotor rub or “chiming” (something we heard when going over bumps from the larger rotor on the Santana) and even without being seasoned, great stopping power with normal brake lever travel. I rode the brake a few times on our Sunday loop in an effort to bed-in the pads and season the rotor. Again, even without being fully broken-in we were able to lock the rear tire on the 8% grade going into our community using only the rear brake. Mind you, we’re only about a 280lb team.
Again, no plastic parts and two adjustment points once the caliper is installed. Instead of the large red plastic fixed brake pad adjusting knob you find on the inboard side of the Avid, the Bengal uses an aluminum pad adjuster that is turned using a 5mm Allen-head driver. You can see the indexing mark I put on the adjuster with a Sharpie in the photo at right, just to make the initial set-up a little more accurate. Once the inboard pad is adjusted and has sufficient clearance to the rotor the adjuster is then held in place by a set-screw that requires a 2mm Allen-head wrench. Keeping a small multi-tool in your seat pack or jersey pocket is a pretty good idea with these.
The outboard pad off-set is not really adjustable the way it is with the Avid BB7. Instead, the aforementioned knurled knob cable stop can be used to compensate for pad wear in much the same way that the Avid in-line cable adjuster is used for ‘on the fly’ adjustments. They work just fine, but are using some of the actuating arm’s travel to move the pad closer to the rotor instead of only moving the pad via a true adjusting mechanism. Just something to be aware of. I would probably make a point of doing a caliper re-alignment when the pads were 1/2 used vs. using only the in-line cable adjuster.
Sadly, I don’t think we have any tortuous rides on the horizon so we may have to find a weekday when we can head over to nearby Kennesaw Mountain to put some big heat into the brake. The 1.5 mile ride up Kennesaw Mountain gives you about 1,050′ of climbing with about 530′ of elevation gain and the speed limit is 25 mph. So, you can easily cook a brake if you want to on the way back down. In fact, we have gotten caught behind some cars on our tandem when we didn’t have our rear disc and had to be very attentive to front & rear brake management to keep brake fade at bay. Sadly, the mountain is closed to all vehicles, including bicycles on the weekends.
More to follow as we put some miles on the Bengal.
In case anyone is curious, I believe Mark has an upcharge of $50 for the Bengal MB700T vs. the basic $165 Avid BB7 kit that he sells for tandems with I.S. mounts and disc rotor compatible hubs. You can find all of his very well thought-out Disc Brake kits on the Precision Tandems Website. If you’re interested in adding a disc to your tandem let me also strongly recommend that you call and talk to Mark or your favorite tandem speciality dealer. There are a lot of subtle differences that need to be taken into consideration to make sure that you’ll get a disc brake installation that works well: there just aren’t any off-the-shelf solutions for a 203mm rear tandem brake that will work on any tandem.
Getting back to the cost, It’s hard to back into the actual cost of the Avid BB7 from a price sheet since Avid doesn’t sell a BB7 with a 203mm rotor that you can bolt onto a tandem. You have to buy the stock BB7 Road, the mounting adapter and the 203mm rotor ala carte as well as a thread-on rotor adapter… assuming you have a drum-brake compatible rear hub. If you have a rear disc hub or already have the thread-on adapter, then you save a few bucks on a kit.