Opedaler

Was just looking at the forum in the Bacchetta site and was looking under the "new bike" thread and someone posted a picture of Bacchetta's supposed new LWB low BB bike. Kind of a nifty looking thing. Looks like a cross between a Stratus and a V2, or in this case an Agio and a Stratus. "fraid I don't know how to "link" sites up so you'll just have to follow the trail.

Anyone know anything about this bike?

PuttPutt

I've seen nothing official from Bacchetta, so it's likely a prototype. As such, you won't get many details. (the red bike is an Burley Koosha). The only difference I can detect is a taller headtube and the addition of a short top tube - this technically makes the Bacchetta, a semi-mono.

Opedaler

Since I'm getting close to decision time (or at least I thought I was) I had to call Bacchetta and get the scoop. Here's their spiel...... It will be out in Sept (or there abouts), price range will be 1300(or there abouts), trial riders are giving it rave reviews, advantage over other LWB's will be handling over some and speed over others.....in other words faster than slow LWB's and better handling than more "twitchy" lwb's. They feel that they've come up with the right combination for a LWB. Of course, they were honest enough to admit that they might be a bit biased. Still, John ,who was answering the questions through Ric, seemed pretty excited. Still a few bugs( they said they were 99% there) but close enough to feel that it would be out this year.

As PP pointed out it does have an uncanny resemblance to the Koosah, which as I've been told was known for it's comfort. If I understood correctly it might have a slightly higher BB than some LWB's (Koosah?). In looking at the pics I've seen, I thought it might be 26/26 but was told this morning that it will be 20/26 much like Burley's bikes.

September!!!!! can I wait that long for my first bent?

PuttPutt

Your the first i've seen use "twitchy" and "lwb's", in the same sentence. SWB's are frequently called "twitchy", but rarely LWB's. Other than the name, I see few, if any improvements over bikes like the Burley Koosha, RANS Stratus (20/26) LE or the Tour Easy. AND the classic Stratus 20/26 (when the lower chain stays are removed).



If nothing else, they did at least one thing correctly - installed a 20" front wheel!.. and would help validate JC's comments about low speed handling.

Opedaler

[QUOTE=PuttPutt]Your the first i've seen use "twitchy" and "lwb's", in the same sentence.

Point taken PP and it wasn't probably the word I was looking for ( and it certainly wasn't the word they used). I was trying to describe the handling difference between a V2 Rans and a Rans Stratus. These were the two bikes that I asked them to compare it to since I have some familiarity with them. I prefer the handling of the Stratus but felt (no computer) that I was faster on the V2.

BlazingPedals

The resemblance is uncanny, isn't it? Softer ride than a Strat?

Opedaler

Uh....well.....I'm not defending something that I've never seen but I THINK they were suggesting that the crank is higher than the Strats giving it slightly more speed but a more comfortable ride than the V2.

And yet, after seeing the pics of the Strat and the Bellandere(that's what they called it).......those brothers must think alike.

PuttPutt

Depends. If the the main (seat) tube's wall thickness and/or diameter was increased, then it could easily be stiffer than the Stratus. IMO, avoiding the Stratus-like chain stays is ignorant, because it forces crude and inefficient chain manage on BOTH the drive and return sides - not unlike the Koosha. I see a handful of other fundamental design errors, but I'll reserve judgment until I see the final draft.

Opedaler

Just curious, not only because of this bike but I've also looked at a Burley Hepcat. Same chain management system it appears to me. Since bike engineering is not my forte', What makes this so bad? Is it added friction, added chain movement or just added wear and maintainence issues? Also, if this a performance issue, is it a major one? Thanks

PuttPutt

The drive side idler must endure significally higher loading than the return side idler. Higher loading means reduced idler and idler bearing life, elevaded noise and vibration, and requires a secure and robust mount. The return idler doesn't suffer the same loading, or the same frictional losses, or require heavy duty mounting - it is essentially, a low-loss chain guide. It's purely a guess on my part, but it looks like the LWB Bacchetta could do without the drive side idler. Unfortunately, if the drive side idler is removed, you would also eliminate the one-and-only place to mount the return idler.

By using a single member between the seat and the bottom bracket, the designer kills three birds with one stone; (1) Greater rigidity between the seat and the pedals, (2) any seat adjustments will retain identical rider-to-pedal relationship, and (3) is cheaper to mass produce. Huge advantages when selling a large number of bikes to a variety of leg lengths. Unfortunately, it doesn't leave the designer many elegant places to hang a return idler if one is needed.

Opedaler

Very interesting and thanks again.

john riley

Regardless of the size of the main tube, I don't see how it could be stiffer than a Stratus, since the rear stays aren't triangulated. In fact, it might pogo (like the Burley LWBs). Burley felt this was a trade-off for comfort, and placed the seat supports forward to allow the frame to flex without affecting the seat.

