JackJohn

Hi all,
I’ve been riding this early 2000s mtb for a while and often wondered about its unusual frame. Compared to more “traditional” mtbs , this has a very low/short/inverted top tube, with sloping unusually going up/down from rear to front. Also, rear suspensions are also atypical in their positioning and attachment to chainstays on seat tube and behind bottom bracket (picture taken from non-driving side for more visibility). Wheels are 26’’ and total weight 15,7kg. I don’t have any other tech specs, this is a French mtb produced by Quantum, which no longer exists.
Any hint on this particular build ? Any drawback or flaw ? Is it too fragile without a real top tube ? I mostly ride it for easy trails, posture is comfortable on both stack and reach, full suspension is practical on dirtier roads, but overall the bike is not much responsive, which seems intuitive given its weight, even though modern bikes are not much lighter. Do you find any reason to change it for a more regular hardtail mtb ?
many thanks for your help !

Chris Pringle

Yours is a hybrid cruising bike. Looks very comfy! The unisex top tube is designed that way for easy access whether you’re a male or female. Nothing too unusual about the rear suspension. There were several bikes with that kind of suspension technology in the mid to late 90’s. This bike will work well in urban areas and on easy/flat dirt paths. I would not recommend to take your bike down a singletrack to fly down a mountain the way you would with a proper hardtail MTB. So, if you enjoy your bike for exercising around a park or around your neighborhood, you really don’t need anything else. If you feel like you’re up for more challenging terrain or would like explore more adventurous parts of your nearby forest or desert, upgrading to a hardtail mountain bike would be absolutely recommended. Good mountain bikes for that purpose start around $1,000 USD for a brand new one. But my recommendation would be to find one in good condition in the second-hand market for much less. Check out your local Craigslist. Given the pandemic, there is an incredible shortage of new bikes on the market and prices have gone up considerably. You will notice this if you visit your local bike shops.

veganbikes

It's a low cost hybrid likely from a big box/sporting goods store. It is a useful design for those with male genitalia and commonly marketed towards females (because of old outdated riding practices) and the geometry is nice and upright which can be decent for some with back issues. This is not a bike great for mountain biking but could be ridden on some light paths and such. If you are looking to mountain bike you will want to get a mountain bike, a hardtail will work fine but get something of quality that will last.

mack_turtle

looks like a terrific neighborhood cruiser, short-distance commuter bike for a relatively short rider. no idea on the specific model or brand, but it's not a "mountain bike."

ClydeClydeson

It is a low-cost hybrid with suspension. Likely wouldn't live too long if you actually did aggressive mountain biking with it, but should be great for shorter rides on paved or semi-hard surfaces.

As for frame strength, the frame is made of steel (you can tell by the welds) and likely overbuilt because nobody likes to be sued. Riding it off your cousin's roof or doing backflips at the bikepark will not end well, but for a grocery getter or commuter it should be fine.

The pivot in the suspension and the lower cost moving parts (derailleurs, bearings) are going to have a race to see what fails first. You may notice the shifting is hard to keep working perfectly, or you might notice the rear end of the frame has side-to-side play or makes creaking or grinding noises. Either way, I recommend riding that bike as-is and doing simple repairs and regular maintenance until it needs any expensive repairs, then get something else.

If you use it on an actual mountain bike trail with rocks and roots and drops, that bike will fail one way or another very quickly.

JackJohn

Many thanks to all of you for your comments and suggestions, it’s much clearer now. Indeed I never pushed the bike too hard, maybe only some rather flat harder forest path, otherwise moderate dirt paths at best. Following your suggestions, I won’t go for hard mountain bike paths with this bike. Maintenance was close to zero in almost 20 years, only recently I changed brakes (with some not so expensive shimano) and tires. Friction shifting is still acceptable, and no worrying noises are heard (yet) from bearings or other parts. I had thought about upgrading to an indexed transmission and new rims, but given what you all said, I’m not sure it would be worth the money.
ClydeClydeson what do you mean by “The pivot in the suspension”? Is it the one behind the bb? Also, when you mention potential side-to-side play in the rear, do you think the pivot may get loose and make chainstays unstable?
Thanks again !

thehammerdog

appears to be an early moots or maybe dean experimental metal is most likely unobtainium very rare...

veganbikes

Did you look at it? Certainly not a Moots or Dean, just look at parts and welds. Also re-read original post where it says Quantum.

JackJohn
Friction shifting can be quite fine. In fact there are some excellent friction shifters still on the market so indexing is not really always an upgrade. A nice Deore XT M700 set up would be fantastic on bike but is friction shifting. However this bike isn't a great candidate, I would spend to keep it running if you are still looking to use it but beyond that I wouldn't upgrade anything on the bike. I would save up and upgrade to a different bike at some point. If you have had it a while you are well do for an upgrade and you can always keep this around as a second bike or something to lock up places where you don't want to lose your nice bike.

The rear pivot would be behind the bottom bracket and could develop play. It doesn't look like what you would see on a proper FS mountain bike with bearings that replaceable or serviceable. You might be able to do something with it but likely not but it is tough to see. Also just FYI when taking a photo always take it of the drive side of the bike the other side is quite boring and is only relevant when showing the entire bike with loads of pictures.

thehammerdog

Dude, it could be an early Ibis custom from 1994 cactus cup grundig?

JackJohn

Thanks, yes I agree, the most likely conclusion will ultimately be to have it as a second bike for short useful rides, upgrading equipment only when needed. Now I need to start looking for a nice hardtail that fits my needs...

As per the photos, as I mentioned earlier I voluntarily took the non driving side, so as to better see the suspension and pivot which were the main issue. But of course the driving side is much more interesting. Here are some photos to complete, with details on the pivot and the brand.

veganbikes

Oh wow, it's tourney with rapid rise. Such a whacky idea Basically keep the bike going with minimal money. Save up that money and test ride some bikes in the meantime and figure out what is going to work well for you. If you plan on actually hitting the trails beyond just a fire road or gravel path then look at hardtail. If you are just going to be on gravel and fire roads and things like that most of the time, look at one of the various gravel bikes out there, some have some pretty good clearance these days so you can run nice wide tires and eliminate the need for suspension which adds weight. If you are looking to really do a lot of mountain biking on some really rough trails a full suspension bike is a good way to go but you are looking at least 2k to get something decent, basically the more you add to the bike parts wise the more it will cost or the lower the quality will be.

JackJohn

Thanks, think I’ll be on medium gravel roads at worst most of the time, maybe a barely challenging forest path sometimes, but likely as an exception. Just a semantic point to clarify my understanding (maybe wrong) of bike type names when it comes to choose a new one : I compare “gravel” bikes to road bikes geometry and “hybrid” bikes to mountain bikes geometry, although I know there’s a lot of overlapping. I guess my choice will be between hybrid and hardtail mountain bikes following some requirements : medium erected posture, medium/long rides (up to 4-5 hours), no difficult up/downhills, no particularly rocky paths but flexibility to small off-road deviations. The question of the front suspension is open and I understand there’s a huge debate about whether have it or not. Is it true that hybrid bikes suspensions can be useless as the models used do not easily “activate” (striction problem) ? I would like to have a suspension comfort, but wonder wether an hybrid bike can provide it. I was for example looking at this model:
https://www.probikeshop.com/en/fr/vt...21/218717.html
it includes a Suntour NCX E RL Air suspension. Is it suitable to what I need ? Or should I forget it and go straight for a hardtail mountain bike ? So many questions...
Any suggestion appreciated. Many thanks.

Chris Pringle

The bike on that website (or similar) would be perfect for the type of riding you described. You get 63mm of travel on that suspension fork which will give you great comfort on gravel roads and dirt paths. The geometry is that of a hardtail mountain bike which might be more familiar and comfortable to you. Most of the components are top-tier and reliable.

For the same price, yes, you can indeed get a hardtail MTB with 100-120mm of fork travel, but you will definitely be “overbiked” - i.e., too much bike with unnecessary specs and features for the type of riding you do, components of lesser quality and most likely a heavier bike.

JackJohn

Crystal clear, I’ll follow this lead then, thanks!

veganbikes

It looks like a "Trekking" bike which will work just fine though front suspension does add a good deal of weight. It is not terrible but it is something to note. However the parts on it are quite decent (XT is right near the top and always a good choice) so I wouldn't say no but in my case I would rather have a carbon fork with loads of clearance and wider tires and cut out a bit of weight but that is me. I am not a huge fan of adding extra weight I don't really need.

JackJohn

If I understand correctly your point, basically for you the front suspension is not necessary for the use described but rather an extra weight ? My fear is to have a bike too hard and shaky on rougher gravel paths, and given I’m not a youngster anymore I’d rather be on the comfy side... but I never rode a rigid bike on those paths so can’t tell how it feels. Do you believe that modern frames are more shock-absorbers such that the difference with or without a 63mm travel suspension is unnoticeable and you only bear a useless extra weight ? According to Chris Pringle it does provide comfort, which suits me well... Thanks for helping clarifying this point.

veganbikes

With a good steel or titanium frame with wide tires you do pretty darn well and with something like the Kinekt seatpost you add in the extra comfort without a ton of weight. However having suspension is not a bad thing for comfort as well but I don't find it as needed unless I am really riding some serious off road stuff. It in the end is up to you. If you think you will benefit from it go for it, if you think you want something lighter than don't.

DMC707

a modern 29” hardtail mountain bike has a much taller front end than the old 26” wheel bikes. A mountain bike with possibly a little higher rise bar than stock may give you all the rise and comfort you need while still being more capable of taking on the occasional more challenging trail than a hybrid bike would —. Something to think about

JackJohn

Ok, I see, thanks !
Useful thought indeed ! With the frame size being a S, I wonder if 29’’ is too big or even easily available, I see that many small frames mount 27,5’’...