I _believe_ the Burley LWBs could be run without the stock idler set-up; i.e. no hard contact with the frame if you just ran the chain straight. I _think_ this bike would be the same. I don't have either bike in front of me, so I couldn't say for sure.

I don't think it would be a big deal to mount an idler for the return side a little lower than where this idler is.

aircooled

It all depends on how much you reroute the drive chain,as far as load is concerned . This is what I did on my V2 . The drive idler is mounted on the radlock .The return realy does nothing but keep the chain from hanging down and looking bad. To compare see Rans site. Picture of my V2 attached I hope. As far as the comparison of the new Bachetta and the stratus.. Hey ! One drops the 20-26 and the other picks it up. The bike doesn't care if it is made in Kansas or Florida. I believe if I wanted to buy a bike like that and not wait till Sept. I would go find me a Burley. And never look back..

Mooo

(gazes into crystal ball, mumbles to self, throws scat into the air, arrives at prediction)
... and the Next Bacchetta "original" will look like
1) a Rans Zenetik
or
2) an Easy Racers Javelin

Any takers?

BlazingPedals

Until they introduced the Agio, I always thought that a LWB Bacchetta would use their trademark 'stick' design, and look like the Javelin now looks. Now that they're starting to become RANS, they may add a large front wheel to the new model and call it the "Formula-B."

Opedaler

[QUOTE=aircooled. I believe if I wanted to buy a bike like that and not wait till Sept. I would go find me a Burley. And never look back..[/QUOTE]

Air, you could have chosen the Koosah or even the stratus but went with the V2. Mind if I ask why and if there are any regrets? Your routing to my untrained eye seems very efficient.....did it affect bike handling at all?........performance?

PuttPutt

Or,... Stracchetta XB

vik 

Bacchetta uses the same chain management system on all their bikes and seems to have no problem winning numerous races and setting course records with this "inefficient" system. I have a bent with no idlers and I can tell you that having that length of chain swaying around is neither efficient or quiet. If you gave me a choice I'd take the Bacchetta idler setup any day.

The loses over a pulley - like the power side idler are very small as long as the pulley shaft is strong enough not to deform. This is demonstrated quite well with the really fast FWD bents that are being built in Europe that have a 90 deg power side bend in the chain line.

PuttPutt

Idler resistance (frictional losses) is essentially the same for racers and commuters. However, the frictional losses they do produce, is less of an issue for racers because the applied wattage is much higher - and therefore a lower, overall percentage of wattage is lost. In other words, the typical, low-horsepower commuter, poking along at lower speeds, will notice the idler's resistance moreso than the high-wattage racer would. A similar analogy also applies to the noise and vibrations produced by idlers (and my biggest gripe). The faster you go (as in racing), wind and tire noise drowns-out idler noise significantly (or completely), so it isn't a noteworthy issue. On low speed commuters, (such as Bacchetta's LWB), it is quite the opposite, I can assure you - And this is especially true if the drive side idler is mounted directly in front of the rider, and on the same tube the seat is mounted on.

Could you be more specific, please?

Tom Bombadil

The new Bacchetta has a strong resemblance to the Rans Stratus.

The Bacchetta Agio looks like a modified Rans Tailwind, in fact, it looks like it is a barely modified never-produced Rans Tailwind 26/20 prototype, picture #3 below.

aircooled

Opendaler! I have had the V2 since 04 .. NO regrets at all , I love the bike.. I brought up the V2 0nly in reference to the idler loading.. As far as perfomance I don't think there is much difference.. No change in handling at all.. It is much quieter and I think looks better.. If your old and slow as I am, looks counts alot..

About the new Bachetta look alike, I chose the Burley line because my wife had a Koosah.. It is a real fine friendly bike.. Nothing wrong with stratus ether.. so i'll bet it will be a fine bike also, but why wait, summer is comming... Take Care Bill

Mooo

Actually, it's astonishingly similar to the 26/20 Tailwind prototype:
Scroll to the bottom of the page.
https://www.ransbikes.com/ITRTailwind-26.htm

Opedaler

OK, more idler info for the uninformed (that would be me). Do the lwb bikes with no top idler (ie drive side idler) like the Tour Easy, Stratus XP etc have a noticable advantge ,both in speed and force required, over bikes with a drive side idler( Stratus LE, the new Ballandere, and the Koosah)?

Also, if one could eliminate the drive side idler (for whatever reason)on the new
Ballandere could one not run an extension down to the return side chain with the idler mounting there? If it doesn't require much strength or stability and only serves to minimize chain flop a light idler extension from the existing idler mount would seem to serve this purpose.

Tom Bombadil

Thanks, I added that picture to my post.

Perhaps we should start a contest to name which Rans is copied next by Bacchetta.

Opedaler

"If your old and slow as I am, looks counts alot.."

Been there......doing that.

" but why wait, summer is comming..."

Yup, delayed gratification has never been my strong suit.